Extract type parameters in types, not just decls

extractor/dbscheme/tables.go

@@ -682,6 +682,9 @@ var ObjectType = NewPrimaryKeyType("@object")
 // ObjectKind is a case type for distinguishing different kinds of built-in and declared objects
 var ObjectKind = NewCaseType(ObjectType, "kind")
 
+// TypeParamParentObjectType is the type of objects that can have type parameters as children
+var TypeParamParentObjectType = NewUnionType("@typeparamparentobject")
+
 // DeclObjectType is the type of declared objects
 var DeclObjectType = NewUnionType("@declobject")
 
@@ -695,7 +698,7 @@ var PkgObjectType = ObjectKind.NewBranch("@pkgobject")
 var TypeObjectType = NewUnionType("@typeobject")
 
 // DeclTypeObjectType is the type of declared named types
-var DeclTypeObjectType = ObjectKind.NewBranch("@decltypeobject", TypeObjectType, DeclObjectType)
+var DeclTypeObjectType = ObjectKind.NewBranch("@decltypeobject", TypeObjectType, DeclObjectType, TypeParamParentObjectType)
 
 // BuiltinTypeObjectType is the type of built-in named types
 var BuiltinTypeObjectType = ObjectKind.NewBranch("@builtintypeobject", TypeObjectType, BuiltinObjectType)
@@ -722,7 +725,7 @@ var DeclVarObjectType = ObjectKind.NewBranch("@declvarobject", VarObjectType, De
 var FunctionObjectType = NewUnionType("@functionobject", ValueObjectType)
 
 // DeclFuncObjectType is the type of declared functions, including (abstract and concrete) methods
-var DeclFuncObjectType = ObjectKind.NewBranch("@declfunctionobject", FunctionObjectType, DeclObjectType)
+var DeclFuncObjectType = ObjectKind.NewBranch("@declfunctionobject", FunctionObjectType, DeclObjectType, TypeParamParentObjectType)
 
 // BuiltinFuncObjectType is the type of built-in functions
 var BuiltinFuncObjectType = ObjectKind.NewBranch("@builtinfunctionobject", FunctionObjectType, BuiltinObjectType)
@@ -1206,8 +1209,11 @@ var VariadicTable = NewTable("variadic",
 	EntityColumn(SignatureType, "id"),
 )
 
+// TypeParamTable is the table describing type parameter types
 var TypeParamTable = NewTable("typeparam",
 	EntityColumn(TypeParamType, "tp").Unique(),
 	StringColumn("name"),
 	EntityColumn(CompositeType, "bound"),
-)
+	EntityColumn(TypeParamParentObjectType, "parent"),
+	IntColumn("idx"),
+).KeySet("parent", "idx")

extractor/extractor.go

@@ -363,6 +363,15 @@ func extractObjects(tw *trap.Writer, scope *types.Scope, scopeLabel trap.Label)
 		obj := scope.Lookup(name)
 		lbl, exists := tw.Labeler.ScopedObjectID(obj, func() trap.Label { return extractType(tw, obj.Type()) })
 		if !exists {
+			if funcObj, ok := obj.(*types.Func); ok {
+				populateTypeParamParents(tw, funcObj.Type().(*types.Signature).TypeParams(), lbl)
+				populateTypeParamParents(tw, funcObj.Type().(*types.Signature).RecvTypeParams(), lbl)
+			}
+			if typeNameObj, ok := obj.(*types.TypeName); ok {
+				if tp, ok := typeNameObj.Type().(*types.Named); ok {
+					populateTypeParamParents(tw, tp.TypeParams(), lbl)
+				}
+			}
 			extractObject(tw, obj, lbl)
 		}
 
@@ -378,10 +387,14 @@ func extractObjects(tw *trap.Writer, scope *types.Scope, scopeLabel trap.Label)
 func extractMethod(tw *trap.Writer, meth *types.Func) trap.Label {
 	// get the receiver type of the method
 	recvtyp := meth.Type().(*types.Signature).Recv().Type()
-	recvlbl := extractType(tw, recvtyp) // ensure receiver type has been extracted
+	// ensure receiver type has been extracted
+	recvlbl := extractType(tw, recvtyp)
+
 	// if the method label does not exist, extract it
 	methlbl, exists := tw.Labeler.MethodID(meth, recvlbl)
 	if !exists {
+		populateTypeParamParents(tw, meth.Type().(*types.Signature).TypeParams(), methlbl)
+		populateTypeParamParents(tw, meth.Type().(*types.Signature).RecvTypeParams(), methlbl)
 		extractObject(tw, meth, methlbl)
 	}
 
@@ -1512,7 +1525,12 @@ func extractType(tw *trap.Writer, tp types.Type) trap.Label {
 			}
 		case *types.TypeParam:
 			kind = dbscheme.TypeParamType.Index()
-			dbscheme.TypeParamTable.Emit(tw, lbl, tp.Obj().Name(), extractType(tw, tp.Constraint()))
+			parentlbl, exists := tw.TypeParamParent[tp]
+			if !exists {
+				log.Fatalf("Parent of type parameter does not exist: %s", tp.String())
+			}
+			constraintLabel := extractType(tw, tp.Constraint())
+			dbscheme.TypeParamTable.Emit(tw, lbl, tp.Obj().Name(), constraintLabel, parentlbl, tp.Index())
 		case *types.Union:
 			kind = dbscheme.TypeSetLiteral.Index()
 			for i := 0; i < tp.Len(); i++ {
@@ -1651,7 +1669,8 @@ func getTypeLabel(tw *trap.Writer, tp types.Type) (trap.Label, bool) {
 			}
 			lbl = tw.Labeler.GlobalID(fmt.Sprintf("{%s};namedtype", entitylbl))
 		case *types.TypeParam:
-			lbl = tw.Labeler.GlobalID(fmt.Sprintf("{%s},{%s};typeparamtype", tp.Obj().Name(), extractType(tw, tp.Constraint())))
+			parentlbl := tw.TypeParamParent[tp]
+			lbl = tw.Labeler.GlobalID(fmt.Sprintf("{%v},%s;typeparamtype", parentlbl, tp.Obj().Name()))
 		case *types.Union:
 			var b strings.Builder
 			for i := 0; i < tp.Len(); i++ {
@@ -1828,3 +1847,12 @@ func extractTypeParamDecls(tw *trap.Writer, fields *ast.FieldList, parent trap.L
 		idx += 1
 	}
 }
+
+// populateTypeParamParents sets `parentlbl` as the parent of the elements of `typeparams`
+func populateTypeParamParents(tw *trap.Writer, typeparams *types.TypeParamList, parentlbl trap.Label) {
+	if typeparams != nil {
+		for idx := 0; idx < typeparams.Len(); idx++ {
+			tw.TypeParamParent[typeparams.At(idx)] = parentlbl
+		}
+	}
+}

extractor/trap/trapwriter.go

@@ -18,14 +18,15 @@ import (
 
 // A Writer provides methods for writing data to a TRAP file
 type Writer struct {
-	zip           *gzip.Writer
-	w             *bufio.Writer
-	file          *os.File
-	Labeler       *Labeler
-	path          string
-	trapFilePath  string
-	Package       *packages.Package
-	TypesOverride map[ast.Expr]types.Type
+	zip             *gzip.Writer
+	w               *bufio.Writer
+	file            *os.File
+	Labeler         *Labeler
+	path            string
+	trapFilePath    string
+	Package         *packages.Package
+	TypesOverride   map[ast.Expr]types.Type
+	TypeParamParent map[*types.TypeParam]Label
 }
 
 func FileFor(path string) (string, error) {
@@ -64,6 +65,7 @@ func NewWriter(path string, pkg *packages.Package) (*Writer, error) {
 		trapFilePath,
 		pkg,
 		make(map[ast.Expr]types.Type),
+		make(map[*types.TypeParam]Label),
 	}
 	tw.Labeler = newLabeler(tw)
 	return tw, nil

ql/lib/go.dbscheme

@@ -227,7 +227,9 @@ has_ellipsis(int id: @callorconversionexpr ref);
 
 variadic(int id: @signaturetype ref);
 
-typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref);
+#keyset[parent, idx]
+typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref,
+          int parent: @typeparamparentobject ref, int idx: int ref);
 
 @container = @file | @folder;
 
@@ -248,7 +250,7 @@ typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound:
 
 @declparent = @file | @declstmt;
 
-@typeparamdeclparent = @functypeexpr | @typespec;
+@typeparamdeclparent = @funcdecl | @typespec;
 
 @funcdef = @funclit | @funcdecl;
 
@@ -439,6 +441,8 @@ case @object.kind of
 | 7 = @builtinfunctionobject
 | 8 = @labelobject;
 
+@typeparamparentobject = @decltypeobject | @declfunctionobject;
+
 @declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
 
 @builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;

ql/lib/semmle/go/Types.qll

@@ -367,10 +367,10 @@ class CompositeType extends @compositetype, Type { }
 /** A type that comes from a type parameter. */
 class TypeParamType extends @typeparamtype, CompositeType {
   /** Gets the name of this type parameter type. */
-  string getParamName() { typeparam(this, result, _) }
+  string getParamName() { typeparam(this, result, _, _, _) }
 
   /** Gets the constraint of this type parameter type. */
-  Type getConstraint() { typeparam(this, _, result) }
+  Type getConstraint() { typeparam(this, _, result, _, _) }
 
   override InterfaceType getUnderlyingType() { result = this.getConstraint().getUnderlyingType() }