[Windows] Use thiscall as the default calling convention for class methods. PR12785

llvm-svn: 160121

5 files changed, 22 insertions, 8 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 27e4de926d3..2a1521e21e8 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -7098,9 +7098,15 @@ bool ASTContext::DeclMustBeEmitted(const Decl *D) {
   return true;
 }
 
-CallingConv ASTContext::getDefaultMethodCallConv() {
+CallingConv ASTContext::getDefaultCXXMethodCallConv(bool isVariadic) {
   // Pass through to the C++ ABI object
-  return ABI->getDefaultMethodCallConv();
+  return ABI->getDefaultMethodCallConv(isVariadic);
+}
+
+CallingConv ASTContext::getCanonicalCallConv(CallingConv CC) const {
+  if (CC == CC_C && !LangOpts.MRTD && getTargetInfo().getCXXABI() != CXXABI_Microsoft)
+    return CC_Default;
+  return CC;
 }
 
 bool ASTContext::isNearlyEmpty(const CXXRecordDecl *RD) const {
diff --git a/clang/lib/AST/CXXABI.h b/clang/lib/AST/CXXABI.h
index 943c43e7919..0d9c869d87c 100644
--- a/clang/lib/AST/CXXABI.h
+++ b/clang/lib/AST/CXXABI.h
@@ -32,7 +32,7 @@ public:
   virtual unsigned getMemberPointerSize(const MemberPointerType *MPT) const = 0;
 
   /// Returns the default calling convention for C++ methods.
-  virtual CallingConv getDefaultMethodCallConv() const = 0;
+  virtual CallingConv getDefaultMethodCallConv(bool isVariadic) const = 0;
 
   // Returns whether the given class is nearly empty, with just virtual pointers
   // and no data except possibly virtual bases.
diff --git a/clang/lib/AST/ItaniumCXXABI.cpp b/clang/lib/AST/ItaniumCXXABI.cpp
index 0027dbf1915..ce1244c5427 100644
--- a/clang/lib/AST/ItaniumCXXABI.cpp
+++ b/clang/lib/AST/ItaniumCXXABI.cpp
@@ -39,7 +39,7 @@ public:
     return 1;
   }
 
-  CallingConv getDefaultMethodCallConv() const {
+  CallingConv getDefaultMethodCallConv(bool isVariadic) const {
     return CC_C;
   }
 
diff --git a/clang/lib/AST/MicrosoftCXXABI.cpp b/clang/lib/AST/MicrosoftCXXABI.cpp
index f33d6fe1f56..51308ea0c0f 100644
--- a/clang/lib/AST/MicrosoftCXXABI.cpp
+++ b/clang/lib/AST/MicrosoftCXXABI.cpp
@@ -29,8 +29,8 @@ public:
 
   unsigned getMemberPointerSize(const MemberPointerType *MPT) const;
 
-  CallingConv getDefaultMethodCallConv() const {
-    if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
+  CallingConv getDefaultMethodCallConv(bool isVariadic) const {
+    if (!isVariadic && Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
       return CC_X86ThisCall;
     else
       return CC_C;
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 37c654d6669..d9fa0579713 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -1159,8 +1159,16 @@ void MicrosoftCXXNameMangler::mangleCallingConvention(const FunctionType *T,
   // that they could be in a DLL and somebody from another module could call
   // them.)
   CallingConv CC = T->getCallConv();
-  if (CC == CC_Default)
-    CC = IsInstMethod ? getASTContext().getDefaultMethodCallConv() : CC_C;
+  if (CC == CC_Default) {
+    if (IsInstMethod) {
+      const FunctionProtoType *FPT =
+        T->getCanonicalTypeUnqualified().getAs<FunctionProtoType>();
+      bool isVariadic = FPT->isVariadic();
+      CC = getASTContext().getDefaultCXXMethodCallConv(isVariadic);
+    } else {
+      CC = CC_C;
+    }
+  }
   switch (CC) {
     default:
       llvm_unreachable("Unsupported CC for mangling");