Avoid backtrace tests matching filenames when searching for functionnames

["Joseph S. Myers" <joseph at codesourcery dot com>]

An issue pointed out with the new backtrace tests was that the test
for substrings of the decoded symbols could spuriously match a
filename instead.  This patch restricts the matching to text after the
first '(' in the name (the filename is before the '('; inside the '()'
are the function name and hex offset).

Tested x86_64.

2013-01-22  Joseph Myers  <joseph@codesourcery.com>

	* debug/tst-backtrace.h: New file.
	* debug/tst-backtrace2.c: Include tst-backtrace.h.
	(fn1): Use match function instead of strstr.
	* debug/tst-backtrace3.c: Include tst-backtrace.h.
	(fn): Use match function instead of strstr.
	* debug/tst-backtrace4.c: Include tst-backtrace.h.
	(handle_signal): Use match function instead of strstr.
	* debug/tst-backtrace5.c: Include tst-backtrace.h.
	(handle_signal): Use match function instead of strstr.

diff --git a/debug/tst-backtrace.h b/debug/tst-backtrace.h
new file mode 100644
index 0000000..3a77449
--- /dev/null
+++ b/debug/tst-backtrace.h
@@ -0,0 +1,31 @@
+/* Test backtrace and backtrace_symbols: common code for examining
+   backtraces.
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Look for a match in SYM from backtrace_symbols to NAME, a fragment
+   of a function name.  */
+
+static inline const char *
+match (const char *sym, const char *name)
+{
+  char *p = strchr (sym, '(');
+  if (p)
+    return strstr (p, name);
+  else
+    return NULL;
+}
diff --git a/debug/tst-backtrace2.c b/debug/tst-backtrace2.c
index e1d4572..0b8ee98 100644
--- a/debug/tst-backtrace2.c
+++ b/debug/tst-backtrace2.c
@@ -22,6 +22,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "tst-backtrace.h"
+
 static int do_test (void);
 #define TEST_FUNCTION do_test ()
 #include "../test-skeleton.c"
@@ -71,14 +73,14 @@ fn1 (void)
   for (i = 0; i < n; ++i)
     printf ("Function %d: %s\n", i, symbols[i]);
   /* Check that the function names obtained are accurate.  */
-  if (strstr (symbols[0], "fn1") == NULL)
+  if (match (symbols[0], "fn1") == NULL)
     {
       FAIL ();
       return;
     }
   /* Symbol names are not available for static functions, so we do not
      check f2.  */
-  if (strstr (symbols[2], "fn3") == NULL)
+  if (match (symbols[2], "fn3") == NULL)
     {
       FAIL ();
       return;
diff --git a/debug/tst-backtrace3.c b/debug/tst-backtrace3.c
index 4d3309b..52f98de 100644
--- a/debug/tst-backtrace3.c
+++ b/debug/tst-backtrace3.c
@@ -22,6 +22,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "tst-backtrace.h"
+
 static int do_test (void);
 #define TEST_FUNCTION do_test ()
 #include "../test-skeleton.c"
@@ -77,7 +79,7 @@ fn (int c)
     printf ("Function %d: %s\n", i, symbols[i]);
   /* Check that the function names obtained are accurate.  */
   for (i = 0; i < n - 1; ++i)
-    if (strstr (symbols[i], "fn") == NULL)
+    if (match (symbols[i], "fn") == NULL)
       {
 	FAIL ();
 	return 1;
diff --git a/debug/tst-backtrace4.c b/debug/tst-backtrace4.c
index 41a3f51..c619a96 100644
--- a/debug/tst-backtrace4.c
+++ b/debug/tst-backtrace4.c
@@ -25,6 +25,8 @@
 #include <signal.h>
 #include <unistd.h>
 
+#include "tst-backtrace.h"
+
 static int do_test (void);
 #define TEST_FUNCTION do_test ()
 #include "../test-skeleton.c"
@@ -79,14 +81,14 @@ handle_signal (int signum)
   for (i = 0; i < n; ++i)
     printf ("Function %d: %s\n", i, symbols[i]);
   /* Check that the function names obtained are accurate.  */
-  if (strstr (symbols[0], "handle_signal") == NULL)
+  if (match (symbols[0], "handle_signal") == NULL)
     {
       FAIL ();
       return;
     }
   /* Do not check name for signal trampoline.  */
   for (i = 2; i < n - 1; i++)
-    if (strstr (symbols[i], "fn") == NULL)
+    if (match (symbols[i], "fn") == NULL)
       {
 	FAIL ();
 	return;
diff --git a/debug/tst-backtrace5.c b/debug/tst-backtrace5.c
index eb16c23..f825931 100644
--- a/debug/tst-backtrace5.c
+++ b/debug/tst-backtrace5.c
@@ -26,6 +26,8 @@
 #include <signal.h>
 #include <unistd.h>
 
+#include "tst-backtrace.h"
+
 static int do_test (void);
 #define TEST_FUNCTION do_test ()
 #include "../test-skeleton.c"
@@ -76,24 +78,24 @@ handle_signal (int signum)
   for (i = 0; i < n; ++i)
     printf ("Function %d: %s\n", i, symbols[i]);
   /* Check that the function names obtained are accurate.  */
-  if (strstr (symbols[0], "handle_signal") == NULL)
+  if (match (symbols[0], "handle_signal") == NULL)
     {
       FAIL ();
       return;
     }
   /* Do not check name for signal trampoline.  */
   i = 2;
-  if (strstr (symbols[i++], "read") == NULL)
+  if (match (symbols[i++], "read") == NULL)
     {
       /* Perhaps symbols[2] is __kernel_vsyscall?  */
-      if (strstr (symbols[i++], "read") == NULL)
+      if (match (symbols[i++], "read") == NULL)
 	{
 	  FAIL ();
 	  return;
 	}
     }
   for (; i < n - 1; i++)
-    if (strstr (symbols[i], "fn") == NULL)
+    if (match (symbols[i], "fn") == NULL)
       {
 	FAIL ();
 	return;

-- 
Joseph S. Myers
joseph@codesourcery.com