[clang] [Clang][Cygwin] Cygwin x86_64 should accept __stdcall (PR #158385)

[Tomohiro Kashiwada via cfe-commits]

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@@ -997,9 +998,37 @@ class LLVM_LIBRARY_VISIBILITY CygwinX86_64TargetInfo : public X86_64TargetInfo {
       Builder.defineMacro("_GNU_SOURCE");
   }
 
+  CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {
+    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_PreserveMost:
+    case CC_PreserveAll:
+    case CC_PreserveNone:
+    case CC_X86_64SysV:
+    case CC_Swift:
+    case CC_SwiftAsync:
+    case CC_X86RegCall:
+    case CC_DeviceKernel:
+      return CCCR_OK;
+    default:
+      return CCCR_Warning;
+    }
+  }
+
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::CharPtrBuiltinVaList;
   }
+
+  TargetInfo::CallingConvKind
+  getCallingConvKind(bool ClangABICompat4) const override {
+    return CCK_MicrosoftWin64;
+  }
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kikairoya wrote:

Ah, thanks, that looks wrong.

https://github.com/llvm/llvm-project/pull/158385