In the MS ABI, ctors return 'this'. Patch by Dmitry Sokolov.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164592 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 35 insertions, 12 deletions

diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index 6a2925bbd9..b000c68a95 100644
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -33,10 +33,7 @@ public:
   void BuildConstructorSignature(const CXXConstructorDecl *Ctor,
                                  CXXCtorType Type,
                                  CanQualType &ResTy,
-                                 SmallVectorImpl<CanQualType> &ArgTys) {
-    // 'this' is already in place
-    // TODO: 'for base' flag
-  }  
+                                 SmallVectorImpl<CanQualType> &ArgTys);
 
   void BuildDestructorSignature(const CXXDestructorDecl *Ctor,
                                 CXXDtorType Type,
@@ -48,15 +45,9 @@ public:
 
   void BuildInstanceFunctionParams(CodeGenFunction &CGF,
                                    QualType &ResTy,
-                                   FunctionArgList &Params) {
-    BuildThisParam(CGF, Params);
-    // TODO: 'for base' flag
-  }
+                                   FunctionArgList &Params);
 
-  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
-    EmitThisParam(CGF);
-    // TODO: 'for base' flag
-  }
+  void EmitInstanceFunctionProlog(CodeGenFunction &CGF);
 
   void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
                        llvm::GlobalVariable *DeclPtr,
@@ -99,10 +90,42 @@ public:
   llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
                                    llvm::Value *allocPtr,
                                    CharUnits cookieSize);
+  static bool needThisReturn(GlobalDecl GD);
 };
 
 }
 
+bool MicrosoftCXXABI::needThisReturn(GlobalDecl GD) {
+  const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl());
+  return isa<CXXConstructorDecl>(MD);
+}
+
+void MicrosoftCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor,
+                                 CXXCtorType Type,
+                                 CanQualType &ResTy,
+                                 SmallVectorImpl<CanQualType> &ArgTys) {
+  // 'this' is already in place
+  // TODO: 'for base' flag
+  // Ctor returns this ptr
+  ResTy = ArgTys[0];
+}
+
+void MicrosoftCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF,
+                                                  QualType &ResTy,
+                                                  FunctionArgList &Params) {
+  BuildThisParam(CGF, Params);
+  if (needThisReturn(CGF.CurGD)) {
+    ResTy = Params[0]->getType();
+  }
+}
+
+void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
+  EmitThisParam(CGF);
+  if (needThisReturn(CGF.CurGD)) {
+    CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
+  }
+}
+
 bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
                                    QualType elementType) {
   // Microsoft seems to completely ignore the possibility of a