From c08e6fdc1ed904c8cabf809c1d581f2e490df4c4 Mon Sep 17 00:00:00 2001
From: Paolo Tranquilli <redsun82@github.com>
Date: Mon, 9 May 2022 17:50:49 +0200
Subject: [PATCH] Swift codegen: add predicate properties

Properties marked with `predicate` in the schema are now accepted.

* in the dbscheme, they will translate to a table with a single `id`
  column (and the table name will not be pluralized)
* in C++ classes, they will translate to `bool` fields
* in QL classes, they will translate to predicates

Closes https://github.com/github/codeql-c-team/issues/1016
---
 swift/codegen/cppgen.py                       |  8 ++-
 swift/codegen/dbschemegen.py                  |  9 +++
 swift/codegen/lib/cpp.py                      |  3 +-
 swift/codegen/lib/ql.py                       | 28 +++++----
 swift/codegen/lib/schema.py                   | 22 ++++---
 swift/codegen/qlgen.py                        |  8 +++
 swift/codegen/schema.yml                      |  1 +
 swift/codegen/templates/cpp_classes.mustache  |  3 +
 swift/codegen/templates/ql_class.mustache     |  8 +--
 swift/codegen/test/test_cpp.py                | 15 ++---
 swift/codegen/test/test_cppgen.py             | 11 ++++
 swift/codegen/test/test_dbschemegen.py        | 35 +++++++++++
 swift/codegen/test/test_ql.py                 | 63 +++++++++++--------
 swift/codegen/test/test_qlgen.py              | 16 ++++-
 swift/codegen/test/test_schema.py             |  2 +
 .../swift/generated/type/AnyFunctionType.qll  |  2 +
 swift/ql/lib/swift.dbscheme                   |  5 ++
 17 files changed, 179 insertions(+), 60 deletions(-)

diff --git a/swift/codegen/cppgen.py b/swift/codegen/cppgen.py
index f45512512aa..eee66a812f0 100644
--- a/swift/codegen/cppgen.py
+++ b/swift/codegen/cppgen.py
@@ -8,6 +8,9 @@ from swift.codegen.lib import cpp, generator, schema
 
 
 def _get_type(t: str, trap_affix: str) -> str:
+    if t is None:
+        # this is a predicate
+        return "bool"
     if t == "string":
         return "std::string"
     if t == "boolean":
@@ -20,12 +23,15 @@ def _get_type(t: str, trap_affix: str) -> str:
 def _get_field(cls: schema.Class, p: schema.Property, trap_affix: str) -> cpp.Field:
     trap_name = None
     if not p.is_single:
-        trap_name = inflection.pluralize(inflection.camelize(f"{cls.name}_{p.name}"))
+        trap_name = inflection.camelize(f"{cls.name}_{p.name}")
+        if not p.is_predicate:
+            trap_name = inflection.pluralize(trap_name)
     args = dict(
         name=p.name + ("_" if p.name in cpp.cpp_keywords else ""),
         type=_get_type(p.type, trap_affix),
         is_optional=p.is_optional,
         is_repeated=p.is_repeated,
+        is_predicate=p.is_predicate,
         trap_name=trap_name,
     )
     args.update(cpp.get_field_override(p.name))
diff --git a/swift/codegen/dbschemegen.py b/swift/codegen/dbschemegen.py
index efe45c0b997..c95316e5499 100755
--- a/swift/codegen/dbschemegen.py
+++ b/swift/codegen/dbschemegen.py
@@ -57,6 +57,15 @@ def cls_to_dbscheme(cls: schema.Class):
                     Column(f.name, dbtype(f.type)),
                 ],
             )
+        elif f.is_predicate:
+            yield Table(
+                keyset=KeySet(["id"]),
+                name=inflection.underscore(f"{cls.name}_{f.name}"),
+                columns=[
+                    Column("id", type=dbtype(cls.name)),
+                 ],
+            )
+
 
 
 def get_declarations(data: schema.Schema):
diff --git a/swift/codegen/lib/cpp.py b/swift/codegen/lib/cpp.py
index 886ef8069e6..82dfbb44bcb 100644
--- a/swift/codegen/lib/cpp.py
+++ b/swift/codegen/lib/cpp.py
@@ -35,6 +35,7 @@ class Field:
     type: str
     is_optional: bool = False
     is_repeated: bool = False
+    is_predicate: bool = False
     trap_name: str = None
     first: bool = False
 
@@ -61,7 +62,7 @@ class Field:
 
     @property
     def is_single(self):
-        return not (self.is_optional or self.is_repeated)
+        return not (self.is_optional or self.is_repeated or self.is_predicate)
 
 
 
diff --git a/swift/codegen/lib/ql.py b/swift/codegen/lib/ql.py
index ee9103fd990..5d4a7076414 100644
--- a/swift/codegen/lib/ql.py
+++ b/swift/codegen/lib/ql.py
@@ -14,29 +14,35 @@ class Param:
 @dataclass
 class Property:
     singular: str
-    type: str
-    tablename: str
-    tableparams: List[Param]
+    type: str = None
+    tablename: str = None
+    tableparams: List[Param] = field(default_factory=list)
     plural: str = None
     first: bool = False
     local_var: str = "x"
     is_optional: bool = False
+    is_predicate: bool = False
 
     def __post_init__(self):
-        assert self.tableparams
-        if self.type_is_class:
-            self.tableparams = [x if x != "result" else self.local_var for x in self.tableparams]
-        self.tableparams = [Param(x) for x in self.tableparams]
-        self.tableparams[0].first = True
+        if self.tableparams:
+            if self.type_is_class:
+                self.tableparams = [x if x != "result" else self.local_var for x in self.tableparams]
+            self.tableparams = [Param(x) for x in self.tableparams]
+            self.tableparams[0].first = True
 
     @property
-    def indefinite_article(self):
+    def getter(self):
+        return f"get{self.singular}" if not self.is_predicate else self.singular
+
+    @property
+    def indefinite_getter(self):
         if self.plural:
-            return "An" if self.singular[0] in "AEIO" else "A"
+            article = "An" if self.singular[0] in "AEIO" else "A"
+            return f"get{article}{self.singular}"
 
     @property
     def type_is_class(self):
-        return self.type[0].isupper()
+        return bool(self.type) and self.type[0].isupper()
 
     @property
     def is_repeated(self):
diff --git a/swift/codegen/lib/schema.py b/swift/codegen/lib/schema.py
index 06ceb4b63bb..a65aaf24dca 100644
--- a/swift/codegen/lib/schema.py
+++ b/swift/codegen/lib/schema.py
@@ -15,9 +15,10 @@ class Property:
     is_single: ClassVar = False
     is_optional: ClassVar = False
     is_repeated: ClassVar = False
+    is_predicate: ClassVar = False
 
     name: str
-    type: str
+    type: str = None
 
 
 @dataclass
@@ -41,6 +42,11 @@ class RepeatedOptionalProperty(Property):
     is_repeated: ClassVar = True
 
 
+@dataclass
+class PredicateProperty(Property):
+    is_predicate: ClassVar = True
+
+
 @dataclass
 class Class:
     name: str
@@ -58,17 +64,15 @@ class Schema:
 
 def _parse_property(name, type):
     if type.endswith("?*"):
-        cls = RepeatedOptionalProperty
-        type = type[:-2]
+        return RepeatedOptionalProperty(name, type[:-2])
     elif type.endswith("*"):
-        cls = RepeatedProperty
-        type = type[:-1]
+        return RepeatedProperty(name, type[:-1])
     elif type.endswith("?"):
-        cls = OptionalProperty
-        type = type[:-1]
+        return OptionalProperty(name, type[:-1])
+    elif type == "predicate":
+        return PredicateProperty(name)
     else:
-        cls = SingleProperty
-    return cls(name, type)
+        return SingleProperty(name, type)
 
 
 class _DirSelector:
diff --git a/swift/codegen/qlgen.py b/swift/codegen/qlgen.py
index 5d08f5a0410..4eea533904a 100755
--- a/swift/codegen/qlgen.py
+++ b/swift/codegen/qlgen.py
@@ -36,6 +36,14 @@ def get_ql_property(cls: schema.Class, prop: schema.Property):
             tableparams=["this", "result"],
             is_optional=True,
         )
+    elif prop.is_predicate:
+        return ql.Property(
+            singular=inflection.camelize(prop.name, uppercase_first_letter=False),
+            type="predicate",
+            tablename=inflection.underscore(f"{cls.name}_{prop.name}"),
+            tableparams=["this"],
+            is_predicate=True,
+        )
 
 
 def get_ql_class(cls: schema.Class):
diff --git a/swift/codegen/schema.yml b/swift/codegen/schema.yml
index 4ea4a8190a6..46e0b508ae5 100644
--- a/swift/codegen/schema.yml
+++ b/swift/codegen/schema.yml
@@ -59,6 +59,7 @@ AnyFunctionType:
   result: Type
   param_types: Type*
   param_labels: string*
+  is_throwing: predicate
 
 AnyGenericType:
   _extends: Type
diff --git a/swift/codegen/templates/cpp_classes.mustache b/swift/codegen/templates/cpp_classes.mustache
index 3e9d12084c9..15e33a378dc 100644
--- a/swift/codegen/templates/cpp_classes.mustache
+++ b/swift/codegen/templates/cpp_classes.mustache
@@ -33,6 +33,9 @@ struct {{name}}{{#final}} : Binding<{{name}}Tag>{{#bases}}, {{ref.name}}{{/bases
     {{ref.name}}::emit(id, out);
     {{/bases}}
     {{#fields}}
+    {{#is_predicate}}
+    if ({{name}}) out << {{trap_name}}{{trap_affix}}{id} << '\n';
+    {{/is_predicate}}
     {{#is_optional}}
     {{^is_repeated}}
     if ({{name}}) out << {{trap_name}}{{trap_affix}}{id, *{{name}}} << '\n';
diff --git a/swift/codegen/templates/ql_class.mustache b/swift/codegen/templates/ql_class.mustache
index 12ca76c9975..89da396be90 100644
--- a/swift/codegen/templates/ql_class.mustache
+++ b/swift/codegen/templates/ql_class.mustache
@@ -21,7 +21,7 @@ class {{name}}Base extends {{db_id}}{{#bases}}, {{.}}{{/bases}} {
   {{/final}}
   {{#properties}}
 
-  {{type}} get{{singular}}({{#is_repeated}}int index{{/is_repeated}}) {
+  {{type}} {{getter}}({{#is_repeated}}int index{{/is_repeated}}) {
     {{#type_is_class}}
     exists({{type}} {{local_var}} |
       {{tablename}}({{#tableparams}}{{^first}}, {{/first}}{{param}}{{/tableparams}})
@@ -34,13 +34,13 @@ class {{name}}Base extends {{db_id}}{{#bases}}, {{.}}{{/bases}} {
   }
   {{#is_repeated}}
 
-  {{type}} get{{indefinite_article}}{{singular}}() {
-    result = get{{singular}}(_)
+  {{type}} {{indefinite_getter}}() {
+    result = {{getter}}(_)
   }
   {{^is_optional}}
 
   int getNumberOf{{plural}}() {
-    result = count(get{{indefinite_article}}{{singular}}())
+    result = count({{indefinite_getter}}())
   }
   {{/is_optional}}
   {{/is_repeated}}
diff --git a/swift/codegen/test/test_cpp.py b/swift/codegen/test/test_cpp.py
index 74dbc2d2182..06ff50f8a51 100644
--- a/swift/codegen/test/test_cpp.py
+++ b/swift/codegen/test/test_cpp.py
@@ -27,14 +27,15 @@ def test_field_get_streamer(type, expected):
     assert f.get_streamer()("value") == expected
 
 
-@pytest.mark.parametrize("is_optional,is_repeated,expected", [
-    (False, False, True),
-    (True, False, False),
-    (False, True, False),
-    (True, True, False),
+@pytest.mark.parametrize("is_optional,is_repeated,is_predicate,expected", [
+    (False, False, False, True),
+    (True, False, False, False),
+    (False, True, False, False),
+    (True, True, False, False),
+    (False, False, True, False),
 ])
-def test_field_is_single(is_optional, is_repeated, expected):
-    f = cpp.Field("name", "type", is_optional=is_optional, is_repeated=is_repeated)
+def test_field_is_single(is_optional, is_repeated, is_predicate, expected):
+    f = cpp.Field("name", "type", is_optional=is_optional, is_repeated=is_repeated, is_predicate=is_predicate)
     assert f.is_single is expected
 
 
diff --git a/swift/codegen/test/test_cppgen.py b/swift/codegen/test/test_cppgen.py
index ac37b7300c5..b4e766af9dc 100644
--- a/swift/codegen/test/test_cppgen.py
+++ b/swift/codegen/test/test_cppgen.py
@@ -92,6 +92,17 @@ def test_class_with_field(generate, type, expected, property_cls, optional, repe
            ]
 
 
+def test_class_with_predicate(generate):
+    assert generate([
+        schema.Class(name="MyClass", properties=[schema.PredicateProperty("prop")]),
+    ]) == [
+               cpp.Class(name="MyClass",
+                         fields=[cpp.Field("prop", "bool", trap_name="MyClassProp", is_predicate=True)],
+                         trap_name="MyClasses",
+                         final=True)
+           ]
+
+
 @pytest.mark.parametrize("name",
                          ["start_line", "start_column", "end_line", "end_column", "index", "num_whatever", "width"])
 def test_class_with_overridden_unsigned_field(generate, name):
diff --git a/swift/codegen/test/test_dbschemegen.py b/swift/codegen/test/test_dbschemegen.py
index 82521fb9892..54f1e1796f7 100644
--- a/swift/codegen/test/test_dbschemegen.py
+++ b/swift/codegen/test/test_dbschemegen.py
@@ -156,6 +156,33 @@ def test_final_class_with_repeated_field(opts, input, renderer, property_cls):
     )
 
 
+def test_final_class_with_predicate_field(opts, input, renderer):
+    input.classes = [
+        schema.Class("Object", properties=[
+            schema.PredicateProperty("foo"),
+        ]),
+    ]
+    assert generate(opts, renderer) == dbscheme.Scheme(
+        src=schema_file,
+        includes=[],
+        declarations=[
+            dbscheme.Table(
+                name="objects",
+                columns=[
+                    dbscheme.Column('id', '@object', binding=True),
+                ]
+            ),
+            dbscheme.Table(
+                name="object_foo",
+                keyset=dbscheme.KeySet(["id"]),
+                columns=[
+                    dbscheme.Column('id', '@object'),
+                ]
+            ),
+        ],
+    )
+
+
 def test_final_class_with_more_fields(opts, input, renderer):
     input.classes = [
         schema.Class("Object", properties=[
@@ -164,6 +191,7 @@ def test_final_class_with_more_fields(opts, input, renderer):
             schema.OptionalProperty("three", "z"),
             schema.RepeatedProperty("four", "u"),
             schema.RepeatedOptionalProperty("five", "v"),
+            schema.PredicateProperty("six"),
         ]),
     ]
     assert generate(opts, renderer) == dbscheme.Scheme(
@@ -204,6 +232,13 @@ def test_final_class_with_more_fields(opts, input, renderer):
                     dbscheme.Column('five', 'v'),
                 ]
             ),
+            dbscheme.Table(
+                name="object_six",
+                keyset=dbscheme.KeySet(["id"]),
+                columns=[
+                    dbscheme.Column('id', '@object'),
+                ]
+            ),
         ],
     )
 
diff --git a/swift/codegen/test/test_ql.py b/swift/codegen/test/test_ql.py
index e87383695c6..caa513c1b15 100644
--- a/swift/codegen/test/test_ql.py
+++ b/swift/codegen/test/test_ql.py
@@ -12,31 +12,32 @@ def test_property_has_first_table_param_marked():
     assert [p.param for p in prop.tableparams] == tableparams
 
 
-def test_property_not_a_class():
-    tableparams = ["x", "result", "y"]
-    prop = ql.Property("Prop", "foo", "props", tableparams)
-    assert not prop.type_is_class
-    assert [p.param for p in prop.tableparams] == tableparams
-
-
-def test_property_is_a_class():
-    tableparams = ["x", "result", "y"]
-    prop = ql.Property("Prop", "Foo", "props", tableparams)
-    assert prop.type_is_class
-    assert [p.param for p in prop.tableparams] == ["x", prop.local_var, "y"]
-
-
-@pytest.mark.parametrize("name,expected_article", [
-    ("Argument", "An"),
-    ("Element", "An"),
-    ("Integer", "An"),
-    ("Operator", "An"),
-    ("Unit", "A"),
-    ("Whatever", "A"),
+@pytest.mark.parametrize("type,expected", [
+    ("Foo", True),
+    ("Bar", True),
+    ("foo", False),
+    ("bar", False),
+    (None, False),
 ])
-def test_property_indefinite_article(name, expected_article):
-    prop = ql.Property(name, "Foo", "props", ["x"], plural="X")
-    assert prop.indefinite_article == expected_article
+def test_property_is_a_class(type, expected):
+    tableparams = ["a", "result", "b"]
+    expected_tableparams = ["a", "x" if expected else "result", "b"]
+    prop = ql.Property("Prop", type, tableparams=tableparams)
+    assert prop.type_is_class is expected
+    assert [p.param for p in prop.tableparams] == expected_tableparams
+
+
+@pytest.mark.parametrize("name,expected_getter", [
+    ("Argument", "getAnArgument"),
+    ("Element", "getAnElement"),
+    ("Integer", "getAnInteger"),
+    ("Operator", "getAnOperator"),
+    ("Unit", "getAUnit"),
+    ("Whatever", "getAWhatever"),
+])
+def test_property_indefinite_article(name, expected_getter):
+    prop = ql.Property(name, plural="X")
+    assert prop.indefinite_getter == expected_getter
 
 
 @pytest.mark.parametrize("plural,expected", [
@@ -49,9 +50,19 @@ def test_property_is_plural(plural, expected):
     assert prop.is_repeated is expected
 
 
-def test_property_no_plural_no_indefinite_article():
+def test_property_no_plural_no_indefinite_getter():
     prop = ql.Property("Prop", "Foo", "props", ["x"])
-    assert prop.indefinite_article is None
+    assert prop.indefinite_getter is None
+
+
+def test_property_getter():
+    prop = ql.Property("Prop", "Foo")
+    assert prop.getter == "getProp"
+
+
+def test_property_predicate_getter():
+    prop = ql.Property("prop", is_predicate=True)
+    assert prop.getter == "prop"
 
 
 def test_class_sorts_bases():
diff --git a/swift/codegen/test/test_qlgen.py b/swift/codegen/test/test_qlgen.py
index d273539e375..e5405406747 100644
--- a/swift/codegen/test/test_qlgen.py
+++ b/swift/codegen/test/test_qlgen.py
@@ -2,7 +2,7 @@ import subprocess
 import sys
 
 from swift.codegen import qlgen
-from swift.codegen.lib import ql, paths
+from swift.codegen.lib import ql
 from swift.codegen.test.utils import *
 
 
@@ -141,6 +141,20 @@ def test_repeated_optional_property(opts, input, renderer):
     }
 
 
+def test_predicate_property(opts, input, renderer):
+    input.classes = [
+        schema.Class("MyObject", properties=[schema.PredicateProperty("is_foo")]),
+    ]
+    assert generate(opts, renderer) == {
+        import_file(): ql.ImportList([stub_import_prefix + "MyObject"]),
+        stub_path() / "MyObject.qll": ql.Stub(name="MyObject", base_import=gen_import_prefix + "MyObject"),
+        ql_output_path() / "MyObject.qll": ql.Class(name="MyObject", final=True, properties=[
+            ql.Property(singular="isFoo", type="predicate", tablename="my_object_is_foo", tableparams=["this"],
+                        is_predicate=True),
+        ])
+    }
+
+
 def test_single_class_property(opts, input, renderer):
     input.classes = [
         schema.Class("MyObject", properties=[schema.SingleProperty("foo", "Bar")]),
diff --git a/swift/codegen/test/test_schema.py b/swift/codegen/test/test_schema.py
index 36367a76b1f..c1b64648894 100644
--- a/swift/codegen/test/test_schema.py
+++ b/swift/codegen/test/test_schema.py
@@ -141,6 +141,7 @@ A:
      two: int?
      three: bool*
      four: x?*
+     five: predicate
 """)
     assert ret.classes == [
         schema.Class(root_name, derived={'A'}),
@@ -149,6 +150,7 @@ A:
             schema.OptionalProperty('two', 'int'),
             schema.RepeatedProperty('three', 'bool'),
             schema.RepeatedOptionalProperty('four', 'x'),
+            schema.PredicateProperty('five'),
         ]),
     ]
 
diff --git a/swift/ql/lib/codeql/swift/generated/type/AnyFunctionType.qll b/swift/ql/lib/codeql/swift/generated/type/AnyFunctionType.qll
index 847017e44f2..6add8032bc1 100644
--- a/swift/ql/lib/codeql/swift/generated/type/AnyFunctionType.qll
+++ b/swift/ql/lib/codeql/swift/generated/type/AnyFunctionType.qll
@@ -25,4 +25,6 @@ class AnyFunctionTypeBase extends @any_function_type, Type {
   string getAParamLabel() { result = getParamLabel(_) }
 
   int getNumberOfParamLabels() { result = count(getAParamLabel()) }
+
+  predicate isThrowing() { any_function_type_is_throwing(this) }
 }
diff --git a/swift/ql/lib/swift.dbscheme b/swift/ql/lib/swift.dbscheme
index fbff22210bf..8d3ab41cf22 100644
--- a/swift/ql/lib/swift.dbscheme
+++ b/swift/ql/lib/swift.dbscheme
@@ -167,6 +167,11 @@ any_function_type_param_labels(
   string param_label: string ref
 );
 
+#keyset[id]
+any_function_type_is_throwing(
+  int id: @any_function_type ref
+);
+
 @any_generic_type =
   @nominal_or_bound_generic_nominal_type
 | @unbound_generic_type