Win64: Silently ignore __stdcall, __fastcall, and __thiscall

MSVC doesn't warn on this. Users are expected to apply the WINAPI macro
to functions passed by pointer to the Win32 API, and this macro expands
to __stdcall. This means we end up with a lot of useless noisy warnings
about ignored calling conventions when compiling code with clang for
Win64.

llvm-svn: 230668

1 files changed, 16 insertions, 4 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 03cd853d66e..a7c8413dd9f 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -3626,19 +3626,31 @@ public:
     IntPtrType = SignedLongLong;
     this->UserLabelPrefix = "";
   }
+
   void getTargetDefines(const LangOptions &Opts,
                                 MacroBuilder &Builder) const override {
     WindowsTargetInfo<X86_64TargetInfo>::getTargetDefines(Opts, Builder);
     Builder.defineMacro("_WIN64");
   }
+
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::CharPtrBuiltinVaList;
   }
+
   CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {
-    return (CC == CC_C ||
-            CC == CC_X86VectorCall ||
-            CC == CC_IntelOclBicc ||
-            CC == CC_X86_64SysV) ? CCCR_OK : CCCR_Warning;
+    switch (CC) {
+    case CC_X86StdCall:
+    case CC_X86ThisCall:
+    case CC_X86FastCall:
+      return CCCR_Ignore;
+    case CC_C:
+    case CC_X86VectorCall:
+    case CC_IntelOclBicc:
+    case CC_X86_64SysV:
+      return CCCR_OK;
+    default:
+      return CCCR_Warning;
+    }
   }
 };
 } // end anonymous namespace