dwarf.c (free_line_header): Don't free dirs if dirs_count == 0.

	* dwarf.c (free_line_header): Don't free dirs if dirs_count == 0.
	(read_line_header): Don't allocate dirs if dirs_count == 0.
	* edtest.c: New file.
	* edtest2.c: New file.
	* Makefile.am (edtest_SOURCES, edtest_LDADD): Define.
	(check_PROGRAMS): Add edtest.
	(edtest2_build.c, gen_edtest2_build): New targets.
	* Makefile.in: Rebuild.

From-SVN: r248295

1 files changed, 266 insertions, 0 deletions

diff --git a/libbacktrace/edtest.c b/libbacktrace/edtest.c
new file mode 100644
index 0000000..daf4dd9
--- /dev/null
+++ b/libbacktrace/edtest.c
@@ -0,0 +1,266 @@
+/* edtest.c -- Test for libbacktrace storage allocation stress handling
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "backtrace.h"
+#include "backtrace-supported.h"
+#include "internal.h"
+
+#if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
+# define IS_DIR_SEPARATOR(c) ((c) == '/' || (c) == '\\')
+#else
+# define IS_DIR_SEPARATOR(c) ((c) == '/')
+#endif
+
+/* The backtrace state.  */
+
+static void *state;
+
+/* The number of failures.  */
+
+int failures = 0;
+
+static int test1 (void) __attribute__ ((noinline, unused));
+static int test1 (void) __attribute__ ((noinline, unused));
+extern int f2 (int);
+extern int f3 (int, int);
+
+static int
+test1 (void)
+{
+  /* Returning a value here and elsewhere avoids a tailcall which
+     would mess up the backtrace.  */
+  return f2 (__LINE__) + 1;
+}
+
+/* Used to collect backtrace info.  */
+
+struct info
+{
+  char *filename;
+  int lineno;
+  char *function;
+};
+
+/* Return the base name in a path.  */
+
+static const char *
+base (const char *p)
+{
+  const char *last;
+  const char *s;
+
+  last = NULL;
+  for (s = p; *s != '\0'; ++s)
+    {
+      if (IS_DIR_SEPARATOR (*s))
+        last = s + 1;
+    }
+  return last != NULL ? last : p;
+}
+
+/* Check an entry in a struct info array.  */
+
+static void
+check (const char *name, int index, const struct info *all, int want_lineno,
+       const char *want_function, const char *want_file, int *failed)
+{
+  if (*failed)
+    return;
+  if (all[index].filename == NULL || all[index].function == NULL)
+    {
+      fprintf (stderr, "%s: [%d]: missing file name or function name\n",
+               name, index);
+      *failed = 1;
+      return;
+    }
+  if (strcmp (base (all[index].filename), want_file) != 0)
+    {
+      fprintf (stderr, "%s: [%d]: got %s expected %s\n", name, index,
+               all[index].filename, want_file);
+      *failed = 1;
+    }
+  if (all[index].lineno != want_lineno)
+    {
+      fprintf (stderr, "%s: [%d]: got %d expected %d\n", name, index,
+               all[index].lineno, want_lineno);
+      *failed = 1;
+    }
+  if (strcmp (all[index].function, want_function) != 0)
+    {
+      fprintf (stderr, "%s: [%d]: got %s expected %s\n", name, index,
+               all[index].function, want_function);
+      *failed = 1;
+    }
+}
+
+/* Passed to backtrace callback function.  */
+
+struct bdata
+{
+  struct info *all;
+  size_t index;
+  size_t max;
+  int failed;
+};
+
+/* An error callback passed to backtrace.  */
+
+static void
+error_callback_one (void *vdata, const char *msg, int errnum)
+{
+  struct bdata *data = (struct bdata *) vdata;
+
+  fprintf (stderr, "%s", msg);
+  if (errnum > 0)
+    fprintf (stderr, ": %s", strerror (errnum));
+  fprintf (stderr, "\n");
+  data->failed = 1;
+}
+
+/* The backtrace callback function.  */
+
+static int
+callback_one (void *vdata, uintptr_t pc ATTRIBUTE_UNUSED,
+              const char *filename, int lineno, const char *function)
+{
+  struct bdata *data = (struct bdata *) vdata;
+  struct info *p;
+
+  if (data->index >= data->max)
+    {
+      fprintf (stderr, "callback_one: callback called too many times\n");
+      data->failed = 1;
+      return 1;
+    }
+
+  p = &data->all[data->index];
+  if (filename == NULL)
+    p->filename = NULL;
+  else
+    {
+      p->filename = strdup (filename);
+      assert (p->filename != NULL);
+    }
+  p->lineno = lineno;
+  if (function == NULL)
+    p->function = NULL;
+  else
+    {
+      p->function = strdup (function);
+      assert (p->function != NULL);
+    }
+  ++data->index;
+
+  return 0;
+}
+
+int
+f3 (int f1line, int f2line)
+{
+  struct info all[20];
+  struct bdata data;
+  int f3line;
+  int i;
+
+  data.all = &all[0];
+  data.index = 0;
+  data.max = 20;
+  data.failed = 0;
+
+  f3line = __LINE__ + 1;
+  i = backtrace_full (state, 0, callback_one, error_callback_one, &data);
+
+  if (i != 0)
+    {
+      fprintf (stderr, "test1: unexpected return value %d\n", i);
+      data.failed = 1;
+    }
+
+  if (data.index < 3)
+    {
+      fprintf (stderr,
+               "test1: not enough frames; got %zu, expected at least 3\n",
+               data.index);
+      data.failed = 1;
+    }
+
+  check ("test1", 0, all, f3line, "f3", "edtest.c", &data.failed);
+  check ("test1", 1, all, f2line, "f2", "edtest2_build.c", &data.failed);
+  check ("test1", 2, all, f1line, "test1", "edtest.c", &data.failed);
+
+  printf ("%s: backtrace_full alloc stress\n", data.failed ? "FAIL" : "PASS");
+
+  if (data.failed)
+    ++failures;
+
+  return failures;
+}
+
+static void
+error_callback_create (void *data ATTRIBUTE_UNUSED, const char *msg,
+                       int errnum)
+{
+  fprintf (stderr, "%s", msg);
+  if (errnum > 0)
+    fprintf (stderr, ": %s", strerror (errnum));
+  fprintf (stderr, "\n");
+  exit (EXIT_FAILURE);
+}
+
+int
+main (int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
+{
+  state = backtrace_create_state (argv[0], BACKTRACE_SUPPORTS_THREADS,
+                                  error_callback_create, NULL);
+
+  // Grab the storage allocation lock prior to doing anything interesting.
+  // The intent here is to insure that the backtrace_alloc code is forced
+  // to always call mmap() for new memory as opposed to reusing previously
+  // allocated memory from the free list. Doing things this way helps
+  // simulate what you might see in a multithreaded program in which there
+  // are racing calls to the allocator.
+  struct backtrace_state *state_internal =
+      (struct backtrace_state *) state;
+  state_internal->lock_alloc = 1;
+
+  // Kick off the test
+  test1();
+
+  exit (failures > 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+}