From patchwork Sun Oct 28 11:27:40 2012
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Subject: [C++] PR 54526 (again)
Date: Sun, 28 Oct 2012 01:27:40 -0000
From: Paolo Carlini <paolo.carlini@oracle.com>
X-Patchwork-Id: 194690
Message-Id: <508D16AC.5070901@oracle.com>
To: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Cc: Jason Merrill <jason@redhat.com>

Hi,

as pointed out in the audit trail, my first patch for this C++11 parsing 
issue was misguided: I changed cp_parser_template_id but in fact C++11 
wants new special *lexing* rules, which must be active outside templates 
too, as the additional test (and the old manded one) shows. Thus the below.

Tested x86_64-linux.

Thanks,
Paolo.

////////////////////////
/libcpp
2012-10-28  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/54526 (again)
	* lex.c (_cpp_lex_direct): In C++11 mode, implement 2.5 p3, bullet 2.

/gcc/cp
2012-10-28  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/54526 (again)
	* parser.c (cp_parser_template_id): Revert core of previous change
	(keep adjusted inform message).

/gcc/testsuite
2012-10-28  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/54526 (again)
	* g++.dg/cpp0x/parse2.C: Extend.
	* g++.old-deja/g++.other/crash28.C: Adjust.


Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c	(revision 192887)
+++ gcc/cp/parser.c	(working copy)
@@ -12655,9 +12655,8 @@ cp_parser_template_id (cp_parser *parser,
       /* Otherwise, emit an error about the invalid digraph, but continue
 	 parsing because we got our argument list.  In C++11 do not emit
 	 any error, per 2.5/3.  */
-      if (cxx_dialect < cxx0x
-	  && permerror (next_token->location,
-			"%<<::%> cannot begin a template-argument list"))
+      if (permerror (next_token->location,
+		     "%<<::%> cannot begin a template-argument list"))
 	{
 	  static bool hint = false;
 	  inform (next_token->location,
Index: gcc/testsuite/g++.dg/cpp0x/parse2.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/parse2.C	(revision 192887)
+++ gcc/testsuite/g++.dg/cpp0x/parse2.C	(working copy)
@@ -10,3 +10,6 @@ int main()
 {
   X<::A> x;
 }
+
+int a;
+bool b = 0<::a;
Index: gcc/testsuite/g++.old-deja/g++.other/crash28.C
===================================================================
--- gcc/testsuite/g++.old-deja/g++.other/crash28.C	(revision 192887)
+++ gcc/testsuite/g++.old-deja/g++.other/crash28.C	(working copy)
@@ -31,5 +31,5 @@ class foo
 };
 void foo::x() throw(bar)
 {
-  if (!b) throw bar (static_cast<::N::X*>(this));	// { dg-error "lambda expressions|expected" } parse error
+  if (!b) throw bar (static_cast<::N::X*>(this));	// { dg-error "lambda expressions|expected|invalid" } parse error
 }
Index: libcpp/lex.c
===================================================================
--- libcpp/lex.c	(revision 192887)
+++ libcpp/lex.c	(working copy)
@@ -2291,6 +2291,25 @@ _cpp_lex_direct (cpp_reader *pfile)
 	  if (*buffer->cur == ':')
 	    {
 	      buffer->cur++;
+
+	      /* C++11 - 2.5 p3, bullet 2.  */
+	      if (CPP_OPTION (pfile, cplusplus)
+		  && (CPP_OPTION (pfile, lang) == CLK_CXX11
+		      || CPP_OPTION (pfile, lang) == CLK_GNUCXX11))
+		{
+		  if (*buffer->cur == ':')
+		    {
+		      buffer->cur++;
+		      if (*buffer->cur != ':' && *buffer->cur != '>')
+			{
+			  --buffer->cur;
+			  --buffer->cur;
+			  break;
+			}
+		      --buffer->cur;
+		    }
+		}
+
 	      result->flags |= DIGRAPH;
 	      result->type = CPP_OPEN_SQUARE;
 	    }