Add tests that backtrace and backtrace_symbols produce correct results.

ChangeLog

@@ -1,3 +1,23 @@
+2013-01-18  Joseph Myers  <joseph@codesourcery.com>
+	    Mark Mitchell  <mark@codesourcery.com>
+	    Tom de Vries  <tom@codesourcery.com>
+	    Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	* debug/tst-backtrace2.c: New file.
+	* debug/tst-backtrace3.c: Likewise.
+	* debug/tst-backtrace4.c: Likewise.
+	* debug/tst-backtrace5.c: Likewise.
+	* debug/Makefile (CFLAGS-tst-backtrace2.c): New variable.
+	(CFLAGS-tst-backtrace3.c): Likewise.
+	(CFLAGS-tst-backtrace4.c): Likewise.
+	(CFLAGS-tst-backtrace5.c): Likewise.
+	(LDFLAGS-tst-backtrace2): Likewise.
+	(LDFLAGS-tst-backtrace3): Likewise.
+	(LDFLAGS-tst-backtrace4): Likewise.
+	(LDFLAGS-tst-backtrace5): Likewise.
+	(tests): Add new tests tst-backtrace2, tst-backtrace3,
+	tst-backtrace4 and tst-backtrace5.
+
 2013-01-18  Anton Blanchard  <anton@samba.org>
 	    Ryan S. Arnold  <rsa@linux.vnet.ibm.com>
 

debug/Makefile

@@ -121,10 +121,22 @@ LDLIBS-tst-lfschk4 = -lstdc++
 LDLIBS-tst-lfschk5 = -lstdc++
 LDLIBS-tst-lfschk6 = -lstdc++
 
+# backtrace_symbols only works if we link with -rdynamic.  backtrace
+# requires unwind tables on most architectures.
+CFLAGS-tst-backtrace2.c += -funwind-tables
+CFLAGS-tst-backtrace3.c += -funwind-tables
+CFLAGS-tst-backtrace4.c += -funwind-tables
+CFLAGS-tst-backtrace5.c += -funwind-tables
+LDFLAGS-tst-backtrace2 = -rdynamic
+LDFLAGS-tst-backtrace3 = -rdynamic
+LDFLAGS-tst-backtrace4 = -rdynamic
+LDFLAGS-tst-backtrace5 = -rdynamic
+
 tests = backtrace-tst tst-longjmp_chk tst-chk1 tst-chk2 tst-chk3 \
 	tst-lfschk1 tst-lfschk2 tst-lfschk3 test-strcpy_chk test-stpcpy_chk \
 	tst-chk4 tst-chk5 tst-chk6 tst-lfschk4 tst-lfschk5 tst-lfschk6 \
-	tst-longjmp_chk2
+	tst-longjmp_chk2 tst-backtrace2 tst-backtrace3 tst-backtrace4 \
+	tst-backtrace5
 
 tests-ifunc := $(stpcpy_chk strcpy_chk:%=test-%-ifunc)
 tests += $(tests-ifunc)

debug/tst-backtrace2.c

@@ -0,0 +1,111 @@
+/* Test backtrace and backtrace_symbols.
+   Copyright (C) 2009-2013 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/>.  */
+
+#include <execinfo.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Set to a non-zero value if the test fails.  */
+int ret;
+
+/* Accesses to X are used to prevent optimization.  */
+volatile int x;
+
+/* Called if the test fails.  */
+#define FAIL() \
+  do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
+
+/* The backtrace should include at least f1, f2, f3, and do_test.  */
+#define NUM_FUNCTIONS 4
+
+/* Use this attribute to prevent inlining, so that all expected frames
+   are present.  */
+#define NO_INLINE __attribute__ ((noinline))
+
+NO_INLINE void
+fn1 (void)
+{
+  void *addresses[NUM_FUNCTIONS];
+  char **symbols;
+  int n;
+  int i;
+
+  /* Get the backtrace addresses.  */
+  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
+  printf ("Obtained backtrace with %d functions\n", n);
+  /*  Check that there are at least four functions.  */
+  if (n < NUM_FUNCTIONS)
+    {
+      FAIL ();
+      return;
+    }
+  /* Convert them to symbols.  */
+  symbols = backtrace_symbols (addresses, n);
+  /* Check that symbols were obtained.  */
+  if (symbols == NULL)
+    {
+      FAIL ();
+      return;
+    }
+  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)
+    {
+      FAIL ();
+      return;
+    }
+  /* Symbol names are not available for static functions, so we do not
+     check f2.  */
+  if (strstr (symbols[2], "fn3") == NULL)
+    {
+      FAIL ();
+      return;
+    }
+  /* Symbol names are not available for static functions, so we do not
+     check do_test.  */
+}
+
+NO_INLINE static int
+fn2 (void)
+{
+  fn1 ();
+  /* Prevent tail calls.  */
+  return x;
+}
+
+NO_INLINE int
+fn3 (void)
+{
+  fn2();
+  /* Prevent tail calls.  */
+  return x;
+}
+
+NO_INLINE static int
+do_test (void)
+{
+  fn3 ();
+  return ret;
+}

debug/tst-backtrace3.c

@@ -0,0 +1,95 @@
+/* Test backtrace and backtrace_symbols for recursive calls.
+   Copyright (C) 2010-2013 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/>.  */
+
+#include <execinfo.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Set to a non-zero value if the test fails.  */
+int ret;
+
+/* Accesses to X are used to prevent optimization.  */
+volatile int x;
+
+/* Called if the test fails.  */
+#define FAIL() \
+  do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
+
+/* The backtrace should include at least 3 * fn, and do_test.  */
+#define NUM_FUNCTIONS 4
+
+/* Use this attribute to prevent inlining, so that all expected frames
+   are present.  */
+#define NO_INLINE __attribute__ ((noinline))
+
+NO_INLINE int
+fn (int c)
+{
+  void *addresses[NUM_FUNCTIONS];
+  char **symbols;
+  int n;
+  int i;
+
+  if (c > 0)
+    {
+      fn (c - 1);
+      return x;
+    }
+  /* Get the backtrace addresses.  */
+  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
+  printf ("Obtained backtrace with %d functions\n", n);
+  /*  Check that there are at least four functions.  */
+  if (n < NUM_FUNCTIONS)
+    {
+      FAIL ();
+      return 1;
+    }
+  /* Convert them to symbols.  */
+  symbols = backtrace_symbols (addresses, n);
+  /* Check that symbols were obtained.  */
+  if (symbols == NULL)
+    {
+      FAIL ();
+      return 1;
+    }
+  for (i = 0; i < n; ++i)
+    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)
+      {
+	FAIL ();
+	return 1;
+      }
+  /* Symbol names are not available for static functions, so we do not
+     check do_test.  */
+  return x;
+}
+
+NO_INLINE static int
+do_test (void)
+{
+  fn (2);
+  return ret;
+}

debug/tst-backtrace4.c

@@ -0,0 +1,134 @@
+/* Test backtrace and backtrace_symbols for signal frames.
+   Copyright (C) 2011-2013 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/>.  */
+
+#include <execinfo.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <unistd.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Set to a non-zero value if the test fails.  */
+volatile int ret;
+
+/* Accesses to X are used to prevent optimization.  */
+volatile int x;
+
+/* Called if the test fails.  */
+#define FAIL() \
+  do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
+
+/* The backtrace should include at least handle_signal, a signal
+   trampoline, 3 * fn, and do_test.  */
+#define NUM_FUNCTIONS 6
+
+/* Use this attribute to prevent inlining, so that all expected frames
+   are present.  */
+#define NO_INLINE __attribute__ ((noinline))
+
+volatile int sig_handled = 0;
+
+void
+handle_signal (int signum)
+{
+  void *addresses[NUM_FUNCTIONS];
+  char **symbols;
+  int n;
+  int i;
+
+  sig_handled = 1;
+
+  /* Get the backtrace addresses.  */
+  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
+  printf ("Obtained backtrace with %d functions\n", n);
+  /*  Check that there are at least six functions.  */
+  if (n < NUM_FUNCTIONS)
+    {
+      FAIL ();
+      return;
+    }
+  /* Convert them to symbols.  */
+  symbols = backtrace_symbols (addresses, n);
+  /* Check that symbols were obtained.  */
+  if (symbols == NULL)
+    {
+      FAIL ();
+      return;
+    }
+  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)
+    {
+      FAIL ();
+      return;
+    }
+  /* Do not check name for signal trampoline.  */
+  for (i = 2; i < n - 1; i++)
+    if (strstr (symbols[i], "fn") == NULL)
+      {
+	FAIL ();
+	return;
+      }
+  /* Symbol names are not available for static functions, so we do not
+     check do_test.  */
+}
+
+NO_INLINE int
+fn (int c)
+{
+  pid_t parent_pid, child_pid;
+
+  if (c > 0)
+    {
+      fn (c - 1);
+      return x;
+    }
+
+  signal (SIGUSR1, handle_signal);
+  parent_pid = getpid ();
+
+  child_pid = fork ();
+  if (child_pid == (pid_t) -1)
+    abort ();
+  else if (child_pid == 0)
+    {
+      sleep (1);
+      kill (parent_pid, SIGUSR1);
+      _exit (0);
+    }
+
+  /* In the parent.  */
+  while (sig_handled == 0)
+    ;
+
+  return 0;
+}
+
+NO_INLINE static int
+do_test (void)
+{
+  fn (2);
+  return ret;
+}

debug/tst-backtrace5.c

@@ -0,0 +1,148 @@
+/* Test backtrace and backtrace_symbols for signal frames, where a
+   system call was interrupted by a signal.
+   Copyright (C) 2011-2013 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/>.  */
+
+#include <execinfo.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <unistd.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Set to a non-zero value if the test fails.  */
+volatile int ret;
+
+/* Accesses to X are used to prevent optimization.  */
+volatile int x;
+
+/* Called if the test fails.  */
+#define FAIL() \
+  do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
+
+/* The backtrace should include at least handle_signal, a signal
+   trampoline, read, 3 * fn, and do_test.  */
+#define NUM_FUNCTIONS 7
+
+/* Use this attribute to prevent inlining, so that all expected frames
+   are present.  */
+#define NO_INLINE __attribute__ ((noinline))
+
+void
+handle_signal (int signum)
+{
+  void *addresses[NUM_FUNCTIONS];
+  char **symbols;
+  int n;
+  int i;
+
+  /* Get the backtrace addresses.  */
+  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
+  printf ("Obtained backtrace with %d functions\n", n);
+  /*  Check that there are at least seven functions.  */
+  if (n < NUM_FUNCTIONS)
+    {
+      FAIL ();
+      return;
+    }
+  /* Convert them to symbols.  */
+  symbols = backtrace_symbols (addresses, n);
+  /* Check that symbols were obtained.  */
+  if (symbols == NULL)
+    {
+      FAIL ();
+      return;
+    }
+  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)
+    {
+      FAIL ();
+      return;
+    }
+  /* Do not check name for signal trampoline.  */
+  i = 2;
+  if (strstr (symbols[i++], "read") == NULL)
+    {
+      /* Perhaps symbols[2] is __kernel_vsyscall?  */
+      if (strstr (symbols[i++], "read") == NULL)
+	{
+	  FAIL ();
+	  return;
+	}
+    }
+  for (; i < n - 1; i++)
+    if (strstr (symbols[i], "fn") == NULL)
+      {
+	FAIL ();
+	return;
+      }
+  /* Symbol names are not available for static functions, so we do not
+     check do_test.  */
+}
+
+NO_INLINE int
+fn (int c)
+{
+  pid_t parent_pid, child_pid;
+  int pipefd[2];
+  char r[1];
+  struct sigaction act;
+
+  if (c > 0)
+    {
+      fn (c - 1);
+      return x;
+    }
+
+  memset (&act, 0, sizeof (act));
+  act.sa_handler = handle_signal;
+  sigemptyset (&act.sa_mask);
+  sigaction (SIGUSR1, &act, NULL);
+  parent_pid = getpid ();
+  if (pipe (pipefd) == -1)
+    abort ();
+
+  child_pid = fork ();
+  if (child_pid == (pid_t) -1)
+    abort ();
+  else if (child_pid == 0)
+    {
+      sleep (1);
+      kill (parent_pid, SIGUSR1);
+      _exit (0);
+    }
+
+  /* In the parent.  */
+  read (pipefd[0], r, 1);
+
+  return 0;
+}
+
+NO_INLINE static int
+do_test (void)
+{
+  fn (2);
+  return ret;
+}