c++: Don't show constructor internal name in error message [PR105483]

We mention 'X::__ct' instead of 'X::X' in the "names the constructor,
not the type" error for this invalid code:

=== cut here ===
struct X {};
void g () {
  X::X x;
}
=== cut here ===

The problem is that we use %<%T::%D%> to build the error message, while
%qE does exactly what we need since we have DECL_CONSTRUCTOR_P. This is
what this patch does.

It also skips until the end of the statement and returns error_mark_node
for this and the preceding if block, to avoid emitting extra (useless)
errors.

	PR c++/105483

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_expression_statement): Use %qE instead of
	incorrect %<%T::%D%>. Skip to end of statement and return
	error_mark_node in case of error.

gcc/testsuite/ChangeLog:

	* g++.dg/parse/error36.C: Adjust test expectation.
	* g++.dg/tc1/dr147.C: Likewise.
	* g++.old-deja/g++.other/typename1.C: Likewise.
	* g++.dg/diagnostic/pr105483.C: New test.

5 files changed, 20 insertions, 9 deletions

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 28ebf2b..a722641 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -13232,18 +13232,22 @@ cp_parser_expression_statement (cp_parser* parser, tree in_statement_expr)
   if (cp_lexer_next_token_is_not (parser->lexer, CPP_SEMICOLON)
       && !cp_parser_uncommitted_to_tentative_parse_p (parser))
     {
+      bool has_errored = true;
       if (TREE_CODE (statement) == SCOPE_REF)
 	error_at (token->location, "need %<typename%> before %qE because "
 		  "%qT is a dependent scope",
 		  statement, TREE_OPERAND (statement, 0));
       else if (is_overloaded_fn (statement)
 	       && DECL_CONSTRUCTOR_P (get_first_fn (statement)))
+	/* A::A a; */
+	error_at (token->location, "%qE names the constructor, not the type",
+		  get_first_fn (statement));
+      else
+	has_errored = false;
+      if (has_errored)
 	{
-	  /* A::A a; */
-	  tree fn = get_first_fn (statement);
-	  error_at (token->location,
-		    "%<%T::%D%> names the constructor, not the type",
-		    DECL_CONTEXT (fn), DECL_NAME (fn));
+	  cp_parser_skip_to_end_of_statement (parser);
+	  return error_mark_node;
 	}
     }
 
diff --git a/gcc/testsuite/g++.dg/diagnostic/pr105483.C b/gcc/testsuite/g++.dg/diagnostic/pr105483.C
new file mode 100644
index 0000000..b935bac
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/pr105483.C
@@ -0,0 +1,7 @@
+// PR c++/105483
+// { dg-do compile }
+
+struct X { };
+void g () {
+  X::X x; // { dg-error "'X::X' names the constructor" }
+}
diff --git a/gcc/testsuite/g++.dg/parse/error36.C b/gcc/testsuite/g++.dg/parse/error36.C
index bf57a6b..73b550e 100644
--- a/gcc/testsuite/g++.dg/parse/error36.C
+++ b/gcc/testsuite/g++.dg/parse/error36.C
@@ -12,7 +12,7 @@ void f(T t)
 {
   typedef A<T>::foo type;	// { dg-error "typename" }
   A<T>::bar b;			// { dg-error "typename" "typename" }
-} // { dg-error "expected ';'" "expected" { target *-*-* } .-1 }
+}
 
 // PR c++/36353
 template <class T> struct B
@@ -20,7 +20,7 @@ template <class T> struct B
   void f()
   {
     A<T>::baz z;		// { dg-error "typename" "typename" }
-  } // { dg-error "expected ';'" "expected" { target *-*-* } .-1 }
+  }
 };
 
 // PR c++/40738
diff --git a/gcc/testsuite/g++.dg/tc1/dr147.C b/gcc/testsuite/g++.dg/tc1/dr147.C
index 6b65649..ced18d1 100644
--- a/gcc/testsuite/g++.dg/tc1/dr147.C
+++ b/gcc/testsuite/g++.dg/tc1/dr147.C
@@ -21,7 +21,7 @@ void A::f()
 void f()
 {
   A::A a; // { dg-error "constructor" "constructor" }
-} // { dg-error "" "error cascade" { target *-*-* } .-1 } error cascade
+}
 }
 
 namespace N2 {
diff --git a/gcc/testsuite/g++.old-deja/g++.other/typename1.C b/gcc/testsuite/g++.old-deja/g++.other/typename1.C
index 4e1a4a8..0f0f68b 100644
--- a/gcc/testsuite/g++.old-deja/g++.other/typename1.C
+++ b/gcc/testsuite/g++.old-deja/g++.other/typename1.C
@@ -14,4 +14,4 @@ template<class T>
 void f()
 {
   Vector<T>::iterator i = 0; // { dg-error "typename" "typename" } missing typename
-} // { dg-error "expected" "expected" { target *-*-* } .-1 }
+}