Revert "PR14569: Omit debug info for thunks"

This reverts commit r189320.

Alexey Samsonov and Dmitry Vyukov presented some arguments for keeping
these around - though it still seems like those tasks could be solved by
a tool just using the symbol table. In a very small number of cases,
thunks may be inlined & debug info might be able to save profilers &
similar tools from misclassifying those cases as part of the caller.

The extra changes here plumb through the VarDecl for various cases to
CodeGenFunction - this provides better fidelity through a few APIs but
generally just causes the CGF::StartFunction to fallback to using the
name of the IR function as the name in the debug info.

The changes to debug-info-global-ctor-dtor.cpp seem like goodness. The
two names that go missing (in favor of only emitting those names as
linkage names) are names that can be demangled - emitting them only as
the linkage name should encourage tools to do just that.

Again, thanks to Dinesh Dwivedi for investigation/work on this issue.

llvm-svn: 189421

1 files changed, 2 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 2579d5bd633..12aa0a2b7c4 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -261,7 +261,8 @@ pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
     if (E->getType()->isArrayType()) {
       CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
           cast<llvm::Constant>(ReferenceTemporary), E->getType(),
-          CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions);
+          CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
+          dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
       CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
     } else {
       CleanupFn =