Omit 'nodebug' method from the class

[probinson]

Summary

CodeGenFunction suppresses debug info for the definition of a method with attribute 'nodebug'.
For consistency, the declaration should also be omitted from the class description.

[probinson]

Repeating the summary because I spaced out on adding reviewers *before* saving... again...

CodeGenFunction suppresses debug info for the definition of a method with attribute 'nodebug'.
For consistency, the declaration should also be omitted from the class description.

[dblaikie]

Looks good - thanks!

test/CodeGenCXX/debug-info-method-nodebug.cpp

6

do you need the int member?

[probinson]

test/CodeGenCXX/debug-info-method-nodebug.cpp

6

No. I'll take it out.
(Leftover from a fatter test that also checked codegen didn't emit any dbg annotations in a definition of absent(). But it turned out there's already CodeGen/attr-nodebug.c which is testing the codegen part, so I removed the definition.)

Hmmm looks like attr-nodebug.c could be more robust... I'll look at that in a bit.

[probinson]

r240664, thanks!

lib/CodeGen/CGDebugInfo.cpp

void CGDebugInfo::CollectCXXMemberFunctions(
   // have templated functions iterate over every declaration to gather
   // the functions.
   for (const auto *I : RD->decls()) {
     const auto *Method = dyn_cast<CXXMethodDecl>(I);
     // If the member is implicit, don't add it to the member list. This avoids
     // the member being added to type units by LLVM, while still allowing it
     // to be emitted into the type declaration/reference inside the compile
     // unit.
+    // Ditto 'nodebug' methods, for consistency with CodeGenFunction.cpp.
     // FIXME: Handle Using(Shadow?)Decls here to create
     // DW_TAG_imported_declarations inside the class for base decls brought into
     // derived classes. GDB doesn't seem to notice/leverage these when I tried
     // it, so I'm not rushing to fix this. (GCC seems to produce them, if
     // referenced)
-    if (!Method || Method->isImplicit())
+    if (!Method || Method->isImplicit() || Method->hasAttr<NoDebugAttr>())
       continue;
 
     if (Method->getType()->getAs<FunctionProtoType>()->getContainedAutoType())
       continue;
 
     // Reuse the existing member function declaration if it exists.
     // It may be associated with the declaration of the type & should be
     // reused as we're building the definition.

test/CodeGenCXX/debug-info-method-nodebug.cpp

+// RUN: %clang_cc1 -emit-llvm -g %s -o - | FileCheck %s
+
+class C {
+  void present();
+  void absent() __attribute__((nodebug));
+  int i;
+};
+
+C c;
+
+// CHECK-NOT: name: "absent"
+// CHECK:     name: "present"
+// CHECK-NOT: name: "absent"