Restore r184205 and associated commits (after commit of r185290)

This allows clang to use the backend parameter attribute 'returned' when generating 'this'-returning constructors and destructors in ARM and MSVC C++ ABIs.

llvm-svn: 185291

1 files changed, 6 insertions, 10 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index c6b498c..bea13d4 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -42,8 +42,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
     AutoreleaseResult(false), BlockInfo(0), BlockPointer(0),
     LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1),
     FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0),
-    DebugInfo(0), DisableDebugInfo(false), CalleeWithThisReturn(0),
-    DidCallStackSave(false),
+    DebugInfo(0), DisableDebugInfo(false), DidCallStackSave(false),
     IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
     NumReturnExprs(0), NumSimpleReturnExprs(0),
     CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
@@ -662,8 +661,12 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   QualType ResTy = FD->getResultType();
 
   CurGD = GD;
-  if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance())
+  const CXXMethodDecl *MD;
+  if ((MD = dyn_cast<CXXMethodDecl>(FD)) && MD->isInstance()) {
+    if (CGM.getCXXABI().HasThisReturn(GD))
+      ResTy = MD->getThisType(getContext());
     CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args);
+  }
 
   for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i)
     Args.push_back(FD->getParamDecl(i));
@@ -672,10 +675,6 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange();
   CurEHLocation = BodyRange.getEnd();
 
-  // CalleeWithThisReturn keeps track of the last callee inside this function
-  // that returns 'this'. Before starting the function, we set it to null.
-  CalleeWithThisReturn = 0;
-
   // Emit the standard function prologue.
   StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin());
 
@@ -727,9 +726,6 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
 
   // Emit the standard function epilogue.
   FinishFunction(BodyRange.getEnd());
-  // CalleeWithThisReturn keeps track of the last callee inside this function
-  // that returns 'this'. After finishing the function, we set it to null.
-  CalleeWithThisReturn = 0;
 
   // If we haven't marked the function nothrow through other means, do
   // a quick pass now to see if we can.