Improve declaration / expression disambiguation around ptr-operators, and use

the presence of an abstract declarator with a ptr-operator as proof that a
construct cannot parse as an expression to improve diagnostics along error
recovery paths.

llvm-svn: 230261

4 files changed, 20 insertions, 4 deletions

diff --git a/clang/test/Parser/cxx-ambig-init-templ.cpp b/clang/test/Parser/cxx-ambig-init-templ.cpp
index 1f692664137..584262c9be4 100644
--- a/clang/test/Parser/cxx-ambig-init-templ.cpp
+++ b/clang/test/Parser/cxx-ambig-init-templ.cpp
@@ -170,6 +170,15 @@ namespace ElaboratedTypeSpecifiers {
   };
 }
 
+namespace AbstractPtrOperatorDeclarator {
+  template <int, typename> struct X {
+    operator int();
+  };
+  struct Y {
+    void f(int a = X<0, int (*)()>());
+  };
+}
+
 namespace PR20459 {
   template <typename EncTraits> struct A {
      void foo(int = EncTraits::template TypeEnc<int, int>::val); // ok
diff --git a/clang/test/Parser/cxx-variadic-func.cpp b/clang/test/Parser/cxx-variadic-func.cpp
index 98a34d3e1bf..c0fad95e468 100644
--- a/clang/test/Parser/cxx-variadic-func.cpp
+++ b/clang/test/Parser/cxx-variadic-func.cpp
@@ -1,8 +1,7 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
 void f(...) {
-  // FIXME: There's no disambiguation here; this is unambiguous.
-  int g(int(...)); // expected-warning {{disambiguated}} expected-note {{paren}}
+  int g(int(...)); // no warning, unambiguously a function declaration
 }
 
 void h(int n..., int m); // expected-error {{expected ')'}} expected-note {{to match}}
diff --git a/clang/test/Parser/recovery.cpp b/clang/test/Parser/recovery.cpp
index 2d5b518c691..f099473e04b 100644
--- a/clang/test/Parser/recovery.cpp
+++ b/clang/test/Parser/recovery.cpp
@@ -203,6 +203,14 @@ namespace pr15133 {
   };
 }
 
+namespace AbstractPtrOperator {
+  // A ptr-operator and no name means we have a declaration and not an
+  // expression.
+  template<typename T> int f(int*, T::type); // expected-error {{missing 'typename'}}
+  template<typename T> int f(int (T::*), T::type); // expected-error {{missing 'typename'}}
+  template<typename T> int f(int (*)(), T::type); // expected-error {{missing 'typename'}}
+}
+
 namespace InvalidEmptyNames {
 // These shouldn't crash, the diagnostics aren't important.
 struct ::, struct ::; // expected-error 2 {{expected identifier}} expected-error 2 {{declaration of anonymous struct must be a definition}} expected-warning {{declaration does not declare anything}}
diff --git a/clang/test/SemaTemplate/rdar9173693.cpp b/clang/test/SemaTemplate/rdar9173693.cpp
index 86b49545a30..1e999cba670 100644
--- a/clang/test/SemaTemplate/rdar9173693.cpp
+++ b/clang/test/SemaTemplate/rdar9173693.cpp
@@ -2,5 +2,5 @@
 
 // <rdar://problem/9173693>
 template< bool C > struct assert { };
-template< bool > struct assert_arg_pred_impl { }; // expected-note 3 {{declared here}}
-template< typename Pred > assert<false> assert_not_arg( void (*)(Pred), typename assert_arg_pred<Pred>::type ); // expected-error 5 {{}}
+template< bool > struct assert_arg_pred_impl { }; // expected-note 2 {{declared here}}
+template< typename Pred > assert<false> assert_not_arg( void (*)(Pred), typename assert_arg_pred<Pred>::type ); // expected-error 3 {{}}