[clang] Include trailing-requires-clause in FunctionDecl's source range

[nridge]

Summary

Fixes https://github.com/clangd/clangd/issues/476

[hokein]

thanks.

clang/test/AST/ast-dump-concepts.cpp

28

could you add one more test (with a function body)?

[nridge]

Address review comment

[nridge]

Rebase to avoid dependency on D84136

clang-tools-extra/clangd/unittests/FindTargetTests.cpp

Code = R"cpp(
     template <typename T, typename U>
     concept Fooable = true;
 
     template <[[Fooable]]<int> T>
     void bar(T t);
   )cpp";
   EXPECT_DECLS("ConceptSpecializationExpr",
                {"template <typename T, typename U> concept Fooable = true;"});
+
+  // trailing requires clause
+  Code = R"cpp(
+      template <typename T>
+      concept Fooable = true;
+
+      template <typename T>
+      void foo() requires [[Fooable]]<T>;
+  )cpp";
+  EXPECT_DECLS("ConceptSpecializationExpr",
+               {"template <typename T> concept Fooable = true;"});
 }
 
 TEST_F(TargetDeclTest, FunctionTemplate) {
   Code = R"cpp(
     // Implicit specialization.
     template<typename T> bool foo(T) { return false; };
     bool x = [[foo]](42);
   )cpp";

clang/include/clang/Sema/DeclSpec.h

for (const auto &Chunk : type_objects())
           Chunk.Fun.hasTrailingReturnType())
         return true;
     return false;
   }
 
   /// \brief Sets a trailing requires clause for this declarator.
   void setTrailingRequiresClause(Expr *TRC) {
     TrailingRequiresClause = TRC;
+
+    SetRangeEnd(TRC->getEndLoc());
   }
 
   /// \brief Sets a trailing requires clause for this declarator.
   Expr *getTrailingRequiresClause() {
     return TrailingRequiresClause;
   }
 
   /// \brief Determine whether a trailing requires clause was written in this

clang/test/AST/ast-dump-concepts.cpp

struct Foo {
   // CHECK-NEXT: `-TemplateArgument {{.*}} type 'int'
   template <binary_concept<int> R>
   Foo(R);
 
   // CHECK:      TemplateTypeParmDecl {{.*}} referenced Concept {{.*}} 'unary_concept'
   // CHECK-NEXT: `-ConceptSpecializationExpr {{.*}} <col:13> 'bool'
   template <unary_concept R>
   Foo(R);
+
+  // CHECK:      FunctionTemplateDecl {{.*}} <line:29:3, line:30:39> {{.*}} Foo<T>
+  template <typename R>
+  Foo(R, int) requires unary_concept<R>;
+
+  // CHECK:      FunctionTemplateDecl {{.*}} <line:33:3, line:35:3> {{.*}} Foo<T>
+  template <typename R>
+  Foo(R, char) requires unary_concept<R> {
+  }
 };