Support __builtin_ms_va_list.

Summary:
This change adds support for `__builtin_ms_va_list`, a GCC extension for
variadic `ms_abi` functions. The existing `__builtin_va_list` support is
inadequate for this because `va_list` is defined differently in the Win64
ABI vs. the System V/AMD64 ABI.

Depends on D1622.

Reviewers: rsmith, rnk, rjmccall

CC: cfe-commits

Differential Revision: http://reviews.llvm.org/D1623

llvm-svn: 247941

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 201bebf9dbb..07c706b49a9 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -61,6 +61,11 @@ ABIInfo::getNaturalAlignIndirectInReg(QualType Ty, bool Realign) const {
                                       /*ByRef*/ false, Realign);
 }
 
+Address ABIInfo::EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
+                             QualType Ty) const {
+  return Address::invalid();
+}
+
 ABIInfo::~ABIInfo() {}
 
 static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT,
@@ -1734,6 +1739,8 @@ public:
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
+  Address EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
+                      QualType Ty) const override;
 
   bool has64BitPointers() const {
     return Has64BitPointers;
@@ -3266,6 +3273,14 @@ Address X86_64ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
   return ResAddr;
 }
 
+Address X86_64ABIInfo::EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
+                                   QualType Ty) const {
+  return emitVoidPtrVAArg(CGF, VAListAddr, Ty, /*indirect*/ false,
+                          CGF.getContext().getTypeInfoInChars(Ty),
+                          CharUnits::fromQuantity(8),
+                          /*allowHigherAlign*/ false);
+}
+
 ABIArgInfo WinX86_64ABIInfo::classify(QualType Ty, unsigned &FreeSSERegs,
                                       bool IsReturnType) const {