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
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index c6a00b1..f8e6c9d 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1037,6 +1037,8 @@
default: return false;
case X86::BI__builtin_cpu_supports:
return SemaBuiltinCpuSupports(TheCall);
+ case X86::BI__builtin_ms_va_start:
+ return SemaBuiltinMSVAStart(TheCall);
case X86::BI_mm_prefetch: i = 1; l = 0; u = 3; break;
case X86::BI__builtin_ia32_sha1rnds4: i = 2, l = 0; u = 3; break;
case X86::BI__builtin_ia32_vpermil2pd:
@@ -2317,9 +2319,10 @@
return false;
}
-/// SemaBuiltinVAStart - Check the arguments to __builtin_va_start for validity.
-/// Emit an error and return true on failure, return false on success.
-bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
+/// Check the arguments to '__builtin_va_start' or '__builtin_ms_va_start'
+/// for validity. Emit an error and return true on failure; return false
+/// on success.
+bool Sema::SemaBuiltinVAStartImpl(CallExpr *TheCall) {
Expr *Fn = TheCall->getCallee();
if (TheCall->getNumArgs() > 2) {
Diag(TheCall->getArg(2)->getLocStart(),
@@ -2397,6 +2400,48 @@
return false;
}
+/// Check the arguments to '__builtin_va_start' for validity, and that
+/// it was called from a function of the native ABI.
+/// Emit an error and return true on failure; return false on success.
+bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
+ // On x86-64 Unix, don't allow this in Win64 ABI functions.
+ // On x64 Windows, don't allow this in System V ABI functions.
+ // (Yes, that means there's no corresponding way to support variadic
+ // System V ABI functions on Windows.)
+ if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86_64) {
+ unsigned OS = Context.getTargetInfo().getTriple().getOS();
+ clang::CallingConv CC = CC_C;
+ if (const FunctionDecl *FD = getCurFunctionDecl())
+ CC = FD->getType()->getAs<FunctionType>()->getCallConv();
+ if ((OS == llvm::Triple::Win32 && CC == CC_X86_64SysV) ||
+ (OS != llvm::Triple::Win32 && CC == CC_X86_64Win64))
+ return Diag(TheCall->getCallee()->getLocStart(),
+ diag::err_va_start_used_in_wrong_abi_function)
+ << (OS != llvm::Triple::Win32);
+ }
+ return SemaBuiltinVAStartImpl(TheCall);
+}
+
+/// Check the arguments to '__builtin_ms_va_start' for validity, and that
+/// it was called from a Win64 ABI function.
+/// Emit an error and return true on failure; return false on success.
+bool Sema::SemaBuiltinMSVAStart(CallExpr *TheCall) {
+ // This only makes sense for x86-64.
+ const llvm::Triple &TT = Context.getTargetInfo().getTriple();
+ Expr *Callee = TheCall->getCallee();
+ if (TT.getArch() != llvm::Triple::x86_64)
+ return Diag(Callee->getLocStart(), diag::err_x86_builtin_32_bit_tgt);
+ // Don't allow this in System V ABI functions.
+ clang::CallingConv CC = CC_C;
+ if (const FunctionDecl *FD = getCurFunctionDecl())
+ CC = FD->getType()->getAs<FunctionType>()->getCallConv();
+ if (CC == CC_X86_64SysV ||
+ (TT.getOS() != llvm::Triple::Win32 && CC != CC_X86_64Win64))
+ return Diag(Callee->getLocStart(),
+ diag::err_ms_va_start_used_in_sysv_function);
+ return SemaBuiltinVAStartImpl(TheCall);
+}
+
bool Sema::SemaBuiltinVAStartARM(CallExpr *Call) {
// void __va_start(va_list *ap, const char *named_addr, size_t slot_size,
// const char *named_addr);