diff --git a/CODEOWNERS b/CODEOWNERS
index 131fb1e767d..503410725a7 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -59,9 +59,5 @@ MODULE.bazel @github/codeql-ci-reviewers
 /.github/workflows/rust.yml @github/codeql-rust
 /.github/workflows/swift.yml @github/codeql-swift
 
-# Misc
-/misc/scripts/accept-expected-changes-from-ci.py @RasmusWL
-/misc/scripts/generate-code-scanning-query-list.py @RasmusWL
-
 # .devcontainer
 /.devcontainer/ @github/codeql-ci-reviewers
diff --git a/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/old.dbscheme b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/old.dbscheme
new file mode 100644
index 00000000000..d13c4c187d7
--- /dev/null
+++ b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/old.dbscheme
@@ -0,0 +1,1511 @@
+/* This is a dummy line to alter the dbscheme, so we can make a database upgrade
+ * without actually changing any of the dbscheme predicates. It contains a date
+ * to allow for such updates in the future as well.
+ *
+ * 2021-07-14
+ *
+ * DO NOT remove this comment carelessly, since it can revert the dbscheme back to a
+ * previously seen state (matching a previously seen SHA), which would make the upgrade
+ * mechanism not work properly.
+ */
+
+/**
+ * An invocation of the compiler. Note that more than one file may be
+ * compiled per invocation. For example, this command compiles three
+ * source files:
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * The `id` simply identifies the invocation, while `cwd` is the working
+ * directory from which the compiler was invoked.
+ */
+compilations(
+    unique int id : @compilation,
+    string cwd : string ref
+);
+
+compilation_info(
+  int id : @compilation ref,
+  string info_key: string ref,
+  string info_value: string ref
+)
+
+/**
+ * The arguments that were passed to the extractor for a compiler
+ * invocation. If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then typically there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | --compiler
+ * 1   | *path to compiler*
+ * 2   | f1.cs
+ * 3   | f2.cs
+ * 4   | f3.cs
+ */
+#keyset[id, num]
+compilation_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The expanded arguments that were passed to the extractor for a
+ * compiler invocation. This is similar to `compilation_args`, but
+ * for a `@someFile.rsp` argument, it includes the arguments from that
+ * file, rather than just taking the argument literally.
+ */
+#keyset[id, num]
+compilation_expanded_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The source files that are compiled by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | f1.cs
+ * 1   | f2.cs
+ * 2   | f3.cs
+ */
+#keyset[id, num]
+compilation_compiling_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The references used by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs /r:ref1.dll /r:ref2.dll /r:ref3.dll
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | ref1.dll
+ * 1   | ref2.dll
+ * 2   | ref3.dll
+ */
+#keyset[id, num]
+compilation_referencing_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The time taken by the extractor for a compiler invocation.
+ *
+ * For each file `num`, there will be rows for
+ *
+ * kind | seconds
+ * ---- | ---
+ * 1    | CPU seconds used by the extractor frontend
+ * 2    | Elapsed seconds during the extractor frontend
+ * 3    | CPU seconds used by the extractor backend
+ * 4    | Elapsed seconds during the extractor backend
+ */
+#keyset[id, num, kind]
+compilation_time(
+    int id : @compilation ref,
+    int num : int ref,
+    /* kind:
+       1 = frontend_cpu_seconds
+       2 = frontend_elapsed_seconds
+       3 = extractor_cpu_seconds
+       4 = extractor_elapsed_seconds
+    */
+    int kind : int ref,
+    float seconds : float ref
+);
+
+/**
+ * An error or warning generated by the extractor.
+ * The diagnostic message `diagnostic` was generated during compiler
+ * invocation `compilation`, and is the `file_number_diagnostic_number`th
+ * message generated while extracting the `file_number`th file of that
+ * invocation.
+ */
+#keyset[compilation, file_number, file_number_diagnostic_number]
+diagnostic_for(
+    unique int diagnostic : @diagnostic ref,
+    int compilation : @compilation ref,
+    int file_number : int ref,
+    int file_number_diagnostic_number : int ref
+);
+
+diagnostics(
+    unique int id: @diagnostic,
+    int severity: int ref,
+    string error_tag: string ref,
+    string error_message: string ref,
+    string full_error_message: string ref,
+    int location: @location ref
+);
+
+extractor_messages(
+    unique int id: @extractor_message,
+    int severity: int ref,
+    string origin : string ref,
+    string text : string ref,
+    string entity : string ref,
+    int location: @location ref,
+    string stack_trace : string ref
+);
+
+/**
+ * If extraction was successful, then `cpu_seconds` and
+ * `elapsed_seconds` are the CPU time and elapsed time (respectively)
+ * that extraction took for compiler invocation `id`.
+ */
+compilation_finished(
+    unique int id : @compilation ref,
+    float cpu_seconds : float ref,
+    float elapsed_seconds : float ref
+);
+
+compilation_assembly(
+  unique int id : @compilation ref,
+  int assembly: @assembly ref
+)
+
+// Populated by the CSV extractor
+externalData(
+   int id: @externalDataElement,
+   string path: string ref,
+   int column: int ref,
+   string value: string ref);
+
+sourceLocationPrefix(
+  string prefix: string ref);
+
+/*
+ * Overlay support
+ */
+
+/**
+ * The CLI will automatically emit the tuple `databaseMetadata("isOverlay", "true")`,
+ * along with an `overlayChangedFiles` tuple for each new/modified/deleted file,
+ * when building an overlay database, and these can be used by the discard predicates.
+ */
+databaseMetadata(
+  string metadataKey : string ref,
+  string value : string ref
+);
+
+overlayChangedFiles(
+  string path : string ref
+);
+
+/*
+ * C# dbscheme
+ */
+
+/** ELEMENTS **/
+
+@element = @declaration | @stmt | @expr | @modifier | @attribute | @namespace_declaration
+         | @using_directive | @type_parameter_constraints | @externalDataElement
+         | @xmllocatable | @asp_element | @namespace | @preprocessor_directive;
+
+@declaration = @callable | @generic | @assignable | @namespace;
+
+@named_element = @namespace | @declaration;
+
+@declaration_with_accessors = @property | @indexer | @event;
+
+@assignable = @variable | @assignable_with_accessors | @event;
+
+@assignable_with_accessors = @property | @indexer;
+
+@attributable = @assembly | @field | @parameter | @operator | @method | @constructor
+              | @destructor | @callable_accessor | @value_or_ref_type | @declaration_with_accessors
+              | @local_function | @lambda_expr;
+
+/** LOCATIONS, ASEMMBLIES, MODULES, FILES and FOLDERS **/
+
+@location = @location_default | @assembly;
+
+@locatable = @declaration_with_accessors | @callable_accessor | @declaration_or_directive
+           | @diagnostic | @extractor_message | @preprocessor_directive | @attribute | @type_mention | @type_parameter_constraints
+           | @declaration_with_accessors | @callable_accessor | @operator | @method
+           | @constructor | @destructor | @field | @local_variable | @parameter | @stmt | @expr
+           | @xmllocatable | @commentline | @commentblock | @asp_element
+
+locations_default(
+  unique int id: @location_default,
+  int file: @file ref,
+  int beginLine: int ref,
+  int beginColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+locations_mapped(
+  unique int id: @location_default ref,
+  int mapped_to: @location_default ref);
+
+@sourceline = @file | @callable | @xmllocatable;
+
+numlines(
+  int element_id: @sourceline ref,
+  int num_lines: int ref,
+  int num_code: int ref,
+  int num_comment: int ref);
+
+assemblies(
+  unique int id: @assembly,
+  int file: @file ref,
+  string fullname: string ref,
+  string name: string ref,
+  string version: string ref);
+
+files(
+  unique int id: @file,
+  string name: string ref);
+
+folders(
+  unique int id: @folder,
+  string name: string ref);
+
+@container = @folder | @file ;
+
+containerparent(
+  int parent: @container ref,
+  unique int child: @container ref);
+
+file_extraction_mode(
+  unique int file: @file ref,
+  int mode: int ref
+  /* 0 = normal, 1 = standalone extractor */
+  );
+
+/** NAMESPACES **/
+
+@type_container = @namespace | @type;
+
+namespaces(
+  unique int id: @namespace,
+  string name: string ref);
+
+namespace_declarations(
+  unique int id: @namespace_declaration,
+  int namespace_id: @namespace ref);
+
+namespace_declaration_location(
+  unique int id: @namespace_declaration ref,
+  int loc: @location ref);
+
+parent_namespace(
+  unique int child_id: @type_container ref,
+  int namespace_id: @namespace ref);
+
+@declaration_or_directive = @namespace_declaration | @type | @using_directive;
+
+parent_namespace_declaration(
+  int child_id: @declaration_or_directive ref, // cannot be unique because of partial classes
+  int namespace_id: @namespace_declaration ref);
+
+@using_directive = @using_namespace_directive | @using_static_directive;
+
+using_global(
+  unique int id: @using_directive ref
+);
+
+using_namespace_directives(
+  unique int id: @using_namespace_directive,
+  int namespace_id: @namespace ref);
+
+using_static_directives(
+  unique int id: @using_static_directive,
+  int type_id: @type_or_ref ref);
+
+using_directive_location(
+  unique int id: @using_directive ref,
+  int loc: @location ref);
+
+@preprocessor_directive = @pragma_warning | @pragma_checksum | @directive_define | @directive_undefine | @directive_warning
+  | @directive_error | @directive_nullable | @directive_line | @directive_region | @directive_endregion | @directive_if
+  | @directive_elif | @directive_else | @directive_endif;
+
+@conditional_directive = @directive_if | @directive_elif;
+@branch_directive = @directive_if | @directive_elif | @directive_else;
+
+directive_ifs(
+  unique int id: @directive_if,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref); /* 0: false, 1: true */
+
+directive_elifs(
+  unique int id: @directive_elif,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref,  /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+directive_elses(
+  unique int id: @directive_else,
+  int branchTaken: int ref,   /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+#keyset[id, start]
+directive_endifs(
+  unique int id: @directive_endif,
+  unique int start: @directive_if ref);
+
+directive_define_symbols(
+  unique int id: @define_symbol_expr ref,
+  string name: string ref);
+
+directive_regions(
+  unique int id: @directive_region,
+  string name: string ref);
+
+#keyset[id, start]
+directive_endregions(
+  unique int id: @directive_endregion,
+  unique int start: @directive_region ref);
+
+directive_lines(
+  unique int id: @directive_line,
+  int kind: int ref); /* 0: default, 1: hidden, 2: numeric, 3: span */
+
+directive_line_value(
+  unique int id: @directive_line ref,
+  int line: int ref);
+
+directive_line_file(
+  unique int id: @directive_line ref,
+  int file: @file ref);
+
+directive_line_offset(
+  unique int id: @directive_line ref,
+  int offset: int ref);
+
+directive_line_span(
+  unique int id: @directive_line ref,
+  int startLine: int ref,
+  int startColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+directive_nullables(
+  unique int id: @directive_nullable,
+  int setting: int ref, /* 0: disable, 1: enable, 2: restore */
+  int target: int ref); /* 0: none, 1: annotations, 2: warnings */
+
+directive_warnings(
+  unique int id: @directive_warning,
+  string message: string ref);
+
+directive_errors(
+  unique int id: @directive_error,
+  string message: string ref);
+
+directive_undefines(
+  unique int id: @directive_undefine,
+  string name: string ref);
+
+directive_defines(
+  unique int id: @directive_define,
+  string name: string ref);
+
+pragma_checksums(
+  unique int id: @pragma_checksum,
+  int file: @file ref,
+  string guid: string ref,
+  string bytes: string ref);
+
+pragma_warnings(
+  unique int id: @pragma_warning,
+  int kind: int ref /* 0 = disable, 1 = restore */);
+
+#keyset[id, index]
+pragma_warning_error_codes(
+  int id: @pragma_warning ref,
+  string errorCode: string ref,
+  int index: int ref);
+
+preprocessor_directive_location(
+  unique int id: @preprocessor_directive ref,
+  int loc: @location ref);
+
+preprocessor_directive_compilation(
+  int id: @preprocessor_directive ref,
+  int compilation: @compilation ref);
+
+preprocessor_directive_active(
+  unique int id: @preprocessor_directive ref,
+  int active: int ref);  /* 0: false, 1: true */
+
+/** TYPES **/
+
+types(
+  unique int id: @type,
+  int kind: int ref,
+  string name: string ref);
+
+case @type.kind of
+   1 = @bool_type
+|  2 = @char_type
+|  3 = @decimal_type
+|  4 = @sbyte_type
+|  5 = @short_type
+|  6 = @int_type
+|  7 = @long_type
+|  8 = @byte_type
+|  9 = @ushort_type
+| 10 = @uint_type
+| 11 = @ulong_type
+| 12 = @float_type
+| 13 = @double_type
+| 14 = @enum_type
+| 15 = @struct_type
+| 17 = @class_type
+| 19 = @interface_type
+| 20 = @delegate_type
+| 21 = @null_type
+| 22 = @type_parameter
+| 23 = @pointer_type
+| 24 = @nullable_type
+| 25 = @array_type
+| 26 = @void_type
+| 27 = @int_ptr_type
+| 28 = @uint_ptr_type
+| 29 = @dynamic_type
+| 30 = @arglist_type
+| 31 = @unknown_type
+| 32 = @tuple_type
+| 33 = @function_pointer_type
+| 34 = @inline_array_type
+| 35 = @extension_type
+  ;
+
+@simple_type = @bool_type | @char_type | @integral_type | @floating_point_type | @decimal_type;
+@integral_type = @signed_integral_type | @unsigned_integral_type;
+@signed_integral_type = @sbyte_type | @short_type | @int_type | @long_type;
+@unsigned_integral_type = @byte_type  | @ushort_type | @uint_type | @ulong_type;
+@floating_point_type = @float_type | @double_type;
+@value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
+            | @uint_ptr_type | @tuple_type | @void_type | @inline_array_type;
+@ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
+          | @dynamic_type | @extension_type;
+@value_or_ref_type = @value_type | @ref_type;
+
+typerefs(
+  unique int id: @typeref,
+  string name: string ref);
+
+typeref_type(
+  int id: @typeref ref,
+  unique int typeId: @type ref);
+
+@type_or_ref = @type | @typeref;
+
+array_element_type(
+  unique int array: @array_type ref,
+  int dimension: int ref,
+  int rank: int ref,
+  int element: @type_or_ref ref);
+
+nullable_underlying_type(
+  unique int nullable: @nullable_type ref,
+  int underlying: @type_or_ref ref);
+
+pointer_referent_type(
+  unique int pointer: @pointer_type ref,
+  int referent: @type_or_ref ref);
+
+enum_underlying_type(
+  unique int enum_id: @enum_type ref,
+  int underlying_type_id: @type_or_ref ref);
+
+delegate_return_type(
+  unique int delegate_id: @delegate_type ref,
+  int return_type_id: @type_or_ref ref);
+
+function_pointer_return_type(
+    unique int function_pointer_id: @function_pointer_type ref,
+    int return_type_id: @type_or_ref ref);
+
+extension_receiver_type(
+  unique int extension: @extension_type ref,
+  int receiver_type_id: @type_or_ref ref);
+
+extend(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+anonymous_types(
+  unique int id: @type ref);
+
+@interface_or_ref = @interface_type | @typeref;
+
+implement(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+type_location(
+  int id: @type ref,
+  int loc: @location ref);
+
+tuple_underlying_type(
+  unique int tuple: @tuple_type ref,
+  int struct: @type_or_ref ref);
+
+#keyset[tuple, index]
+tuple_element(
+  int tuple: @tuple_type ref,
+  int index: int ref,
+  unique int field: @field ref);
+
+attributes(
+  unique int id: @attribute,
+  int kind: int ref,
+  int type_id: @type_or_ref ref,
+  int target:  @attributable ref);
+
+case @attribute.kind of
+  0 = @attribute_default
+| 1 = @attribute_return
+| 2 = @attribute_assembly
+| 3 = @attribute_module
+;
+
+attribute_location(
+  int id: @attribute ref,
+  int loc: @location ref);
+
+@type_mention_parent = @element | @type_mention;
+
+type_mention(
+  unique int id: @type_mention,
+  int type_id: @type_or_ref ref,
+  int parent: @type_mention_parent ref);
+
+type_mention_location(
+  unique int id: @type_mention ref,
+  int loc: @location ref);
+
+@has_type_annotation = @assignable | @type_parameter | @callable | @expr | @delegate_type | @generic | @function_pointer_type;
+
+/**
+ * A direct annotation on an entity, for example `string? x;`.
+ *
+ * Annotations:
+ * 2 = reftype is not annotated "!"
+ * 3 = reftype is annotated "?"
+ * 4 = readonly ref type / in parameter
+ * 5 = ref type parameter, return or local variable
+ * 6 = out parameter
+ *
+ * Note that the annotation depends on the element it annotates.
+ * @assignable: The annotation is on the type of the assignable, for example the variable type.
+ * @type_parameter: The annotation is on the reftype constraint
+ * @callable: The annotation is on the return type
+ * @array_type: The annotation is on the element type
+ */
+type_annotation(int id: @has_type_annotation ref, int annotation: int ref);
+
+nullability(unique int nullability: @nullability, int kind: int ref);
+
+case @nullability.kind of
+  0 = @oblivious
+| 1 = @not_annotated
+| 2 = @annotated
+;
+
+#keyset[parent, index]
+nullability_parent(int nullability: @nullability ref, int index: int ref, int parent: @nullability ref)
+
+type_nullability(int id: @has_type_annotation ref, int nullability: @nullability ref);
+
+/**
+ * The nullable flow state of an expression, as determined by Roslyn.
+ *   0 = none (default, not populated)
+ *   1 = not null
+ *   2 = maybe null
+ */
+expr_flowstate(unique int id: @expr ref, int state: int ref);
+
+/** GENERICS **/
+
+@generic = @type | @method | @local_function;
+
+type_parameters(
+  unique int id: @type_parameter ref,
+  int index: int ref,
+  int generic_id: @generic ref,
+  int variance: int ref /* none = 0, out = 1, in = 2 */);
+
+#keyset[constructed_id, index]
+type_arguments(
+  int id: @type_or_ref ref,
+  int index: int ref,
+  int constructed_id: @generic_or_ref ref);
+
+@generic_or_ref = @generic | @typeref;
+
+constructed_generic(
+  unique int constructed: @generic ref,
+  int generic: @generic_or_ref ref);
+
+type_parameter_constraints(
+  unique int id: @type_parameter_constraints,
+  int param_id: @type_parameter ref);
+
+type_parameter_constraints_location(
+  int id: @type_parameter_constraints ref,
+  int loc: @location ref);
+
+general_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int kind: int ref /* class = 1, struct = 2, new = 3 */);
+
+specific_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref);
+
+specific_type_parameter_nullability(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref,
+  int nullability: @nullability ref);
+
+/** FUNCTION POINTERS */
+
+function_pointer_calling_conventions(
+  int id: @function_pointer_type ref,
+  int kind: int ref);
+
+#keyset[id, index]
+has_unmanaged_calling_conventions(
+  int id: @function_pointer_type ref,
+  int index: int ref,
+  int conv_id: @type_or_ref ref);
+
+/** MODIFIERS */
+
+@modifiable = @modifiable_direct | @event_accessor;
+
+@modifiable_direct = @member | @accessor | @local_function | @anonymous_function_expr;
+
+modifiers(
+  unique int id: @modifier,
+  string name: string ref);
+
+has_modifiers(
+  int id: @modifiable_direct ref,
+  int mod_id: @modifier ref);
+
+/** MEMBERS **/
+
+@member = @method | @constructor | @destructor | @field | @property | @event | @operator | @indexer | @type;
+
+@named_exprorstmt = @goto_stmt | @labeled_stmt | @expr;
+
+@virtualizable = @method | @property | @indexer | @event | @operator;
+
+exprorstmt_name(
+  unique int parent_id: @named_exprorstmt ref,
+  string name: string ref);
+
+nested_types(
+  unique int id: @type ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @type ref);
+
+properties(
+  unique int id: @property,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @property ref);
+
+property_location(
+  int id: @property ref,
+  int loc: @location ref);
+
+indexers(
+  unique int id: @indexer,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @indexer ref);
+
+indexer_location(
+  int id: @indexer ref,
+  int loc: @location ref);
+
+accessors(
+  unique int id: @accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_member_id: @member ref,
+  int unbound_id: @accessor ref);
+
+case @accessor.kind of
+  1 = @getter
+| 2 = @setter
+  ;
+
+init_only_accessors(
+  unique int id: @accessor ref);
+
+accessor_location(
+  int id: @accessor ref,
+  int loc: @location ref);
+
+events(
+  unique int id: @event,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @event ref);
+
+event_location(
+  int id: @event ref,
+  int loc: @location ref);
+
+event_accessors(
+  unique int id: @event_accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_event_id: @event ref,
+  int unbound_id: @event_accessor ref);
+
+case @event_accessor.kind of
+  1 = @add_event_accessor
+| 2 = @remove_event_accessor
+  ;
+
+event_accessor_location(
+  int id: @event_accessor ref,
+  int loc: @location ref);
+
+operators(
+  unique int id: @operator,
+  string name: string ref,
+  string symbol: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @operator ref);
+
+operator_location(
+  int id: @operator ref,
+  int loc: @location ref);
+
+constant_value(
+  int id: @variable ref,
+  string value: string ref);
+
+/** CALLABLES **/
+
+@callable = @method | @constructor | @destructor | @operator | @callable_accessor | @anonymous_function_expr | @local_function;
+
+@callable_accessor = @accessor | @event_accessor;
+
+methods(
+  unique int id: @method,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @method ref);
+
+method_location(
+  int id: @method ref,
+  int loc: @location ref);
+
+constructors(
+  unique int id: @constructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @constructor ref);
+
+constructor_location(
+  int id: @constructor ref,
+  int loc: @location ref);
+
+destructors(
+  unique int id: @destructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @destructor ref);
+
+destructor_location(
+  int id: @destructor ref,
+  int loc: @location ref);
+
+overrides(
+  int id: @callable ref,
+  int base_id: @callable ref);
+
+explicitly_implements(
+  int id: @member ref,
+  int interface_id: @interface_or_ref ref);
+
+local_functions(
+    unique int id: @local_function,
+    string name: string ref,
+    int return_type: @type ref,
+    int unbound_id: @local_function ref);
+
+local_function_stmts(
+    unique int fn: @local_function_stmt ref,
+    int stmt: @local_function ref);
+
+/** VARIABLES **/
+
+@variable = @local_scope_variable | @field;
+
+@local_scope_variable = @local_variable | @parameter;
+
+fields(
+  unique int id: @field,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @field ref);
+
+case @field.kind of
+  1 = @addressable_field
+| 2 = @constant
+  ;
+
+field_location(
+  int id: @field ref,
+  int loc: @location ref);
+
+localvars(
+  unique int id: @local_variable,
+  int kind: int ref,
+  string name: string ref,
+  int implicitly_typed: int ref /* 0 = no, 1 = yes */,
+  int type_id: @type_or_ref ref,
+  int parent_id: @local_var_decl_expr ref);
+
+case @local_variable.kind of
+  1 = @addressable_local_variable
+| 2 = @local_constant
+| 3 = @local_variable_ref
+  ;
+
+localvar_location(
+  unique int id: @local_variable ref,
+  int loc: @location ref);
+
+@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type | @extension_type;
+
+#keyset[name, parent_id]
+#keyset[index, parent_id]
+params(
+  unique int id: @parameter,
+  string name: string ref,
+  int type_id: @type_or_ref ref,
+  int index: int ref,
+  int mode: int ref, /* value = 0, ref = 1, out = 2, params/array = 3, this = 4, in = 5, ref readonly = 6 */
+  int parent_id: @parameterizable ref,
+  int unbound_id: @parameter ref);
+
+param_location(
+  int id: @parameter ref,
+  int loc: @location ref);
+
+@has_scoped_annotation = @local_scope_variable
+
+scoped_annotation(
+  int id: @has_scoped_annotation ref,
+  int kind: int ref // scoped ref = 1, scoped value = 2
+  );
+
+/** STATEMENTS **/
+
+@exprorstmt_parent = @control_flow_element | @top_level_exprorstmt_parent;
+
+statements(
+  unique int id: @stmt,
+  int kind: int ref);
+
+#keyset[index, parent]
+stmt_parent(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_stmt_parent = @callable;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+stmt_parent_top_level(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @top_level_stmt_parent ref);
+
+case @stmt.kind of
+   1 = @block_stmt
+|  2 = @expr_stmt
+|  3 = @if_stmt
+|  4 = @switch_stmt
+|  5 = @while_stmt
+|  6 = @do_stmt
+|  7 = @for_stmt
+|  8 = @foreach_stmt
+|  9 = @break_stmt
+| 10 = @continue_stmt
+| 11 = @goto_stmt
+| 12 = @goto_case_stmt
+| 13 = @goto_default_stmt
+| 14 = @throw_stmt
+| 15 = @return_stmt
+| 16 = @yield_stmt
+| 17 = @try_stmt
+| 18 = @checked_stmt
+| 19 = @unchecked_stmt
+| 20 = @lock_stmt
+| 21 = @using_block_stmt
+| 22 = @var_decl_stmt
+| 23 = @const_decl_stmt
+| 24 = @empty_stmt
+| 25 = @unsafe_stmt
+| 26 = @fixed_stmt
+| 27 = @label_stmt
+| 28 = @catch
+| 29 = @case_stmt
+| 30 = @local_function_stmt
+| 31 = @using_decl_stmt
+  ;
+
+@using_stmt = @using_block_stmt | @using_decl_stmt;
+
+@labeled_stmt = @label_stmt | @case;
+
+@decl_stmt = @var_decl_stmt | @const_decl_stmt | @using_decl_stmt;
+
+@cond_stmt = @if_stmt | @switch_stmt;
+
+@loop_stmt = @while_stmt | @do_stmt | @for_stmt | @foreach_stmt;
+
+@jump_stmt = @break_stmt | @goto_any_stmt | @continue_stmt | @throw_stmt | @return_stmt
+           | @yield_stmt;
+
+@goto_any_stmt = @goto_default_stmt | @goto_case_stmt | @goto_stmt;
+
+
+stmt_location(
+  unique int id: @stmt ref,
+  int loc: @location ref);
+
+catch_type(
+  unique int catch_id: @catch ref,
+  int type_id: @type_or_ref ref,
+  int kind: int ref /* explicit = 1, implicit = 2 */);
+
+foreach_stmt_info(
+  unique int id: @foreach_stmt ref,
+  int kind: int ref /* non-async = 1, async = 2 */);
+
+@foreach_symbol =  @method | @property | @type_or_ref;
+
+#keyset[id, kind]
+foreach_stmt_desugar(
+  int id: @foreach_stmt ref,
+  int symbol: @foreach_symbol ref,
+  int kind: int ref /* GetEnumeratorMethod = 1, CurrentProperty = 2, MoveNextMethod = 3, DisposeMethod = 4, ElementType = 5 */);
+
+/** EXPRESSIONS **/
+
+expressions(
+  unique int id: @expr,
+  int kind: int ref,
+  int type_id: @type_or_ref ref);
+
+#keyset[index, parent]
+expr_parent(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_expr_parent = @attribute | @field | @property | @indexer | @parameter | @directive_if | @directive_elif;
+
+@top_level_exprorstmt_parent = @top_level_expr_parent | @top_level_stmt_parent;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+expr_parent_top_level(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @top_level_exprorstmt_parent ref);
+
+case @expr.kind of
+/* literal */
+   1 = @bool_literal_expr
+|  2 = @char_literal_expr
+|  3 = @decimal_literal_expr
+|  4 = @int_literal_expr
+|  5 = @long_literal_expr
+|  6 = @uint_literal_expr
+|  7 = @ulong_literal_expr
+|  8 = @float_literal_expr
+|  9 = @double_literal_expr
+| 10 = @utf16_string_literal_expr
+| 11 = @null_literal_expr
+/* primary & unary */
+| 12 = @this_access_expr
+| 13 = @base_access_expr
+| 14 = @local_variable_access_expr
+| 15 = @parameter_access_expr
+| 16 = @field_access_expr
+| 17 = @property_access_expr
+| 18 = @method_access_expr
+| 19 = @event_access_expr
+| 20 = @indexer_access_expr
+| 21 = @array_access_expr
+| 22 = @type_access_expr
+| 23 = @typeof_expr
+| 24 = @method_invocation_expr
+| 25 = @delegate_invocation_expr
+| 26 = @operator_invocation_expr
+| 27 = @cast_expr
+| 28 = @object_creation_expr
+| 29 = @explicit_delegate_creation_expr
+| 30 = @implicit_delegate_creation_expr
+| 31 = @array_creation_expr
+| 32 = @default_expr
+| 33 = @plus_expr
+| 34 = @minus_expr
+| 35 = @bit_not_expr
+| 36 = @log_not_expr
+| 37 = @post_incr_expr
+| 38 = @post_decr_expr
+| 39 = @pre_incr_expr
+| 40 = @pre_decr_expr
+/* multiplicative */
+| 41 = @mul_expr
+| 42 = @div_expr
+| 43 = @rem_expr
+/* additive */
+| 44 = @add_expr
+| 45 = @sub_expr
+/* shift */
+| 46 = @lshift_expr
+| 47 = @rshift_expr
+/* relational */
+| 48 = @lt_expr
+| 49 = @gt_expr
+| 50 = @le_expr
+| 51 = @ge_expr
+/* equality */
+| 52 = @eq_expr
+| 53 = @ne_expr
+/* logical */
+| 54 = @bit_and_expr
+| 55 = @bit_xor_expr
+| 56 = @bit_or_expr
+| 57 = @log_and_expr
+| 58 = @log_or_expr
+/* type testing */
+| 59 = @is_expr
+| 60 = @as_expr
+/* null coalescing */
+| 61 = @null_coalescing_expr
+/* conditional */
+| 62 = @conditional_expr
+/* assignment */
+| 63 = @simple_assign_expr
+| 64 = @assign_add_expr
+| 65 = @assign_sub_expr
+| 66 = @assign_mul_expr
+| 67 = @assign_div_expr
+| 68 = @assign_rem_expr
+| 69 = @assign_and_expr
+| 70 = @assign_xor_expr
+| 71 = @assign_or_expr
+| 72 = @assign_lshift_expr
+| 73 = @assign_rshift_expr
+/* more */
+| 74 = @object_init_expr
+| 75 = @collection_init_expr
+| 76 = @array_init_expr
+| 77 = @checked_expr
+| 78 = @unchecked_expr
+| 79 = @constructor_init_expr
+| 80 = @add_event_expr
+| 81 = @remove_event_expr
+| 82 = @par_expr
+| 83 = @local_var_decl_expr
+| 84 = @lambda_expr
+| 85 = @anonymous_method_expr
+| 86 = @namespace_expr
+/* dynamic */
+| 92 = @dynamic_element_access_expr
+| 93 = @dynamic_member_access_expr
+/* unsafe */
+| 100 = @pointer_indirection_expr
+| 101 = @address_of_expr
+| 102 = @sizeof_expr
+/* async */
+| 103 = @await_expr
+/* C# 6.0 */
+| 104 = @nameof_expr
+| 105 = @interpolated_string_expr
+| 106 = @unknown_expr
+/* C# 7.0 */
+| 107 = @throw_expr
+| 108 = @tuple_expr
+| 109 = @local_function_invocation_expr
+| 110 = @ref_expr
+| 111 = @discard_expr
+/* C# 8.0 */
+| 112 = @range_expr
+| 113 = @index_expr
+| 114 = @switch_expr
+| 115 = @recursive_pattern_expr
+| 116 = @property_pattern_expr
+| 117 = @positional_pattern_expr
+| 118 = @switch_case_expr
+| 119 = @assign_coalesce_expr
+| 120 = @suppress_nullable_warning_expr
+| 121 = @namespace_access_expr
+/* C# 9.0 */
+| 122 = @lt_pattern_expr
+| 123 = @gt_pattern_expr
+| 124 = @le_pattern_expr
+| 125 = @ge_pattern_expr
+| 126 = @not_pattern_expr
+| 127 = @and_pattern_expr
+| 128 = @or_pattern_expr
+| 129 = @function_pointer_invocation_expr
+| 130 = @with_expr
+/* C# 11.0 */
+| 131 = @list_pattern_expr
+| 132 = @slice_pattern_expr
+| 133 = @urshift_expr
+| 134 = @assign_urshift_expr
+| 135 = @utf8_string_literal_expr
+/* C# 12.0 */
+| 136 = @collection_expr
+| 137 = @spread_element_expr
+| 138 = @interpolated_string_insert_expr
+/* Preprocessor */
+| 999 = @define_symbol_expr
+;
+
+@switch = @switch_stmt | @switch_expr;
+@case = @case_stmt | @switch_case_expr;
+@pattern_match = @case | @is_expr;
+@unary_pattern_expr = @not_pattern_expr;
+@relational_pattern_expr = @gt_pattern_expr | @lt_pattern_expr | @ge_pattern_expr | @le_pattern_expr;
+@binary_pattern_expr = @and_pattern_expr | @or_pattern_expr;
+
+@integer_literal_expr = @int_literal_expr | @long_literal_expr | @uint_literal_expr | @ulong_literal_expr;
+@real_literal_expr = @float_literal_expr | @double_literal_expr | @decimal_literal_expr;
+@string_literal_expr = @utf16_string_literal_expr | @utf8_string_literal_expr;
+@literal_expr = @bool_literal_expr | @char_literal_expr | @integer_literal_expr | @real_literal_expr
+              | @string_literal_expr | @null_literal_expr;
+
+@assign_expr = @simple_assign_expr | @assign_op_expr | @local_var_decl_expr;
+@assign_op_call_expr = @assign_arith_expr | @assign_bitwise_expr
+@assign_op_expr =  @assign_op_call_expr | @assign_event_expr | @assign_coalesce_expr;
+@assign_event_expr = @add_event_expr | @remove_event_expr;
+
+@add_operation = @add_expr | @assign_add_expr;
+@sub_operation = @sub_expr | @assign_sub_expr;
+@mul_operation = @mul_expr | @assign_mul_expr;
+@div_operation = @div_expr | @assign_div_expr;
+@rem_operation = @rem_expr | @assign_rem_expr;
+@and_operation = @bit_and_expr | @assign_and_expr;
+@xor_operation = @bit_xor_expr | @assign_xor_expr;
+@or_operation = @bit_or_expr | @assign_or_expr;
+@lshift_operation = @lshift_expr | @assign_lshift_expr;
+@rshift_operation = @rshift_expr | @assign_rshift_expr;
+@urshift_operation = @urshift_expr | @assign_urshift_expr;
+@null_coalescing_operation = @null_coalescing_expr | @assign_coalesce_expr;
+
+@assign_arith_expr = @assign_add_expr | @assign_sub_expr | @assign_mul_expr | @assign_div_expr
+                   | @assign_rem_expr
+@assign_bitwise_expr = @assign_and_expr | @assign_or_expr | @assign_xor_expr
+                   | @assign_lshift_expr | @assign_rshift_expr | @assign_urshift_expr;
+
+@member_access_expr = @field_access_expr | @property_access_expr | @indexer_access_expr | @event_access_expr
+                    | @method_access_expr | @type_access_expr | @dynamic_member_access_expr;
+@access_expr = @member_access_expr | @this_access_expr | @base_access_expr | @assignable_access_expr | @namespace_access_expr;
+@element_access_expr = @indexer_access_expr | @array_access_expr | @dynamic_element_access_expr;
+
+@local_variable_access = @local_variable_access_expr | @local_var_decl_expr;
+@local_scope_variable_access_expr = @parameter_access_expr | @local_variable_access;
+@variable_access_expr = @local_scope_variable_access_expr | @field_access_expr;
+
+@assignable_access_expr = @variable_access_expr | @property_access_expr | @element_access_expr
+                        | @event_access_expr | @dynamic_member_access_expr;
+
+@objectorcollection_init_expr = @object_init_expr | @collection_init_expr;
+
+@delegate_creation_expr = @explicit_delegate_creation_expr | @implicit_delegate_creation_expr;
+
+@bin_arith_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
+@bin_arith_operation = @mul_operation | @div_operation | @rem_operation | @add_operation | @sub_operation;
+
+@incr_operation =  @pre_incr_expr | @post_incr_expr;
+@decr_operation =  @pre_decr_expr | @post_decr_expr;
+@mut_operation = @incr_operation | @decr_operation;
+@un_arith_operation = @plus_expr | @minus_expr | @mut_operation;
+@arith_operation = @bin_arith_operation | @un_arith_operation;
+
+@ternary_log_operation = @conditional_expr;
+@bin_log_operation = @log_and_expr | @log_or_expr | @null_coalescing_operation;
+@un_log_operation = @log_not_expr;
+@log_operation = @un_log_operation | @bin_log_operation | @ternary_log_operation;
+
+@bin_bit_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
+              | @rshift_expr | @urshift_expr;
+@bin_bit_operation = @and_operation | @or_operation | @xor_operation | @lshift_operation
+              | @rshift_operation | @urshift_operation;
+@un_bit_expr = @bit_not_expr;
+@un_bit_operation = @un_bit_expr;
+@bit_expr = @un_bit_expr | @bin_bit_expr;
+@bit_operation = @un_bit_operation | @bin_bit_operation;
+
+@equality_op_expr =  @eq_expr | @ne_expr;
+@rel_op_expr = @gt_expr | @lt_expr| @ge_expr | @le_expr;
+@comp_expr = @equality_op_expr | @rel_op_expr;
+
+@operation_expr = @un_operation | @bin_operation | @ternary_operation;
+
+@ternary_operation = @ternary_log_operation;
+@bin_operation = @assign_expr | @bin_arith_operation | @bin_log_operation | @bin_bit_operation | @comp_expr;
+@un_operation = @un_arith_operation | @un_log_operation | @un_bit_operation | @sizeof_expr
+              | @pointer_indirection_expr | @address_of_expr;
+
+@anonymous_function_expr = @lambda_expr | @anonymous_method_expr;
+
+@op_invoke_expr = @operator_invocation_expr | @assign_op_call_expr
+@call = @method_invocation_expr | @constructor_init_expr | @op_invoke_expr
+      | @delegate_invocation_expr | @object_creation_expr | @call_access_expr
+      | @local_function_invocation_expr | @function_pointer_invocation_expr;
+
+@call_access_expr = @property_access_expr | @event_access_expr | @indexer_access_expr;
+
+@late_bindable_expr = @dynamic_element_access_expr | @dynamic_member_access_expr
+                    | @object_creation_expr | @method_invocation_expr | @op_invoke_expr;
+
+@throw_element = @throw_expr | @throw_stmt;
+
+@implicitly_typeable_object_creation_expr = @object_creation_expr | @explicit_delegate_creation_expr;
+
+implicitly_typed_array_creation(
+  unique int id: @array_creation_expr ref);
+
+explicitly_sized_array_creation(
+  unique int id: @array_creation_expr ref);
+
+stackalloc_array_creation(
+  unique int id: @array_creation_expr ref);
+
+implicitly_typed_object_creation(
+  unique int id: @implicitly_typeable_object_creation_expr ref);
+
+mutator_invocation_mode(
+  unique int id: @operator_invocation_expr ref,
+  int mode: int ref /* prefix = 1, postfix = 2*/);
+
+expr_value(
+  unique int id: @expr ref,
+  string value: string ref);
+
+expr_call(
+  unique int caller_id: @expr ref,
+  int target_id: @callable ref);
+
+expr_access(
+  unique int accesser_id: @access_expr ref,
+  int target_id: @accessible ref);
+
+@accessible = @method | @assignable | @local_function | @namespace;
+
+expr_location(
+  unique int id: @expr ref,
+  int loc: @location ref);
+
+dynamic_member_name(
+  unique int id: @late_bindable_expr ref,
+  string name: string ref);
+
+@qualifiable_expr = @member_access_expr
+                  | @method_invocation_expr
+                  | @element_access_expr
+                  | @assign_op_call_expr;
+
+conditional_access(
+  unique int id: @qualifiable_expr ref);
+
+expr_argument(
+  unique int id: @expr ref,
+  int mode: int ref);
+  /* mode is the same as params: value = 0, ref = 1, out = 2 */
+
+expr_argument_name(
+  unique int id: @expr ref,
+  string name: string ref);
+
+lambda_expr_return_type(
+  unique int id: @lambda_expr ref,
+  int type_id: @type_or_ref ref);
+
+/* Compiler generated */
+
+compiler_generated(unique int id: @element ref);
+
+/** CONTROL/DATA FLOW **/
+
+@control_flow_element = @stmt | @expr | @parameter;
+
+/* XML Files */
+
+xmlEncoding  (
+  unique int id: @file ref,
+  string encoding: string ref);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+/* Comments */
+
+commentline(
+  unique int id: @commentline,
+  int kind: int ref,
+  string text: string ref,
+  string rawtext: string ref);
+
+case @commentline.kind of
+  0 = @singlelinecomment
+| 1 = @xmldoccomment
+| 2 = @multilinecomment;
+
+commentline_location(
+  unique int id: @commentline ref,
+  int loc: @location ref);
+
+commentblock(
+  unique int id : @commentblock);
+
+commentblock_location(
+  unique int id: @commentblock ref,
+  int loc: @location ref);
+
+commentblock_binding(
+  int id: @commentblock ref,
+  int entity: @element ref,
+  int bindtype: int ref);    /* 0: Parent, 1: Best, 2: Before, 3: After */
+
+commentblock_child(
+  int id: @commentblock ref,
+  int commentline: @commentline ref,
+  int index: int ref);
+
+/* ASP.NET */
+
+case @asp_element.kind of
+  0=@asp_close_tag
+| 1=@asp_code
+| 2=@asp_comment
+| 3=@asp_data_binding
+| 4=@asp_directive
+| 5=@asp_open_tag
+| 6=@asp_quoted_string
+| 7=@asp_text
+| 8=@asp_xml_directive;
+
+@asp_attribute = @asp_code | @asp_data_binding | @asp_quoted_string;
+
+asp_elements(
+  unique int id: @asp_element,
+  int kind: int ref,
+  int loc: @location ref);
+
+asp_comment_server(unique int comment: @asp_comment ref);
+asp_code_inline(unique int code: @asp_code ref);
+asp_directive_attribute(
+  int directive: @asp_directive ref,
+  int index: int ref,
+  string name: string ref,
+  int value: @asp_quoted_string ref);
+asp_directive_name(
+  unique int directive: @asp_directive ref,
+  string name: string ref);
+asp_element_body(
+  unique int element: @asp_element ref,
+  string body: string ref);
+asp_tag_attribute(
+  int tag: @asp_open_tag ref,
+  int index: int ref,
+  string name: string ref,
+  int attribute: @asp_attribute ref);
+asp_tag_name(
+  unique int tag: @asp_open_tag ref,
+  string name: string ref);
+asp_tag_isempty(int tag: @asp_open_tag ref);
diff --git a/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/semmlecode.csharp.dbscheme b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/semmlecode.csharp.dbscheme
new file mode 100644
index 00000000000..3cabc77473c
--- /dev/null
+++ b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/semmlecode.csharp.dbscheme
@@ -0,0 +1,1505 @@
+/* This is a dummy line to alter the dbscheme, so we can make a database upgrade
+ * without actually changing any of the dbscheme predicates. It contains a date
+ * to allow for such updates in the future as well.
+ *
+ * 2021-07-14
+ *
+ * DO NOT remove this comment carelessly, since it can revert the dbscheme back to a
+ * previously seen state (matching a previously seen SHA), which would make the upgrade
+ * mechanism not work properly.
+ */
+
+/**
+ * An invocation of the compiler. Note that more than one file may be
+ * compiled per invocation. For example, this command compiles three
+ * source files:
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * The `id` simply identifies the invocation, while `cwd` is the working
+ * directory from which the compiler was invoked.
+ */
+compilations(
+    unique int id : @compilation,
+    string cwd : string ref
+);
+
+compilation_info(
+  int id : @compilation ref,
+  string info_key: string ref,
+  string info_value: string ref
+)
+
+/**
+ * The arguments that were passed to the extractor for a compiler
+ * invocation. If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then typically there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | --compiler
+ * 1   | *path to compiler*
+ * 2   | f1.cs
+ * 3   | f2.cs
+ * 4   | f3.cs
+ */
+#keyset[id, num]
+compilation_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The expanded arguments that were passed to the extractor for a
+ * compiler invocation. This is similar to `compilation_args`, but
+ * for a `@someFile.rsp` argument, it includes the arguments from that
+ * file, rather than just taking the argument literally.
+ */
+#keyset[id, num]
+compilation_expanded_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The source files that are compiled by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | f1.cs
+ * 1   | f2.cs
+ * 2   | f3.cs
+ */
+#keyset[id, num]
+compilation_compiling_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The references used by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs /r:ref1.dll /r:ref2.dll /r:ref3.dll
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | ref1.dll
+ * 1   | ref2.dll
+ * 2   | ref3.dll
+ */
+#keyset[id, num]
+compilation_referencing_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The time taken by the extractor for a compiler invocation.
+ *
+ * For each file `num`, there will be rows for
+ *
+ * kind | seconds
+ * ---- | ---
+ * 1    | CPU seconds used by the extractor frontend
+ * 2    | Elapsed seconds during the extractor frontend
+ * 3    | CPU seconds used by the extractor backend
+ * 4    | Elapsed seconds during the extractor backend
+ */
+#keyset[id, num, kind]
+compilation_time(
+    int id : @compilation ref,
+    int num : int ref,
+    /* kind:
+       1 = frontend_cpu_seconds
+       2 = frontend_elapsed_seconds
+       3 = extractor_cpu_seconds
+       4 = extractor_elapsed_seconds
+    */
+    int kind : int ref,
+    float seconds : float ref
+);
+
+/**
+ * An error or warning generated by the extractor.
+ * The diagnostic message `diagnostic` was generated during compiler
+ * invocation `compilation`, and is the `file_number_diagnostic_number`th
+ * message generated while extracting the `file_number`th file of that
+ * invocation.
+ */
+#keyset[compilation, file_number, file_number_diagnostic_number]
+diagnostic_for(
+    unique int diagnostic : @diagnostic ref,
+    int compilation : @compilation ref,
+    int file_number : int ref,
+    int file_number_diagnostic_number : int ref
+);
+
+diagnostics(
+    unique int id: @diagnostic,
+    int severity: int ref,
+    string error_tag: string ref,
+    string error_message: string ref,
+    string full_error_message: string ref,
+    int location: @location ref
+);
+
+extractor_messages(
+    unique int id: @extractor_message,
+    int severity: int ref,
+    string origin : string ref,
+    string text : string ref,
+    string entity : string ref,
+    int location: @location ref,
+    string stack_trace : string ref
+);
+
+/**
+ * If extraction was successful, then `cpu_seconds` and
+ * `elapsed_seconds` are the CPU time and elapsed time (respectively)
+ * that extraction took for compiler invocation `id`.
+ */
+compilation_finished(
+    unique int id : @compilation ref,
+    float cpu_seconds : float ref,
+    float elapsed_seconds : float ref
+);
+
+compilation_assembly(
+  unique int id : @compilation ref,
+  int assembly: @assembly ref
+)
+
+// Populated by the CSV extractor
+externalData(
+   int id: @externalDataElement,
+   string path: string ref,
+   int column: int ref,
+   string value: string ref);
+
+sourceLocationPrefix(
+  string prefix: string ref);
+
+/*
+ * Overlay support
+ */
+
+/**
+ * The CLI will automatically emit the tuple `databaseMetadata("isOverlay", "true")`,
+ * along with an `overlayChangedFiles` tuple for each new/modified/deleted file,
+ * when building an overlay database, and these can be used by the discard predicates.
+ */
+databaseMetadata(
+  string metadataKey : string ref,
+  string value : string ref
+);
+
+overlayChangedFiles(
+  string path : string ref
+);
+
+/*
+ * C# dbscheme
+ */
+
+/** ELEMENTS **/
+
+@element = @declaration | @stmt | @expr | @modifier | @attribute | @namespace_declaration
+         | @using_directive | @type_parameter_constraints | @externalDataElement
+         | @xmllocatable | @asp_element | @namespace | @preprocessor_directive;
+
+@declaration = @callable | @generic | @assignable | @namespace;
+
+@named_element = @namespace | @declaration;
+
+@declaration_with_accessors = @property | @indexer | @event;
+
+@assignable = @variable | @assignable_with_accessors | @event;
+
+@assignable_with_accessors = @property | @indexer;
+
+@attributable = @assembly | @field | @parameter | @operator | @method | @constructor
+              | @destructor | @callable_accessor | @value_or_ref_type | @declaration_with_accessors
+              | @local_function | @lambda_expr;
+
+/** LOCATIONS, ASEMMBLIES, MODULES, FILES and FOLDERS **/
+
+@location = @location_default | @assembly;
+
+@locatable = @declaration_with_accessors | @callable_accessor | @declaration_or_directive
+           | @diagnostic | @extractor_message | @preprocessor_directive | @attribute | @type_mention | @type_parameter_constraints
+           | @declaration_with_accessors | @callable_accessor | @operator | @method
+           | @constructor | @destructor | @field | @local_variable | @parameter | @stmt | @expr
+           | @xmllocatable | @commentline | @commentblock | @asp_element
+
+locations_default(
+  unique int id: @location_default,
+  int file: @file ref,
+  int beginLine: int ref,
+  int beginColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+locations_mapped(
+  unique int id: @location_default ref,
+  int mapped_to: @location_default ref);
+
+@sourceline = @file | @callable | @xmllocatable;
+
+numlines(
+  int element_id: @sourceline ref,
+  int num_lines: int ref,
+  int num_code: int ref,
+  int num_comment: int ref);
+
+assemblies(
+  unique int id: @assembly,
+  int file: @file ref,
+  string fullname: string ref,
+  string name: string ref,
+  string version: string ref);
+
+files(
+  unique int id: @file,
+  string name: string ref);
+
+folders(
+  unique int id: @folder,
+  string name: string ref);
+
+@container = @folder | @file ;
+
+containerparent(
+  int parent: @container ref,
+  unique int child: @container ref);
+
+file_extraction_mode(
+  unique int file: @file ref,
+  int mode: int ref
+  /* 0 = normal, 1 = standalone extractor */
+  );
+
+/** NAMESPACES **/
+
+@type_container = @namespace | @type;
+
+namespaces(
+  unique int id: @namespace,
+  string name: string ref);
+
+namespace_declarations(
+  unique int id: @namespace_declaration,
+  int namespace_id: @namespace ref);
+
+namespace_declaration_location(
+  unique int id: @namespace_declaration ref,
+  int loc: @location ref);
+
+parent_namespace(
+  unique int child_id: @type_container ref,
+  int namespace_id: @namespace ref);
+
+@declaration_or_directive = @namespace_declaration | @type | @using_directive;
+
+parent_namespace_declaration(
+  int child_id: @declaration_or_directive ref, // cannot be unique because of partial classes
+  int namespace_id: @namespace_declaration ref);
+
+@using_directive = @using_namespace_directive | @using_static_directive;
+
+using_global(
+  unique int id: @using_directive ref
+);
+
+using_namespace_directives(
+  unique int id: @using_namespace_directive,
+  int namespace_id: @namespace ref);
+
+using_static_directives(
+  unique int id: @using_static_directive,
+  int type_id: @type_or_ref ref);
+
+using_directive_location(
+  unique int id: @using_directive ref,
+  int loc: @location ref);
+
+@preprocessor_directive = @pragma_warning | @pragma_checksum | @directive_define | @directive_undefine | @directive_warning
+  | @directive_error | @directive_nullable | @directive_line | @directive_region | @directive_endregion | @directive_if
+  | @directive_elif | @directive_else | @directive_endif;
+
+@conditional_directive = @directive_if | @directive_elif;
+@branch_directive = @directive_if | @directive_elif | @directive_else;
+
+directive_ifs(
+  unique int id: @directive_if,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref); /* 0: false, 1: true */
+
+directive_elifs(
+  unique int id: @directive_elif,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref,  /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+directive_elses(
+  unique int id: @directive_else,
+  int branchTaken: int ref,   /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+#keyset[id, start]
+directive_endifs(
+  unique int id: @directive_endif,
+  unique int start: @directive_if ref);
+
+directive_define_symbols(
+  unique int id: @define_symbol_expr ref,
+  string name: string ref);
+
+directive_regions(
+  unique int id: @directive_region,
+  string name: string ref);
+
+#keyset[id, start]
+directive_endregions(
+  unique int id: @directive_endregion,
+  unique int start: @directive_region ref);
+
+directive_lines(
+  unique int id: @directive_line,
+  int kind: int ref); /* 0: default, 1: hidden, 2: numeric, 3: span */
+
+directive_line_value(
+  unique int id: @directive_line ref,
+  int line: int ref);
+
+directive_line_file(
+  unique int id: @directive_line ref,
+  int file: @file ref);
+
+directive_line_offset(
+  unique int id: @directive_line ref,
+  int offset: int ref);
+
+directive_line_span(
+  unique int id: @directive_line ref,
+  int startLine: int ref,
+  int startColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+directive_nullables(
+  unique int id: @directive_nullable,
+  int setting: int ref, /* 0: disable, 1: enable, 2: restore */
+  int target: int ref); /* 0: none, 1: annotations, 2: warnings */
+
+directive_warnings(
+  unique int id: @directive_warning,
+  string message: string ref);
+
+directive_errors(
+  unique int id: @directive_error,
+  string message: string ref);
+
+directive_undefines(
+  unique int id: @directive_undefine,
+  string name: string ref);
+
+directive_defines(
+  unique int id: @directive_define,
+  string name: string ref);
+
+pragma_checksums(
+  unique int id: @pragma_checksum,
+  int file: @file ref,
+  string guid: string ref,
+  string bytes: string ref);
+
+pragma_warnings(
+  unique int id: @pragma_warning,
+  int kind: int ref /* 0 = disable, 1 = restore */);
+
+#keyset[id, index]
+pragma_warning_error_codes(
+  int id: @pragma_warning ref,
+  string errorCode: string ref,
+  int index: int ref);
+
+preprocessor_directive_location(
+  unique int id: @preprocessor_directive ref,
+  int loc: @location ref);
+
+preprocessor_directive_compilation(
+  int id: @preprocessor_directive ref,
+  int compilation: @compilation ref);
+
+preprocessor_directive_active(
+  unique int id: @preprocessor_directive ref,
+  int active: int ref);  /* 0: false, 1: true */
+
+/** TYPES **/
+
+types(
+  unique int id: @type,
+  int kind: int ref,
+  string name: string ref);
+
+case @type.kind of
+   1 = @bool_type
+|  2 = @char_type
+|  3 = @decimal_type
+|  4 = @sbyte_type
+|  5 = @short_type
+|  6 = @int_type
+|  7 = @long_type
+|  8 = @byte_type
+|  9 = @ushort_type
+| 10 = @uint_type
+| 11 = @ulong_type
+| 12 = @float_type
+| 13 = @double_type
+| 14 = @enum_type
+| 15 = @struct_type
+| 17 = @class_type
+| 19 = @interface_type
+| 20 = @delegate_type
+| 21 = @null_type
+| 22 = @type_parameter
+| 23 = @pointer_type
+| 24 = @nullable_type
+| 25 = @array_type
+| 26 = @void_type
+| 27 = @int_ptr_type
+| 28 = @uint_ptr_type
+| 29 = @dynamic_type
+| 30 = @arglist_type
+| 31 = @unknown_type
+| 32 = @tuple_type
+| 33 = @function_pointer_type
+| 34 = @inline_array_type
+| 35 = @extension_type
+  ;
+
+@simple_type = @bool_type | @char_type | @integral_type | @floating_point_type | @decimal_type;
+@integral_type = @signed_integral_type | @unsigned_integral_type;
+@signed_integral_type = @sbyte_type | @short_type | @int_type | @long_type;
+@unsigned_integral_type = @byte_type  | @ushort_type | @uint_type | @ulong_type;
+@floating_point_type = @float_type | @double_type;
+@value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
+            | @uint_ptr_type | @tuple_type | @void_type | @inline_array_type;
+@ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
+          | @dynamic_type | @extension_type;
+@value_or_ref_type = @value_type | @ref_type;
+
+typerefs(
+  unique int id: @typeref,
+  string name: string ref);
+
+typeref_type(
+  int id: @typeref ref,
+  unique int typeId: @type ref);
+
+@type_or_ref = @type | @typeref;
+
+array_element_type(
+  unique int array: @array_type ref,
+  int dimension: int ref,
+  int rank: int ref,
+  int element: @type_or_ref ref);
+
+nullable_underlying_type(
+  unique int nullable: @nullable_type ref,
+  int underlying: @type_or_ref ref);
+
+pointer_referent_type(
+  unique int pointer: @pointer_type ref,
+  int referent: @type_or_ref ref);
+
+enum_underlying_type(
+  unique int enum_id: @enum_type ref,
+  int underlying_type_id: @type_or_ref ref);
+
+delegate_return_type(
+  unique int delegate_id: @delegate_type ref,
+  int return_type_id: @type_or_ref ref);
+
+function_pointer_return_type(
+    unique int function_pointer_id: @function_pointer_type ref,
+    int return_type_id: @type_or_ref ref);
+
+extension_receiver_type(
+  unique int extension: @extension_type ref,
+  int receiver_type_id: @type_or_ref ref);
+
+extend(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+anonymous_types(
+  unique int id: @type ref);
+
+@interface_or_ref = @interface_type | @typeref;
+
+implement(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+type_location(
+  int id: @type ref,
+  int loc: @location ref);
+
+tuple_underlying_type(
+  unique int tuple: @tuple_type ref,
+  int struct: @type_or_ref ref);
+
+#keyset[tuple, index]
+tuple_element(
+  int tuple: @tuple_type ref,
+  int index: int ref,
+  unique int field: @field ref);
+
+attributes(
+  unique int id: @attribute,
+  int kind: int ref,
+  int type_id: @type_or_ref ref,
+  int target:  @attributable ref);
+
+case @attribute.kind of
+  0 = @attribute_default
+| 1 = @attribute_return
+| 2 = @attribute_assembly
+| 3 = @attribute_module
+;
+
+attribute_location(
+  int id: @attribute ref,
+  int loc: @location ref);
+
+@type_mention_parent = @element | @type_mention;
+
+type_mention(
+  unique int id: @type_mention,
+  int type_id: @type_or_ref ref,
+  int parent: @type_mention_parent ref);
+
+type_mention_location(
+  unique int id: @type_mention ref,
+  int loc: @location ref);
+
+@has_type_annotation = @assignable | @type_parameter | @callable | @expr | @delegate_type | @generic | @function_pointer_type;
+
+/**
+ * A direct annotation on an entity, for example `string? x;`.
+ *
+ * Annotations:
+ * 2 = reftype is not annotated "!"
+ * 3 = reftype is annotated "?"
+ * 4 = readonly ref type / in parameter
+ * 5 = ref type parameter, return or local variable
+ * 6 = out parameter
+ *
+ * Note that the annotation depends on the element it annotates.
+ * @assignable: The annotation is on the type of the assignable, for example the variable type.
+ * @type_parameter: The annotation is on the reftype constraint
+ * @callable: The annotation is on the return type
+ * @array_type: The annotation is on the element type
+ */
+type_annotation(int id: @has_type_annotation ref, int annotation: int ref);
+
+nullability(unique int nullability: @nullability, int kind: int ref);
+
+case @nullability.kind of
+  0 = @oblivious
+| 1 = @not_annotated
+| 2 = @annotated
+;
+
+#keyset[parent, index]
+nullability_parent(int nullability: @nullability ref, int index: int ref, int parent: @nullability ref)
+
+type_nullability(int id: @has_type_annotation ref, int nullability: @nullability ref);
+
+/**
+ * The nullable flow state of an expression, as determined by Roslyn.
+ *   0 = none (default, not populated)
+ *   1 = not null
+ *   2 = maybe null
+ */
+expr_flowstate(unique int id: @expr ref, int state: int ref);
+
+/** GENERICS **/
+
+@generic = @type | @method | @local_function;
+
+type_parameters(
+  unique int id: @type_parameter ref,
+  int index: int ref,
+  int generic_id: @generic ref,
+  int variance: int ref /* none = 0, out = 1, in = 2 */);
+
+#keyset[constructed_id, index]
+type_arguments(
+  int id: @type_or_ref ref,
+  int index: int ref,
+  int constructed_id: @generic_or_ref ref);
+
+@generic_or_ref = @generic | @typeref;
+
+constructed_generic(
+  unique int constructed: @generic ref,
+  int generic: @generic_or_ref ref);
+
+type_parameter_constraints(
+  unique int id: @type_parameter_constraints,
+  int param_id: @type_parameter ref);
+
+type_parameter_constraints_location(
+  int id: @type_parameter_constraints ref,
+  int loc: @location ref);
+
+general_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int kind: int ref /* class = 1, struct = 2, new = 3 */);
+
+specific_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref);
+
+specific_type_parameter_nullability(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref,
+  int nullability: @nullability ref);
+
+/** FUNCTION POINTERS */
+
+function_pointer_calling_conventions(
+  int id: @function_pointer_type ref,
+  int kind: int ref);
+
+#keyset[id, index]
+has_unmanaged_calling_conventions(
+  int id: @function_pointer_type ref,
+  int index: int ref,
+  int conv_id: @type_or_ref ref);
+
+/** MODIFIERS */
+
+@modifiable = @modifiable_direct | @event_accessor;
+
+@modifiable_direct = @member | @accessor | @local_function | @anonymous_function_expr;
+
+modifiers(
+  unique int id: @modifier,
+  string name: string ref);
+
+has_modifiers(
+  int id: @modifiable_direct ref,
+  int mod_id: @modifier ref);
+
+/** MEMBERS **/
+
+@member = @method | @constructor | @destructor | @field | @property | @event | @operator | @indexer | @type;
+
+@named_exprorstmt = @goto_stmt | @labeled_stmt | @expr;
+
+@virtualizable = @method | @property | @indexer | @event | @operator;
+
+exprorstmt_name(
+  unique int parent_id: @named_exprorstmt ref,
+  string name: string ref);
+
+nested_types(
+  unique int id: @type ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @type ref);
+
+properties(
+  unique int id: @property,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @property ref);
+
+property_location(
+  int id: @property ref,
+  int loc: @location ref);
+
+indexers(
+  unique int id: @indexer,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @indexer ref);
+
+indexer_location(
+  int id: @indexer ref,
+  int loc: @location ref);
+
+accessors(
+  unique int id: @accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_member_id: @member ref,
+  int unbound_id: @accessor ref);
+
+case @accessor.kind of
+  1 = @getter
+| 2 = @setter
+  ;
+
+init_only_accessors(
+  unique int id: @accessor ref);
+
+accessor_location(
+  int id: @accessor ref,
+  int loc: @location ref);
+
+events(
+  unique int id: @event,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @event ref);
+
+event_location(
+  int id: @event ref,
+  int loc: @location ref);
+
+event_accessors(
+  unique int id: @event_accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_event_id: @event ref,
+  int unbound_id: @event_accessor ref);
+
+case @event_accessor.kind of
+  1 = @add_event_accessor
+| 2 = @remove_event_accessor
+  ;
+
+event_accessor_location(
+  int id: @event_accessor ref,
+  int loc: @location ref);
+
+operators(
+  unique int id: @operator,
+  string name: string ref,
+  string symbol: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @operator ref);
+
+operator_location(
+  int id: @operator ref,
+  int loc: @location ref);
+
+constant_value(
+  int id: @variable ref,
+  string value: string ref);
+
+/** CALLABLES **/
+
+@callable = @method | @constructor | @destructor | @operator | @callable_accessor | @anonymous_function_expr | @local_function;
+
+@callable_accessor = @accessor | @event_accessor;
+
+methods(
+  unique int id: @method,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @method ref);
+
+method_location(
+  int id: @method ref,
+  int loc: @location ref);
+
+constructors(
+  unique int id: @constructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @constructor ref);
+
+constructor_location(
+  int id: @constructor ref,
+  int loc: @location ref);
+
+destructors(
+  unique int id: @destructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @destructor ref);
+
+destructor_location(
+  int id: @destructor ref,
+  int loc: @location ref);
+
+overrides(
+  int id: @callable ref,
+  int base_id: @callable ref);
+
+explicitly_implements(
+  int id: @member ref,
+  int interface_id: @interface_or_ref ref);
+
+local_functions(
+    unique int id: @local_function,
+    string name: string ref,
+    int return_type: @type ref,
+    int unbound_id: @local_function ref);
+
+local_function_stmts(
+    unique int fn: @local_function_stmt ref,
+    int stmt: @local_function ref);
+
+/** VARIABLES **/
+
+@variable = @local_scope_variable | @field;
+
+@local_scope_variable = @local_variable | @parameter;
+
+fields(
+  unique int id: @field,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @field ref);
+
+case @field.kind of
+  1 = @addressable_field
+| 2 = @constant
+  ;
+
+field_location(
+  int id: @field ref,
+  int loc: @location ref);
+
+localvars(
+  unique int id: @local_variable,
+  int kind: int ref,
+  string name: string ref,
+  int implicitly_typed: int ref /* 0 = no, 1 = yes */,
+  int type_id: @type_or_ref ref,
+  int parent_id: @local_var_decl_expr ref);
+
+case @local_variable.kind of
+  1 = @addressable_local_variable
+| 2 = @local_constant
+| 3 = @local_variable_ref
+  ;
+
+localvar_location(
+  unique int id: @local_variable ref,
+  int loc: @location ref);
+
+@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type | @extension_type;
+
+#keyset[name, parent_id]
+#keyset[index, parent_id]
+params(
+  unique int id: @parameter,
+  string name: string ref,
+  int type_id: @type_or_ref ref,
+  int index: int ref,
+  int mode: int ref, /* value = 0, ref = 1, out = 2, params/array = 3, this = 4, in = 5, ref readonly = 6 */
+  int parent_id: @parameterizable ref,
+  int unbound_id: @parameter ref);
+
+param_location(
+  int id: @parameter ref,
+  int loc: @location ref);
+
+@has_scoped_annotation = @local_scope_variable
+
+scoped_annotation(
+  int id: @has_scoped_annotation ref,
+  int kind: int ref // scoped ref = 1, scoped value = 2
+  );
+
+/** STATEMENTS **/
+
+@exprorstmt_parent = @control_flow_element | @top_level_exprorstmt_parent;
+
+statements(
+  unique int id: @stmt,
+  int kind: int ref);
+
+#keyset[index, parent]
+stmt_parent(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_stmt_parent = @callable;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+stmt_parent_top_level(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @top_level_stmt_parent ref);
+
+case @stmt.kind of
+   1 = @block_stmt
+|  2 = @expr_stmt
+|  3 = @if_stmt
+|  4 = @switch_stmt
+|  5 = @while_stmt
+|  6 = @do_stmt
+|  7 = @for_stmt
+|  8 = @foreach_stmt
+|  9 = @break_stmt
+| 10 = @continue_stmt
+| 11 = @goto_stmt
+| 12 = @goto_case_stmt
+| 13 = @goto_default_stmt
+| 14 = @throw_stmt
+| 15 = @return_stmt
+| 16 = @yield_stmt
+| 17 = @try_stmt
+| 18 = @checked_stmt
+| 19 = @unchecked_stmt
+| 20 = @lock_stmt
+| 21 = @using_block_stmt
+| 22 = @var_decl_stmt
+| 23 = @const_decl_stmt
+| 24 = @empty_stmt
+| 25 = @unsafe_stmt
+| 26 = @fixed_stmt
+| 27 = @label_stmt
+| 28 = @catch
+| 29 = @case_stmt
+| 30 = @local_function_stmt
+| 31 = @using_decl_stmt
+  ;
+
+@using_stmt = @using_block_stmt | @using_decl_stmt;
+
+@labeled_stmt = @label_stmt | @case;
+
+@decl_stmt = @var_decl_stmt | @const_decl_stmt | @using_decl_stmt;
+
+@cond_stmt = @if_stmt | @switch_stmt;
+
+@loop_stmt = @while_stmt | @do_stmt | @for_stmt | @foreach_stmt;
+
+@jump_stmt = @break_stmt | @goto_any_stmt | @continue_stmt | @throw_stmt | @return_stmt
+           | @yield_stmt;
+
+@goto_any_stmt = @goto_default_stmt | @goto_case_stmt | @goto_stmt;
+
+
+stmt_location(
+  unique int id: @stmt ref,
+  int loc: @location ref);
+
+catch_type(
+  unique int catch_id: @catch ref,
+  int type_id: @type_or_ref ref,
+  int kind: int ref /* explicit = 1, implicit = 2 */);
+
+foreach_stmt_info(
+  unique int id: @foreach_stmt ref,
+  int kind: int ref /* non-async = 1, async = 2 */);
+
+@foreach_symbol =  @method | @property | @type_or_ref;
+
+#keyset[id, kind]
+foreach_stmt_desugar(
+  int id: @foreach_stmt ref,
+  int symbol: @foreach_symbol ref,
+  int kind: int ref /* GetEnumeratorMethod = 1, CurrentProperty = 2, MoveNextMethod = 3, DisposeMethod = 4, ElementType = 5 */);
+
+/** EXPRESSIONS **/
+
+expressions(
+  unique int id: @expr,
+  int kind: int ref,
+  int type_id: @type_or_ref ref);
+
+#keyset[index, parent]
+expr_parent(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_expr_parent = @attribute | @field | @property | @indexer | @parameter | @directive_if | @directive_elif;
+
+@top_level_exprorstmt_parent = @top_level_expr_parent | @top_level_stmt_parent;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+expr_parent_top_level(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @top_level_exprorstmt_parent ref);
+
+case @expr.kind of
+/* literal */
+   1 = @bool_literal_expr
+|  2 = @char_literal_expr
+|  3 = @decimal_literal_expr
+|  4 = @int_literal_expr
+|  5 = @long_literal_expr
+|  6 = @uint_literal_expr
+|  7 = @ulong_literal_expr
+|  8 = @float_literal_expr
+|  9 = @double_literal_expr
+| 10 = @utf16_string_literal_expr
+| 11 = @null_literal_expr
+/* primary & unary */
+| 12 = @this_access_expr
+| 13 = @base_access_expr
+| 14 = @local_variable_access_expr
+| 15 = @parameter_access_expr
+| 16 = @field_access_expr
+| 17 = @property_access_expr
+| 18 = @method_access_expr
+| 19 = @event_access_expr
+| 20 = @indexer_access_expr
+| 21 = @array_access_expr
+| 22 = @type_access_expr
+| 23 = @typeof_expr
+| 24 = @method_invocation_expr
+| 25 = @delegate_invocation_expr
+| 26 = @operator_invocation_expr
+| 27 = @cast_expr
+| 28 = @object_creation_expr
+| 29 = @explicit_delegate_creation_expr
+| 30 = @implicit_delegate_creation_expr
+| 31 = @array_creation_expr
+| 32 = @default_expr
+| 33 = @plus_expr
+| 34 = @minus_expr
+| 35 = @bit_not_expr
+| 36 = @log_not_expr
+| 37 = @post_incr_expr
+| 38 = @post_decr_expr
+| 39 = @pre_incr_expr
+| 40 = @pre_decr_expr
+/* multiplicative */
+| 41 = @mul_expr
+| 42 = @div_expr
+| 43 = @rem_expr
+/* additive */
+| 44 = @add_expr
+| 45 = @sub_expr
+/* shift */
+| 46 = @lshift_expr
+| 47 = @rshift_expr
+/* relational */
+| 48 = @lt_expr
+| 49 = @gt_expr
+| 50 = @le_expr
+| 51 = @ge_expr
+/* equality */
+| 52 = @eq_expr
+| 53 = @ne_expr
+/* logical */
+| 54 = @bit_and_expr
+| 55 = @bit_xor_expr
+| 56 = @bit_or_expr
+| 57 = @log_and_expr
+| 58 = @log_or_expr
+/* type testing */
+| 59 = @is_expr
+| 60 = @as_expr
+/* null coalescing */
+| 61 = @null_coalescing_expr
+/* conditional */
+| 62 = @conditional_expr
+/* assignment */
+| 63 = @simple_assign_expr
+| 64 = @assign_add_expr
+| 65 = @assign_sub_expr
+| 66 = @assign_mul_expr
+| 67 = @assign_div_expr
+| 68 = @assign_rem_expr
+| 69 = @assign_and_expr
+| 70 = @assign_xor_expr
+| 71 = @assign_or_expr
+| 72 = @assign_lshift_expr
+| 73 = @assign_rshift_expr
+/* more */
+| 74 = @object_init_expr
+| 75 = @collection_init_expr
+| 76 = @array_init_expr
+| 77 = @checked_expr
+| 78 = @unchecked_expr
+| 79 = @constructor_init_expr
+| 80 = @add_event_expr
+| 81 = @remove_event_expr
+| 82 = @par_expr
+| 83 = @local_var_decl_expr
+| 84 = @lambda_expr
+| 85 = @anonymous_method_expr
+| 86 = @namespace_expr
+/* dynamic */
+| 92 = @dynamic_element_access_expr
+| 93 = @dynamic_member_access_expr
+/* unsafe */
+| 100 = @pointer_indirection_expr
+| 101 = @address_of_expr
+| 102 = @sizeof_expr
+/* async */
+| 103 = @await_expr
+/* C# 6.0 */
+| 104 = @nameof_expr
+| 105 = @interpolated_string_expr
+| 106 = @unknown_expr
+/* C# 7.0 */
+| 107 = @throw_expr
+| 108 = @tuple_expr
+| 109 = @local_function_invocation_expr
+| 110 = @ref_expr
+| 111 = @discard_expr
+/* C# 8.0 */
+| 112 = @range_expr
+| 113 = @index_expr
+| 114 = @switch_expr
+| 115 = @recursive_pattern_expr
+| 116 = @property_pattern_expr
+| 117 = @positional_pattern_expr
+| 118 = @switch_case_expr
+| 119 = @assign_coalesce_expr
+| 120 = @suppress_nullable_warning_expr
+| 121 = @namespace_access_expr
+/* C# 9.0 */
+| 122 = @lt_pattern_expr
+| 123 = @gt_pattern_expr
+| 124 = @le_pattern_expr
+| 125 = @ge_pattern_expr
+| 126 = @not_pattern_expr
+| 127 = @and_pattern_expr
+| 128 = @or_pattern_expr
+| 129 = @function_pointer_invocation_expr
+| 130 = @with_expr
+/* C# 11.0 */
+| 131 = @list_pattern_expr
+| 132 = @slice_pattern_expr
+| 133 = @urshift_expr
+| 134 = @assign_urshift_expr
+| 135 = @utf8_string_literal_expr
+/* C# 12.0 */
+| 136 = @collection_expr
+| 137 = @spread_element_expr
+| 138 = @interpolated_string_insert_expr
+/* Preprocessor */
+| 999 = @define_symbol_expr
+;
+
+@switch = @switch_stmt | @switch_expr;
+@case = @case_stmt | @switch_case_expr;
+@pattern_match = @case | @is_expr;
+@unary_pattern_expr = @not_pattern_expr;
+@relational_pattern_expr = @gt_pattern_expr | @lt_pattern_expr | @ge_pattern_expr | @le_pattern_expr;
+@binary_pattern_expr = @and_pattern_expr | @or_pattern_expr;
+
+@integer_literal_expr = @int_literal_expr | @long_literal_expr | @uint_literal_expr | @ulong_literal_expr;
+@real_literal_expr = @float_literal_expr | @double_literal_expr | @decimal_literal_expr;
+@string_literal_expr = @utf16_string_literal_expr | @utf8_string_literal_expr;
+@literal_expr = @bool_literal_expr | @char_literal_expr | @integer_literal_expr | @real_literal_expr
+              | @string_literal_expr | @null_literal_expr;
+
+@assign_expr = @simple_assign_expr | @assign_op_expr | @local_var_decl_expr;
+@assign_op_call_expr = @assign_arith_expr | @assign_bitwise_expr
+@assign_op_expr =  @assign_op_call_expr | @assign_event_expr | @assign_coalesce_expr;
+@assign_event_expr = @add_event_expr | @remove_event_expr;
+
+@add_operation = @add_expr | @assign_add_expr;
+@sub_operation = @sub_expr | @assign_sub_expr;
+@mul_operation = @mul_expr | @assign_mul_expr;
+@div_operation = @div_expr | @assign_div_expr;
+@rem_operation = @rem_expr | @assign_rem_expr;
+@and_operation = @bit_and_expr | @assign_and_expr;
+@xor_operation = @bit_xor_expr | @assign_xor_expr;
+@or_operation = @bit_or_expr | @assign_or_expr;
+@lshift_operation = @lshift_expr | @assign_lshift_expr;
+@rshift_operation = @rshift_expr | @assign_rshift_expr;
+@urshift_operation = @urshift_expr | @assign_urshift_expr;
+@null_coalescing_operation = @null_coalescing_expr | @assign_coalesce_expr;
+
+@assign_arith_expr = @assign_add_expr | @assign_sub_expr | @assign_mul_expr | @assign_div_expr
+                   | @assign_rem_expr
+@assign_bitwise_expr = @assign_and_expr | @assign_or_expr | @assign_xor_expr
+                   | @assign_lshift_expr | @assign_rshift_expr | @assign_urshift_expr;
+
+@member_access_expr = @field_access_expr | @property_access_expr | @indexer_access_expr | @event_access_expr
+                    | @method_access_expr | @type_access_expr | @dynamic_member_access_expr;
+@access_expr = @member_access_expr | @this_access_expr | @base_access_expr | @assignable_access_expr | @namespace_access_expr;
+@element_access_expr = @indexer_access_expr | @array_access_expr | @dynamic_element_access_expr;
+
+@local_variable_access = @local_variable_access_expr | @local_var_decl_expr;
+@local_scope_variable_access_expr = @parameter_access_expr | @local_variable_access;
+@variable_access_expr = @local_scope_variable_access_expr | @field_access_expr;
+
+@assignable_access_expr = @variable_access_expr | @property_access_expr | @element_access_expr
+                        | @event_access_expr | @dynamic_member_access_expr;
+
+@objectorcollection_init_expr = @object_init_expr | @collection_init_expr;
+
+@delegate_creation_expr = @explicit_delegate_creation_expr | @implicit_delegate_creation_expr;
+
+@bin_arith_op_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
+@incr_op_expr =  @pre_incr_expr | @post_incr_expr;
+@decr_op_expr =  @pre_decr_expr | @post_decr_expr;
+@mut_op_expr = @incr_op_expr | @decr_op_expr;
+@un_arith_op_expr = @plus_expr | @minus_expr | @mut_op_expr;
+@arith_op_expr = @bin_arith_op_expr | @un_arith_op_expr;
+
+@ternary_log_op_expr = @conditional_expr;
+@bin_log_op_expr = @log_and_expr | @log_or_expr | @null_coalescing_expr;
+@un_log_op_expr = @log_not_expr;
+@log_expr = @un_log_op_expr | @bin_log_op_expr | @ternary_log_op_expr;
+
+@bin_bit_op_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
+                 | @rshift_expr | @urshift_expr;
+@un_bit_op_expr = @bit_not_expr;
+@bit_expr = @un_bit_op_expr | @bin_bit_op_expr;
+
+@equality_op_expr =  @eq_expr | @ne_expr;
+@rel_op_expr = @gt_expr | @lt_expr| @ge_expr | @le_expr;
+@comp_expr = @equality_op_expr | @rel_op_expr;
+
+@op_expr = @un_op | @bin_op | @ternary_op;
+
+@ternary_op = @ternary_log_op_expr;
+@bin_op = @assign_expr | @bin_arith_op_expr | @bin_log_op_expr | @bin_bit_op_expr | @comp_expr;
+@un_op = @un_arith_op_expr | @un_log_op_expr | @un_bit_op_expr | @sizeof_expr
+       | @pointer_indirection_expr | @address_of_expr;
+
+@anonymous_function_expr = @lambda_expr | @anonymous_method_expr;
+
+@op_invoke_expr = @operator_invocation_expr | @assign_op_call_expr
+@call = @method_invocation_expr | @constructor_init_expr | @op_invoke_expr
+      | @delegate_invocation_expr | @object_creation_expr | @call_access_expr
+      | @local_function_invocation_expr | @function_pointer_invocation_expr;
+
+@call_access_expr = @property_access_expr | @event_access_expr | @indexer_access_expr;
+
+@late_bindable_expr = @dynamic_element_access_expr | @dynamic_member_access_expr
+                    | @object_creation_expr | @method_invocation_expr | @op_invoke_expr;
+
+@throw_element = @throw_expr | @throw_stmt;
+
+@implicitly_typeable_object_creation_expr = @object_creation_expr | @explicit_delegate_creation_expr;
+
+implicitly_typed_array_creation(
+  unique int id: @array_creation_expr ref);
+
+explicitly_sized_array_creation(
+  unique int id: @array_creation_expr ref);
+
+stackalloc_array_creation(
+  unique int id: @array_creation_expr ref);
+
+implicitly_typed_object_creation(
+  unique int id: @implicitly_typeable_object_creation_expr ref);
+
+mutator_invocation_mode(
+  unique int id: @operator_invocation_expr ref,
+  int mode: int ref /* prefix = 1, postfix = 2*/);
+
+expr_value(
+  unique int id: @expr ref,
+  string value: string ref);
+
+expr_call(
+  unique int caller_id: @expr ref,
+  int target_id: @callable ref);
+
+expr_access(
+  unique int accesser_id: @access_expr ref,
+  int target_id: @accessible ref);
+
+@accessible = @method | @assignable | @local_function | @namespace;
+
+expr_location(
+  unique int id: @expr ref,
+  int loc: @location ref);
+
+dynamic_member_name(
+  unique int id: @late_bindable_expr ref,
+  string name: string ref);
+
+@qualifiable_expr = @member_access_expr
+                  | @method_invocation_expr
+                  | @element_access_expr
+                  | @assign_op_call_expr;
+
+conditional_access(
+  unique int id: @qualifiable_expr ref);
+
+expr_argument(
+  unique int id: @expr ref,
+  int mode: int ref);
+  /* mode is the same as params: value = 0, ref = 1, out = 2 */
+
+expr_argument_name(
+  unique int id: @expr ref,
+  string name: string ref);
+
+lambda_expr_return_type(
+  unique int id: @lambda_expr ref,
+  int type_id: @type_or_ref ref);
+
+/* Compiler generated */
+
+compiler_generated(unique int id: @element ref);
+
+/** CONTROL/DATA FLOW **/
+
+@control_flow_element = @stmt | @expr | @parameter;
+
+/* XML Files */
+
+xmlEncoding  (
+  unique int id: @file ref,
+  string encoding: string ref);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+/* Comments */
+
+commentline(
+  unique int id: @commentline,
+  int kind: int ref,
+  string text: string ref,
+  string rawtext: string ref);
+
+case @commentline.kind of
+  0 = @singlelinecomment
+| 1 = @xmldoccomment
+| 2 = @multilinecomment;
+
+commentline_location(
+  unique int id: @commentline ref,
+  int loc: @location ref);
+
+commentblock(
+  unique int id : @commentblock);
+
+commentblock_location(
+  unique int id: @commentblock ref,
+  int loc: @location ref);
+
+commentblock_binding(
+  int id: @commentblock ref,
+  int entity: @element ref,
+  int bindtype: int ref);    /* 0: Parent, 1: Best, 2: Before, 3: After */
+
+commentblock_child(
+  int id: @commentblock ref,
+  int commentline: @commentline ref,
+  int index: int ref);
+
+/* ASP.NET */
+
+case @asp_element.kind of
+  0=@asp_close_tag
+| 1=@asp_code
+| 2=@asp_comment
+| 3=@asp_data_binding
+| 4=@asp_directive
+| 5=@asp_open_tag
+| 6=@asp_quoted_string
+| 7=@asp_text
+| 8=@asp_xml_directive;
+
+@asp_attribute = @asp_code | @asp_data_binding | @asp_quoted_string;
+
+asp_elements(
+  unique int id: @asp_element,
+  int kind: int ref,
+  int loc: @location ref);
+
+asp_comment_server(unique int comment: @asp_comment ref);
+asp_code_inline(unique int code: @asp_code ref);
+asp_directive_attribute(
+  int directive: @asp_directive ref,
+  int index: int ref,
+  string name: string ref,
+  int value: @asp_quoted_string ref);
+asp_directive_name(
+  unique int directive: @asp_directive ref,
+  string name: string ref);
+asp_element_body(
+  unique int element: @asp_element ref,
+  string body: string ref);
+asp_tag_attribute(
+  int tag: @asp_open_tag ref,
+  int index: int ref,
+  string name: string ref,
+  int attribute: @asp_attribute ref);
+asp_tag_name(
+  unique int tag: @asp_open_tag ref,
+  string name: string ref);
+asp_tag_isempty(int tag: @asp_open_tag ref);
diff --git a/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/upgrade.properties b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/upgrade.properties
new file mode 100644
index 00000000000..85b8a1e6c23
--- /dev/null
+++ b/csharp/downgrades/d13c4c187d7318fd2b8f35c7e8d7f4dc26be68b1/upgrade.properties
@@ -0,0 +1,2 @@
+description: Restructure and rename types related to operations.
+compatibility: full
diff --git a/csharp/ql/lib/change-notes/2026-06-12-restructure-operations.md b/csharp/ql/lib/change-notes/2026-06-12-restructure-operations.md
new file mode 100644
index 00000000000..89459c5b981
--- /dev/null
+++ b/csharp/ql/lib/change-notes/2026-06-12-restructure-operations.md
@@ -0,0 +1,4 @@
+---
+category: breaking
+---
+* Renamed types related to *operation* expressions. The QL classes `BinaryArithmeticOperation`, `BinaryBitwiseOperation`, and `BinaryLogicalOperation` now include compound assignments; for example, `BinaryArithmeticOperation` now includes `a += b`.
diff --git a/csharp/ql/lib/experimental/code/csharp/Cryptography/NonCryptographicHashes.qll b/csharp/ql/lib/experimental/code/csharp/Cryptography/NonCryptographicHashes.qll
index 130e563a663..ae4b4ad3f61 100644
--- a/csharp/ql/lib/experimental/code/csharp/Cryptography/NonCryptographicHashes.qll
+++ b/csharp/ql/lib/experimental/code/csharp/Cryptography/NonCryptographicHashes.qll
@@ -50,15 +50,15 @@ private predicate maybeUsedInElfHashFunction(Variable v, Operation xor, Operatio
   |
     add instanceof AddOperation and
     e1.getAChild*() = add.getAnOperand() and
-    e1 instanceof BinaryBitwiseOperation and
-    e2 = e1.(BinaryBitwiseOperation).getLeftOperand() and
+    e1 instanceof BinaryBitwiseExpr and
+    e2 = e1.(BinaryBitwiseExpr).getLeftOperand() and
     v = addAssign.getTargetVariable() and
     addAssign.getAChild*() = add and
     (xor instanceof BitwiseXorExpr or xor instanceof AssignXorExpr) and
     addAssign.getControlFlowNode().getASuccessor*() = xor.getControlFlowNode() and
     xorAssign.getAChild*() = xor and
     v = xorAssign.getTargetVariable() and
-    (notOp instanceof UnaryBitwiseOperation or notOp instanceof AssignBitwiseOperation) and
+    (notOp instanceof UnaryBitwiseOperation or notOp instanceof AssignBitwiseExpr) and
     xor.getControlFlowNode().getASuccessor*() = notOp.getControlFlowNode() and
     notAssign.getAChild*() = notOp and
     v = notAssign.getTargetVariable() and
diff --git a/csharp/ql/lib/semmle/code/csharp/Assignable.qll b/csharp/ql/lib/semmle/code/csharp/Assignable.qll
index 7bd432d48ce..89dc594ec3f 100644
--- a/csharp/ql/lib/semmle/code/csharp/Assignable.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Assignable.qll
@@ -290,7 +290,7 @@ module AssignableInternal {
     newtype TAssignableDefinition =
       TAssignmentDefinition(Assignment a) {
         not a.getLeftOperand() instanceof TupleExpr and
-        not a instanceof AssignCallOperation and
+        not a instanceof AssignCallExpr and
         not a instanceof AssignCoalesceExpr
       } or
       TTupleAssignmentDefinition(AssignExpr ae, Expr leaf) { tupleAssignmentDefinition(ae, leaf) } or
@@ -324,7 +324,7 @@ module AssignableInternal {
       TAddressOfDefinition(AddressOfExpr aoe) or
       TPatternDefinition(TopLevelPatternDecl tlpd) or
       TAssignOperationDefinition(AssignOperation ao) {
-        ao instanceof AssignCallOperation and not ao instanceof CompoundAssignmentOperatorCall
+        ao instanceof AssignCallExpr and not ao instanceof CompoundAssignmentOperatorCall
         or
         ao instanceof AssignCoalesceExpr
       }
diff --git a/csharp/ql/lib/semmle/code/csharp/controlflow/Guards.qll b/csharp/ql/lib/semmle/code/csharp/controlflow/Guards.qll
index 3353866e334..e252d855da6 100644
--- a/csharp/ql/lib/semmle/code/csharp/controlflow/Guards.qll
+++ b/csharp/ql/lib/semmle/code/csharp/controlflow/Guards.qll
@@ -912,18 +912,17 @@ module Internal {
       )
     or
     // In C#, `null + 1` has type `int?` with value `null`
-    exists(BinaryOperation bo, Expr o |
-      bo instanceof BinaryArithmeticOperation or
-      bo instanceof AssignArithmeticOperation
-    |
-      result = bo and
-      bo.getAnOperand() = e and
-      bo.getAnOperand() = o and
-      // The other operand must be provably non-null in order
-      // for `only if` to hold
-      nonNullValueImplied(o) and
-      e != o
-    )
+    result =
+      any(BinaryArithmeticOperation bao |
+        exists(Expr o |
+          bao.getAnOperand() = e and
+          bao.getAnOperand() = o and
+          // The other operand must be provably non-null in order
+          // for `only if` to hold
+          nonNullValueImplied(o) and
+          e != o
+        )
+      )
   }
 
   /**
@@ -934,10 +933,10 @@ module Internal {
       any(QualifiableExpr qe |
         qe.isConditional() and
         result = qe.getQualifier()
-      ) or
+      )
+    or
     // In C#, `null + 1` has type `int?` with value `null`
-    e = any(BinaryArithmeticOperation bao | result = bao.getAnOperand()) or
-    e = any(AssignArithmeticOperation aao | result = aao.getAnOperand())
+    e = any(BinaryArithmeticOperation bao | result = bao.getAnOperand())
   }
 
   deprecated predicate isGuard(Expr e, GuardValue val) {
diff --git a/csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraph.qll b/csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraph.qll
index 7e87fa32568..18a967eee28 100644
--- a/csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraph.qll
+++ b/csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraph.qll
@@ -172,6 +172,10 @@ module Ast implements AstSig<Location> {
 
   class DoStmt = CS::DoStmt;
 
+  class UntilStmt extends LoopStmt {
+    UntilStmt() { none() }
+  }
+
   final private class FinalForStmt = CS::ForStmt;
 
   class ForStmt extends FinalForStmt {
diff --git a/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll b/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll
index 909ba3b9d42..c5541d5a705 100644
--- a/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll
@@ -124,9 +124,7 @@ private module Internal {
       TDispatchDynamicOperatorCall(DynamicOperatorCall doc) or
       TDispatchDynamicMemberAccess(DynamicMemberAccess dma) or
       TDispatchDynamicElementAccess(DynamicElementAccess dea) or
-      TDispatchDynamicEventAccess(
-        AssignArithmeticOperation aao, DynamicMemberAccess dma, string name
-      ) {
+      TDispatchDynamicEventAccess(AssignArithmeticExpr aao, DynamicMemberAccess dma, string name) {
         isPotentialEventCall(aao, dma, name)
       } or
       TDispatchDynamicObjectCreation(DynamicObjectCreation doc) or
@@ -230,7 +228,7 @@ private module Internal {
    * accessor.
    */
   private predicate isPotentialEventCall(
-    AssignArithmeticOperation aao, DynamicMemberAccess dma, string name
+    AssignArithmeticExpr aao, DynamicMemberAccess dma, string name
   ) {
     aao instanceof DynamicOperatorCall and
     dma = aao.getLeftOperand() and
@@ -1397,9 +1395,7 @@ private module Internal {
   private class DispatchDynamicEventAccess extends DispatchReflectionOrDynamicCall,
     TDispatchDynamicEventAccess
   {
-    override AssignArithmeticOperation getCall() {
-      this = TDispatchDynamicEventAccess(result, _, _)
-    }
+    override AssignArithmeticExpr getCall() { this = TDispatchDynamicEventAccess(result, _, _) }
 
     override string getName() { this = TDispatchDynamicEventAccess(_, _, result) }
 
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/ArithmeticOperation.qll b/csharp/ql/lib/semmle/code/csharp/exprs/ArithmeticOperation.qll
index 193c48ed3a2..2b909ac1b99 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/ArithmeticOperation.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/ArithmeticOperation.qll
@@ -11,19 +11,27 @@ import Expr
  * (`UnaryArithmeticOperation`) or a binary arithmetic operation
  * (`BinaryArithmeticOperation`).
  */
-class ArithmeticOperation extends Operation, @arith_op_expr {
+class ArithmeticOperation extends Operation, @arith_operation {
   override string getOperator() { none() }
 }
 
 /**
- * A unary arithmetic operation. Either a unary minus operation
- * (`UnaryMinusExpr`), a unary plus operation (`UnaryPlusExpr`),
- * or a mutator operation (`MutatorOperation`).
+ * A binary arithmetic operation. Either a binary arithmetic expression (`BinaryArithmeticExpr`) or
+ * an arithmetic assignment expression (`AssignArithmeticExpr`).
  */
-class UnaryArithmeticOperation extends ArithmeticOperation, UnaryOperation, @un_arith_op_expr { }
+class BinaryArithmeticOperation extends ArithmeticOperation, BinaryOperation, @bin_arith_operation {
+  override string getOperator() { none() }
+}
 
 /**
- * A unary minus operation, for example `-x`.
+ * A unary arithmetic operation. Either a unary minus expression
+ * (`UnaryMinusExpr`), a unary plus expression (`UnaryPlusExpr`),
+ * or a mutator operation (`MutatorOperation`).
+ */
+class UnaryArithmeticOperation extends ArithmeticOperation, UnaryOperation, @un_arith_operation { }
+
+/**
+ * A unary minus expression, for example `-x`.
  */
 class UnaryMinusExpr extends UnaryArithmeticOperation, @minus_expr {
   override string getOperator() { result = "-" }
@@ -32,7 +40,7 @@ class UnaryMinusExpr extends UnaryArithmeticOperation, @minus_expr {
 }
 
 /**
- * A unary plus operation, for example `+x`.
+ * A unary plus expression, for example `+x`.
  */
 class UnaryPlusExpr extends UnaryArithmeticOperation, @plus_expr {
   override string getOperator() { result = "+" }
@@ -44,40 +52,40 @@ class UnaryPlusExpr extends UnaryArithmeticOperation, @plus_expr {
  * A mutator operation. Either an increment operation (`IncrementOperation`)
  * or a decrement operation (`DecrementOperation`).
  */
-class MutatorOperation extends UnaryArithmeticOperation, @mut_op_expr { }
+class MutatorOperation extends UnaryArithmeticOperation, @mut_operation { }
 
 /**
- * An increment operation. Either a postfix increment operation
- * (`PostIncrExpr`) or a prefix increment operation (`PreIncrExpr`).
+ * An increment operation. Either a postfix increment expression
+ * (`PostIncrExpr`) or a prefix increment expression (`PreIncrExpr`).
  */
-class IncrementOperation extends MutatorOperation, @incr_op_expr {
+class IncrementOperation extends MutatorOperation, @incr_operation {
   override string getOperator() { result = "++" }
 }
 
 /**
- * A decrement operation. Either a postfix decrement operation
- * (`PostDecrExpr`) or a prefix decrement operation (`PreDecrExpr`).
+ * A decrement operation. Either a postfix decrement expression
+ * (`PostDecrExpr`) or a prefix decrement expression (`PreDecrExpr`).
  */
-class DecrementOperation extends MutatorOperation, @decr_op_expr {
+class DecrementOperation extends MutatorOperation, @decr_operation {
   override string getOperator() { result = "--" }
 }
 
 /**
- * A prefix increment operation, for example `++x`.
+ * A prefix increment expression, for example `++x`.
  */
 class PreIncrExpr extends IncrementOperation, @pre_incr_expr {
   override string getAPrimaryQlClass() { result = "PreIncrExpr" }
 }
 
 /**
- * A prefix decrement operation, for example `--x`.
+ * A prefix decrement expression, for example `--x`.
  */
 class PreDecrExpr extends DecrementOperation, @pre_decr_expr {
   override string getAPrimaryQlClass() { result = "PreDecrExpr" }
 }
 
 /**
- * A postfix increment operation, for example `x++`.
+ * A postfix increment expression, for example `x++`.
  */
 class PostIncrExpr extends IncrementOperation, @post_incr_expr {
   override string toString() { result = "..." + this.getOperator() }
@@ -86,7 +94,7 @@ class PostIncrExpr extends IncrementOperation, @post_incr_expr {
 }
 
 /**
- * A postfix decrement operation, for example `x--`.
+ * A postfix decrement expression, for example `x--`.
  */
 class PostDecrExpr extends DecrementOperation, @post_decr_expr {
   override string toString() { result = "..." + this.getOperator() }
@@ -95,55 +103,84 @@ class PostDecrExpr extends DecrementOperation, @post_decr_expr {
 }
 
 /**
- * A binary arithmetic operation. Either an addition operation
- * (`AddExpr`), a subtraction operation (`SubExpr`), a multiplication
- * operation (`MulExpr`), a division operation (`DivExpr`), or a
- * remainder operation (`RemExpr`).
+ * An addition operation, either `x + y` or `x += y`.
  */
-class BinaryArithmeticOperation extends ArithmeticOperation, BinaryOperation, @bin_arith_op_expr {
-  override string getOperator() { none() }
+class AddOperation extends BinaryArithmeticOperation, @add_operation { }
+
+/**
+ * A subtraction operation, either `x - y` or `x -= y`.
+ */
+class SubOperation extends BinaryArithmeticOperation, @sub_operation { }
+
+/**
+ * A multiplication operation, either `x * y` or `x *= y`.
+ */
+class MulOperation extends BinaryArithmeticOperation, @mul_operation { }
+
+/**
+ * A division operation, either `x / y` or `x /= y`.
+ */
+class DivOperation extends BinaryArithmeticOperation, @div_operation {
+  /** Gets the numerator of this division operation. */
+  Expr getNumerator() { result = this.getLeftOperand() }
+
+  /** Gets the denominator of this division operation. */
+  Expr getDenominator() { result = this.getRightOperand() }
 }
 
 /**
- * An addition operation, for example `x + y`.
+ * A remainder operation, either `x % y` or `x %= y`.
  */
-class AddExpr extends BinaryArithmeticOperation, AddOperation, @add_expr {
+class RemOperation extends BinaryArithmeticOperation, @rem_operation { }
+
+/**
+ * A binary arithmetic expression. Either an addition expression
+ * (`AddExpr`), a subtraction expression (`SubExpr`), a multiplication
+ * expression (`MulExpr`), a division expression (`DivExpr`), or a
+ * remainder expression (`RemExpr`).
+ */
+class BinaryArithmeticExpr extends BinaryArithmeticOperation, @bin_arith_expr { }
+
+/**
+ * An addition expression, for example `x + y`.
+ */
+class AddExpr extends BinaryArithmeticExpr, AddOperation, @add_expr {
   override string getOperator() { result = "+" }
 
   override string getAPrimaryQlClass() { result = "AddExpr" }
 }
 
 /**
- * A subtraction operation, for example `x - y`.
+ * A subtraction expression, for example `x - y`.
  */
-class SubExpr extends BinaryArithmeticOperation, SubOperation, @sub_expr {
+class SubExpr extends BinaryArithmeticExpr, SubOperation, @sub_expr {
   override string getOperator() { result = "-" }
 
   override string getAPrimaryQlClass() { result = "SubExpr" }
 }
 
 /**
- * A multiplication operation, for example `x * y`.
+ * A multiplication expression, for example `x * y`.
  */
-class MulExpr extends BinaryArithmeticOperation, MulOperation, @mul_expr {
+class MulExpr extends BinaryArithmeticExpr, MulOperation, @mul_expr {
   override string getOperator() { result = "*" }
 
   override string getAPrimaryQlClass() { result = "MulExpr" }
 }
 
 /**
- * A division operation, for example `x / y`.
+ * A division expression, for example `x / y`.
  */
-class DivExpr extends BinaryArithmeticOperation, DivOperation, @div_expr {
+class DivExpr extends BinaryArithmeticExpr, DivOperation, @div_expr {
   override string getOperator() { result = "/" }
 
   override string getAPrimaryQlClass() { result = "DivExpr" }
 }
 
 /**
- * A remainder operation, for example `x % y`.
+ * A remainder expression, for example `x % y`.
  */
-class RemExpr extends BinaryArithmeticOperation, RemOperation, @rem_expr {
+class RemExpr extends BinaryArithmeticExpr, RemOperation, @rem_expr {
   override string getOperator() { result = "%" }
 
   override string getAPrimaryQlClass() { result = "RemExpr" }
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/Assignment.qll b/csharp/ql/lib/semmle/code/csharp/exprs/Assignment.qll
index f65b13bf8ec..cc31883c646 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Assignment.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Assignment.qll
@@ -72,9 +72,9 @@ class AssignExpr extends Assignment, @simple_assign_expr {
 }
 
 /**
- * An assignment operation. Either an arithmetic assignment operation
- * (`AssignArithmeticOperation`), a bitwise assignment operation
- * (`AssignBitwiseOperation`), an event assignment (`AddOrRemoveEventExpr`), or
+ * An assignment operation. Either an arithmetic assignment expression
+ * (`AssignArithmeticExpr`), a bitwise assignment expression
+ * (`AssignBitwiseExpr`), an event assignment (`AddOrRemoveEventExpr`), or
  * a null-coalescing assignment (`AssignCoalesceExpr`).
  */
 class AssignOperation extends Assignment, @assign_op_expr {
@@ -94,134 +94,147 @@ class AssignOperation extends Assignment, @assign_op_expr {
 }
 
 /**
- * A compound assignment operation that invokes an operator.
+ * A compound assignment expression that invokes an operator.
  *
  * (1) `x += y` invokes the compound assignment operator `+=` (if it exists).
  * (2) `x += y` invokes the operator `+` and assigns `x + y` to `x`.
  *
- * Either an arithmetic assignment operation (`AssignArithmeticOperation`) or a bitwise
- * assignment operation (`AssignBitwiseOperation`).
+ * Either an arithmetic assignment expression (`AssignArithmeticExpr`) or a bitwise
+ * assignment expression (`AssignBitwiseExpr`).
  */
-class AssignCallOperation extends AssignOperation, OperatorCall, QualifiableExpr,
-  @assign_op_call_expr
-{
+class AssignCallExpr extends AssignOperation, OperatorCall, QualifiableExpr, @assign_op_call_expr {
   override string toString() { result = AssignOperation.super.toString() }
 }
 
 /**
- * An arithmetic assignment operation. Either an addition assignment operation
- * (`AssignAddExpr`), a subtraction assignment operation (`AssignSubExpr`), a
- * multiplication assignment operation (`AssignMulExpr`), a division assignment
- * operation (`AssignDivExpr`), or a remainder assignment operation
- * (`AssignRemExpr`).
+ * DEPRECATED: Use `AssignCallExpr` instead.
  */
-class AssignArithmeticOperation extends AssignCallOperation, @assign_arith_expr { }
+deprecated class AssignCallOperation = AssignCallExpr;
 
 /**
- * An addition assignment operation, for example `x += y`.
+ * An arithmetic assignment expression. Either an addition assignment expression
+ * (`AssignAddExpr`), a subtraction assignment expression (`AssignSubExpr`), a
+ * multiplication assignment expression (`AssignMulExpr`), a division assignment
+ * expression (`AssignDivExpr`), or a remainder assignment expression
+ * (`AssignRemExpr`).
  */
-class AssignAddExpr extends AssignArithmeticOperation, AddOperation, @assign_add_expr {
+class AssignArithmeticExpr extends AssignCallExpr, @assign_arith_expr { }
+
+/**
+ * DEPRECATED: Use `AssignArithmeticExpr` instead.
+ */
+deprecated class AssignArithmeticOperation = AssignArithmeticExpr;
+
+/**
+ * An addition assignment expression, for example `x += y`.
+ */
+class AssignAddExpr extends AssignArithmeticExpr, AddOperation, @assign_add_expr {
   override string getOperator() { result = "+=" }
 
   override string getAPrimaryQlClass() { result = "AssignAddExpr" }
 }
 
 /**
- * A subtraction assignment operation, for example `x -= y`.
+ * A subtraction assignment expression, for example `x -= y`.
  */
-class AssignSubExpr extends AssignArithmeticOperation, SubOperation, @assign_sub_expr {
+class AssignSubExpr extends AssignArithmeticExpr, SubOperation, @assign_sub_expr {
   override string getOperator() { result = "-=" }
 
   override string getAPrimaryQlClass() { result = "AssignSubExpr" }
 }
 
 /**
- * An multiplication assignment operation, for example `x *= y`.
+ * A multiplication assignment expression, for example `x *= y`.
  */
-class AssignMulExpr extends AssignArithmeticOperation, MulOperation, @assign_mul_expr {
+class AssignMulExpr extends AssignArithmeticExpr, MulOperation, @assign_mul_expr {
   override string getOperator() { result = "*=" }
 
   override string getAPrimaryQlClass() { result = "AssignMulExpr" }
 }
 
 /**
- * An division assignment operation, for example `x /= y`.
+ * A division assignment expression, for example `x /= y`.
  */
-class AssignDivExpr extends AssignArithmeticOperation, DivOperation, @assign_div_expr {
+class AssignDivExpr extends AssignArithmeticExpr, DivOperation, @assign_div_expr {
   override string getOperator() { result = "/=" }
 
   override string getAPrimaryQlClass() { result = "AssignDivExpr" }
 }
 
 /**
- * A remainder assignment operation, for example `x %= y`.
+ * A remainder assignment expression, for example `x %= y`.
  */
-class AssignRemExpr extends AssignArithmeticOperation, RemOperation, @assign_rem_expr {
+class AssignRemExpr extends AssignArithmeticExpr, RemOperation, @assign_rem_expr {
   override string getOperator() { result = "%=" }
 
   override string getAPrimaryQlClass() { result = "AssignRemExpr" }
 }
 
 /**
- * A bitwise assignment operation. Either a bitwise-and assignment
- * operation (`AssignAndExpr`), a bitwise-or assignment
- * operation (`AssignOrExpr`), a bitwise exclusive-or assignment
- * operation (`AssignXorExpr`), a left-shift assignment
- * operation (`AssignLeftShiftExpr`), or a right-shift assignment
- * operation (`AssignRightShiftExpr`), or an unsigned right-shift assignment
- * operation (`AssignUnsignedRightShiftExpr`).
+ * A bitwise assignment expression. Either a bitwise-and assignment
+ * expression (`AssignAndExpr`), a bitwise-or assignment
+ * expression (`AssignOrExpr`), a bitwise exclusive-or assignment
+ * expression (`AssignXorExpr`), a left-shift assignment
+ * expression (`AssignLeftShiftExpr`), or a right-shift assignment
+ * expression (`AssignRightShiftExpr`), or an unsigned right-shift assignment
+ * expression (`AssignUnsignedRightShiftExpr`).
  */
-class AssignBitwiseOperation extends AssignCallOperation, @assign_bitwise_expr { }
+class AssignBitwiseExpr extends AssignCallExpr, @assign_bitwise_expr { }
 
 /**
- * A bitwise-and assignment operation, for example `x &= y`.
+ * DEPRECATED: Use `AssignBitwiseExpr` instead.
  */
-class AssignAndExpr extends AssignBitwiseOperation, BitwiseAndOperation, @assign_and_expr {
+deprecated class AssignBitwiseOperation = AssignBitwiseExpr;
+
+/**
+ * A bitwise-and assignment expression, for example `x &= y`.
+ */
+class AssignAndExpr extends AssignBitwiseExpr, BitwiseAndOperation, @assign_and_expr {
   override string getOperator() { result = "&=" }
 
   override string getAPrimaryQlClass() { result = "AssignAndExpr" }
 }
 
 /**
- * A bitwise-or assignment operation, for example `x |= y`.
+ * A bitwise-or assignment expression, for example `x |= y`.
  */
-class AssignOrExpr extends AssignBitwiseOperation, BitwiseOrOperation, @assign_or_expr {
+class AssignOrExpr extends AssignBitwiseExpr, BitwiseOrOperation, @assign_or_expr {
   override string getOperator() { result = "|=" }
 
   override string getAPrimaryQlClass() { result = "AssignOrExpr" }
 }
 
 /**
- * A bitwise exclusive-or assignment operation, for example `x ^= y`.
+ * A bitwise exclusive-or assignment expression, for example `x ^= y`.
  */
-class AssignXorExpr extends AssignBitwiseOperation, BitwiseXorOperation, @assign_xor_expr {
+class AssignXorExpr extends AssignBitwiseExpr, BitwiseXorOperation, @assign_xor_expr {
   override string getOperator() { result = "^=" }
 
   override string getAPrimaryQlClass() { result = "AssignXorExpr" }
 }
 
 /**
- * A left-shift assignment operation, for example `x <<= y`.
+ * A left-shift assignment expression, for example `x <<= y`.
  */
-class AssignLeftShiftExpr extends AssignBitwiseOperation, LeftShiftOperation, @assign_lshift_expr {
+class AssignLeftShiftExpr extends AssignBitwiseExpr, LeftShiftOperation, @assign_lshift_expr {
   override string getOperator() { result = "<<=" }
 
   override string getAPrimaryQlClass() { result = "AssignLeftShiftExpr" }
 }
 
 /**
- * A right-shift assignment operation, for example `x >>= y`.
+ * A right-shift assignment expression, for example `x >>= y`.
  */
-class AssignRightShiftExpr extends AssignBitwiseOperation, RightShiftOperation, @assign_rshift_expr {
+class AssignRightShiftExpr extends AssignBitwiseExpr, RightShiftOperation, @assign_rshift_expr {
   override string getOperator() { result = ">>=" }
 
   override string getAPrimaryQlClass() { result = "AssignRightShiftExpr" }
 }
 
 /**
- * An unsigned right-shift assignment operation, for example `x >>>= y`.
+ * An unsigned right-shift assignment expression, for example `x >>>= y`.
  */
-class AssignUnsignedRightShiftExpr extends AssignBitwiseOperation, UnsignedRightShiftOperation,
+class AssignUnsignedRightShiftExpr extends AssignBitwiseExpr, UnsignedRightShiftOperation,
   @assign_urshift_expr
 {
   override string getOperator() { result = ">>>=" }
@@ -297,10 +310,10 @@ class RemoveEventExpr extends AddOrRemoveEventExpr, @remove_event_expr {
 }
 
 /**
- * A null-coalescing assignment operation, for example `x ??= y`.
+ * A null-coalescing assignment expression, for example `x ??= y`.
  */
 class AssignCoalesceExpr extends AssignOperation, NullCoalescingOperation, @assign_coalesce_expr {
-  override string toString() { result = "... ??= ..." }
+  override string getOperator() { result = "??=" }
 
   override string getAPrimaryQlClass() { result = "AssignCoalesceExpr" }
 }
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/BitwiseOperation.qll b/csharp/ql/lib/semmle/code/csharp/exprs/BitwiseOperation.qll
index 14bb3d74e2b..b6449f71a48 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/BitwiseOperation.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/BitwiseOperation.qll
@@ -10,16 +10,16 @@ import Expr
  * A bitwise operation. Either a unary bitwise operation (`UnaryBitwiseOperation`)
  * or a binary bitwise operation (`BinaryBitwiseOperation`).
  */
-class BitwiseOperation extends Operation, @bit_expr { }
+class BitwiseOperation extends Operation, @bit_operation { }
 
 /**
  * A unary bitwise operation, that is, a bitwise complement operation
  * (`ComplementExpr`).
  */
-class UnaryBitwiseOperation extends BitwiseOperation, UnaryOperation, @un_bit_op_expr { }
+class UnaryBitwiseOperation extends BitwiseOperation, UnaryOperation, @un_bit_operation { }
 
 /**
- * A bitwise complement operation, for example `~x`.
+ * A bitwise complement expression, for example `~x`.
  */
 class ComplementExpr extends UnaryBitwiseOperation, @bit_not_expr {
   override string getOperator() { result = "~" }
@@ -28,67 +28,101 @@ class ComplementExpr extends UnaryBitwiseOperation, @bit_not_expr {
 }
 
 /**
- * A binary bitwise operation. Either a bitwise-and operation
- * (`BitwiseAndExpr`), a bitwise-or operation (`BitwiseOrExpr`),
- * a bitwise exclusive-or operation (`BitwiseXorExpr`), a left-shift
- * operation (`LeftShiftExpr`), a right-shift operation (`RightShiftExpr`),
- * or an unsigned right-shift operation (`UnsignedRightShiftExpr`).
+ * A binary bitwise operation. Either a binary bitwise expression (`BinaryBitwiseExpr`) or
+ * a bitwise assignment expression (`AssignBitwiseExpr`).
  */
-class BinaryBitwiseOperation extends BitwiseOperation, BinaryOperation, @bin_bit_op_expr {
+class BinaryBitwiseOperation extends BitwiseOperation, BinaryOperation, @bin_bit_operation {
   override string getOperator() { none() }
 }
 
 /**
- * A left-shift operation, for example `x << y`.
+ * A bitwise-and operation, either `x & y` or `x &= y`.
  */
-class LeftShiftExpr extends BinaryBitwiseOperation, LeftShiftOperation, @lshift_expr {
+class BitwiseAndOperation extends BinaryBitwiseOperation, @and_operation { }
+
+/**
+ * A bitwise-or operation, either `x | y` or `x |= y`.
+ */
+class BitwiseOrOperation extends BinaryBitwiseOperation, @or_operation { }
+
+/**
+ * A bitwise exclusive-or operation, either `x ^ y` or `x ^= y`.
+ */
+class BitwiseXorOperation extends BinaryBitwiseOperation, @xor_operation { }
+
+/**
+ * A left-shift operation, either `x << y` or `x <<= y`.
+ */
+class LeftShiftOperation extends BinaryBitwiseOperation, @lshift_operation { }
+
+/**
+ * A right-shift operation, either `x >> y` or `x >>= y`.
+ */
+class RightShiftOperation extends BinaryBitwiseOperation, @rshift_operation { }
+
+/**
+ * An unsigned right-shift operation, either `x >>> y` or `x >>>= y`.
+ */
+class UnsignedRightShiftOperation extends BinaryBitwiseOperation, @urshift_operation { }
+
+/**
+ * A binary bitwise expression. Either a bitwise-and expression
+ * (`BitwiseAndExpr`), a bitwise-or expression (`BitwiseOrExpr`),
+ * a bitwise exclusive-or expression (`BitwiseXorExpr`), a left-shift
+ * expression (`LeftShiftExpr`), a right-shift expression (`RightShiftExpr`),
+ * or an unsigned right-shift expression (`UnsignedRightShiftExpr`).
+ */
+class BinaryBitwiseExpr extends BinaryBitwiseOperation, @bin_bit_expr { }
+
+/**
+ * A left-shift expression, for example `x << y`.
+ */
+class LeftShiftExpr extends BinaryBitwiseExpr, LeftShiftOperation, @lshift_expr {
   override string getOperator() { result = "<<" }
 
   override string getAPrimaryQlClass() { result = "LeftShiftExpr" }
 }
 
 /**
- * A right-shift operation, for example `x >> y`.
+ * A right-shift expression, for example `x >> y`.
  */
-class RightShiftExpr extends BinaryBitwiseOperation, RightShiftOperation, @rshift_expr {
+class RightShiftExpr extends BinaryBitwiseExpr, RightShiftOperation, @rshift_expr {
   override string getOperator() { result = ">>" }
 
   override string getAPrimaryQlClass() { result = "RightShiftExpr" }
 }
 
 /**
- * An unsigned right-shift operation, for example `x >>> y`.
+ * An unsigned right-shift expression, for example `x >>> y`.
  */
-class UnsignedRightShiftExpr extends BinaryBitwiseOperation, UnsignedRightShiftOperation,
-  @urshift_expr
-{
+class UnsignedRightShiftExpr extends BinaryBitwiseExpr, UnsignedRightShiftOperation, @urshift_expr {
   override string getOperator() { result = ">>>" }
 
   override string getAPrimaryQlClass() { result = "UnsignedRightShiftExpr" }
 }
 
 /**
- * A bitwise-and operation, for example `x & y`.
+ * A bitwise-and expression, for example `x & y`.
  */
-class BitwiseAndExpr extends BinaryBitwiseOperation, BitwiseAndOperation, @bit_and_expr {
+class BitwiseAndExpr extends BinaryBitwiseExpr, BitwiseAndOperation, @bit_and_expr {
   override string getOperator() { result = "&" }
 
   override string getAPrimaryQlClass() { result = "BitwiseAndExpr" }
 }
 
 /**
- * A bitwise-or operation, for example `x | y`.
+ * A bitwise-or expression, for example `x | y`.
  */
-class BitwiseOrExpr extends BinaryBitwiseOperation, BitwiseOrOperation, @bit_or_expr {
+class BitwiseOrExpr extends BinaryBitwiseExpr, BitwiseOrOperation, @bit_or_expr {
   override string getOperator() { result = "|" }
 
   override string getAPrimaryQlClass() { result = "BitwiseOrExpr" }
 }
 
 /**
- * A bitwise exclusive-or operation, for example `x ^ y`.
+ * A bitwise exclusive-or expression, for example `x ^ y`.
  */
-class BitwiseXorExpr extends BinaryBitwiseOperation, BitwiseXorOperation, @bit_xor_expr {
+class BitwiseXorExpr extends BinaryBitwiseExpr, BitwiseXorOperation, @bit_xor_expr {
   override string getOperator() { result = "^" }
 
   override string getAPrimaryQlClass() { result = "BitwiseXorExpr" }
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll b/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
index a358e73970c..f69afb74c20 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
@@ -609,7 +609,7 @@ class InstanceMutatorOperatorCall extends MutatorOperatorCall {
  * }
  * ```
  */
-class CompoundAssignmentOperatorCall extends AssignCallOperation {
+class CompoundAssignmentOperatorCall extends AssignCallExpr {
   CompoundAssignmentOperatorCall() { this.getTarget() instanceof CompoundAssignmentOperator }
 
   override Expr getArgument(int i) { result = this.getChildExpr(i + 1) and i >= 0 }
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/Expr.qll b/csharp/ql/lib/semmle/code/csharp/exprs/Expr.qll
index a26afb00490..857212f90aa 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Expr.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Expr.qll
@@ -14,7 +14,6 @@ import Creation
 import Dynamic
 import Literal
 import LogicalOperation
-import Operation
 import semmle.code.csharp.controlflow.ControlFlowElement
 import semmle.code.csharp.Location
 import semmle.code.csharp.Stmt
@@ -212,7 +211,7 @@ class LocalConstantDeclExpr extends LocalVariableDeclExpr {
  * (`UnaryOperation`), a binary operation (`BinaryOperation`), or a
  * ternary operation (`TernaryOperation`).
  */
-class Operation extends Expr, @op_expr {
+class Operation extends Expr, @operation_expr {
   /** Gets the name of the operator in this operation. */
   string getOperator() { none() }
 
@@ -227,7 +226,7 @@ class Operation extends Expr, @op_expr {
  * indirection operation (`PointerIndirectionExpr`), an address-of operation
  * (`AddressOfExpr`), or a unary logical operation (`UnaryLogicalOperation`).
  */
-class UnaryOperation extends Operation, @un_op {
+class UnaryOperation extends Operation, @un_operation {
   /** Gets the operand of this unary operation. */
   Expr getOperand() { result = this.getChild(0) }
 
@@ -241,7 +240,7 @@ class UnaryOperation extends Operation, @un_op {
  * a binary logical operation (`BinaryLogicalOperation`), or an
  * assignment (`Assignment`).
  */
-class BinaryOperation extends Operation, @bin_op {
+class BinaryOperation extends Operation, @bin_operation {
   /** Gets the left operand of this binary operation. */
   Expr getLeftOperand() { result = this.getChild(0) }
 
@@ -264,7 +263,7 @@ class BinaryOperation extends Operation, @bin_op {
  * A ternary operation, that is, a ternary conditional operation
  * (`ConditionalExpr`).
  */
-class TernaryOperation extends Operation, @ternary_op { }
+class TernaryOperation extends Operation, @ternary_operation { }
 
 /**
  * A parenthesized expression, for example `(2 + 3)` in
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/LogicalOperation.qll b/csharp/ql/lib/semmle/code/csharp/exprs/LogicalOperation.qll
index 4161f734c9b..22b24202041 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/LogicalOperation.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/LogicalOperation.qll
@@ -11,14 +11,14 @@ import Expr
  * a binary logical operation (`BinaryLogicalOperation`), or a ternary logical
  * operation (`TernaryLogicalOperation`).
  */
-class LogicalOperation extends Operation, @log_expr {
+class LogicalOperation extends Operation, @log_operation {
   override string getOperator() { none() }
 }
 
 /**
  * A unary logical operation, that is, a logical 'not' (`LogicalNotExpr`).
  */
-class UnaryLogicalOperation extends LogicalOperation, UnaryOperation, @un_log_op_expr { }
+class UnaryLogicalOperation extends LogicalOperation, UnaryOperation, @un_log_operation { }
 
 /**
  * A logical 'not', for example `!String.IsNullOrEmpty(s)`.
@@ -31,10 +31,10 @@ class LogicalNotExpr extends UnaryLogicalOperation, @log_not_expr {
 
 /**
  * A binary logical operation. Either a logical 'and' (`LogicalAndExpr`),
- * a logical 'or' (`LogicalAndExpr`), or a null-coalescing operation
- * (`NullCoalescingExpr`).
+ * a logical 'or' (`LogicalOrExpr`), or a null-coalescing operation
+ * (`NullCoalescingOperation`).
  */
-class BinaryLogicalOperation extends LogicalOperation, BinaryOperation, @bin_log_op_expr {
+class BinaryLogicalOperation extends LogicalOperation, BinaryOperation, @bin_log_operation {
   override string getOperator() { none() }
 }
 
@@ -57,7 +57,12 @@ class LogicalOrExpr extends BinaryLogicalOperation, @log_or_expr {
 }
 
 /**
- * A null-coalescing operation, for example `s ?? ""` on line 2 in
+ * A null-coalescing operation, either `x ?? y` or `x ??= y`.
+ */
+class NullCoalescingOperation extends BinaryLogicalOperation, @null_coalescing_operation { }
+
+/**
+ * A null-coalescing expression, for example `s ?? ""` on line 2 in
  *
  * ```csharp
  * string NonNullOrEmpty(string s) {
@@ -65,9 +70,7 @@ class LogicalOrExpr extends BinaryLogicalOperation, @log_or_expr {
  * }
  * ```
  */
-class NullCoalescingExpr extends BinaryLogicalOperation, NullCoalescingOperation,
-  @null_coalescing_expr
-{
+class NullCoalescingExpr extends NullCoalescingOperation, @null_coalescing_expr {
   override string getOperator() { result = "??" }
 
   override string getAPrimaryQlClass() { result = "NullCoalescingExpr" }
@@ -77,7 +80,7 @@ class NullCoalescingExpr extends BinaryLogicalOperation, NullCoalescingOperation
  * A ternary logical operation, that is, a ternary conditional expression
  * (`ConditionalExpr`).
  */
-class TernaryLogicalOperation extends LogicalOperation, TernaryOperation, @ternary_log_op_expr { }
+class TernaryLogicalOperation extends LogicalOperation, TernaryOperation, @ternary_log_operation { }
 
 /**
  * A conditional expression, for example `s != null ? s.Length : -1`
diff --git a/csharp/ql/lib/semmle/code/csharp/exprs/Operation.qll b/csharp/ql/lib/semmle/code/csharp/exprs/Operation.qll
index 1f816baea86..19de7f20ee3 100644
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Operation.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Operation.qll
@@ -1,71 +1,6 @@
 /**
  * Provides classes for operations that also have compound assignment forms.
  */
+deprecated module;
 
 import Expr
-
-/**
- * An addition operation, either `x + y` or `x += y`.
- */
-class AddOperation extends BinaryOperation, @add_operation { }
-
-/**
- * A subtraction operation, either `x - y` or `x -= y`.
- */
-class SubOperation extends BinaryOperation, @sub_operation { }
-
-/**
- * A multiplication operation, either `x * y` or `x *= y`.
- */
-class MulOperation extends BinaryOperation, @mul_operation { }
-
-/**
- * A division operation, either `x / y` or `x /= y`.
- */
-class DivOperation extends BinaryOperation, @div_operation {
-  /** Gets the numerator of this division operation. */
-  Expr getNumerator() { result = this.getLeftOperand() }
-
-  /** Gets the denominator of this division operation. */
-  Expr getDenominator() { result = this.getRightOperand() }
-}
-
-/**
- * A remainder operation, either `x % y` or `x %= y`.
- */
-class RemOperation extends BinaryOperation, @rem_operation { }
-
-/**
- * A bitwise-and operation, either `x & y` or `x &= y`.
- */
-class BitwiseAndOperation extends BinaryOperation, @and_operation { }
-
-/**
- * A bitwise-or operation, either `x | y` or `x |= y`.
- */
-class BitwiseOrOperation extends BinaryOperation, @or_operation { }
-
-/**
- * A bitwise exclusive-or operation, either `x ^ y` or `x ^= y`.
- */
-class BitwiseXorOperation extends BinaryOperation, @xor_operation { }
-
-/**
- * A left-shift operation, either `x << y` or `x <<= y`.
- */
-class LeftShiftOperation extends BinaryOperation, @lshift_operation { }
-
-/**
- * A right-shift operation, either `x >> y` or `x >>= y`.
- */
-class RightShiftOperation extends BinaryOperation, @rshift_operation { }
-
-/**
- * An unsigned right-shift operation, either `x >>> y` or `x >>>= y`.
- */
-class UnsignedRightShiftOperation extends BinaryOperation, @urshift_operation { }
-
-/**
- * A null-coalescing operation, either `x ?? y` or `x ??= y`.
- */
-class NullCoalescingOperation extends BinaryOperation, @null_coalescing_operation { }
diff --git a/csharp/ql/lib/semmlecode.csharp.dbscheme b/csharp/ql/lib/semmlecode.csharp.dbscheme
index 3cabc77473c..d13c4c187d7 100644
--- a/csharp/ql/lib/semmlecode.csharp.dbscheme
+++ b/csharp/ql/lib/semmlecode.csharp.dbscheme
@@ -1254,33 +1254,39 @@ case @expr.kind of
 
 @delegate_creation_expr = @explicit_delegate_creation_expr | @implicit_delegate_creation_expr;
 
-@bin_arith_op_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
-@incr_op_expr =  @pre_incr_expr | @post_incr_expr;
-@decr_op_expr =  @pre_decr_expr | @post_decr_expr;
-@mut_op_expr = @incr_op_expr | @decr_op_expr;
-@un_arith_op_expr = @plus_expr | @minus_expr | @mut_op_expr;
-@arith_op_expr = @bin_arith_op_expr | @un_arith_op_expr;
+@bin_arith_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
+@bin_arith_operation = @mul_operation | @div_operation | @rem_operation | @add_operation | @sub_operation;
 
-@ternary_log_op_expr = @conditional_expr;
-@bin_log_op_expr = @log_and_expr | @log_or_expr | @null_coalescing_expr;
-@un_log_op_expr = @log_not_expr;
-@log_expr = @un_log_op_expr | @bin_log_op_expr | @ternary_log_op_expr;
+@incr_operation =  @pre_incr_expr | @post_incr_expr;
+@decr_operation =  @pre_decr_expr | @post_decr_expr;
+@mut_operation = @incr_operation | @decr_operation;
+@un_arith_operation = @plus_expr | @minus_expr | @mut_operation;
+@arith_operation = @bin_arith_operation | @un_arith_operation;
 
-@bin_bit_op_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
-                 | @rshift_expr | @urshift_expr;
-@un_bit_op_expr = @bit_not_expr;
-@bit_expr = @un_bit_op_expr | @bin_bit_op_expr;
+@ternary_log_operation = @conditional_expr;
+@bin_log_operation = @log_and_expr | @log_or_expr | @null_coalescing_operation;
+@un_log_operation = @log_not_expr;
+@log_operation = @un_log_operation | @bin_log_operation | @ternary_log_operation;
+
+@bin_bit_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
+              | @rshift_expr | @urshift_expr;
+@bin_bit_operation = @and_operation | @or_operation | @xor_operation | @lshift_operation
+              | @rshift_operation | @urshift_operation;
+@un_bit_expr = @bit_not_expr;
+@un_bit_operation = @un_bit_expr;
+@bit_expr = @un_bit_expr | @bin_bit_expr;
+@bit_operation = @un_bit_operation | @bin_bit_operation;
 
 @equality_op_expr =  @eq_expr | @ne_expr;
 @rel_op_expr = @gt_expr | @lt_expr| @ge_expr | @le_expr;
 @comp_expr = @equality_op_expr | @rel_op_expr;
 
-@op_expr = @un_op | @bin_op | @ternary_op;
+@operation_expr = @un_operation | @bin_operation | @ternary_operation;
 
-@ternary_op = @ternary_log_op_expr;
-@bin_op = @assign_expr | @bin_arith_op_expr | @bin_log_op_expr | @bin_bit_op_expr | @comp_expr;
-@un_op = @un_arith_op_expr | @un_log_op_expr | @un_bit_op_expr | @sizeof_expr
-       | @pointer_indirection_expr | @address_of_expr;
+@ternary_operation = @ternary_log_operation;
+@bin_operation = @assign_expr | @bin_arith_operation | @bin_log_operation | @bin_bit_operation | @comp_expr;
+@un_operation = @un_arith_operation | @un_log_operation | @un_bit_operation | @sizeof_expr
+              | @pointer_indirection_expr | @address_of_expr;
 
 @anonymous_function_expr = @lambda_expr | @anonymous_method_expr;
 
diff --git a/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/old.dbscheme b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/old.dbscheme
new file mode 100644
index 00000000000..3cabc77473c
--- /dev/null
+++ b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/old.dbscheme
@@ -0,0 +1,1505 @@
+/* This is a dummy line to alter the dbscheme, so we can make a database upgrade
+ * without actually changing any of the dbscheme predicates. It contains a date
+ * to allow for such updates in the future as well.
+ *
+ * 2021-07-14
+ *
+ * DO NOT remove this comment carelessly, since it can revert the dbscheme back to a
+ * previously seen state (matching a previously seen SHA), which would make the upgrade
+ * mechanism not work properly.
+ */
+
+/**
+ * An invocation of the compiler. Note that more than one file may be
+ * compiled per invocation. For example, this command compiles three
+ * source files:
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * The `id` simply identifies the invocation, while `cwd` is the working
+ * directory from which the compiler was invoked.
+ */
+compilations(
+    unique int id : @compilation,
+    string cwd : string ref
+);
+
+compilation_info(
+  int id : @compilation ref,
+  string info_key: string ref,
+  string info_value: string ref
+)
+
+/**
+ * The arguments that were passed to the extractor for a compiler
+ * invocation. If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then typically there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | --compiler
+ * 1   | *path to compiler*
+ * 2   | f1.cs
+ * 3   | f2.cs
+ * 4   | f3.cs
+ */
+#keyset[id, num]
+compilation_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The expanded arguments that were passed to the extractor for a
+ * compiler invocation. This is similar to `compilation_args`, but
+ * for a `@someFile.rsp` argument, it includes the arguments from that
+ * file, rather than just taking the argument literally.
+ */
+#keyset[id, num]
+compilation_expanded_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The source files that are compiled by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | f1.cs
+ * 1   | f2.cs
+ * 2   | f3.cs
+ */
+#keyset[id, num]
+compilation_compiling_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The references used by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs /r:ref1.dll /r:ref2.dll /r:ref3.dll
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | ref1.dll
+ * 1   | ref2.dll
+ * 2   | ref3.dll
+ */
+#keyset[id, num]
+compilation_referencing_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The time taken by the extractor for a compiler invocation.
+ *
+ * For each file `num`, there will be rows for
+ *
+ * kind | seconds
+ * ---- | ---
+ * 1    | CPU seconds used by the extractor frontend
+ * 2    | Elapsed seconds during the extractor frontend
+ * 3    | CPU seconds used by the extractor backend
+ * 4    | Elapsed seconds during the extractor backend
+ */
+#keyset[id, num, kind]
+compilation_time(
+    int id : @compilation ref,
+    int num : int ref,
+    /* kind:
+       1 = frontend_cpu_seconds
+       2 = frontend_elapsed_seconds
+       3 = extractor_cpu_seconds
+       4 = extractor_elapsed_seconds
+    */
+    int kind : int ref,
+    float seconds : float ref
+);
+
+/**
+ * An error or warning generated by the extractor.
+ * The diagnostic message `diagnostic` was generated during compiler
+ * invocation `compilation`, and is the `file_number_diagnostic_number`th
+ * message generated while extracting the `file_number`th file of that
+ * invocation.
+ */
+#keyset[compilation, file_number, file_number_diagnostic_number]
+diagnostic_for(
+    unique int diagnostic : @diagnostic ref,
+    int compilation : @compilation ref,
+    int file_number : int ref,
+    int file_number_diagnostic_number : int ref
+);
+
+diagnostics(
+    unique int id: @diagnostic,
+    int severity: int ref,
+    string error_tag: string ref,
+    string error_message: string ref,
+    string full_error_message: string ref,
+    int location: @location ref
+);
+
+extractor_messages(
+    unique int id: @extractor_message,
+    int severity: int ref,
+    string origin : string ref,
+    string text : string ref,
+    string entity : string ref,
+    int location: @location ref,
+    string stack_trace : string ref
+);
+
+/**
+ * If extraction was successful, then `cpu_seconds` and
+ * `elapsed_seconds` are the CPU time and elapsed time (respectively)
+ * that extraction took for compiler invocation `id`.
+ */
+compilation_finished(
+    unique int id : @compilation ref,
+    float cpu_seconds : float ref,
+    float elapsed_seconds : float ref
+);
+
+compilation_assembly(
+  unique int id : @compilation ref,
+  int assembly: @assembly ref
+)
+
+// Populated by the CSV extractor
+externalData(
+   int id: @externalDataElement,
+   string path: string ref,
+   int column: int ref,
+   string value: string ref);
+
+sourceLocationPrefix(
+  string prefix: string ref);
+
+/*
+ * Overlay support
+ */
+
+/**
+ * The CLI will automatically emit the tuple `databaseMetadata("isOverlay", "true")`,
+ * along with an `overlayChangedFiles` tuple for each new/modified/deleted file,
+ * when building an overlay database, and these can be used by the discard predicates.
+ */
+databaseMetadata(
+  string metadataKey : string ref,
+  string value : string ref
+);
+
+overlayChangedFiles(
+  string path : string ref
+);
+
+/*
+ * C# dbscheme
+ */
+
+/** ELEMENTS **/
+
+@element = @declaration | @stmt | @expr | @modifier | @attribute | @namespace_declaration
+         | @using_directive | @type_parameter_constraints | @externalDataElement
+         | @xmllocatable | @asp_element | @namespace | @preprocessor_directive;
+
+@declaration = @callable | @generic | @assignable | @namespace;
+
+@named_element = @namespace | @declaration;
+
+@declaration_with_accessors = @property | @indexer | @event;
+
+@assignable = @variable | @assignable_with_accessors | @event;
+
+@assignable_with_accessors = @property | @indexer;
+
+@attributable = @assembly | @field | @parameter | @operator | @method | @constructor
+              | @destructor | @callable_accessor | @value_or_ref_type | @declaration_with_accessors
+              | @local_function | @lambda_expr;
+
+/** LOCATIONS, ASEMMBLIES, MODULES, FILES and FOLDERS **/
+
+@location = @location_default | @assembly;
+
+@locatable = @declaration_with_accessors | @callable_accessor | @declaration_or_directive
+           | @diagnostic | @extractor_message | @preprocessor_directive | @attribute | @type_mention | @type_parameter_constraints
+           | @declaration_with_accessors | @callable_accessor | @operator | @method
+           | @constructor | @destructor | @field | @local_variable | @parameter | @stmt | @expr
+           | @xmllocatable | @commentline | @commentblock | @asp_element
+
+locations_default(
+  unique int id: @location_default,
+  int file: @file ref,
+  int beginLine: int ref,
+  int beginColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+locations_mapped(
+  unique int id: @location_default ref,
+  int mapped_to: @location_default ref);
+
+@sourceline = @file | @callable | @xmllocatable;
+
+numlines(
+  int element_id: @sourceline ref,
+  int num_lines: int ref,
+  int num_code: int ref,
+  int num_comment: int ref);
+
+assemblies(
+  unique int id: @assembly,
+  int file: @file ref,
+  string fullname: string ref,
+  string name: string ref,
+  string version: string ref);
+
+files(
+  unique int id: @file,
+  string name: string ref);
+
+folders(
+  unique int id: @folder,
+  string name: string ref);
+
+@container = @folder | @file ;
+
+containerparent(
+  int parent: @container ref,
+  unique int child: @container ref);
+
+file_extraction_mode(
+  unique int file: @file ref,
+  int mode: int ref
+  /* 0 = normal, 1 = standalone extractor */
+  );
+
+/** NAMESPACES **/
+
+@type_container = @namespace | @type;
+
+namespaces(
+  unique int id: @namespace,
+  string name: string ref);
+
+namespace_declarations(
+  unique int id: @namespace_declaration,
+  int namespace_id: @namespace ref);
+
+namespace_declaration_location(
+  unique int id: @namespace_declaration ref,
+  int loc: @location ref);
+
+parent_namespace(
+  unique int child_id: @type_container ref,
+  int namespace_id: @namespace ref);
+
+@declaration_or_directive = @namespace_declaration | @type | @using_directive;
+
+parent_namespace_declaration(
+  int child_id: @declaration_or_directive ref, // cannot be unique because of partial classes
+  int namespace_id: @namespace_declaration ref);
+
+@using_directive = @using_namespace_directive | @using_static_directive;
+
+using_global(
+  unique int id: @using_directive ref
+);
+
+using_namespace_directives(
+  unique int id: @using_namespace_directive,
+  int namespace_id: @namespace ref);
+
+using_static_directives(
+  unique int id: @using_static_directive,
+  int type_id: @type_or_ref ref);
+
+using_directive_location(
+  unique int id: @using_directive ref,
+  int loc: @location ref);
+
+@preprocessor_directive = @pragma_warning | @pragma_checksum | @directive_define | @directive_undefine | @directive_warning
+  | @directive_error | @directive_nullable | @directive_line | @directive_region | @directive_endregion | @directive_if
+  | @directive_elif | @directive_else | @directive_endif;
+
+@conditional_directive = @directive_if | @directive_elif;
+@branch_directive = @directive_if | @directive_elif | @directive_else;
+
+directive_ifs(
+  unique int id: @directive_if,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref); /* 0: false, 1: true */
+
+directive_elifs(
+  unique int id: @directive_elif,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref,  /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+directive_elses(
+  unique int id: @directive_else,
+  int branchTaken: int ref,   /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+#keyset[id, start]
+directive_endifs(
+  unique int id: @directive_endif,
+  unique int start: @directive_if ref);
+
+directive_define_symbols(
+  unique int id: @define_symbol_expr ref,
+  string name: string ref);
+
+directive_regions(
+  unique int id: @directive_region,
+  string name: string ref);
+
+#keyset[id, start]
+directive_endregions(
+  unique int id: @directive_endregion,
+  unique int start: @directive_region ref);
+
+directive_lines(
+  unique int id: @directive_line,
+  int kind: int ref); /* 0: default, 1: hidden, 2: numeric, 3: span */
+
+directive_line_value(
+  unique int id: @directive_line ref,
+  int line: int ref);
+
+directive_line_file(
+  unique int id: @directive_line ref,
+  int file: @file ref);
+
+directive_line_offset(
+  unique int id: @directive_line ref,
+  int offset: int ref);
+
+directive_line_span(
+  unique int id: @directive_line ref,
+  int startLine: int ref,
+  int startColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+directive_nullables(
+  unique int id: @directive_nullable,
+  int setting: int ref, /* 0: disable, 1: enable, 2: restore */
+  int target: int ref); /* 0: none, 1: annotations, 2: warnings */
+
+directive_warnings(
+  unique int id: @directive_warning,
+  string message: string ref);
+
+directive_errors(
+  unique int id: @directive_error,
+  string message: string ref);
+
+directive_undefines(
+  unique int id: @directive_undefine,
+  string name: string ref);
+
+directive_defines(
+  unique int id: @directive_define,
+  string name: string ref);
+
+pragma_checksums(
+  unique int id: @pragma_checksum,
+  int file: @file ref,
+  string guid: string ref,
+  string bytes: string ref);
+
+pragma_warnings(
+  unique int id: @pragma_warning,
+  int kind: int ref /* 0 = disable, 1 = restore */);
+
+#keyset[id, index]
+pragma_warning_error_codes(
+  int id: @pragma_warning ref,
+  string errorCode: string ref,
+  int index: int ref);
+
+preprocessor_directive_location(
+  unique int id: @preprocessor_directive ref,
+  int loc: @location ref);
+
+preprocessor_directive_compilation(
+  int id: @preprocessor_directive ref,
+  int compilation: @compilation ref);
+
+preprocessor_directive_active(
+  unique int id: @preprocessor_directive ref,
+  int active: int ref);  /* 0: false, 1: true */
+
+/** TYPES **/
+
+types(
+  unique int id: @type,
+  int kind: int ref,
+  string name: string ref);
+
+case @type.kind of
+   1 = @bool_type
+|  2 = @char_type
+|  3 = @decimal_type
+|  4 = @sbyte_type
+|  5 = @short_type
+|  6 = @int_type
+|  7 = @long_type
+|  8 = @byte_type
+|  9 = @ushort_type
+| 10 = @uint_type
+| 11 = @ulong_type
+| 12 = @float_type
+| 13 = @double_type
+| 14 = @enum_type
+| 15 = @struct_type
+| 17 = @class_type
+| 19 = @interface_type
+| 20 = @delegate_type
+| 21 = @null_type
+| 22 = @type_parameter
+| 23 = @pointer_type
+| 24 = @nullable_type
+| 25 = @array_type
+| 26 = @void_type
+| 27 = @int_ptr_type
+| 28 = @uint_ptr_type
+| 29 = @dynamic_type
+| 30 = @arglist_type
+| 31 = @unknown_type
+| 32 = @tuple_type
+| 33 = @function_pointer_type
+| 34 = @inline_array_type
+| 35 = @extension_type
+  ;
+
+@simple_type = @bool_type | @char_type | @integral_type | @floating_point_type | @decimal_type;
+@integral_type = @signed_integral_type | @unsigned_integral_type;
+@signed_integral_type = @sbyte_type | @short_type | @int_type | @long_type;
+@unsigned_integral_type = @byte_type  | @ushort_type | @uint_type | @ulong_type;
+@floating_point_type = @float_type | @double_type;
+@value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
+            | @uint_ptr_type | @tuple_type | @void_type | @inline_array_type;
+@ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
+          | @dynamic_type | @extension_type;
+@value_or_ref_type = @value_type | @ref_type;
+
+typerefs(
+  unique int id: @typeref,
+  string name: string ref);
+
+typeref_type(
+  int id: @typeref ref,
+  unique int typeId: @type ref);
+
+@type_or_ref = @type | @typeref;
+
+array_element_type(
+  unique int array: @array_type ref,
+  int dimension: int ref,
+  int rank: int ref,
+  int element: @type_or_ref ref);
+
+nullable_underlying_type(
+  unique int nullable: @nullable_type ref,
+  int underlying: @type_or_ref ref);
+
+pointer_referent_type(
+  unique int pointer: @pointer_type ref,
+  int referent: @type_or_ref ref);
+
+enum_underlying_type(
+  unique int enum_id: @enum_type ref,
+  int underlying_type_id: @type_or_ref ref);
+
+delegate_return_type(
+  unique int delegate_id: @delegate_type ref,
+  int return_type_id: @type_or_ref ref);
+
+function_pointer_return_type(
+    unique int function_pointer_id: @function_pointer_type ref,
+    int return_type_id: @type_or_ref ref);
+
+extension_receiver_type(
+  unique int extension: @extension_type ref,
+  int receiver_type_id: @type_or_ref ref);
+
+extend(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+anonymous_types(
+  unique int id: @type ref);
+
+@interface_or_ref = @interface_type | @typeref;
+
+implement(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+type_location(
+  int id: @type ref,
+  int loc: @location ref);
+
+tuple_underlying_type(
+  unique int tuple: @tuple_type ref,
+  int struct: @type_or_ref ref);
+
+#keyset[tuple, index]
+tuple_element(
+  int tuple: @tuple_type ref,
+  int index: int ref,
+  unique int field: @field ref);
+
+attributes(
+  unique int id: @attribute,
+  int kind: int ref,
+  int type_id: @type_or_ref ref,
+  int target:  @attributable ref);
+
+case @attribute.kind of
+  0 = @attribute_default
+| 1 = @attribute_return
+| 2 = @attribute_assembly
+| 3 = @attribute_module
+;
+
+attribute_location(
+  int id: @attribute ref,
+  int loc: @location ref);
+
+@type_mention_parent = @element | @type_mention;
+
+type_mention(
+  unique int id: @type_mention,
+  int type_id: @type_or_ref ref,
+  int parent: @type_mention_parent ref);
+
+type_mention_location(
+  unique int id: @type_mention ref,
+  int loc: @location ref);
+
+@has_type_annotation = @assignable | @type_parameter | @callable | @expr | @delegate_type | @generic | @function_pointer_type;
+
+/**
+ * A direct annotation on an entity, for example `string? x;`.
+ *
+ * Annotations:
+ * 2 = reftype is not annotated "!"
+ * 3 = reftype is annotated "?"
+ * 4 = readonly ref type / in parameter
+ * 5 = ref type parameter, return or local variable
+ * 6 = out parameter
+ *
+ * Note that the annotation depends on the element it annotates.
+ * @assignable: The annotation is on the type of the assignable, for example the variable type.
+ * @type_parameter: The annotation is on the reftype constraint
+ * @callable: The annotation is on the return type
+ * @array_type: The annotation is on the element type
+ */
+type_annotation(int id: @has_type_annotation ref, int annotation: int ref);
+
+nullability(unique int nullability: @nullability, int kind: int ref);
+
+case @nullability.kind of
+  0 = @oblivious
+| 1 = @not_annotated
+| 2 = @annotated
+;
+
+#keyset[parent, index]
+nullability_parent(int nullability: @nullability ref, int index: int ref, int parent: @nullability ref)
+
+type_nullability(int id: @has_type_annotation ref, int nullability: @nullability ref);
+
+/**
+ * The nullable flow state of an expression, as determined by Roslyn.
+ *   0 = none (default, not populated)
+ *   1 = not null
+ *   2 = maybe null
+ */
+expr_flowstate(unique int id: @expr ref, int state: int ref);
+
+/** GENERICS **/
+
+@generic = @type | @method | @local_function;
+
+type_parameters(
+  unique int id: @type_parameter ref,
+  int index: int ref,
+  int generic_id: @generic ref,
+  int variance: int ref /* none = 0, out = 1, in = 2 */);
+
+#keyset[constructed_id, index]
+type_arguments(
+  int id: @type_or_ref ref,
+  int index: int ref,
+  int constructed_id: @generic_or_ref ref);
+
+@generic_or_ref = @generic | @typeref;
+
+constructed_generic(
+  unique int constructed: @generic ref,
+  int generic: @generic_or_ref ref);
+
+type_parameter_constraints(
+  unique int id: @type_parameter_constraints,
+  int param_id: @type_parameter ref);
+
+type_parameter_constraints_location(
+  int id: @type_parameter_constraints ref,
+  int loc: @location ref);
+
+general_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int kind: int ref /* class = 1, struct = 2, new = 3 */);
+
+specific_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref);
+
+specific_type_parameter_nullability(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref,
+  int nullability: @nullability ref);
+
+/** FUNCTION POINTERS */
+
+function_pointer_calling_conventions(
+  int id: @function_pointer_type ref,
+  int kind: int ref);
+
+#keyset[id, index]
+has_unmanaged_calling_conventions(
+  int id: @function_pointer_type ref,
+  int index: int ref,
+  int conv_id: @type_or_ref ref);
+
+/** MODIFIERS */
+
+@modifiable = @modifiable_direct | @event_accessor;
+
+@modifiable_direct = @member | @accessor | @local_function | @anonymous_function_expr;
+
+modifiers(
+  unique int id: @modifier,
+  string name: string ref);
+
+has_modifiers(
+  int id: @modifiable_direct ref,
+  int mod_id: @modifier ref);
+
+/** MEMBERS **/
+
+@member = @method | @constructor | @destructor | @field | @property | @event | @operator | @indexer | @type;
+
+@named_exprorstmt = @goto_stmt | @labeled_stmt | @expr;
+
+@virtualizable = @method | @property | @indexer | @event | @operator;
+
+exprorstmt_name(
+  unique int parent_id: @named_exprorstmt ref,
+  string name: string ref);
+
+nested_types(
+  unique int id: @type ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @type ref);
+
+properties(
+  unique int id: @property,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @property ref);
+
+property_location(
+  int id: @property ref,
+  int loc: @location ref);
+
+indexers(
+  unique int id: @indexer,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @indexer ref);
+
+indexer_location(
+  int id: @indexer ref,
+  int loc: @location ref);
+
+accessors(
+  unique int id: @accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_member_id: @member ref,
+  int unbound_id: @accessor ref);
+
+case @accessor.kind of
+  1 = @getter
+| 2 = @setter
+  ;
+
+init_only_accessors(
+  unique int id: @accessor ref);
+
+accessor_location(
+  int id: @accessor ref,
+  int loc: @location ref);
+
+events(
+  unique int id: @event,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @event ref);
+
+event_location(
+  int id: @event ref,
+  int loc: @location ref);
+
+event_accessors(
+  unique int id: @event_accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_event_id: @event ref,
+  int unbound_id: @event_accessor ref);
+
+case @event_accessor.kind of
+  1 = @add_event_accessor
+| 2 = @remove_event_accessor
+  ;
+
+event_accessor_location(
+  int id: @event_accessor ref,
+  int loc: @location ref);
+
+operators(
+  unique int id: @operator,
+  string name: string ref,
+  string symbol: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @operator ref);
+
+operator_location(
+  int id: @operator ref,
+  int loc: @location ref);
+
+constant_value(
+  int id: @variable ref,
+  string value: string ref);
+
+/** CALLABLES **/
+
+@callable = @method | @constructor | @destructor | @operator | @callable_accessor | @anonymous_function_expr | @local_function;
+
+@callable_accessor = @accessor | @event_accessor;
+
+methods(
+  unique int id: @method,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @method ref);
+
+method_location(
+  int id: @method ref,
+  int loc: @location ref);
+
+constructors(
+  unique int id: @constructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @constructor ref);
+
+constructor_location(
+  int id: @constructor ref,
+  int loc: @location ref);
+
+destructors(
+  unique int id: @destructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @destructor ref);
+
+destructor_location(
+  int id: @destructor ref,
+  int loc: @location ref);
+
+overrides(
+  int id: @callable ref,
+  int base_id: @callable ref);
+
+explicitly_implements(
+  int id: @member ref,
+  int interface_id: @interface_or_ref ref);
+
+local_functions(
+    unique int id: @local_function,
+    string name: string ref,
+    int return_type: @type ref,
+    int unbound_id: @local_function ref);
+
+local_function_stmts(
+    unique int fn: @local_function_stmt ref,
+    int stmt: @local_function ref);
+
+/** VARIABLES **/
+
+@variable = @local_scope_variable | @field;
+
+@local_scope_variable = @local_variable | @parameter;
+
+fields(
+  unique int id: @field,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @field ref);
+
+case @field.kind of
+  1 = @addressable_field
+| 2 = @constant
+  ;
+
+field_location(
+  int id: @field ref,
+  int loc: @location ref);
+
+localvars(
+  unique int id: @local_variable,
+  int kind: int ref,
+  string name: string ref,
+  int implicitly_typed: int ref /* 0 = no, 1 = yes */,
+  int type_id: @type_or_ref ref,
+  int parent_id: @local_var_decl_expr ref);
+
+case @local_variable.kind of
+  1 = @addressable_local_variable
+| 2 = @local_constant
+| 3 = @local_variable_ref
+  ;
+
+localvar_location(
+  unique int id: @local_variable ref,
+  int loc: @location ref);
+
+@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type | @extension_type;
+
+#keyset[name, parent_id]
+#keyset[index, parent_id]
+params(
+  unique int id: @parameter,
+  string name: string ref,
+  int type_id: @type_or_ref ref,
+  int index: int ref,
+  int mode: int ref, /* value = 0, ref = 1, out = 2, params/array = 3, this = 4, in = 5, ref readonly = 6 */
+  int parent_id: @parameterizable ref,
+  int unbound_id: @parameter ref);
+
+param_location(
+  int id: @parameter ref,
+  int loc: @location ref);
+
+@has_scoped_annotation = @local_scope_variable
+
+scoped_annotation(
+  int id: @has_scoped_annotation ref,
+  int kind: int ref // scoped ref = 1, scoped value = 2
+  );
+
+/** STATEMENTS **/
+
+@exprorstmt_parent = @control_flow_element | @top_level_exprorstmt_parent;
+
+statements(
+  unique int id: @stmt,
+  int kind: int ref);
+
+#keyset[index, parent]
+stmt_parent(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_stmt_parent = @callable;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+stmt_parent_top_level(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @top_level_stmt_parent ref);
+
+case @stmt.kind of
+   1 = @block_stmt
+|  2 = @expr_stmt
+|  3 = @if_stmt
+|  4 = @switch_stmt
+|  5 = @while_stmt
+|  6 = @do_stmt
+|  7 = @for_stmt
+|  8 = @foreach_stmt
+|  9 = @break_stmt
+| 10 = @continue_stmt
+| 11 = @goto_stmt
+| 12 = @goto_case_stmt
+| 13 = @goto_default_stmt
+| 14 = @throw_stmt
+| 15 = @return_stmt
+| 16 = @yield_stmt
+| 17 = @try_stmt
+| 18 = @checked_stmt
+| 19 = @unchecked_stmt
+| 20 = @lock_stmt
+| 21 = @using_block_stmt
+| 22 = @var_decl_stmt
+| 23 = @const_decl_stmt
+| 24 = @empty_stmt
+| 25 = @unsafe_stmt
+| 26 = @fixed_stmt
+| 27 = @label_stmt
+| 28 = @catch
+| 29 = @case_stmt
+| 30 = @local_function_stmt
+| 31 = @using_decl_stmt
+  ;
+
+@using_stmt = @using_block_stmt | @using_decl_stmt;
+
+@labeled_stmt = @label_stmt | @case;
+
+@decl_stmt = @var_decl_stmt | @const_decl_stmt | @using_decl_stmt;
+
+@cond_stmt = @if_stmt | @switch_stmt;
+
+@loop_stmt = @while_stmt | @do_stmt | @for_stmt | @foreach_stmt;
+
+@jump_stmt = @break_stmt | @goto_any_stmt | @continue_stmt | @throw_stmt | @return_stmt
+           | @yield_stmt;
+
+@goto_any_stmt = @goto_default_stmt | @goto_case_stmt | @goto_stmt;
+
+
+stmt_location(
+  unique int id: @stmt ref,
+  int loc: @location ref);
+
+catch_type(
+  unique int catch_id: @catch ref,
+  int type_id: @type_or_ref ref,
+  int kind: int ref /* explicit = 1, implicit = 2 */);
+
+foreach_stmt_info(
+  unique int id: @foreach_stmt ref,
+  int kind: int ref /* non-async = 1, async = 2 */);
+
+@foreach_symbol =  @method | @property | @type_or_ref;
+
+#keyset[id, kind]
+foreach_stmt_desugar(
+  int id: @foreach_stmt ref,
+  int symbol: @foreach_symbol ref,
+  int kind: int ref /* GetEnumeratorMethod = 1, CurrentProperty = 2, MoveNextMethod = 3, DisposeMethod = 4, ElementType = 5 */);
+
+/** EXPRESSIONS **/
+
+expressions(
+  unique int id: @expr,
+  int kind: int ref,
+  int type_id: @type_or_ref ref);
+
+#keyset[index, parent]
+expr_parent(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_expr_parent = @attribute | @field | @property | @indexer | @parameter | @directive_if | @directive_elif;
+
+@top_level_exprorstmt_parent = @top_level_expr_parent | @top_level_stmt_parent;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+expr_parent_top_level(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @top_level_exprorstmt_parent ref);
+
+case @expr.kind of
+/* literal */
+   1 = @bool_literal_expr
+|  2 = @char_literal_expr
+|  3 = @decimal_literal_expr
+|  4 = @int_literal_expr
+|  5 = @long_literal_expr
+|  6 = @uint_literal_expr
+|  7 = @ulong_literal_expr
+|  8 = @float_literal_expr
+|  9 = @double_literal_expr
+| 10 = @utf16_string_literal_expr
+| 11 = @null_literal_expr
+/* primary & unary */
+| 12 = @this_access_expr
+| 13 = @base_access_expr
+| 14 = @local_variable_access_expr
+| 15 = @parameter_access_expr
+| 16 = @field_access_expr
+| 17 = @property_access_expr
+| 18 = @method_access_expr
+| 19 = @event_access_expr
+| 20 = @indexer_access_expr
+| 21 = @array_access_expr
+| 22 = @type_access_expr
+| 23 = @typeof_expr
+| 24 = @method_invocation_expr
+| 25 = @delegate_invocation_expr
+| 26 = @operator_invocation_expr
+| 27 = @cast_expr
+| 28 = @object_creation_expr
+| 29 = @explicit_delegate_creation_expr
+| 30 = @implicit_delegate_creation_expr
+| 31 = @array_creation_expr
+| 32 = @default_expr
+| 33 = @plus_expr
+| 34 = @minus_expr
+| 35 = @bit_not_expr
+| 36 = @log_not_expr
+| 37 = @post_incr_expr
+| 38 = @post_decr_expr
+| 39 = @pre_incr_expr
+| 40 = @pre_decr_expr
+/* multiplicative */
+| 41 = @mul_expr
+| 42 = @div_expr
+| 43 = @rem_expr
+/* additive */
+| 44 = @add_expr
+| 45 = @sub_expr
+/* shift */
+| 46 = @lshift_expr
+| 47 = @rshift_expr
+/* relational */
+| 48 = @lt_expr
+| 49 = @gt_expr
+| 50 = @le_expr
+| 51 = @ge_expr
+/* equality */
+| 52 = @eq_expr
+| 53 = @ne_expr
+/* logical */
+| 54 = @bit_and_expr
+| 55 = @bit_xor_expr
+| 56 = @bit_or_expr
+| 57 = @log_and_expr
+| 58 = @log_or_expr
+/* type testing */
+| 59 = @is_expr
+| 60 = @as_expr
+/* null coalescing */
+| 61 = @null_coalescing_expr
+/* conditional */
+| 62 = @conditional_expr
+/* assignment */
+| 63 = @simple_assign_expr
+| 64 = @assign_add_expr
+| 65 = @assign_sub_expr
+| 66 = @assign_mul_expr
+| 67 = @assign_div_expr
+| 68 = @assign_rem_expr
+| 69 = @assign_and_expr
+| 70 = @assign_xor_expr
+| 71 = @assign_or_expr
+| 72 = @assign_lshift_expr
+| 73 = @assign_rshift_expr
+/* more */
+| 74 = @object_init_expr
+| 75 = @collection_init_expr
+| 76 = @array_init_expr
+| 77 = @checked_expr
+| 78 = @unchecked_expr
+| 79 = @constructor_init_expr
+| 80 = @add_event_expr
+| 81 = @remove_event_expr
+| 82 = @par_expr
+| 83 = @local_var_decl_expr
+| 84 = @lambda_expr
+| 85 = @anonymous_method_expr
+| 86 = @namespace_expr
+/* dynamic */
+| 92 = @dynamic_element_access_expr
+| 93 = @dynamic_member_access_expr
+/* unsafe */
+| 100 = @pointer_indirection_expr
+| 101 = @address_of_expr
+| 102 = @sizeof_expr
+/* async */
+| 103 = @await_expr
+/* C# 6.0 */
+| 104 = @nameof_expr
+| 105 = @interpolated_string_expr
+| 106 = @unknown_expr
+/* C# 7.0 */
+| 107 = @throw_expr
+| 108 = @tuple_expr
+| 109 = @local_function_invocation_expr
+| 110 = @ref_expr
+| 111 = @discard_expr
+/* C# 8.0 */
+| 112 = @range_expr
+| 113 = @index_expr
+| 114 = @switch_expr
+| 115 = @recursive_pattern_expr
+| 116 = @property_pattern_expr
+| 117 = @positional_pattern_expr
+| 118 = @switch_case_expr
+| 119 = @assign_coalesce_expr
+| 120 = @suppress_nullable_warning_expr
+| 121 = @namespace_access_expr
+/* C# 9.0 */
+| 122 = @lt_pattern_expr
+| 123 = @gt_pattern_expr
+| 124 = @le_pattern_expr
+| 125 = @ge_pattern_expr
+| 126 = @not_pattern_expr
+| 127 = @and_pattern_expr
+| 128 = @or_pattern_expr
+| 129 = @function_pointer_invocation_expr
+| 130 = @with_expr
+/* C# 11.0 */
+| 131 = @list_pattern_expr
+| 132 = @slice_pattern_expr
+| 133 = @urshift_expr
+| 134 = @assign_urshift_expr
+| 135 = @utf8_string_literal_expr
+/* C# 12.0 */
+| 136 = @collection_expr
+| 137 = @spread_element_expr
+| 138 = @interpolated_string_insert_expr
+/* Preprocessor */
+| 999 = @define_symbol_expr
+;
+
+@switch = @switch_stmt | @switch_expr;
+@case = @case_stmt | @switch_case_expr;
+@pattern_match = @case | @is_expr;
+@unary_pattern_expr = @not_pattern_expr;
+@relational_pattern_expr = @gt_pattern_expr | @lt_pattern_expr | @ge_pattern_expr | @le_pattern_expr;
+@binary_pattern_expr = @and_pattern_expr | @or_pattern_expr;
+
+@integer_literal_expr = @int_literal_expr | @long_literal_expr | @uint_literal_expr | @ulong_literal_expr;
+@real_literal_expr = @float_literal_expr | @double_literal_expr | @decimal_literal_expr;
+@string_literal_expr = @utf16_string_literal_expr | @utf8_string_literal_expr;
+@literal_expr = @bool_literal_expr | @char_literal_expr | @integer_literal_expr | @real_literal_expr
+              | @string_literal_expr | @null_literal_expr;
+
+@assign_expr = @simple_assign_expr | @assign_op_expr | @local_var_decl_expr;
+@assign_op_call_expr = @assign_arith_expr | @assign_bitwise_expr
+@assign_op_expr =  @assign_op_call_expr | @assign_event_expr | @assign_coalesce_expr;
+@assign_event_expr = @add_event_expr | @remove_event_expr;
+
+@add_operation = @add_expr | @assign_add_expr;
+@sub_operation = @sub_expr | @assign_sub_expr;
+@mul_operation = @mul_expr | @assign_mul_expr;
+@div_operation = @div_expr | @assign_div_expr;
+@rem_operation = @rem_expr | @assign_rem_expr;
+@and_operation = @bit_and_expr | @assign_and_expr;
+@xor_operation = @bit_xor_expr | @assign_xor_expr;
+@or_operation = @bit_or_expr | @assign_or_expr;
+@lshift_operation = @lshift_expr | @assign_lshift_expr;
+@rshift_operation = @rshift_expr | @assign_rshift_expr;
+@urshift_operation = @urshift_expr | @assign_urshift_expr;
+@null_coalescing_operation = @null_coalescing_expr | @assign_coalesce_expr;
+
+@assign_arith_expr = @assign_add_expr | @assign_sub_expr | @assign_mul_expr | @assign_div_expr
+                   | @assign_rem_expr
+@assign_bitwise_expr = @assign_and_expr | @assign_or_expr | @assign_xor_expr
+                   | @assign_lshift_expr | @assign_rshift_expr | @assign_urshift_expr;
+
+@member_access_expr = @field_access_expr | @property_access_expr | @indexer_access_expr | @event_access_expr
+                    | @method_access_expr | @type_access_expr | @dynamic_member_access_expr;
+@access_expr = @member_access_expr | @this_access_expr | @base_access_expr | @assignable_access_expr | @namespace_access_expr;
+@element_access_expr = @indexer_access_expr | @array_access_expr | @dynamic_element_access_expr;
+
+@local_variable_access = @local_variable_access_expr | @local_var_decl_expr;
+@local_scope_variable_access_expr = @parameter_access_expr | @local_variable_access;
+@variable_access_expr = @local_scope_variable_access_expr | @field_access_expr;
+
+@assignable_access_expr = @variable_access_expr | @property_access_expr | @element_access_expr
+                        | @event_access_expr | @dynamic_member_access_expr;
+
+@objectorcollection_init_expr = @object_init_expr | @collection_init_expr;
+
+@delegate_creation_expr = @explicit_delegate_creation_expr | @implicit_delegate_creation_expr;
+
+@bin_arith_op_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
+@incr_op_expr =  @pre_incr_expr | @post_incr_expr;
+@decr_op_expr =  @pre_decr_expr | @post_decr_expr;
+@mut_op_expr = @incr_op_expr | @decr_op_expr;
+@un_arith_op_expr = @plus_expr | @minus_expr | @mut_op_expr;
+@arith_op_expr = @bin_arith_op_expr | @un_arith_op_expr;
+
+@ternary_log_op_expr = @conditional_expr;
+@bin_log_op_expr = @log_and_expr | @log_or_expr | @null_coalescing_expr;
+@un_log_op_expr = @log_not_expr;
+@log_expr = @un_log_op_expr | @bin_log_op_expr | @ternary_log_op_expr;
+
+@bin_bit_op_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
+                 | @rshift_expr | @urshift_expr;
+@un_bit_op_expr = @bit_not_expr;
+@bit_expr = @un_bit_op_expr | @bin_bit_op_expr;
+
+@equality_op_expr =  @eq_expr | @ne_expr;
+@rel_op_expr = @gt_expr | @lt_expr| @ge_expr | @le_expr;
+@comp_expr = @equality_op_expr | @rel_op_expr;
+
+@op_expr = @un_op | @bin_op | @ternary_op;
+
+@ternary_op = @ternary_log_op_expr;
+@bin_op = @assign_expr | @bin_arith_op_expr | @bin_log_op_expr | @bin_bit_op_expr | @comp_expr;
+@un_op = @un_arith_op_expr | @un_log_op_expr | @un_bit_op_expr | @sizeof_expr
+       | @pointer_indirection_expr | @address_of_expr;
+
+@anonymous_function_expr = @lambda_expr | @anonymous_method_expr;
+
+@op_invoke_expr = @operator_invocation_expr | @assign_op_call_expr
+@call = @method_invocation_expr | @constructor_init_expr | @op_invoke_expr
+      | @delegate_invocation_expr | @object_creation_expr | @call_access_expr
+      | @local_function_invocation_expr | @function_pointer_invocation_expr;
+
+@call_access_expr = @property_access_expr | @event_access_expr | @indexer_access_expr;
+
+@late_bindable_expr = @dynamic_element_access_expr | @dynamic_member_access_expr
+                    | @object_creation_expr | @method_invocation_expr | @op_invoke_expr;
+
+@throw_element = @throw_expr | @throw_stmt;
+
+@implicitly_typeable_object_creation_expr = @object_creation_expr | @explicit_delegate_creation_expr;
+
+implicitly_typed_array_creation(
+  unique int id: @array_creation_expr ref);
+
+explicitly_sized_array_creation(
+  unique int id: @array_creation_expr ref);
+
+stackalloc_array_creation(
+  unique int id: @array_creation_expr ref);
+
+implicitly_typed_object_creation(
+  unique int id: @implicitly_typeable_object_creation_expr ref);
+
+mutator_invocation_mode(
+  unique int id: @operator_invocation_expr ref,
+  int mode: int ref /* prefix = 1, postfix = 2*/);
+
+expr_value(
+  unique int id: @expr ref,
+  string value: string ref);
+
+expr_call(
+  unique int caller_id: @expr ref,
+  int target_id: @callable ref);
+
+expr_access(
+  unique int accesser_id: @access_expr ref,
+  int target_id: @accessible ref);
+
+@accessible = @method | @assignable | @local_function | @namespace;
+
+expr_location(
+  unique int id: @expr ref,
+  int loc: @location ref);
+
+dynamic_member_name(
+  unique int id: @late_bindable_expr ref,
+  string name: string ref);
+
+@qualifiable_expr = @member_access_expr
+                  | @method_invocation_expr
+                  | @element_access_expr
+                  | @assign_op_call_expr;
+
+conditional_access(
+  unique int id: @qualifiable_expr ref);
+
+expr_argument(
+  unique int id: @expr ref,
+  int mode: int ref);
+  /* mode is the same as params: value = 0, ref = 1, out = 2 */
+
+expr_argument_name(
+  unique int id: @expr ref,
+  string name: string ref);
+
+lambda_expr_return_type(
+  unique int id: @lambda_expr ref,
+  int type_id: @type_or_ref ref);
+
+/* Compiler generated */
+
+compiler_generated(unique int id: @element ref);
+
+/** CONTROL/DATA FLOW **/
+
+@control_flow_element = @stmt | @expr | @parameter;
+
+/* XML Files */
+
+xmlEncoding  (
+  unique int id: @file ref,
+  string encoding: string ref);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+/* Comments */
+
+commentline(
+  unique int id: @commentline,
+  int kind: int ref,
+  string text: string ref,
+  string rawtext: string ref);
+
+case @commentline.kind of
+  0 = @singlelinecomment
+| 1 = @xmldoccomment
+| 2 = @multilinecomment;
+
+commentline_location(
+  unique int id: @commentline ref,
+  int loc: @location ref);
+
+commentblock(
+  unique int id : @commentblock);
+
+commentblock_location(
+  unique int id: @commentblock ref,
+  int loc: @location ref);
+
+commentblock_binding(
+  int id: @commentblock ref,
+  int entity: @element ref,
+  int bindtype: int ref);    /* 0: Parent, 1: Best, 2: Before, 3: After */
+
+commentblock_child(
+  int id: @commentblock ref,
+  int commentline: @commentline ref,
+  int index: int ref);
+
+/* ASP.NET */
+
+case @asp_element.kind of
+  0=@asp_close_tag
+| 1=@asp_code
+| 2=@asp_comment
+| 3=@asp_data_binding
+| 4=@asp_directive
+| 5=@asp_open_tag
+| 6=@asp_quoted_string
+| 7=@asp_text
+| 8=@asp_xml_directive;
+
+@asp_attribute = @asp_code | @asp_data_binding | @asp_quoted_string;
+
+asp_elements(
+  unique int id: @asp_element,
+  int kind: int ref,
+  int loc: @location ref);
+
+asp_comment_server(unique int comment: @asp_comment ref);
+asp_code_inline(unique int code: @asp_code ref);
+asp_directive_attribute(
+  int directive: @asp_directive ref,
+  int index: int ref,
+  string name: string ref,
+  int value: @asp_quoted_string ref);
+asp_directive_name(
+  unique int directive: @asp_directive ref,
+  string name: string ref);
+asp_element_body(
+  unique int element: @asp_element ref,
+  string body: string ref);
+asp_tag_attribute(
+  int tag: @asp_open_tag ref,
+  int index: int ref,
+  string name: string ref,
+  int attribute: @asp_attribute ref);
+asp_tag_name(
+  unique int tag: @asp_open_tag ref,
+  string name: string ref);
+asp_tag_isempty(int tag: @asp_open_tag ref);
diff --git a/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/semmlecode.csharp.dbscheme b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/semmlecode.csharp.dbscheme
new file mode 100644
index 00000000000..d13c4c187d7
--- /dev/null
+++ b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/semmlecode.csharp.dbscheme
@@ -0,0 +1,1511 @@
+/* This is a dummy line to alter the dbscheme, so we can make a database upgrade
+ * without actually changing any of the dbscheme predicates. It contains a date
+ * to allow for such updates in the future as well.
+ *
+ * 2021-07-14
+ *
+ * DO NOT remove this comment carelessly, since it can revert the dbscheme back to a
+ * previously seen state (matching a previously seen SHA), which would make the upgrade
+ * mechanism not work properly.
+ */
+
+/**
+ * An invocation of the compiler. Note that more than one file may be
+ * compiled per invocation. For example, this command compiles three
+ * source files:
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * The `id` simply identifies the invocation, while `cwd` is the working
+ * directory from which the compiler was invoked.
+ */
+compilations(
+    unique int id : @compilation,
+    string cwd : string ref
+);
+
+compilation_info(
+  int id : @compilation ref,
+  string info_key: string ref,
+  string info_value: string ref
+)
+
+/**
+ * The arguments that were passed to the extractor for a compiler
+ * invocation. If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then typically there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | --compiler
+ * 1   | *path to compiler*
+ * 2   | f1.cs
+ * 3   | f2.cs
+ * 4   | f3.cs
+ */
+#keyset[id, num]
+compilation_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The expanded arguments that were passed to the extractor for a
+ * compiler invocation. This is similar to `compilation_args`, but
+ * for a `@someFile.rsp` argument, it includes the arguments from that
+ * file, rather than just taking the argument literally.
+ */
+#keyset[id, num]
+compilation_expanded_args(
+    int id : @compilation ref,
+    int num : int ref,
+    string arg : string ref
+);
+
+/**
+ * The source files that are compiled by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | f1.cs
+ * 1   | f2.cs
+ * 2   | f3.cs
+ */
+#keyset[id, num]
+compilation_compiling_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The references used by a compiler invocation.
+ * If `id` is for the compiler invocation
+ *
+ *   csc f1.cs f2.cs f3.cs /r:ref1.dll /r:ref2.dll /r:ref3.dll
+ *
+ * then there will be rows for
+ *
+ * num | arg
+ * --- | ---
+ * 0   | ref1.dll
+ * 1   | ref2.dll
+ * 2   | ref3.dll
+ */
+#keyset[id, num]
+compilation_referencing_files(
+    int id : @compilation ref,
+    int num : int ref,
+    int file : @file ref
+);
+
+/**
+ * The time taken by the extractor for a compiler invocation.
+ *
+ * For each file `num`, there will be rows for
+ *
+ * kind | seconds
+ * ---- | ---
+ * 1    | CPU seconds used by the extractor frontend
+ * 2    | Elapsed seconds during the extractor frontend
+ * 3    | CPU seconds used by the extractor backend
+ * 4    | Elapsed seconds during the extractor backend
+ */
+#keyset[id, num, kind]
+compilation_time(
+    int id : @compilation ref,
+    int num : int ref,
+    /* kind:
+       1 = frontend_cpu_seconds
+       2 = frontend_elapsed_seconds
+       3 = extractor_cpu_seconds
+       4 = extractor_elapsed_seconds
+    */
+    int kind : int ref,
+    float seconds : float ref
+);
+
+/**
+ * An error or warning generated by the extractor.
+ * The diagnostic message `diagnostic` was generated during compiler
+ * invocation `compilation`, and is the `file_number_diagnostic_number`th
+ * message generated while extracting the `file_number`th file of that
+ * invocation.
+ */
+#keyset[compilation, file_number, file_number_diagnostic_number]
+diagnostic_for(
+    unique int diagnostic : @diagnostic ref,
+    int compilation : @compilation ref,
+    int file_number : int ref,
+    int file_number_diagnostic_number : int ref
+);
+
+diagnostics(
+    unique int id: @diagnostic,
+    int severity: int ref,
+    string error_tag: string ref,
+    string error_message: string ref,
+    string full_error_message: string ref,
+    int location: @location ref
+);
+
+extractor_messages(
+    unique int id: @extractor_message,
+    int severity: int ref,
+    string origin : string ref,
+    string text : string ref,
+    string entity : string ref,
+    int location: @location ref,
+    string stack_trace : string ref
+);
+
+/**
+ * If extraction was successful, then `cpu_seconds` and
+ * `elapsed_seconds` are the CPU time and elapsed time (respectively)
+ * that extraction took for compiler invocation `id`.
+ */
+compilation_finished(
+    unique int id : @compilation ref,
+    float cpu_seconds : float ref,
+    float elapsed_seconds : float ref
+);
+
+compilation_assembly(
+  unique int id : @compilation ref,
+  int assembly: @assembly ref
+)
+
+// Populated by the CSV extractor
+externalData(
+   int id: @externalDataElement,
+   string path: string ref,
+   int column: int ref,
+   string value: string ref);
+
+sourceLocationPrefix(
+  string prefix: string ref);
+
+/*
+ * Overlay support
+ */
+
+/**
+ * The CLI will automatically emit the tuple `databaseMetadata("isOverlay", "true")`,
+ * along with an `overlayChangedFiles` tuple for each new/modified/deleted file,
+ * when building an overlay database, and these can be used by the discard predicates.
+ */
+databaseMetadata(
+  string metadataKey : string ref,
+  string value : string ref
+);
+
+overlayChangedFiles(
+  string path : string ref
+);
+
+/*
+ * C# dbscheme
+ */
+
+/** ELEMENTS **/
+
+@element = @declaration | @stmt | @expr | @modifier | @attribute | @namespace_declaration
+         | @using_directive | @type_parameter_constraints | @externalDataElement
+         | @xmllocatable | @asp_element | @namespace | @preprocessor_directive;
+
+@declaration = @callable | @generic | @assignable | @namespace;
+
+@named_element = @namespace | @declaration;
+
+@declaration_with_accessors = @property | @indexer | @event;
+
+@assignable = @variable | @assignable_with_accessors | @event;
+
+@assignable_with_accessors = @property | @indexer;
+
+@attributable = @assembly | @field | @parameter | @operator | @method | @constructor
+              | @destructor | @callable_accessor | @value_or_ref_type | @declaration_with_accessors
+              | @local_function | @lambda_expr;
+
+/** LOCATIONS, ASEMMBLIES, MODULES, FILES and FOLDERS **/
+
+@location = @location_default | @assembly;
+
+@locatable = @declaration_with_accessors | @callable_accessor | @declaration_or_directive
+           | @diagnostic | @extractor_message | @preprocessor_directive | @attribute | @type_mention | @type_parameter_constraints
+           | @declaration_with_accessors | @callable_accessor | @operator | @method
+           | @constructor | @destructor | @field | @local_variable | @parameter | @stmt | @expr
+           | @xmllocatable | @commentline | @commentblock | @asp_element
+
+locations_default(
+  unique int id: @location_default,
+  int file: @file ref,
+  int beginLine: int ref,
+  int beginColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+locations_mapped(
+  unique int id: @location_default ref,
+  int mapped_to: @location_default ref);
+
+@sourceline = @file | @callable | @xmllocatable;
+
+numlines(
+  int element_id: @sourceline ref,
+  int num_lines: int ref,
+  int num_code: int ref,
+  int num_comment: int ref);
+
+assemblies(
+  unique int id: @assembly,
+  int file: @file ref,
+  string fullname: string ref,
+  string name: string ref,
+  string version: string ref);
+
+files(
+  unique int id: @file,
+  string name: string ref);
+
+folders(
+  unique int id: @folder,
+  string name: string ref);
+
+@container = @folder | @file ;
+
+containerparent(
+  int parent: @container ref,
+  unique int child: @container ref);
+
+file_extraction_mode(
+  unique int file: @file ref,
+  int mode: int ref
+  /* 0 = normal, 1 = standalone extractor */
+  );
+
+/** NAMESPACES **/
+
+@type_container = @namespace | @type;
+
+namespaces(
+  unique int id: @namespace,
+  string name: string ref);
+
+namespace_declarations(
+  unique int id: @namespace_declaration,
+  int namespace_id: @namespace ref);
+
+namespace_declaration_location(
+  unique int id: @namespace_declaration ref,
+  int loc: @location ref);
+
+parent_namespace(
+  unique int child_id: @type_container ref,
+  int namespace_id: @namespace ref);
+
+@declaration_or_directive = @namespace_declaration | @type | @using_directive;
+
+parent_namespace_declaration(
+  int child_id: @declaration_or_directive ref, // cannot be unique because of partial classes
+  int namespace_id: @namespace_declaration ref);
+
+@using_directive = @using_namespace_directive | @using_static_directive;
+
+using_global(
+  unique int id: @using_directive ref
+);
+
+using_namespace_directives(
+  unique int id: @using_namespace_directive,
+  int namespace_id: @namespace ref);
+
+using_static_directives(
+  unique int id: @using_static_directive,
+  int type_id: @type_or_ref ref);
+
+using_directive_location(
+  unique int id: @using_directive ref,
+  int loc: @location ref);
+
+@preprocessor_directive = @pragma_warning | @pragma_checksum | @directive_define | @directive_undefine | @directive_warning
+  | @directive_error | @directive_nullable | @directive_line | @directive_region | @directive_endregion | @directive_if
+  | @directive_elif | @directive_else | @directive_endif;
+
+@conditional_directive = @directive_if | @directive_elif;
+@branch_directive = @directive_if | @directive_elif | @directive_else;
+
+directive_ifs(
+  unique int id: @directive_if,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref); /* 0: false, 1: true */
+
+directive_elifs(
+  unique int id: @directive_elif,
+  int branchTaken: int ref,     /* 0: false, 1: true */
+  int conditionValue: int ref,  /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+directive_elses(
+  unique int id: @directive_else,
+  int branchTaken: int ref,   /* 0: false, 1: true */
+  int parent: @directive_if ref,
+  int index: int ref);
+
+#keyset[id, start]
+directive_endifs(
+  unique int id: @directive_endif,
+  unique int start: @directive_if ref);
+
+directive_define_symbols(
+  unique int id: @define_symbol_expr ref,
+  string name: string ref);
+
+directive_regions(
+  unique int id: @directive_region,
+  string name: string ref);
+
+#keyset[id, start]
+directive_endregions(
+  unique int id: @directive_endregion,
+  unique int start: @directive_region ref);
+
+directive_lines(
+  unique int id: @directive_line,
+  int kind: int ref); /* 0: default, 1: hidden, 2: numeric, 3: span */
+
+directive_line_value(
+  unique int id: @directive_line ref,
+  int line: int ref);
+
+directive_line_file(
+  unique int id: @directive_line ref,
+  int file: @file ref);
+
+directive_line_offset(
+  unique int id: @directive_line ref,
+  int offset: int ref);
+
+directive_line_span(
+  unique int id: @directive_line ref,
+  int startLine: int ref,
+  int startColumn: int ref,
+  int endLine: int ref,
+  int endColumn: int ref);
+
+directive_nullables(
+  unique int id: @directive_nullable,
+  int setting: int ref, /* 0: disable, 1: enable, 2: restore */
+  int target: int ref); /* 0: none, 1: annotations, 2: warnings */
+
+directive_warnings(
+  unique int id: @directive_warning,
+  string message: string ref);
+
+directive_errors(
+  unique int id: @directive_error,
+  string message: string ref);
+
+directive_undefines(
+  unique int id: @directive_undefine,
+  string name: string ref);
+
+directive_defines(
+  unique int id: @directive_define,
+  string name: string ref);
+
+pragma_checksums(
+  unique int id: @pragma_checksum,
+  int file: @file ref,
+  string guid: string ref,
+  string bytes: string ref);
+
+pragma_warnings(
+  unique int id: @pragma_warning,
+  int kind: int ref /* 0 = disable, 1 = restore */);
+
+#keyset[id, index]
+pragma_warning_error_codes(
+  int id: @pragma_warning ref,
+  string errorCode: string ref,
+  int index: int ref);
+
+preprocessor_directive_location(
+  unique int id: @preprocessor_directive ref,
+  int loc: @location ref);
+
+preprocessor_directive_compilation(
+  int id: @preprocessor_directive ref,
+  int compilation: @compilation ref);
+
+preprocessor_directive_active(
+  unique int id: @preprocessor_directive ref,
+  int active: int ref);  /* 0: false, 1: true */
+
+/** TYPES **/
+
+types(
+  unique int id: @type,
+  int kind: int ref,
+  string name: string ref);
+
+case @type.kind of
+   1 = @bool_type
+|  2 = @char_type
+|  3 = @decimal_type
+|  4 = @sbyte_type
+|  5 = @short_type
+|  6 = @int_type
+|  7 = @long_type
+|  8 = @byte_type
+|  9 = @ushort_type
+| 10 = @uint_type
+| 11 = @ulong_type
+| 12 = @float_type
+| 13 = @double_type
+| 14 = @enum_type
+| 15 = @struct_type
+| 17 = @class_type
+| 19 = @interface_type
+| 20 = @delegate_type
+| 21 = @null_type
+| 22 = @type_parameter
+| 23 = @pointer_type
+| 24 = @nullable_type
+| 25 = @array_type
+| 26 = @void_type
+| 27 = @int_ptr_type
+| 28 = @uint_ptr_type
+| 29 = @dynamic_type
+| 30 = @arglist_type
+| 31 = @unknown_type
+| 32 = @tuple_type
+| 33 = @function_pointer_type
+| 34 = @inline_array_type
+| 35 = @extension_type
+  ;
+
+@simple_type = @bool_type | @char_type | @integral_type | @floating_point_type | @decimal_type;
+@integral_type = @signed_integral_type | @unsigned_integral_type;
+@signed_integral_type = @sbyte_type | @short_type | @int_type | @long_type;
+@unsigned_integral_type = @byte_type  | @ushort_type | @uint_type | @ulong_type;
+@floating_point_type = @float_type | @double_type;
+@value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
+            | @uint_ptr_type | @tuple_type | @void_type | @inline_array_type;
+@ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
+          | @dynamic_type | @extension_type;
+@value_or_ref_type = @value_type | @ref_type;
+
+typerefs(
+  unique int id: @typeref,
+  string name: string ref);
+
+typeref_type(
+  int id: @typeref ref,
+  unique int typeId: @type ref);
+
+@type_or_ref = @type | @typeref;
+
+array_element_type(
+  unique int array: @array_type ref,
+  int dimension: int ref,
+  int rank: int ref,
+  int element: @type_or_ref ref);
+
+nullable_underlying_type(
+  unique int nullable: @nullable_type ref,
+  int underlying: @type_or_ref ref);
+
+pointer_referent_type(
+  unique int pointer: @pointer_type ref,
+  int referent: @type_or_ref ref);
+
+enum_underlying_type(
+  unique int enum_id: @enum_type ref,
+  int underlying_type_id: @type_or_ref ref);
+
+delegate_return_type(
+  unique int delegate_id: @delegate_type ref,
+  int return_type_id: @type_or_ref ref);
+
+function_pointer_return_type(
+    unique int function_pointer_id: @function_pointer_type ref,
+    int return_type_id: @type_or_ref ref);
+
+extension_receiver_type(
+  unique int extension: @extension_type ref,
+  int receiver_type_id: @type_or_ref ref);
+
+extend(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+anonymous_types(
+  unique int id: @type ref);
+
+@interface_or_ref = @interface_type | @typeref;
+
+implement(
+  int sub: @type ref,
+  int super: @type_or_ref ref);
+
+type_location(
+  int id: @type ref,
+  int loc: @location ref);
+
+tuple_underlying_type(
+  unique int tuple: @tuple_type ref,
+  int struct: @type_or_ref ref);
+
+#keyset[tuple, index]
+tuple_element(
+  int tuple: @tuple_type ref,
+  int index: int ref,
+  unique int field: @field ref);
+
+attributes(
+  unique int id: @attribute,
+  int kind: int ref,
+  int type_id: @type_or_ref ref,
+  int target:  @attributable ref);
+
+case @attribute.kind of
+  0 = @attribute_default
+| 1 = @attribute_return
+| 2 = @attribute_assembly
+| 3 = @attribute_module
+;
+
+attribute_location(
+  int id: @attribute ref,
+  int loc: @location ref);
+
+@type_mention_parent = @element | @type_mention;
+
+type_mention(
+  unique int id: @type_mention,
+  int type_id: @type_or_ref ref,
+  int parent: @type_mention_parent ref);
+
+type_mention_location(
+  unique int id: @type_mention ref,
+  int loc: @location ref);
+
+@has_type_annotation = @assignable | @type_parameter | @callable | @expr | @delegate_type | @generic | @function_pointer_type;
+
+/**
+ * A direct annotation on an entity, for example `string? x;`.
+ *
+ * Annotations:
+ * 2 = reftype is not annotated "!"
+ * 3 = reftype is annotated "?"
+ * 4 = readonly ref type / in parameter
+ * 5 = ref type parameter, return or local variable
+ * 6 = out parameter
+ *
+ * Note that the annotation depends on the element it annotates.
+ * @assignable: The annotation is on the type of the assignable, for example the variable type.
+ * @type_parameter: The annotation is on the reftype constraint
+ * @callable: The annotation is on the return type
+ * @array_type: The annotation is on the element type
+ */
+type_annotation(int id: @has_type_annotation ref, int annotation: int ref);
+
+nullability(unique int nullability: @nullability, int kind: int ref);
+
+case @nullability.kind of
+  0 = @oblivious
+| 1 = @not_annotated
+| 2 = @annotated
+;
+
+#keyset[parent, index]
+nullability_parent(int nullability: @nullability ref, int index: int ref, int parent: @nullability ref)
+
+type_nullability(int id: @has_type_annotation ref, int nullability: @nullability ref);
+
+/**
+ * The nullable flow state of an expression, as determined by Roslyn.
+ *   0 = none (default, not populated)
+ *   1 = not null
+ *   2 = maybe null
+ */
+expr_flowstate(unique int id: @expr ref, int state: int ref);
+
+/** GENERICS **/
+
+@generic = @type | @method | @local_function;
+
+type_parameters(
+  unique int id: @type_parameter ref,
+  int index: int ref,
+  int generic_id: @generic ref,
+  int variance: int ref /* none = 0, out = 1, in = 2 */);
+
+#keyset[constructed_id, index]
+type_arguments(
+  int id: @type_or_ref ref,
+  int index: int ref,
+  int constructed_id: @generic_or_ref ref);
+
+@generic_or_ref = @generic | @typeref;
+
+constructed_generic(
+  unique int constructed: @generic ref,
+  int generic: @generic_or_ref ref);
+
+type_parameter_constraints(
+  unique int id: @type_parameter_constraints,
+  int param_id: @type_parameter ref);
+
+type_parameter_constraints_location(
+  int id: @type_parameter_constraints ref,
+  int loc: @location ref);
+
+general_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int kind: int ref /* class = 1, struct = 2, new = 3 */);
+
+specific_type_parameter_constraints(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref);
+
+specific_type_parameter_nullability(
+  int id: @type_parameter_constraints ref,
+  int base_id: @type_or_ref ref,
+  int nullability: @nullability ref);
+
+/** FUNCTION POINTERS */
+
+function_pointer_calling_conventions(
+  int id: @function_pointer_type ref,
+  int kind: int ref);
+
+#keyset[id, index]
+has_unmanaged_calling_conventions(
+  int id: @function_pointer_type ref,
+  int index: int ref,
+  int conv_id: @type_or_ref ref);
+
+/** MODIFIERS */
+
+@modifiable = @modifiable_direct | @event_accessor;
+
+@modifiable_direct = @member | @accessor | @local_function | @anonymous_function_expr;
+
+modifiers(
+  unique int id: @modifier,
+  string name: string ref);
+
+has_modifiers(
+  int id: @modifiable_direct ref,
+  int mod_id: @modifier ref);
+
+/** MEMBERS **/
+
+@member = @method | @constructor | @destructor | @field | @property | @event | @operator | @indexer | @type;
+
+@named_exprorstmt = @goto_stmt | @labeled_stmt | @expr;
+
+@virtualizable = @method | @property | @indexer | @event | @operator;
+
+exprorstmt_name(
+  unique int parent_id: @named_exprorstmt ref,
+  string name: string ref);
+
+nested_types(
+  unique int id: @type ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @type ref);
+
+properties(
+  unique int id: @property,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @property ref);
+
+property_location(
+  int id: @property ref,
+  int loc: @location ref);
+
+indexers(
+  unique int id: @indexer,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @indexer ref);
+
+indexer_location(
+  int id: @indexer ref,
+  int loc: @location ref);
+
+accessors(
+  unique int id: @accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_member_id: @member ref,
+  int unbound_id: @accessor ref);
+
+case @accessor.kind of
+  1 = @getter
+| 2 = @setter
+  ;
+
+init_only_accessors(
+  unique int id: @accessor ref);
+
+accessor_location(
+  int id: @accessor ref,
+  int loc: @location ref);
+
+events(
+  unique int id: @event,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @event ref);
+
+event_location(
+  int id: @event ref,
+  int loc: @location ref);
+
+event_accessors(
+  unique int id: @event_accessor,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_event_id: @event ref,
+  int unbound_id: @event_accessor ref);
+
+case @event_accessor.kind of
+  1 = @add_event_accessor
+| 2 = @remove_event_accessor
+  ;
+
+event_accessor_location(
+  int id: @event_accessor ref,
+  int loc: @location ref);
+
+operators(
+  unique int id: @operator,
+  string name: string ref,
+  string symbol: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @operator ref);
+
+operator_location(
+  int id: @operator ref,
+  int loc: @location ref);
+
+constant_value(
+  int id: @variable ref,
+  string value: string ref);
+
+/** CALLABLES **/
+
+@callable = @method | @constructor | @destructor | @operator | @callable_accessor | @anonymous_function_expr | @local_function;
+
+@callable_accessor = @accessor | @event_accessor;
+
+methods(
+  unique int id: @method,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @method ref);
+
+method_location(
+  int id: @method ref,
+  int loc: @location ref);
+
+constructors(
+  unique int id: @constructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @constructor ref);
+
+constructor_location(
+  int id: @constructor ref,
+  int loc: @location ref);
+
+destructors(
+  unique int id: @destructor,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int unbound_id: @destructor ref);
+
+destructor_location(
+  int id: @destructor ref,
+  int loc: @location ref);
+
+overrides(
+  int id: @callable ref,
+  int base_id: @callable ref);
+
+explicitly_implements(
+  int id: @member ref,
+  int interface_id: @interface_or_ref ref);
+
+local_functions(
+    unique int id: @local_function,
+    string name: string ref,
+    int return_type: @type ref,
+    int unbound_id: @local_function ref);
+
+local_function_stmts(
+    unique int fn: @local_function_stmt ref,
+    int stmt: @local_function ref);
+
+/** VARIABLES **/
+
+@variable = @local_scope_variable | @field;
+
+@local_scope_variable = @local_variable | @parameter;
+
+fields(
+  unique int id: @field,
+  int kind: int ref,
+  string name: string ref,
+  int declaring_type_id: @type ref,
+  int type_id: @type_or_ref ref,
+  int unbound_id: @field ref);
+
+case @field.kind of
+  1 = @addressable_field
+| 2 = @constant
+  ;
+
+field_location(
+  int id: @field ref,
+  int loc: @location ref);
+
+localvars(
+  unique int id: @local_variable,
+  int kind: int ref,
+  string name: string ref,
+  int implicitly_typed: int ref /* 0 = no, 1 = yes */,
+  int type_id: @type_or_ref ref,
+  int parent_id: @local_var_decl_expr ref);
+
+case @local_variable.kind of
+  1 = @addressable_local_variable
+| 2 = @local_constant
+| 3 = @local_variable_ref
+  ;
+
+localvar_location(
+  unique int id: @local_variable ref,
+  int loc: @location ref);
+
+@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type | @extension_type;
+
+#keyset[name, parent_id]
+#keyset[index, parent_id]
+params(
+  unique int id: @parameter,
+  string name: string ref,
+  int type_id: @type_or_ref ref,
+  int index: int ref,
+  int mode: int ref, /* value = 0, ref = 1, out = 2, params/array = 3, this = 4, in = 5, ref readonly = 6 */
+  int parent_id: @parameterizable ref,
+  int unbound_id: @parameter ref);
+
+param_location(
+  int id: @parameter ref,
+  int loc: @location ref);
+
+@has_scoped_annotation = @local_scope_variable
+
+scoped_annotation(
+  int id: @has_scoped_annotation ref,
+  int kind: int ref // scoped ref = 1, scoped value = 2
+  );
+
+/** STATEMENTS **/
+
+@exprorstmt_parent = @control_flow_element | @top_level_exprorstmt_parent;
+
+statements(
+  unique int id: @stmt,
+  int kind: int ref);
+
+#keyset[index, parent]
+stmt_parent(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_stmt_parent = @callable;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+stmt_parent_top_level(
+  unique int stmt: @stmt ref,
+  int index: int ref,
+  int parent: @top_level_stmt_parent ref);
+
+case @stmt.kind of
+   1 = @block_stmt
+|  2 = @expr_stmt
+|  3 = @if_stmt
+|  4 = @switch_stmt
+|  5 = @while_stmt
+|  6 = @do_stmt
+|  7 = @for_stmt
+|  8 = @foreach_stmt
+|  9 = @break_stmt
+| 10 = @continue_stmt
+| 11 = @goto_stmt
+| 12 = @goto_case_stmt
+| 13 = @goto_default_stmt
+| 14 = @throw_stmt
+| 15 = @return_stmt
+| 16 = @yield_stmt
+| 17 = @try_stmt
+| 18 = @checked_stmt
+| 19 = @unchecked_stmt
+| 20 = @lock_stmt
+| 21 = @using_block_stmt
+| 22 = @var_decl_stmt
+| 23 = @const_decl_stmt
+| 24 = @empty_stmt
+| 25 = @unsafe_stmt
+| 26 = @fixed_stmt
+| 27 = @label_stmt
+| 28 = @catch
+| 29 = @case_stmt
+| 30 = @local_function_stmt
+| 31 = @using_decl_stmt
+  ;
+
+@using_stmt = @using_block_stmt | @using_decl_stmt;
+
+@labeled_stmt = @label_stmt | @case;
+
+@decl_stmt = @var_decl_stmt | @const_decl_stmt | @using_decl_stmt;
+
+@cond_stmt = @if_stmt | @switch_stmt;
+
+@loop_stmt = @while_stmt | @do_stmt | @for_stmt | @foreach_stmt;
+
+@jump_stmt = @break_stmt | @goto_any_stmt | @continue_stmt | @throw_stmt | @return_stmt
+           | @yield_stmt;
+
+@goto_any_stmt = @goto_default_stmt | @goto_case_stmt | @goto_stmt;
+
+
+stmt_location(
+  unique int id: @stmt ref,
+  int loc: @location ref);
+
+catch_type(
+  unique int catch_id: @catch ref,
+  int type_id: @type_or_ref ref,
+  int kind: int ref /* explicit = 1, implicit = 2 */);
+
+foreach_stmt_info(
+  unique int id: @foreach_stmt ref,
+  int kind: int ref /* non-async = 1, async = 2 */);
+
+@foreach_symbol =  @method | @property | @type_or_ref;
+
+#keyset[id, kind]
+foreach_stmt_desugar(
+  int id: @foreach_stmt ref,
+  int symbol: @foreach_symbol ref,
+  int kind: int ref /* GetEnumeratorMethod = 1, CurrentProperty = 2, MoveNextMethod = 3, DisposeMethod = 4, ElementType = 5 */);
+
+/** EXPRESSIONS **/
+
+expressions(
+  unique int id: @expr,
+  int kind: int ref,
+  int type_id: @type_or_ref ref);
+
+#keyset[index, parent]
+expr_parent(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @control_flow_element ref);
+
+@top_level_expr_parent = @attribute | @field | @property | @indexer | @parameter | @directive_if | @directive_elif;
+
+@top_level_exprorstmt_parent = @top_level_expr_parent | @top_level_stmt_parent;
+
+// [index, parent] is not a keyset because the same parent may be compiled multiple times
+expr_parent_top_level(
+  unique int expr: @expr ref,
+  int index: int ref,
+  int parent: @top_level_exprorstmt_parent ref);
+
+case @expr.kind of
+/* literal */
+   1 = @bool_literal_expr
+|  2 = @char_literal_expr
+|  3 = @decimal_literal_expr
+|  4 = @int_literal_expr
+|  5 = @long_literal_expr
+|  6 = @uint_literal_expr
+|  7 = @ulong_literal_expr
+|  8 = @float_literal_expr
+|  9 = @double_literal_expr
+| 10 = @utf16_string_literal_expr
+| 11 = @null_literal_expr
+/* primary & unary */
+| 12 = @this_access_expr
+| 13 = @base_access_expr
+| 14 = @local_variable_access_expr
+| 15 = @parameter_access_expr
+| 16 = @field_access_expr
+| 17 = @property_access_expr
+| 18 = @method_access_expr
+| 19 = @event_access_expr
+| 20 = @indexer_access_expr
+| 21 = @array_access_expr
+| 22 = @type_access_expr
+| 23 = @typeof_expr
+| 24 = @method_invocation_expr
+| 25 = @delegate_invocation_expr
+| 26 = @operator_invocation_expr
+| 27 = @cast_expr
+| 28 = @object_creation_expr
+| 29 = @explicit_delegate_creation_expr
+| 30 = @implicit_delegate_creation_expr
+| 31 = @array_creation_expr
+| 32 = @default_expr
+| 33 = @plus_expr
+| 34 = @minus_expr
+| 35 = @bit_not_expr
+| 36 = @log_not_expr
+| 37 = @post_incr_expr
+| 38 = @post_decr_expr
+| 39 = @pre_incr_expr
+| 40 = @pre_decr_expr
+/* multiplicative */
+| 41 = @mul_expr
+| 42 = @div_expr
+| 43 = @rem_expr
+/* additive */
+| 44 = @add_expr
+| 45 = @sub_expr
+/* shift */
+| 46 = @lshift_expr
+| 47 = @rshift_expr
+/* relational */
+| 48 = @lt_expr
+| 49 = @gt_expr
+| 50 = @le_expr
+| 51 = @ge_expr
+/* equality */
+| 52 = @eq_expr
+| 53 = @ne_expr
+/* logical */
+| 54 = @bit_and_expr
+| 55 = @bit_xor_expr
+| 56 = @bit_or_expr
+| 57 = @log_and_expr
+| 58 = @log_or_expr
+/* type testing */
+| 59 = @is_expr
+| 60 = @as_expr
+/* null coalescing */
+| 61 = @null_coalescing_expr
+/* conditional */
+| 62 = @conditional_expr
+/* assignment */
+| 63 = @simple_assign_expr
+| 64 = @assign_add_expr
+| 65 = @assign_sub_expr
+| 66 = @assign_mul_expr
+| 67 = @assign_div_expr
+| 68 = @assign_rem_expr
+| 69 = @assign_and_expr
+| 70 = @assign_xor_expr
+| 71 = @assign_or_expr
+| 72 = @assign_lshift_expr
+| 73 = @assign_rshift_expr
+/* more */
+| 74 = @object_init_expr
+| 75 = @collection_init_expr
+| 76 = @array_init_expr
+| 77 = @checked_expr
+| 78 = @unchecked_expr
+| 79 = @constructor_init_expr
+| 80 = @add_event_expr
+| 81 = @remove_event_expr
+| 82 = @par_expr
+| 83 = @local_var_decl_expr
+| 84 = @lambda_expr
+| 85 = @anonymous_method_expr
+| 86 = @namespace_expr
+/* dynamic */
+| 92 = @dynamic_element_access_expr
+| 93 = @dynamic_member_access_expr
+/* unsafe */
+| 100 = @pointer_indirection_expr
+| 101 = @address_of_expr
+| 102 = @sizeof_expr
+/* async */
+| 103 = @await_expr
+/* C# 6.0 */
+| 104 = @nameof_expr
+| 105 = @interpolated_string_expr
+| 106 = @unknown_expr
+/* C# 7.0 */
+| 107 = @throw_expr
+| 108 = @tuple_expr
+| 109 = @local_function_invocation_expr
+| 110 = @ref_expr
+| 111 = @discard_expr
+/* C# 8.0 */
+| 112 = @range_expr
+| 113 = @index_expr
+| 114 = @switch_expr
+| 115 = @recursive_pattern_expr
+| 116 = @property_pattern_expr
+| 117 = @positional_pattern_expr
+| 118 = @switch_case_expr
+| 119 = @assign_coalesce_expr
+| 120 = @suppress_nullable_warning_expr
+| 121 = @namespace_access_expr
+/* C# 9.0 */
+| 122 = @lt_pattern_expr
+| 123 = @gt_pattern_expr
+| 124 = @le_pattern_expr
+| 125 = @ge_pattern_expr
+| 126 = @not_pattern_expr
+| 127 = @and_pattern_expr
+| 128 = @or_pattern_expr
+| 129 = @function_pointer_invocation_expr
+| 130 = @with_expr
+/* C# 11.0 */
+| 131 = @list_pattern_expr
+| 132 = @slice_pattern_expr
+| 133 = @urshift_expr
+| 134 = @assign_urshift_expr
+| 135 = @utf8_string_literal_expr
+/* C# 12.0 */
+| 136 = @collection_expr
+| 137 = @spread_element_expr
+| 138 = @interpolated_string_insert_expr
+/* Preprocessor */
+| 999 = @define_symbol_expr
+;
+
+@switch = @switch_stmt | @switch_expr;
+@case = @case_stmt | @switch_case_expr;
+@pattern_match = @case | @is_expr;
+@unary_pattern_expr = @not_pattern_expr;
+@relational_pattern_expr = @gt_pattern_expr | @lt_pattern_expr | @ge_pattern_expr | @le_pattern_expr;
+@binary_pattern_expr = @and_pattern_expr | @or_pattern_expr;
+
+@integer_literal_expr = @int_literal_expr | @long_literal_expr | @uint_literal_expr | @ulong_literal_expr;
+@real_literal_expr = @float_literal_expr | @double_literal_expr | @decimal_literal_expr;
+@string_literal_expr = @utf16_string_literal_expr | @utf8_string_literal_expr;
+@literal_expr = @bool_literal_expr | @char_literal_expr | @integer_literal_expr | @real_literal_expr
+              | @string_literal_expr | @null_literal_expr;
+
+@assign_expr = @simple_assign_expr | @assign_op_expr | @local_var_decl_expr;
+@assign_op_call_expr = @assign_arith_expr | @assign_bitwise_expr
+@assign_op_expr =  @assign_op_call_expr | @assign_event_expr | @assign_coalesce_expr;
+@assign_event_expr = @add_event_expr | @remove_event_expr;
+
+@add_operation = @add_expr | @assign_add_expr;
+@sub_operation = @sub_expr | @assign_sub_expr;
+@mul_operation = @mul_expr | @assign_mul_expr;
+@div_operation = @div_expr | @assign_div_expr;
+@rem_operation = @rem_expr | @assign_rem_expr;
+@and_operation = @bit_and_expr | @assign_and_expr;
+@xor_operation = @bit_xor_expr | @assign_xor_expr;
+@or_operation = @bit_or_expr | @assign_or_expr;
+@lshift_operation = @lshift_expr | @assign_lshift_expr;
+@rshift_operation = @rshift_expr | @assign_rshift_expr;
+@urshift_operation = @urshift_expr | @assign_urshift_expr;
+@null_coalescing_operation = @null_coalescing_expr | @assign_coalesce_expr;
+
+@assign_arith_expr = @assign_add_expr | @assign_sub_expr | @assign_mul_expr | @assign_div_expr
+                   | @assign_rem_expr
+@assign_bitwise_expr = @assign_and_expr | @assign_or_expr | @assign_xor_expr
+                   | @assign_lshift_expr | @assign_rshift_expr | @assign_urshift_expr;
+
+@member_access_expr = @field_access_expr | @property_access_expr | @indexer_access_expr | @event_access_expr
+                    | @method_access_expr | @type_access_expr | @dynamic_member_access_expr;
+@access_expr = @member_access_expr | @this_access_expr | @base_access_expr | @assignable_access_expr | @namespace_access_expr;
+@element_access_expr = @indexer_access_expr | @array_access_expr | @dynamic_element_access_expr;
+
+@local_variable_access = @local_variable_access_expr | @local_var_decl_expr;
+@local_scope_variable_access_expr = @parameter_access_expr | @local_variable_access;
+@variable_access_expr = @local_scope_variable_access_expr | @field_access_expr;
+
+@assignable_access_expr = @variable_access_expr | @property_access_expr | @element_access_expr
+                        | @event_access_expr | @dynamic_member_access_expr;
+
+@objectorcollection_init_expr = @object_init_expr | @collection_init_expr;
+
+@delegate_creation_expr = @explicit_delegate_creation_expr | @implicit_delegate_creation_expr;
+
+@bin_arith_expr = @mul_expr | @div_expr | @rem_expr | @add_expr | @sub_expr;
+@bin_arith_operation = @mul_operation | @div_operation | @rem_operation | @add_operation | @sub_operation;
+
+@incr_operation =  @pre_incr_expr | @post_incr_expr;
+@decr_operation =  @pre_decr_expr | @post_decr_expr;
+@mut_operation = @incr_operation | @decr_operation;
+@un_arith_operation = @plus_expr | @minus_expr | @mut_operation;
+@arith_operation = @bin_arith_operation | @un_arith_operation;
+
+@ternary_log_operation = @conditional_expr;
+@bin_log_operation = @log_and_expr | @log_or_expr | @null_coalescing_operation;
+@un_log_operation = @log_not_expr;
+@log_operation = @un_log_operation | @bin_log_operation | @ternary_log_operation;
+
+@bin_bit_expr =  @bit_and_expr | @bit_or_expr | @bit_xor_expr | @lshift_expr
+              | @rshift_expr | @urshift_expr;
+@bin_bit_operation = @and_operation | @or_operation | @xor_operation | @lshift_operation
+              | @rshift_operation | @urshift_operation;
+@un_bit_expr = @bit_not_expr;
+@un_bit_operation = @un_bit_expr;
+@bit_expr = @un_bit_expr | @bin_bit_expr;
+@bit_operation = @un_bit_operation | @bin_bit_operation;
+
+@equality_op_expr =  @eq_expr | @ne_expr;
+@rel_op_expr = @gt_expr | @lt_expr| @ge_expr | @le_expr;
+@comp_expr = @equality_op_expr | @rel_op_expr;
+
+@operation_expr = @un_operation | @bin_operation | @ternary_operation;
+
+@ternary_operation = @ternary_log_operation;
+@bin_operation = @assign_expr | @bin_arith_operation | @bin_log_operation | @bin_bit_operation | @comp_expr;
+@un_operation = @un_arith_operation | @un_log_operation | @un_bit_operation | @sizeof_expr
+              | @pointer_indirection_expr | @address_of_expr;
+
+@anonymous_function_expr = @lambda_expr | @anonymous_method_expr;
+
+@op_invoke_expr = @operator_invocation_expr | @assign_op_call_expr
+@call = @method_invocation_expr | @constructor_init_expr | @op_invoke_expr
+      | @delegate_invocation_expr | @object_creation_expr | @call_access_expr
+      | @local_function_invocation_expr | @function_pointer_invocation_expr;
+
+@call_access_expr = @property_access_expr | @event_access_expr | @indexer_access_expr;
+
+@late_bindable_expr = @dynamic_element_access_expr | @dynamic_member_access_expr
+                    | @object_creation_expr | @method_invocation_expr | @op_invoke_expr;
+
+@throw_element = @throw_expr | @throw_stmt;
+
+@implicitly_typeable_object_creation_expr = @object_creation_expr | @explicit_delegate_creation_expr;
+
+implicitly_typed_array_creation(
+  unique int id: @array_creation_expr ref);
+
+explicitly_sized_array_creation(
+  unique int id: @array_creation_expr ref);
+
+stackalloc_array_creation(
+  unique int id: @array_creation_expr ref);
+
+implicitly_typed_object_creation(
+  unique int id: @implicitly_typeable_object_creation_expr ref);
+
+mutator_invocation_mode(
+  unique int id: @operator_invocation_expr ref,
+  int mode: int ref /* prefix = 1, postfix = 2*/);
+
+expr_value(
+  unique int id: @expr ref,
+  string value: string ref);
+
+expr_call(
+  unique int caller_id: @expr ref,
+  int target_id: @callable ref);
+
+expr_access(
+  unique int accesser_id: @access_expr ref,
+  int target_id: @accessible ref);
+
+@accessible = @method | @assignable | @local_function | @namespace;
+
+expr_location(
+  unique int id: @expr ref,
+  int loc: @location ref);
+
+dynamic_member_name(
+  unique int id: @late_bindable_expr ref,
+  string name: string ref);
+
+@qualifiable_expr = @member_access_expr
+                  | @method_invocation_expr
+                  | @element_access_expr
+                  | @assign_op_call_expr;
+
+conditional_access(
+  unique int id: @qualifiable_expr ref);
+
+expr_argument(
+  unique int id: @expr ref,
+  int mode: int ref);
+  /* mode is the same as params: value = 0, ref = 1, out = 2 */
+
+expr_argument_name(
+  unique int id: @expr ref,
+  string name: string ref);
+
+lambda_expr_return_type(
+  unique int id: @lambda_expr ref,
+  int type_id: @type_or_ref ref);
+
+/* Compiler generated */
+
+compiler_generated(unique int id: @element ref);
+
+/** CONTROL/DATA FLOW **/
+
+@control_flow_element = @stmt | @expr | @parameter;
+
+/* XML Files */
+
+xmlEncoding  (
+  unique int id: @file ref,
+  string encoding: string ref);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+/* Comments */
+
+commentline(
+  unique int id: @commentline,
+  int kind: int ref,
+  string text: string ref,
+  string rawtext: string ref);
+
+case @commentline.kind of
+  0 = @singlelinecomment
+| 1 = @xmldoccomment
+| 2 = @multilinecomment;
+
+commentline_location(
+  unique int id: @commentline ref,
+  int loc: @location ref);
+
+commentblock(
+  unique int id : @commentblock);
+
+commentblock_location(
+  unique int id: @commentblock ref,
+  int loc: @location ref);
+
+commentblock_binding(
+  int id: @commentblock ref,
+  int entity: @element ref,
+  int bindtype: int ref);    /* 0: Parent, 1: Best, 2: Before, 3: After */
+
+commentblock_child(
+  int id: @commentblock ref,
+  int commentline: @commentline ref,
+  int index: int ref);
+
+/* ASP.NET */
+
+case @asp_element.kind of
+  0=@asp_close_tag
+| 1=@asp_code
+| 2=@asp_comment
+| 3=@asp_data_binding
+| 4=@asp_directive
+| 5=@asp_open_tag
+| 6=@asp_quoted_string
+| 7=@asp_text
+| 8=@asp_xml_directive;
+
+@asp_attribute = @asp_code | @asp_data_binding | @asp_quoted_string;
+
+asp_elements(
+  unique int id: @asp_element,
+  int kind: int ref,
+  int loc: @location ref);
+
+asp_comment_server(unique int comment: @asp_comment ref);
+asp_code_inline(unique int code: @asp_code ref);
+asp_directive_attribute(
+  int directive: @asp_directive ref,
+  int index: int ref,
+  string name: string ref,
+  int value: @asp_quoted_string ref);
+asp_directive_name(
+  unique int directive: @asp_directive ref,
+  string name: string ref);
+asp_element_body(
+  unique int element: @asp_element ref,
+  string body: string ref);
+asp_tag_attribute(
+  int tag: @asp_open_tag ref,
+  int index: int ref,
+  string name: string ref,
+  int attribute: @asp_attribute ref);
+asp_tag_name(
+  unique int tag: @asp_open_tag ref,
+  string name: string ref);
+asp_tag_isempty(int tag: @asp_open_tag ref);
diff --git a/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/upgrade.properties b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/upgrade.properties
new file mode 100644
index 00000000000..85b8a1e6c23
--- /dev/null
+++ b/csharp/ql/lib/upgrades/3cabc77473cbbda95edebafea345c2e3fdfa12d9/upgrade.properties
@@ -0,0 +1,2 @@
+description: Restructure and rename types related to operations.
+compatibility: full
diff --git a/csharp/ql/test/library-tests/csharp11/operators.expected b/csharp/ql/test/library-tests/csharp11/operators.expected
index 177019a3ea0..dfd131dbfa9 100644
--- a/csharp/ql/test/library-tests/csharp11/operators.expected
+++ b/csharp/ql/test/library-tests/csharp11/operators.expected
@@ -1,6 +1,7 @@
 binarybitwise
 | Operators.cs:7:18:7:25 | ... >>> ... | Operators.cs:7:18:7:19 | access to local variable x1 | Operators.cs:7:25:7:25 | 2 | >>> | UnsignedRightShiftExpr |
 | Operators.cs:10:18:10:25 | ... >>> ... | Operators.cs:10:18:10:19 | access to local variable y1 | Operators.cs:10:25:10:25 | 3 | >>> | UnsignedRightShiftExpr |
+| Operators.cs:13:9:13:16 | ... >>>= ... | Operators.cs:13:9:13:9 | access to local variable z | Operators.cs:13:16:13:16 | 5 | >>>= | AssignUnsignedRightShiftExpr |
 assignbitwise
 | Operators.cs:13:9:13:16 | ... >>>= ... | Operators.cs:13:9:13:9 | access to local variable z | Operators.cs:13:16:13:16 | 5 | >>>= | AssignUnsignedRightShiftExpr |
 userdefined
diff --git a/csharp/ql/test/library-tests/csharp11/operators.ql b/csharp/ql/test/library-tests/csharp11/operators.ql
index f1543e2d744..da14d2b6cb7 100644
--- a/csharp/ql/test/library-tests/csharp11/operators.ql
+++ b/csharp/ql/test/library-tests/csharp11/operators.ql
@@ -11,7 +11,7 @@ query predicate binarybitwise(
 }
 
 query predicate assignbitwise(
-  AssignBitwiseOperation op, Expr left, Expr right, string name, string qlclass
+  AssignBitwiseExpr op, Expr left, Expr right, string name, string qlclass
 ) {
   op.getFile().getStem() = "Operators" and
   left = op.getLeftOperand() and
diff --git a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs
index 1fa43ba456e..bf731715abf 100644
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs
@@ -442,4 +442,31 @@ namespace My.Qltest
 
         static void Sink(object o) { }
     }
+
+    // Test operator overloads
+    public class N
+    {
+        public void operator +=(N y) => throw null;
+
+        public void operator checked +=(N y) => throw null;
+
+        public void M1(N n)
+        {
+            var n0 = new N();
+            n += n0;
+            Sink(n);
+        }
+
+        public void M2(N n)
+        {
+            var n0 = new N();
+            checked
+            {
+                n += n0;
+            }
+            Sink(n);
+        }
+
+        static void Sink(object o) { }
+    }
 }
diff --git a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected
index b0256d6c41d..62bf675dc60 100644
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected
@@ -32,14 +32,16 @@ models
 | 31 | Summary: My.Qltest; Library; false; GetValue; (); ; Argument[this].SyntheticField[X]; ReturnValue; value; dfc-generated |
 | 32 | Summary: My.Qltest; Library; false; MixedFlowArgs; (System.Object,System.Object); ; Argument[1]; ReturnValue; value; manual |
 | 33 | Summary: My.Qltest; Library; false; SetValue; (System.Object); ; Argument[0]; Argument[this].SyntheticField[X]; value; dfc-generated |
-| 34 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; Method1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
-| 35 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; StaticMethod1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
-| 36 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; get_Property1; (System.Object); ; Argument[0].SyntheticField[TestExtensions.Property1]; ReturnValue; value; manual |
-| 37 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; set_Property1; (System.Object,System.Object); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.Property1]; value; manual |
-| 38 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
-| 39 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericStaticMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
-| 40 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; get_GenericProperty1; (T); ; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; ReturnValue; value; manual |
-| 41 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; set_GenericProperty1; (T,T); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; value; manual |
+| 34 | Summary: My.Qltest; N; false; op_AdditionAssignment; (My.Qltest.N); ; Argument[0]; Argument[this]; taint; manual |
+| 35 | Summary: My.Qltest; N; false; op_CheckedAdditionAssignment; (My.Qltest.N); ; Argument[0]; Argument[this]; taint; manual |
+| 36 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; Method1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
+| 37 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; StaticMethod1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
+| 38 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; get_Property1; (System.Object); ; Argument[0].SyntheticField[TestExtensions.Property1]; ReturnValue; value; manual |
+| 39 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; set_Property1; (System.Object,System.Object); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.Property1]; value; manual |
+| 40 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
+| 41 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericStaticMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
+| 42 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; get_GenericProperty1; (T); ; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; ReturnValue; value; manual |
+| 43 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; set_GenericProperty1; (T,T); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; value; manual |
 edges
 | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | ExternalFlow.cs:10:29:10:32 | access to local variable arg1 : Object | provenance |  |
 | ExternalFlow.cs:9:27:9:38 | object creation of type Object : Object | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | provenance |  |
@@ -162,69 +164,77 @@ edges
 | ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:374:17:374:18 | access to local variable o1 : Object | ExternalFlow.cs:375:18:375:19 | access to local variable o1 | provenance |  |
-| ExternalFlow.cs:374:22:374:24 | access to local variable obj : Object | ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | provenance | MaD:34 |
+| ExternalFlow.cs:374:22:374:24 | access to local variable obj : Object | ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | provenance | MaD:36 |
 | ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | ExternalFlow.cs:374:17:374:18 | access to local variable o1 : Object | provenance |  |
 | ExternalFlow.cs:377:17:377:18 | access to local variable o2 : Object | ExternalFlow.cs:378:18:378:19 | access to local variable o2 | provenance |  |
 | ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | ExternalFlow.cs:377:17:377:18 | access to local variable o2 : Object | provenance |  |
-| ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | provenance | MaD:34 |
+| ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | provenance | MaD:36 |
 | ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:384:17:384:18 | access to local variable o1 : Object | ExternalFlow.cs:385:18:385:19 | access to local variable o1 | provenance |  |
 | ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | ExternalFlow.cs:384:17:384:18 | access to local variable o1 : Object | provenance |  |
-| ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | provenance | MaD:35 |
+| ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | provenance | MaD:37 |
 | ExternalFlow.cs:387:17:387:18 | access to local variable o2 : Object | ExternalFlow.cs:388:18:388:19 | access to local variable o2 | provenance |  |
 | ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | ExternalFlow.cs:387:17:387:18 | access to local variable o2 : Object | provenance |  |
-| ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | provenance | MaD:35 |
+| ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | provenance | MaD:37 |
 | ExternalFlow.cs:393:17:393:19 | access to local variable obj : Object | ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:393:23:393:34 | object creation of type Object : Object | ExternalFlow.cs:393:17:393:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance |  |
-| ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:37 |
+| ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:39 |
 | ExternalFlow.cs:395:17:395:18 | access to local variable o1 : Object | ExternalFlow.cs:396:18:396:19 | access to local variable o1 | provenance |  |
-| ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | provenance | MaD:36 |
+| ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | provenance | MaD:38 |
 | ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | ExternalFlow.cs:395:17:395:18 | access to local variable o1 : Object | provenance |  |
 | ExternalFlow.cs:401:17:401:19 | access to local variable obj : Object | ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:401:23:401:34 | object creation of type Object : Object | ExternalFlow.cs:401:17:401:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance |  |
-| ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:37 |
+| ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:39 |
 | ExternalFlow.cs:403:17:403:18 | access to local variable o1 : Object | ExternalFlow.cs:404:18:404:19 | access to local variable o1 | provenance |  |
 | ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | ExternalFlow.cs:403:17:403:18 | access to local variable o1 : Object | provenance |  |
-| ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | provenance | MaD:36 |
+| ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | provenance | MaD:38 |
 | ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:410:17:410:18 | access to local variable o1 : Object | ExternalFlow.cs:411:18:411:19 | access to local variable o1 | provenance |  |
-| ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | provenance | MaD:38 |
+| ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | provenance | MaD:40 |
 | ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | ExternalFlow.cs:410:17:410:18 | access to local variable o1 : Object | provenance |  |
 | ExternalFlow.cs:413:17:413:18 | access to local variable o2 : Object | ExternalFlow.cs:414:18:414:19 | access to local variable o2 | provenance |  |
 | ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | ExternalFlow.cs:413:17:413:18 | access to local variable o2 : Object | provenance |  |
-| ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | provenance | MaD:38 |
+| ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | provenance | MaD:40 |
 | ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:420:17:420:18 | access to local variable o1 : Object | ExternalFlow.cs:421:18:421:19 | access to local variable o1 | provenance |  |
 | ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | ExternalFlow.cs:420:17:420:18 | access to local variable o1 : Object | provenance |  |
-| ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | provenance | MaD:39 |
+| ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | provenance | MaD:41 |
 | ExternalFlow.cs:423:17:423:18 | access to local variable o2 : Object | ExternalFlow.cs:424:18:424:19 | access to local variable o2 | provenance |  |
 | ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | ExternalFlow.cs:423:17:423:18 | access to local variable o2 : Object | provenance |  |
-| ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | provenance | MaD:39 |
+| ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | provenance | MaD:41 |
 | ExternalFlow.cs:429:17:429:19 | access to local variable obj : Object | ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | ExternalFlow.cs:429:17:429:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [property GenericProperty1] : Object | ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [property GenericProperty1] : Object | provenance |  |
 | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance |  |
 | ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [property GenericProperty1] : Object | provenance |  |
-| ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:41 |
+| ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:43 |
 | ExternalFlow.cs:431:17:431:18 | access to local variable o1 : Object | ExternalFlow.cs:432:18:432:19 | access to local variable o1 | provenance |  |
 | ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [property GenericProperty1] : Object | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | provenance |  |
-| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | provenance | MaD:40 |
+| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | provenance | MaD:42 |
 | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | ExternalFlow.cs:431:17:431:18 | access to local variable o1 : Object | provenance |  |
 | ExternalFlow.cs:437:17:437:19 | access to local variable obj : Object | ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | ExternalFlow.cs:437:17:437:19 | access to local variable obj : Object | provenance |  |
 | ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance |  |
-| ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:41 |
+| ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:43 |
 | ExternalFlow.cs:439:17:439:18 | access to local variable o1 : Object | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | provenance |  |
 | ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | ExternalFlow.cs:439:17:439:18 | access to local variable o1 : Object | provenance |  |
-| ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | provenance | MaD:40 |
+| ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | provenance | MaD:42 |
+| ExternalFlow.cs:455:17:455:18 | access to local variable n0 : N | ExternalFlow.cs:456:18:456:19 | access to local variable n0 : N | provenance |  |
+| ExternalFlow.cs:455:22:455:28 | object creation of type N : N | ExternalFlow.cs:455:17:455:18 | access to local variable n0 : N | provenance |  |
+| ExternalFlow.cs:456:13:456:13 | [post] access to parameter n : N | ExternalFlow.cs:457:18:457:18 | access to parameter n | provenance |  |
+| ExternalFlow.cs:456:18:456:19 | access to local variable n0 : N | ExternalFlow.cs:456:13:456:13 | [post] access to parameter n : N | provenance | MaD:34 |
+| ExternalFlow.cs:462:17:462:18 | access to local variable n0 : N | ExternalFlow.cs:465:22:465:23 | access to local variable n0 : N | provenance |  |
+| ExternalFlow.cs:462:22:462:28 | object creation of type N : N | ExternalFlow.cs:462:17:462:18 | access to local variable n0 : N | provenance |  |
+| ExternalFlow.cs:465:17:465:17 | [post] access to parameter n : N | ExternalFlow.cs:467:18:467:18 | access to parameter n | provenance |  |
+| ExternalFlow.cs:465:22:465:23 | access to local variable n0 : N | ExternalFlow.cs:465:17:465:17 | [post] access to parameter n : N | provenance | MaD:35 |
 nodes
 | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | semmle.label | access to local variable arg1 : Object |
 | ExternalFlow.cs:9:27:9:38 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
@@ -443,6 +453,16 @@ nodes
 | ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | semmle.label | call to extension accessor get_GenericProperty1 : Object |
 | ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | semmle.label | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object |
 | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:455:17:455:18 | access to local variable n0 : N | semmle.label | access to local variable n0 : N |
+| ExternalFlow.cs:455:22:455:28 | object creation of type N : N | semmle.label | object creation of type N : N |
+| ExternalFlow.cs:456:13:456:13 | [post] access to parameter n : N | semmle.label | [post] access to parameter n : N |
+| ExternalFlow.cs:456:18:456:19 | access to local variable n0 : N | semmle.label | access to local variable n0 : N |
+| ExternalFlow.cs:457:18:457:18 | access to parameter n | semmle.label | access to parameter n |
+| ExternalFlow.cs:462:17:462:18 | access to local variable n0 : N | semmle.label | access to local variable n0 : N |
+| ExternalFlow.cs:462:22:462:28 | object creation of type N : N | semmle.label | object creation of type N : N |
+| ExternalFlow.cs:465:17:465:17 | [post] access to parameter n : N | semmle.label | [post] access to parameter n : N |
+| ExternalFlow.cs:465:22:465:23 | access to local variable n0 : N | semmle.label | access to local variable n0 : N |
+| ExternalFlow.cs:467:18:467:18 | access to parameter n | semmle.label | access to parameter n |
 subpaths
 | ExternalFlow.cs:84:29:84:32 | access to local variable objs : null [element] : Object | ExternalFlow.cs:84:35:84:35 | o : Object | ExternalFlow.cs:84:40:84:40 | access to parameter o : Object | ExternalFlow.cs:84:25:84:41 | call to method Map<Object,Object> : T[] [element] : Object |
 invalidModelRow
@@ -489,3 +509,5 @@ invalidModelRow
 | ExternalFlow.cs:424:18:424:19 | access to local variable o2 | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | ExternalFlow.cs:424:18:424:19 | access to local variable o2 | $@ | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | object creation of type Object : Object |
 | ExternalFlow.cs:432:18:432:19 | access to local variable o1 | ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | ExternalFlow.cs:432:18:432:19 | access to local variable o1 | $@ | ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | object creation of type Object : Object |
 | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | $@ | ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:457:18:457:18 | access to parameter n | ExternalFlow.cs:455:22:455:28 | object creation of type N : N | ExternalFlow.cs:457:18:457:18 | access to parameter n | $@ | ExternalFlow.cs:455:22:455:28 | object creation of type N : N | object creation of type N : N |
+| ExternalFlow.cs:467:18:467:18 | access to parameter n | ExternalFlow.cs:462:22:462:28 | object creation of type N : N | ExternalFlow.cs:467:18:467:18 | access to parameter n | $@ | ExternalFlow.cs:462:22:462:28 | object creation of type N : N | object creation of type N : N |
diff --git a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml
index 21e66b84066..9fe50b16354 100644
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml
@@ -53,6 +53,8 @@ extensions:
       - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "GenericStaticMethod1", "(T)", "", "Argument[0]", "ReturnValue", "value", "manual"]
       - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "get_GenericProperty1", "(T)", "", "Argument[0].SyntheticField[TestExtensions.GenericProperty1]", "ReturnValue", "value", "manual"]
       - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "set_GenericProperty1", "(T,T)", "", "Argument[1]", "Argument[0].SyntheticField[TestExtensions.GenericProperty1]", "value", "manual"]
+      - ["My.Qltest", "N", false, "op_AdditionAssignment", "(My.Qltest.N)", "", "Argument[0]", "Argument[this]", "taint", "manual"]
+      - ["My.Qltest", "N", false, "op_CheckedAdditionAssignment", "(My.Qltest.N)", "", "Argument[0]", "Argument[this]", "taint", "manual"]
 
   - addsTo:
       pack: codeql/csharp-all
diff --git a/java/ql/lib/semmle/code/java/ControlFlowGraph.qll b/java/ql/lib/semmle/code/java/ControlFlowGraph.qll
index d2d13a79d35..51f3046e1bf 100644
--- a/java/ql/lib/semmle/code/java/ControlFlowGraph.qll
+++ b/java/ql/lib/semmle/code/java/ControlFlowGraph.qll
@@ -84,6 +84,10 @@ private module Ast implements AstSig<Location> {
 
   class DoStmt = J::DoStmt;
 
+  class UntilStmt extends LoopStmt {
+    UntilStmt() { none() }
+  }
+
   final private class FinalForStmt = J::ForStmt;
 
   class ForStmt extends FinalForStmt {
diff --git a/java/ql/test/query-tests/Nullness/B.java b/java/ql/test/query-tests/Nullness/B.java
index 14ff2b35935..bc8b0bac154 100644
--- a/java/ql/test/query-tests/Nullness/B.java
+++ b/java/ql/test/query-tests/Nullness/B.java
@@ -331,7 +331,7 @@ public class B {
       x = new Object();
     }
     if(y instanceof String) {
-      x.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+      x.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     }
   }
 
@@ -341,7 +341,7 @@ public class B {
       x = new Object();
     }
     if(!(y instanceof String)) {
-      x.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+      x.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     }
   }
 
@@ -351,7 +351,7 @@ public class B {
       x = new Object();
     }
     if(y == z) {
-      x.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+      x.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     }
 
     Object x2 = null;
@@ -359,7 +359,7 @@ public class B {
       x2 = new Object();
     }
     if(y != z) {
-      x2.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+      x2.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     }
 
     Object x3 = null;
@@ -367,7 +367,7 @@ public class B {
       x3 = new Object();
     }
     if(!(y == z)) {
-      x3.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+      x3.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     }
   }
 
@@ -462,7 +462,7 @@ public class B {
       cur = a[i];
       if (!prev) {
         // correctly guarded by !cur from the _previous_ iteration
-        x.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+        x.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
       } else {
         x = new Object();
       }
@@ -484,7 +484,7 @@ public class B {
           t = new Object();
         }
         // correctly guarded by t: null -> String -> Object
-        x.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+        x.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
       }
     }
   }
@@ -573,7 +573,7 @@ public class B {
       } finally {
       }
     }
-    s.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
+    s.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // Spurious NPE - false positive
     // CFG reachability does not distinguish abrupt successors
   }
 }
diff --git a/java/ql/test/query-tests/Nullness/C.java b/java/ql/test/query-tests/Nullness/C.java
index 0ecc0c23f88..bbe2eb597b2 100644
--- a/java/ql/test/query-tests/Nullness/C.java
+++ b/java/ql/test/query-tests/Nullness/C.java
@@ -6,8 +6,8 @@ public class C {
     long[][] a2 = null;
     boolean haveA2 = ix < len && (a2 = a1[ix]) != null;
     long[] a3 = null;
-    final boolean haveA3 = haveA2 && (a3 = a2[ix]) != null; // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
-    if (haveA3) a3[0] = 0; // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+    final boolean haveA3 = haveA2 && (a3 = a2[ix]) != null; // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+    if (haveA3) a3[0] = 0; // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
   }
 
   public void ex2(boolean x, boolean y) {
@@ -18,7 +18,7 @@ public class C {
       s2 = (s1 == null) ? null : "";
     }
     if (s2 != null)
-      s1.hashCode(); // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+      s1.hashCode(); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
   }
 
   public void ex3(List<String> ss) {
@@ -48,7 +48,7 @@ public class C {
         slice = new ArrayList<>();
         result.add(slice);
       }
-      slice.add(str); // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+      slice.add(str); // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
       ++index;
       iter.remove();
     }
@@ -141,7 +141,7 @@ public class C {
   public void ex10(int[] a) {
     int n = a == null ? 0 : a.length;
     for (int i = 0; i < n; i++) {
-      int x = a[i]; // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+      int x = a[i]; // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
       if (x > 7)
         a = new int[n];
     }
@@ -216,7 +216,7 @@ public class C {
     if (o1 == o2) {
       return;
     }
-    if (o1.equals(o2)) { // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+    if (o1.equals(o2)) { // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
       return;
     }
   }
@@ -230,7 +230,7 @@ public class C {
   public static void ex16(C c) {
     int[] xs = c.getFoo16() != null ? new int[5] : null;
     if (c.getFoo16() != null) {
-      xs[0]++; // $ Alert[java/dereferenced-value-may-be-null] // NPE - false positive
+      xs[0]++; // $ SPURIOUS: Alert[java/dereferenced-value-may-be-null] // NPE - false positive
     }
   }
 
diff --git a/java/ql/test/query-tests/UseBraces/UseBraces.java b/java/ql/test/query-tests/UseBraces/UseBraces.java
index 0177d68571e..1e5487f1f7b 100644
--- a/java/ql/test/query-tests/UseBraces/UseBraces.java
+++ b/java/ql/test/query-tests/UseBraces/UseBraces.java
@@ -11,25 +11,25 @@ class UseBraces
 	{
 		int x = 0, y;
 		int[] branches = new int[10];
-		
+
 		// If-then statement
-		
+
 		if(1==1)
 		{
 			f();
 		}
 			g();	// No alert
-			
-		if(1==1)	
+
+		if(1==1)
 			f();
 		g();		// No alert
-		
+
 		if(1==1)
 			f(); // $ Alert
-			g();	// Alert
-			
+			g();
+
 		if(1==1)
-			f();	g();	// $ Alert // Alert
+			f();	g();	// $ Alert
 
 		// If-then-else statement
 
@@ -41,29 +41,29 @@ class UseBraces
 		{
 			g();
 		}
-		
+
 			g();	// No alert
-			
+
 		if(1==2)
 			f();
 		else
 			g();
 		f();		// No alert
-			
+
 		if(true)
 		{
 			f();
 		}
 		else
 			f(); // $ Alert
-			g();	// Alert
-			
+			g();
+
 		if(true)
 		{
 			f();
 		}
 		else
-			f();  g();	// $ Alert // Alert
+			f();  g();	// $ Alert
 
 		// While statement
 
@@ -80,44 +80,44 @@ class UseBraces
 
 		while(bb   )
 			f(); // $ Alert
-			g();		// Alert
+			g();
 			g();		// No alert
 
 		while(bb   )
-			f();	g();		// $ Alert // Alert
+			f();	g();		// $ Alert
 
 
 		while(bb)
 			if (x != 0) x = 1;
 
 		// Do-while statement
-		
+
 		do
 			f();
 		while(false);
 			g();	// No alert
-		
+
 		// For statement
 		for(int i=0; i<10; ++i)
 		{
 			f();
 		}
 			g();
-			
+
 		for(int i=0; i<10; ++i)
 			f();
 		g();
-		
+
 		for(int i=0; i<10; ++i)
 			f(); // $ Alert
-			g();				// Alert
+			g();
 
 		for(int i=0; i<10; ++i)
-			f(); g();			// $ Alert // Alert
+			f(); g();			// $ Alert
+
 
-		
 		// Foreach statement
-		
+
 		for( int b : branches)
 			x += b;
 		f();
@@ -130,42 +130,42 @@ class UseBraces
 
 		for( int b : branches)
 			f(); // $ Alert
-			g();			// Alert
+			g();
 
 		for( int b : branches)
-			f(); g();		// $ Alert // Alert
+			f(); g();		// $ Alert
 
 		// Nested ifs
 		if( true )
 		if(false)
 			f();
 		g();	// No alert
-		
+
 		if( true )
 			if(false) // $ Alert
 				f();
-			g();	// Alert
-		
+			g();
+
 		if( true )
 			;
-		else 
+		else
 		if (false)
 			f();
 		g();	// No alert
 
 		if( true )
 			;
-		else 
+		else
 			if (false)
 				f();
-			g();	// false negative
+			g();  // $ MISSING: Alert // false negative
 
 		if( true )
 			;
 		else if (false)
 			f();  // $ Alert
-			g();	// Alert
-		
+			g();
+
 		// Nested combinations
 		if (true)
 		while (x<10)
@@ -175,7 +175,7 @@ class UseBraces
 		if (true)
 			while (x<10) // $ Alert
 				f();
-			g();	// Alert
+			g();
 
 		while (x<10)
 		if (true)
@@ -185,7 +185,7 @@ class UseBraces
 		while (x<10)
 			if (true) // $ Alert
 				f();
-			g();	// Alert
+			g();
 
 		if (true)
 			f();
diff --git a/java/ql/test/query-tests/security/CWE-113/semmle/tests/ResponseSplitting.java b/java/ql/test/query-tests/security/CWE-113/semmle/tests/ResponseSplitting.java
index abe71180838..7162c1c3a4d 100644
--- a/java/ql/test/query-tests/security/CWE-113/semmle/tests/ResponseSplitting.java
+++ b/java/ql/test/query-tests/security/CWE-113/semmle/tests/ResponseSplitting.java
@@ -62,10 +62,10 @@ public class ResponseSplitting extends HttpServlet {
 		response.setHeader("h", t.replace('\n', ' ').replace('\r', ' '));
 
 		// FALSE NEGATIVE: replace only some line breaks
-		response.setHeader("h", t.replace('\n', ' '));
+		response.setHeader("h", t.replace('\n', ' ')); // $ MISSING: Alert
 
 		// FALSE NEGATIVE: replace only some line breaks
-		response.setHeader("h", t.replaceAll("\r", ""));
+		response.setHeader("h", t.replaceAll("\r", "")); // $ MISSING: Alert
 
 		// GOOD: replace all linebreaks with a simple regex
 		response.setHeader("h", t.replaceAll("\n", "").replaceAll("\r", ""));
diff --git a/java/ql/test/query-tests/security/CWE-190/semmle/tests/ArithmeticTainted.java b/java/ql/test/query-tests/security/CWE-190/semmle/tests/ArithmeticTainted.java
index 0167af87497..4c47046d3de 100644
--- a/java/ql/test/query-tests/security/CWE-190/semmle/tests/ArithmeticTainted.java
+++ b/java/ql/test/query-tests/security/CWE-190/semmle/tests/ArithmeticTainted.java
@@ -78,7 +78,7 @@ public class ArithmeticTainted {
 				// FALSE NEGATIVE: stillTainted could still be very large, even
 				// after
 				// it has had arithmetic done on it
-				int output = stillTainted + 100;
+				int output = stillTainted + 100; // $ MISSING: Alert[java/tainted-arithmetic]
 			}
 		}
 
@@ -107,7 +107,7 @@ public class ArithmeticTainted {
 			}
 			int output = data + 1;
 		}
-		
+
 		{
 			double x= Double.MAX_VALUE;
 			// OK: CWE-190 only pertains to integer arithmetic
diff --git a/java/ql/test/query-tests/security/CWE-190/semmle/tests/Test.java b/java/ql/test/query-tests/security/CWE-190/semmle/tests/Test.java
index ed1cf0bbe1f..d274f538754 100644
--- a/java/ql/test/query-tests/security/CWE-190/semmle/tests/Test.java
+++ b/java/ql/test/query-tests/security/CWE-190/semmle/tests/Test.java
@@ -84,7 +84,7 @@ class Test {
 			// FALSE POSITIVE: the query check purely based on the type, it
 			// can't try to
 			// determine whether the value may in fact always be in bounds
-			i += j; // $ Alert[java/implicit-cast-in-compound-assignment]
+			i += j; // $ SPURIOUS: Alert[java/implicit-cast-in-compound-assignment]
 		}
 
 		// ArithmeticWithExtremeValues
@@ -224,7 +224,7 @@ class Test {
 				// FALSE NEGATIVE: stillLarge could still be very large, even
 				// after
 				// it has had arithmetic done on it
-				int output = stillLarge + 100;
+				int output = stillLarge + 100; // $ MISSING: Alert[java/uncontrolled-arithmetic]
 			}
 		}
 
@@ -263,7 +263,7 @@ class Test {
 				// FALSE NEGATIVE: stillLarge could still be very large, even
 				// after
 				// it has had arithmetic done on it
-				int output = stillLarge + 100;
+				int output = stillLarge + 100; // $ MISSING: Alert[java/uncontrolled-arithmetic]
 			}
 		}
 
diff --git a/java/ql/test/query-tests/security/CWE-311/CWE-319/HttpsUrlsTest.java b/java/ql/test/query-tests/security/CWE-311/CWE-319/HttpsUrlsTest.java
index 362361a7171..4db4abe8c50 100644
--- a/java/ql/test/query-tests/security/CWE-311/CWE-319/HttpsUrlsTest.java
+++ b/java/ql/test/query-tests/security/CWE-311/CWE-319/HttpsUrlsTest.java
@@ -17,7 +17,7 @@ interface Hello extends java.rmi.Remote {
 
 class HelloImpl implements Hello {
 	public static void main(String[] args) {
-		try {	
+		try {
 			// HttpsUrls
 			{
 				String protocol = "http://"; // $ Source[java/non-https-url]
@@ -31,7 +31,7 @@ class HelloImpl implements Hello {
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
 				String protocol = "http"; // $ Source[java/non-https-url]
 				URL u = new URL(protocol, "www.secret.example.org", "foo");
@@ -44,7 +44,7 @@ class HelloImpl implements Hello {
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
 				String protocol = "http://"; // $ Source[java/non-https-url]
 				// the second URL overwrites the first, as it has a protocol
@@ -58,7 +58,7 @@ class HelloImpl implements Hello {
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
 				String protocol = "https://";
 				URL u = new URL(protocol + "www.secret.example.org/");
@@ -70,7 +70,7 @@ class HelloImpl implements Hello {
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
 				String protocol = "https";
 				URL u = new URL(protocol, "www.secret.example.org", "foo");
@@ -82,27 +82,27 @@ class HelloImpl implements Hello {
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
-				String protocol = "http"; // $ Source[java/non-https-url]
+				String protocol = "http"; // $ SPURIOUS: Source[java/non-https-url]
 				URL u = new URL(protocol, "internal-url", "foo");
 				// FALSE POSITIVE: the query has no way of knowing whether the url will
 				// resolve to somewhere outside the internal network, where there
 				// are unlikely to be interception attempts
-				HttpsURLConnection hu = (HttpsURLConnection) u.openConnection(); // $ Alert[java/non-https-url]
+				HttpsURLConnection hu = (HttpsURLConnection) u.openConnection(); // $ SPURIOUS: Alert[java/non-https-url]
 				hu.setRequestMethod("PUT");
 				hu.connect();
 				OutputStream os = hu.getOutputStream();
 				hu.disconnect();
 			}
-			
+
 			{
 				String input = "URL is: http://www.secret-example.org";
 				String url = input.substring(8);
 				URL u = new URL(url);
 				// FALSE NEGATIVE: we cannot tell that the substring results in a url
 				// string
-				HttpsURLConnection hu = (HttpsURLConnection) u.openConnection();
+				HttpsURLConnection hu = (HttpsURLConnection) u.openConnection(); // $ MISSING: Alert[java/non-https-url]
 				hu.setRequestMethod("PUT");
 				hu.connect();
 				OutputStream os = hu.getOutputStream();
diff --git a/shared/controlflow/codeql/controlflow/ControlFlowGraph.qll b/shared/controlflow/codeql/controlflow/ControlFlowGraph.qll
index 81b1d1a2e00..522a416c768 100644
--- a/shared/controlflow/codeql/controlflow/ControlFlowGraph.qll
+++ b/shared/controlflow/codeql/controlflow/ControlFlowGraph.qll
@@ -119,6 +119,12 @@ signature module AstSig<LocationSig Location> {
     Expr getCondition();
   }
 
+  /** An `until` loop statement. */
+  class UntilStmt extends LoopStmt {
+    /** Gets the boolean condition of this `until` loop. */
+    Expr getCondition();
+  }
+
   /** A traditional C-style `for` loop. */
   class ForStmt extends LoopStmt {
     /** Gets the initializer of the loop at the specified (zero-based) position, if any. */
@@ -608,6 +614,7 @@ module Make0<LocationSig Location, AstSig<Location> Ast> {
         any(IfStmt ifstmt).getCondition() = n or
         any(WhileStmt whilestmt).getCondition() = n or
         any(DoStmt dostmt).getCondition() = n or
+        any(UntilStmt untilstmt).getCondition() = n or
         any(ForStmt forstmt).getCondition() = n or
         any(ConditionalExpr condexpr).getCondition() = n or
         any(CatchClause catch).getCondition() = n or
@@ -1513,7 +1520,12 @@ module Make0<LocationSig Location, AstSig<Location> Ast> {
           n2.isBefore(ifstmt.getCondition())
           or
           n1.isAfterTrue(ifstmt.getCondition()) and
-          n2.isBefore(ifstmt.getThen())
+          (
+            n2.isBefore(ifstmt.getThen())
+            or
+            not exists(ifstmt.getThen()) and
+            n2.isAfter(ifstmt)
+          )
           or
           n1.isAfterFalse(ifstmt.getCondition()) and
           (
@@ -1530,9 +1542,9 @@ module Make0<LocationSig Location, AstSig<Location> Ast> {
           n2.isAfter(ifstmt)
         )
         or
-        exists(WhileStmt whilestmt |
-          n1.isBefore(whilestmt) and
-          n2.isAdditional(whilestmt, loopHeaderTag())
+        exists(LoopStmt loopstmt | loopstmt instanceof WhileStmt or loopstmt instanceof UntilStmt |
+          n1.isBefore(loopstmt) and
+          n2.isAdditional(loopstmt, loopHeaderTag())
         )
         or
         exists(DoStmt dostmt |
@@ -1540,16 +1552,20 @@ module Make0<LocationSig Location, AstSig<Location> Ast> {
           n2.isBefore(dostmt.getBody())
         )
         or
-        exists(LoopStmt loopstmt, AstNode cond |
-          loopstmt.(WhileStmt).getCondition() = cond or loopstmt.(DoStmt).getCondition() = cond
+        exists(LoopStmt loopstmt, AstNode cond, boolean while |
+          loopstmt.(WhileStmt).getCondition() = cond and while = true
+          or
+          loopstmt.(DoStmt).getCondition() = cond and while = true
+          or
+          loopstmt.(UntilStmt).getCondition() = cond and while = false
         |
           n1.isAdditional(loopstmt, loopHeaderTag()) and
           n2.isBefore(cond)
           or
-          n1.isAfterTrue(cond) and
+          n1.isAfterValue(cond, any(BooleanSuccessor b | b.getValue() = while)) and
           n2.isBefore(loopstmt.getBody())
           or
-          n1.isAfterFalse(cond) and
+          n1.isAfterValue(cond, any(BooleanSuccessor b | b.getValue() = while.booleanNot())) and
           n2.isAfter(loopstmt)
           or
           n1.isAfter(loopstmt.getBody()) and
diff --git a/shared/tree-sitter-extractor/src/extractor/mod.rs b/shared/tree-sitter-extractor/src/extractor/mod.rs
index e8e608c3244..436ff9f65a1 100644
--- a/shared/tree-sitter-extractor/src/extractor/mod.rs
+++ b/shared/tree-sitter-extractor/src/extractor/mod.rs
@@ -333,6 +333,9 @@ pub fn extract(
             .run_from_tree(&tree, source)
             .unwrap_or_else(|e| panic!("Desugaring failed for {path_str}: {e}"));
         traverse_yeast(&ast, &mut visitor);
+        // Comments and other `extra` nodes are not represented in the desugared
+        // AST, so recover them directly from the original parse tree.
+        traverse_extras(&tree, &mut visitor);
     } else {
         traverse(&tree, &mut visitor);
     }
@@ -365,6 +368,8 @@ struct Visitor<'a> {
     ast_node_parent_table_name: String,
     /// Language-specific name of the tokeninfo table
     tokeninfo_table_name: String,
+    /// Language-specific name of the trivia tokeninfo table
+    trivia_tokeninfo_table_name: String,
     /// A lookup table from type name to node types
     schema: &'a NodeTypeMap,
     /// A stack for gathering information from child nodes. Whenever a node is
@@ -395,11 +400,33 @@ impl<'a> Visitor<'a> {
             ast_node_location_table_name: format!("{language_prefix}_ast_node_location"),
             ast_node_parent_table_name: format!("{language_prefix}_ast_node_parent"),
             tokeninfo_table_name: format!("{language_prefix}_tokeninfo"),
+            trivia_tokeninfo_table_name: format!("{language_prefix}_trivia_tokeninfo"),
             schema,
             stack: Vec::new(),
         }
     }
 
+    /// Emits a `TriviaToken` for the given `extra` node (e.g. a comment) from
+    /// the original parse tree. Trivia tokens carry a location and their source
+    /// text, but are not attached to a parent in the (possibly desugared) AST.
+    fn emit_trivia_token(&mut self, node: &Node) {
+        let id = self.trap_writer.fresh_id();
+        let loc = location_for(self, self.file_label, node);
+        let loc_label = location_label(self.trap_writer, loc);
+        self.trap_writer.add_tuple(
+            &self.ast_node_location_table_name,
+            vec![trap::Arg::Label(id), trap::Arg::Label(loc_label)],
+        );
+        self.trap_writer.add_tuple(
+            &self.trivia_tokeninfo_table_name,
+            vec![
+                trap::Arg::Label(id),
+                trap::Arg::Int(node.kind_id() as usize),
+                sliced_source_arg(self.source, node),
+            ],
+        );
+    }
+
     fn record_parse_error(&mut self, loc: trap::Label, mesg: &diagnostics::DiagnosticMessage) {
         self.diagnostics_writer.write(mesg);
         let id = self.trap_writer.fresh_id();
@@ -835,6 +862,24 @@ fn traverse(tree: &Tree, visitor: &mut Visitor) {
     }
 }
 
+/// Walks the original tree-sitter tree and emits a `TriviaToken` for every
+/// `extra` node (e.g. a comment). Used to preserve comments that would
+/// otherwise be lost after a desugaring pass rewrites the tree.
+fn traverse_extras(tree: &Tree, visitor: &mut Visitor) {
+    emit_extras_in(visitor, tree.root_node());
+}
+
+fn emit_extras_in(visitor: &mut Visitor, node: Node<'_>) {
+    let mut cursor = node.walk();
+    for child in node.children(&mut cursor) {
+        if child.is_extra() {
+            visitor.emit_trivia_token(&child);
+        } else {
+            emit_extras_in(visitor, child);
+        }
+    }
+}
+
 fn traverse_yeast(tree: &yeast::Ast, visitor: &mut Visitor) {
     use yeast::Cursor;
     let mut cursor = tree.walk();
diff --git a/shared/tree-sitter-extractor/src/generator/mod.rs b/shared/tree-sitter-extractor/src/generator/mod.rs
index da13322fe60..d3880a74579 100644
--- a/shared/tree-sitter-extractor/src/generator/mod.rs
+++ b/shared/tree-sitter-extractor/src/generator/mod.rs
@@ -68,7 +68,12 @@ pub fn generate(
         let node_parent_table_name = format!("{}_ast_node_parent", &prefix);
         let token_name = format!("{}_token", &prefix);
         let tokeninfo_name = format!("{}_tokeninfo", &prefix);
+        let trivia_token_name = format!("{}_trivia_token", &prefix);
+        let trivia_tokeninfo_name = format!("{}_trivia_tokeninfo", &prefix);
         let reserved_word_name = format!("{}_reserved_word", &prefix);
+        // When a desugaring is configured, comments and other `extra` nodes are
+        // preserved from the original parse tree as `TriviaToken`s.
+        let has_trivia_tokens = language.desugar.is_some();
         let effective_node_types: String = match language
             .desugar
             .as_ref()
@@ -85,28 +90,35 @@ pub fn generate(
         let nodes = node_types::read_node_types_str(&prefix, &effective_node_types)?;
         let (dbscheme_entries, mut ast_node_members, token_kinds) = convert_nodes(&nodes);
         ast_node_members.insert(&token_name);
+        if has_trivia_tokens {
+            ast_node_members.insert(&trivia_token_name);
+        }
         writeln!(&mut dbscheme_writer, "/*- {} dbscheme -*/", language.name)?;
         dbscheme::write(&mut dbscheme_writer, &dbscheme_entries)?;
         let token_case = create_token_case(&token_name, token_kinds);
-        dbscheme::write(
-            &mut dbscheme_writer,
-            &[
-                dbscheme::Entry::Table(create_tokeninfo(&tokeninfo_name, &token_name)),
-                dbscheme::Entry::Case(token_case),
-                dbscheme::Entry::Union(dbscheme::Union {
-                    name: &ast_node_name,
-                    members: ast_node_members,
-                }),
-                dbscheme::Entry::Table(create_ast_node_location_table(
-                    &node_location_table_name,
-                    &ast_node_name,
-                )),
-                dbscheme::Entry::Table(create_ast_node_parent_table(
-                    &node_parent_table_name,
-                    &ast_node_name,
-                )),
-            ],
-        )?;
+        let mut dbscheme_tail = vec![
+            dbscheme::Entry::Table(create_tokeninfo(&tokeninfo_name, &token_name)),
+            dbscheme::Entry::Case(token_case),
+        ];
+        if has_trivia_tokens {
+            dbscheme_tail.push(dbscheme::Entry::Table(create_tokeninfo(
+                &trivia_tokeninfo_name,
+                &trivia_token_name,
+            )));
+        }
+        dbscheme_tail.push(dbscheme::Entry::Union(dbscheme::Union {
+            name: &ast_node_name,
+            members: ast_node_members,
+        }));
+        dbscheme_tail.push(dbscheme::Entry::Table(create_ast_node_location_table(
+            &node_location_table_name,
+            &ast_node_name,
+        )));
+        dbscheme_tail.push(dbscheme::Entry::Table(create_ast_node_parent_table(
+            &node_parent_table_name,
+            &ast_node_name,
+        )));
+        dbscheme::write(&mut dbscheme_writer, &dbscheme_tail)?;
 
         let mut body = vec![
             ql::TopLevel::Class(ql_gen::create_ast_node_class(
@@ -116,6 +128,12 @@ pub fn generate(
             )),
             ql::TopLevel::Class(ql_gen::create_token_class(&token_name, &tokeninfo_name)),
         ];
+        if has_trivia_tokens {
+            body.push(ql::TopLevel::Class(ql_gen::create_trivia_token_class(
+                &trivia_token_name,
+                &trivia_tokeninfo_name,
+            )));
+        }
         // Only emit the ReservedWord class when there are actually unnamed token
         // types in the schema (i.e., @{prefix}_reserved_word exists in the dbscheme).
         // When converting from a YEAST YAML schema that has no unnamed tokens, this
diff --git a/shared/tree-sitter-extractor/src/generator/ql_gen.rs b/shared/tree-sitter-extractor/src/generator/ql_gen.rs
index bb990beacc8..f827b12580e 100644
--- a/shared/tree-sitter-extractor/src/generator/ql_gen.rs
+++ b/shared/tree-sitter-extractor/src/generator/ql_gen.rs
@@ -199,6 +199,70 @@ pub fn create_token_class<'a>(token_type: &'a str, tokeninfo: &'a str) -> ql::Cl
     }
 }
 
+/// Creates the `TriviaToken` class. Trivia tokens (e.g. comments) are
+/// `extra` nodes preserved from the original parse tree even when the tree has
+/// been rewritten by a desugaring pass. They are not part of the regular
+/// `Token` hierarchy because they do not appear in the (possibly desugared)
+/// output schema.
+pub fn create_trivia_token_class<'a>(
+    trivia_token_type: &'a str,
+    trivia_tokeninfo: &'a str,
+) -> ql::Class<'a> {
+    let trivia_tokeninfo_arity = 3; // id, kind, value
+    let get_value = ql::Predicate {
+        qldoc: Some(String::from("Gets the source text of this trivia token.")),
+        name: "getValue",
+        overridden: false,
+        is_private: false,
+        is_final: true,
+        return_type: Some(ql::Type::String),
+        formal_parameters: vec![],
+        body: create_get_field_expr_for_column_storage(
+            "result",
+            trivia_tokeninfo,
+            1,
+            trivia_tokeninfo_arity,
+        ),
+        overlay: None,
+    };
+    let to_string = ql::Predicate {
+        qldoc: Some(String::from(
+            "Gets a string representation of this element.",
+        )),
+        name: "toString",
+        overridden: true,
+        is_private: false,
+        is_final: true,
+        return_type: Some(ql::Type::String),
+        formal_parameters: vec![],
+        body: ql::Expression::Equals(
+            Box::new(ql::Expression::Var("result")),
+            Box::new(ql::Expression::Dot(
+                Box::new(ql::Expression::Var("this")),
+                "getValue",
+                vec![],
+            )),
+        ),
+        overlay: None,
+    };
+    ql::Class {
+        qldoc: Some(String::from(
+            "A trivia token, such as a comment, preserved from the original parse tree.",
+        )),
+        name: "TriviaToken",
+        is_abstract: false,
+        supertypes: vec![ql::Type::At(trivia_token_type), ql::Type::Normal("AstNode")]
+            .into_iter()
+            .collect(),
+        characteristic_predicate: None,
+        predicates: vec![
+            get_value,
+            to_string,
+            create_get_a_primary_ql_class("TriviaToken", false),
+        ],
+    }
+}
+
 // Creates the `ReservedWord` class.
 pub fn create_reserved_word_class(db_name: &str) -> ql::Class<'_> {
     let class_name = "ReservedWord";
diff --git a/unified/ql/lib/codeql/unified/Ast.qll b/unified/ql/lib/codeql/unified/Ast.qll
index d9060c26f0f..b6d6a76b549 100644
--- a/unified/ql/lib/codeql/unified/Ast.qll
+++ b/unified/ql/lib/codeql/unified/Ast.qll
@@ -61,6 +61,18 @@ module Unified {
     override string getAPrimaryQlClass() { result = "Token" }
   }
 
+  /** A trivia token, such as a comment, preserved from the original parse tree. */
+  class TriviaToken extends @unified_trivia_token, AstNode {
+    /** Gets the source text of this trivia token. */
+    final string getValue() { unified_trivia_tokeninfo(this, _, result) }
+
+    /** Gets a string representation of this element. */
+    final override string toString() { result = this.getValue() }
+
+    /** Gets the name of the primary QL class for this element. */
+    override string getAPrimaryQlClass() { result = "TriviaToken" }
+  }
+
   /** Gets the file containing the given `node`. */
   private @file getNodeFile(@unified_ast_node node) {
     exists(@location_default loc | unified_ast_node_location(node, loc) |
diff --git a/unified/ql/lib/codeql/unified/Comments.qll b/unified/ql/lib/codeql/unified/Comments.qll
new file mode 100644
index 00000000000..e839af2dbee
--- /dev/null
+++ b/unified/ql/lib/codeql/unified/Comments.qll
@@ -0,0 +1,18 @@
+/** Provides classes for working with comments. */
+
+private import unified
+
+/**
+ * A comment appearing in the source code.
+ */
+class Comment extends TriviaToken {
+  // At the moment, comments are the only type trivia token we extract
+  /**
+   * Gets the text inside this comment, not counting the delimeters.
+   */
+  string getCommentText() {
+    result = this.getValue().regexpCapture("//(.*)", 1)
+    or
+    result = this.getValue().regexpCapture("(?s)/\\*(.*)\\*/", 1)
+  }
+}
diff --git a/unified/ql/lib/unified.dbscheme b/unified/ql/lib/unified.dbscheme
index 28718d79423..31b3ec6c3ed 100644
--- a/unified/ql/lib/unified.dbscheme
+++ b/unified/ql/lib/unified.dbscheme
@@ -334,7 +334,13 @@ case @unified_token.kind of
 ;
 
 
-@unified_ast_node = @unified_apply_pattern | @unified_binary_expr | @unified_block_stmt | @unified_call_expr | @unified_expr_condition | @unified_expr_stmt | @unified_guard_if_stmt | @unified_if_stmt | @unified_lambda_expr | @unified_let_pattern_condition | @unified_member_access_expr | @unified_name_expr | @unified_parameter | @unified_sequence_condition | @unified_token | @unified_top_level | @unified_tuple_pattern | @unified_unary_expr | @unified_var_pattern | @unified_variable_declaration_stmt | @unified_variable_declarator
+unified_trivia_tokeninfo(
+  unique int id: @unified_trivia_token,
+  int kind: int ref,
+  string value: string ref
+);
+
+@unified_ast_node = @unified_apply_pattern | @unified_binary_expr | @unified_block_stmt | @unified_call_expr | @unified_expr_condition | @unified_expr_stmt | @unified_guard_if_stmt | @unified_if_stmt | @unified_lambda_expr | @unified_let_pattern_condition | @unified_member_access_expr | @unified_name_expr | @unified_parameter | @unified_sequence_condition | @unified_token | @unified_top_level | @unified_trivia_token | @unified_tuple_pattern | @unified_unary_expr | @unified_var_pattern | @unified_variable_declaration_stmt | @unified_variable_declarator
 
 unified_ast_node_location(
   unique int node: @unified_ast_node ref,
diff --git a/unified/ql/lib/unified.qll b/unified/ql/lib/unified.qll
new file mode 100644
index 00000000000..4f7387ef8f1
--- /dev/null
+++ b/unified/ql/lib/unified.qll
@@ -0,0 +1,8 @@
+/**
+ * Provides classes for working with the AST, as well as files and locations.
+ */
+
+import codeql.Locations
+import codeql.files.FileSystem
+import codeql.unified.Ast::Unified
+import codeql.unified.Comments
diff --git a/unified/ql/test/library-tests/comments/comments.expected b/unified/ql/test/library-tests/comments/comments.expected
new file mode 100644
index 00000000000..04e09d06e54
--- /dev/null
+++ b/unified/ql/test/library-tests/comments/comments.expected
@@ -0,0 +1,3 @@
+| comments.swift:1:1:1:22 | // Hello this is swift |  Hello this is swift |
+| comments.swift:3:1:6:3 | /*\n * This is a multi-line comment\n * It should be ignored by the parser\n */ | \n * This is a multi-line comment\n * It should be ignored by the parser\n  |
+| comments.swift:9:5:9:36 | // This is a single-line comment |  This is a single-line comment |
diff --git a/unified/ql/test/library-tests/comments/comments.ql b/unified/ql/test/library-tests/comments/comments.ql
new file mode 100644
index 00000000000..db64ff737a7
--- /dev/null
+++ b/unified/ql/test/library-tests/comments/comments.ql
@@ -0,0 +1,3 @@
+import unified
+
+query predicate comments(Comment c, string text) { text = c.getCommentText() }
diff --git a/unified/ql/test/library-tests/comments/comments.swift b/unified/ql/test/library-tests/comments/comments.swift
new file mode 100644
index 00000000000..9f133142ef2
--- /dev/null
+++ b/unified/ql/test/library-tests/comments/comments.swift
@@ -0,0 +1,11 @@
+// Hello this is swift
+
+/*
+ * This is a multi-line comment
+ * It should be ignored by the parser
+ */
+
+func hello() {
+    // This is a single-line comment
+    print("Hello, world!")
+}