Mark lambda closure classes as being implicitly-generated.

Summary: Closure classes for C++ lambdas are always compiler-generated.  This one-line change calls setImplicit(true) on them at creation time, such that a default RecursiveASTVisitor (or any for which shouldVisitImplicitCode returns false) will skip them.

Reviewers: rsmith, dblaikie

Reviewed By: dblaikie

CC: klimek, revane, cfe-commits, jordan_rose

Differential Revision: http://llvm-reviews.chandlerc.com/D1593

llvm-svn: 190073

clang/lib/AST/DeclCXX.cpp

@@ -114,6 +114,7 @@ CXXRecordDecl *CXXRecordDecl::CreateLambda(const ASTContext &C, DeclContext *DC,
   R->IsBeingDefined = true;
   R->DefinitionData = new (C) struct LambdaDefinitionData(R, Info, Dependent);
   R->MayHaveOutOfDateDef = false;
+  R->setImplicit(true);
   C.getTypeDeclType(R, /*PrevDecl=*/0);
   return R;
 }

clang/unittests/Tooling/RecursiveASTVisitorTest.cpp

@@ -522,4 +522,30 @@ TEST(RecursiveASTVisitor, HasCaptureDefaultLoc) {
                               LambdaDefaultCaptureVisitor::Lang_CXX11));
 }
 
+// Checks for lambda classes that are not marked as implicitly-generated.
+// (There should be none.)
+class ClassVisitor : public ExpectedLocationVisitor<ClassVisitor> {
+public:
+  ClassVisitor() : SawNonImplicitLambdaClass(false) {}
+  bool VisitCXXRecordDecl(CXXRecordDecl* record) {
+    if (record->isLambda() && !record->isImplicit())
+      SawNonImplicitLambdaClass = true;
+    return true;
+  }
+
+  bool sawOnlyImplicitLambdaClasses() const {
+    return !SawNonImplicitLambdaClass;
+  }
+
+private:
+  bool SawNonImplicitLambdaClass;
+};
+
+TEST(RecursiveASTVisitor, LambdaClosureTypesAreImplicit) {
+  ClassVisitor Visitor;
+  EXPECT_TRUE(Visitor.runOver("auto lambda = []{};",
+			      ClassVisitor::Lang_CXX11));
+  EXPECT_TRUE(Visitor.sawOnlyImplicitLambdaClasses());
+}
+
 } // end namespace clang