[hip] Fix ambiguity from >>> of CUDA.

Summary:
- For template arguments ending with `>>>`, we should cease lookahead
  and treat it as type-id firstly, so that deduction could work
  properly.

Reviewers: tra, yaxunl

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D61396

llvm-svn: 360214

clang/lib/Parse/ParseTentative.cpp

@@ -590,9 +590,11 @@ bool Parser::isCXXTypeId(TentativeCXXTypeIdContext Context, bool &isAmbiguous) {
     } else if (Context == TypeIdAsTemplateArgument &&
                (Tok.isOneOf(tok::greater, tok::comma) ||
                 (getLangOpts().CPlusPlus11 &&
-                 (Tok.is(tok::greatergreater) ||
+                 (Tok.isOneOf(tok::greatergreater,
+                              tok::greatergreatergreater) ||
                   (Tok.is(tok::ellipsis) &&
                    NextToken().isOneOf(tok::greater, tok::greatergreater,
+                                       tok::greatergreatergreater,
                                        tok::comma)))))) {
       TPR = TPResult::True;
       isAmbiguous = true;

clang/test/Parser/cuda-kernel-call-c++11.cu

@@ -3,6 +3,10 @@
 template<typename T=int> struct S {};
 template<typename> void f();
 
+template<typename T, typename... V> struct S<T(V...)> {};
+
+template<typename ...T> struct V {};
+template<typename ...T> struct V<void(T)...> {};
 
 void foo(void) {
   // In C++11 mode, all of these are expected to parse correctly, and the CUDA
@@ -21,4 +25,11 @@ void foo(void) {
 
   (void)(&f<S<S<int>>>==0);
   (void)(&f<S<S<>>>==0);
+
+  S<S<S<void()>>> s6;
+}
+
+template<typename ...T>
+void bar(T... args) {
+  S<S<V<void(T)...>>> s7;
 }