[OpenCL][Sema] Improve BuildResolvedCallExpr handling of builtins

[mantognini]

Summary

This is a follow-up on https://reviews.llvm.org/D52879, addressing a few issues.

This:

• adds a FIXME for later improvement for specific builtins: I previously have only checked OpenCL ones and ensured tests cover those.
• fixed the CallExpr type.

[riccibruno]

Much better. LGTM with a small format nit.

lib/Sema/SemaExpr.cpp

5556 ↗

(On Diff #176157)

This goes over 80 cols.

[Anastasia]

lib/Sema/SemaExpr.cpp

5556 ↗

(On Diff #176157)

I think the format is normally

// FIXME: text...
// more text...

No extra spaces on the next line. :)

cfe/trunk/lib/Sema/SemaExpr.cpp

if (Caller->hasAttr<ARMInterruptAttr>()) {
       if (VFP && (!FDecl || !FDecl->hasAttr<ARMInterruptAttr>()))
         Diag(Fn->getExprLoc(), diag::warn_arm_interrupt_calling_convention);
     }
 
   // Promote the function operand.
   // We special-case function promotion here because we only allow promoting
   // builtin functions to function pointers in the callee of a call.
   ExprResult Result;
-  QualType ReturnTy;
+  QualType ResultTy;
   if (BuiltinID &&
       Fn->getType()->isSpecificBuiltinType(BuiltinType::BuiltinFn)) {
     // Extract the return type from the (builtin) function pointer type.
-    auto FnPtrTy = Context.getPointerType(FDecl->getType());
+    // FIXME Several builtins still have setType in
+    //       Sema::CheckBuiltinFunctionCall. One should review their
+    //       definitions in Builtins.def to ensure they are correct before
+    //       removing setType calls.
+    QualType FnPtrTy = Context.getPointerType(FDecl->getType());
     Result = ImpCastExprToType(Fn, FnPtrTy, CK_BuiltinFnToFnPtr).get();
-    auto FnTy = FnPtrTy->getPointeeType()->castAs<FunctionType>();
-    ReturnTy = FnTy->getReturnType();
+    ResultTy = FDecl->getCallResultType();
   } else {
     Result = CallExprUnaryConversions(Fn);
-    ReturnTy = Context.BoolTy;
+    ResultTy = Context.BoolTy;
   }
   if (Result.isInvalid())
     return ExprError();
   Fn = Result.get();
 
   // Make the call expr early, before semantic checks.  This guarantees cleanup
   // of arguments and function on error.
   CallExpr *TheCall;
   if (Config)
     TheCall =
         new (Context) CUDAKernelCallExpr(Context, Fn, cast<CallExpr>(Config),
-                                         Args, ReturnTy, VK_RValue, RParenLoc);
+                                         Args, ResultTy, VK_RValue, RParenLoc);
   else
     TheCall = new (Context)
-        CallExpr(Context, Fn, Args, ReturnTy, VK_RValue, RParenLoc);
+        CallExpr(Context, Fn, Args, ResultTy, VK_RValue, RParenLoc);
 
   if (!getLangOpts().CPlusPlus) {
     // C cannot always handle TypoExpr nodes in builtin calls and direct
     // function calls as their argument checking don't necessarily handle
     // dependent types properly, so make sure any TypoExprs have been
     // dealt with.
     ExprResult Result = CorrectDelayedTyposInExpr(TheCall);
     if (!Result.isUsable()) return ExprError();