Delay check for prototype on __fastcall functions until after MergeFunctionDecl.

In C, it is only known after merging decls if a function with 0 arguments has
a prototype.  Fixes PR20386, see that for more notes.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214408 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 17 deletions

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 4ad066a7a7..47df3a69aa 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -4564,23 +4564,12 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state,
     }
   }
 
-  // Diagnose the use of X86 fastcall on unprototyped functions.
-  if (CC == CC_X86FastCall) {
-    if (isa<FunctionNoProtoType>(fn)) {
-      S.Diag(attr.getLoc(), diag::err_cconv_knr)
-        << FunctionType::getNameForCallConv(CC);
-      attr.setInvalid();
-      return true;
-    }
-
-    // Also diagnose fastcall with regparm.
-    if (fn->getHasRegParm()) {
-      S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
-        << "regparm"
-        << FunctionType::getNameForCallConv(CC);
-      attr.setInvalid();
-      return true;
-    }
+  // Also diagnose fastcall with regparm.
+  if (CC == CC_X86FastCall && fn->getHasRegParm()) {
+    S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
+        << "regparm" << FunctionType::getNameForCallConv(CC_X86FastCall);
+    attr.setInvalid();
+    return true;
   }
 
   // Modify the CC from the wrapped function type, wrap it all back, and then