fix PR c++/16117

This patch fixes PR c++/16117.

gdb has an extension so that users can use expressions like FILE::NAME
to choose a variable of the given name from the given file.  The bug
is that this extension takes precedence over ordinary C++ expressions
of the same form.  You might think this is merely hypothetical, but
now that C++ headers commonly do not use an extension, it is more
common.

This patch fixes the bug by making two related changes.  First, it
changes gdb to prefer the ordinary C++ meaning of a symbol over the
extended meaning.  Second, it arranges for single-quoting of the
symbol to indicate a preference for the extension.

Built and regtested on x86-64 Fedora 18.
New test case included.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	PR c++/16117:
	* c-exp.y (lex_one_token): Add "is_quoted_name" argument.
	(classify_name): Likewise.  Prefer a field of "this" over a
	filename.
	(classify_inner_name, yylex): Update.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	* gdb.texinfo (Variables): Note gdb rules for ambiguous cases.
	Add example.

2013-11-15  Tom Tromey  <tromey@redhat.com>

	* gdb.cp/includefile: New file.
	* gdb.cp/filename.exp: New file.
	* gdb.cp/filename.cc: New file.

1 files changed, 36 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.cp/filename.cc b/gdb/testsuite/gdb.cp/filename.cc
new file mode 100644
index 0000000..716f48b
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/filename.cc
@@ -0,0 +1,36 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "includefile"
+
+class C {
+public:
+  int includefile[1];
+
+  C() {
+    includefile[0] = 23;
+  }
+
+  void m() {
+    /* stop here */
+  }
+};
+
+int main() {
+  C c;
+  c.m();
+}