Fix the following bug submitted by Justin Handville.

int main(int argc, char* argv[])
{
  return 0;
}

After speaking briefly with Chris, we decided this should be a front-end fix.

The fix...have Sema::GetTypeForDeclarator() do the default function/array conversion, as
I outlined in the 9/9 email on this topic.

Since this conversion is done before Sema::ParseParamDeclarator(), I thought I could
remove the conversion from Sema::ParseParamDeclarator(). Unfortunately, this didn't work.
The conversion apparently needs to be done in both places (which doesn't make sense to me).

Will investigate.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41811 91177308-0d34-0410-b5e6-96231b3b80d8

Sema/SemaType.cpp

@@ -261,11 +261,28 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
         for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
           QualType ArgTy = QualType::getFromOpaquePtr(FTI.ArgInfo[i].TypeInfo);
           assert(!ArgTy.isNull() && "Couldn't parse type?");
-          
+          //
+          // Perform the default function/array conversion (C99 6.7.5.3p[7,8]).
+          // This matches the conversion that is done in 
+          // Sema::ParseParamDeclarator(). Without this conversion, the
+          // argument type in the function prototype *will not* match the
+          // type in ParmVarDecl (which makes the code generator unhappy).
+          //
+          // FIXME: We still apparently need the conversion in 
+          // Sema::ParseParamDeclarator(). This doesn't make any sense, since
+          // it should be driving off the type being created here.
+          // 
+          // FIXME: If a source translation tool needs to see the original type,
+          // then we need to consider storing both types somewhere...
+          // 
+          if (const ArrayType *AT = ArgTy->getAsArrayType())
+            ArgTy = Context.getPointerType(AT->getElementType());
+          else if (ArgTy->isFunctionType())
+            ArgTy = Context.getPointerType(ArgTy);
           // Look for 'void'.  void is allowed only as a single argument to a
           // function with no other parameters (C99 6.7.5.3p10).  We record
           // int(void) as a FunctionTypeProto with an empty argument list.
-          if (ArgTy->isVoidType()) {
+          else if (ArgTy->isVoidType()) {
             // If this is something like 'float(int, void)', reject it.  'void'
             // is an incomplete type (C99 6.2.5p19) and function decls cannot
             // have arguments of incomplete type.