Copy in libbacktrace from gcc

This copies in libbacktrace from the gcc repository as it was in the
commit 62e420293a293608f383d9b9c7f2debd666e9fc9.  GDB is going to
start using this library soon.

A dependency between GDB and libbacktrace has already been added to
the top level Makefile, so, after this commit, when building GDB,
libbacktrace will be built first.  However, libbacktrace is not yet
linked into GDB, or used by GDB in any way.

It is possible to stop libbacktrace being built by configuring the
tree with --disable-libbacktrace.

This commit does NOT update src-release.sh, that will be done in the
next commit, this commit ONLY imports libbacktrace from gcc.  This
means that if you try to make a release of GDB from exactly this
commit then the release tar file will not include libbacktrace.
However, as libbacktrace is an optional dependency this is fine.

1 files changed, 508 insertions, 0 deletions

diff --git a/libbacktrace/xztest.c b/libbacktrace/xztest.c
new file mode 100644
index 0000000..b2533cb
--- /dev/null
+++ b/libbacktrace/xztest.c
@@ -0,0 +1,508 @@
+/* xztest.c -- Test for libbacktrace LZMA decoder.
+   Copyright (C) 2020-2021 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+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 <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifdef HAVE_LIBLZMA
+#include <lzma.h>
+#endif
+
+#include "backtrace.h"
+#include "backtrace-supported.h"
+
+#include "internal.h"
+#include "testlib.h"
+
+#ifndef HAVE_CLOCK_GETTIME
+
+typedef int xclockid_t;
+
+static int
+xclock_gettime (xclockid_t id ATTRIBUTE_UNUSED,
+		struct timespec *ts ATTRIBUTE_UNUSED)
+{
+  errno = EINVAL;
+  return -1;
+}
+
+#define clockid_t xclockid_t
+#define clock_gettime xclock_gettime
+#undef CLOCK_REALTIME
+#define CLOCK_REALTIME 0
+
+#endif /* !defined(HAVE_CLOCK_GETTIME) */
+
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+#define LIBLZMA_CLOCK_GETTIME_ARG CLOCK_PROCESS_CPUTIME_ID
+#else
+#define LIBLZMA_CLOCK_GETTIME_ARG CLOCK_REALTIME
+#endif
+
+/* Some tests for the local lzma inflation code.  */
+
+struct lzma_test
+{
+  const char *name;
+  const char *uncompressed;
+  size_t uncompressed_len;
+  const char *compressed;
+  size_t compressed_len;
+};
+
+/* Error callback.  */
+
+static void
+error_callback_compress (void *vdata 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);
+}
+
+static const struct lzma_test tests[] =
+{
+  {
+    "empty",
+    "",
+    0,
+    ("\xfd\x37\x7a\x58\x5a\x00\x00\x04\xe6\xd6\xb4\x46\x00\x00\x00\x00"
+     "\x1c\xdf\x44\x21\x1f\xb6\xf3\x7d\x01\x00\x00\x00\x00\x04\x59\x5a"),
+    32,
+  },
+  {
+    "hello",
+    "hello, world\n",
+    0,
+    ("\xfd\x37\x7a\x58\x5a\x00\x00\x04\xe6\xd6\xb4\x46\x02\x00\x21\x01"
+     "\x16\x00\x00\x00\x74\x2f\xe5\xa3\x01\x00\x0c\x68\x65\x6c\x6c\x6f"
+     "\x2c\x20\x77\x6f\x72\x6c\x64\x0a\x00\x00\x00\x00\x7b\x46\x5a\x81"
+     "\xc9\x12\xb8\xea\x00\x01\x25\x0d\x71\x19\xc4\xb6\x1f\xb6\xf3\x7d"
+     "\x01\x00\x00\x00\x00\x04\x59\x5a"),
+    72,
+  },
+  {
+    "goodbye",
+    "goodbye, world",
+    0,
+    ("\xfd\x37\x7a\x58\x5a\x00\x00\x04\xe6\xd6\xb4\x46\x02\x00\x21\x01"
+     "\x16\x00\x00\x00\x74\x2f\xe5\xa3\x01\x00\x0d\x67\x6f\x6f\x64\x62"
+     "\x79\x65\x2c\x20\x77\x6f\x72\x6c\x64\x00\x00\x00\xf6\xf8\xa3\x33"
+     "\x8c\x4e\xc9\x68\x00\x01\x26\x0e\x08\x1b\xe0\x04\x1f\xb6\xf3\x7d"
+     "\x01\x00\x00\x00\x00\x04\x59\x5a"),
+    72,
+  },
+};
+
+/* Test the hand coded samples.  */
+
+static void
+test_samples (struct backtrace_state *state)
+{
+  size_t i;
+
+  for (i = 0; i < sizeof tests / sizeof tests[0]; ++i)
+    {
+      unsigned char *uncompressed;
+      size_t uncompressed_len;
+
+      uncompressed = NULL;
+      uncompressed_len = 0;
+      if (!backtrace_uncompress_lzma (state,
+				      ((const unsigned char *)
+				       tests[i].compressed),
+				      tests[i].compressed_len,
+				      error_callback_compress, NULL,
+				      &uncompressed, &uncompressed_len))
+	{
+	  fprintf (stderr, "test %s: uncompress failed\n", tests[i].name);
+	  ++failures;
+	}
+      else
+	{
+	  size_t v;
+
+	  v = tests[i].uncompressed_len;
+	  if (v == 0)
+	    v = strlen (tests[i].uncompressed);
+	  if (uncompressed_len != v)
+	    {
+	      fprintf (stderr,
+		       "test %s: got uncompressed length %zu, want %zu\n",
+		       tests[i].name, uncompressed_len, v);
+	      ++failures;
+	    }
+	  else if (memcmp (tests[i].uncompressed, uncompressed, v) != 0)
+	    {
+	      size_t j;
+
+	      fprintf (stderr, "test %s: uncompressed data mismatch\n",
+		       tests[i].name);
+	      for (j = 0; j < v; ++j)
+		if (tests[i].uncompressed[j] != uncompressed[j])
+		  fprintf (stderr, "  %zu: got %#x want %#x\n", j,
+			   uncompressed[j], tests[i].uncompressed[j]);
+	      ++failures;
+	    }
+	  else
+	    printf ("PASS: lzma %s\n", tests[i].name);
+
+	  backtrace_free (state, uncompressed, uncompressed_len,
+			  error_callback_compress, NULL);
+	}
+    }
+}
+
+#if HAVE_LIBLZMA
+
+/* Given a set of TRIALS timings, discard the lowest and highest
+   values and return the mean average of the rest.  */
+
+static size_t
+average_time (const size_t *times, size_t trials)
+{
+  size_t imax;
+  size_t max;
+  size_t imin;
+  size_t min;
+  size_t i;
+  size_t sum;
+
+  imin = 0;
+  imax = 0;
+  min = times[0];
+  max = times[0];
+  for (i = 1; i < trials; ++i)
+    {
+      if (times[i] < min)
+	{
+	  imin = i;
+	  min = times[i];
+	}
+      if (times[i] > max)
+	{
+	  imax = i;
+	  max = times[i];
+	}
+    }
+
+  sum = 0;
+  for (i = 0; i < trials; ++i)
+    {
+      if (i != imax && i != imin)
+	sum += times[i];
+    }
+  return sum / (trials - 2);
+}
+
+#endif
+
+/* Test a larger text, if available.  */
+
+static void
+test_large (struct backtrace_state *state ATTRIBUTE_UNUSED)
+{
+#if HAVE_LIBLZMA
+  unsigned char *orig_buf;
+  size_t orig_bufsize;
+  size_t i;
+  lzma_stream initial_stream = LZMA_STREAM_INIT;
+  lzma_stream stream;
+  unsigned char *compressed_buf;
+  size_t compressed_bufsize;
+  unsigned char *uncompressed_buf;
+  size_t uncompressed_bufsize;
+  unsigned char *spare_buf;
+  int r;
+  clockid_t cid;
+  struct timespec ts1;
+  struct timespec ts2;
+  size_t ctime;
+  size_t ztime;
+  const size_t trials = 16;
+  size_t ctimes[16];
+  size_t ztimes[16];
+  static const char * const names[] = {
+    "Isaac.Newton-Opticks.txt",
+    "../libgo/go/testdata/Isaac.Newton-Opticks.txt",
+  };
+
+  orig_buf = NULL;
+  orig_bufsize = 0;
+  uncompressed_buf = NULL;
+  compressed_buf = NULL;
+
+  for (i = 0; i < sizeof names / sizeof names[0]; ++i)
+    {
+      size_t len;
+      char *namebuf;
+      FILE *e;
+      struct stat st;
+      char *rbuf;
+      size_t got;
+
+      len = strlen (SRCDIR) + strlen (names[i]) + 2;
+      namebuf = malloc (len);
+      if (namebuf == NULL)
+	{
+	  perror ("malloc");
+	  goto fail;
+	}
+      snprintf (namebuf, len, "%s/%s", SRCDIR, names[i]);
+      e = fopen (namebuf, "r");
+      free (namebuf);
+      if (e == NULL)
+	continue;
+      if (fstat (fileno (e), &st) < 0)
+	{
+	  perror ("fstat");
+	  fclose (e);
+	  continue;
+	}
+      rbuf = malloc (st.st_size);
+      if (rbuf == NULL)
+	{
+	  perror ("malloc");
+	  goto fail;
+	}
+      got = fread (rbuf, 1, st.st_size, e);
+      fclose (e);
+      if (got > 0)
+	{
+	  orig_buf = (unsigned char *) rbuf;
+	  orig_bufsize = got;
+	  break;
+	}
+      free (rbuf);
+    }
+
+  if (orig_buf == NULL)
+    {
+      /* We couldn't find an input file.  */
+      printf ("UNSUPPORTED: lzma large\n");
+      return;
+    }
+
+  stream = initial_stream;
+  r =  lzma_easy_encoder (&stream, 6, LZMA_CHECK_CRC32);
+  if (r != LZMA_OK)
+    {
+      fprintf (stderr, "lzma_easy_encoder failed: %d\n", r);
+      goto fail;
+    }
+
+  compressed_bufsize = orig_bufsize + 100;
+  compressed_buf = malloc (compressed_bufsize);
+  if (compressed_buf == NULL)
+    {
+      perror ("malloc");
+      goto fail;
+    }
+
+  stream.next_in = orig_buf;
+  stream.avail_in = orig_bufsize;
+  stream.next_out = compressed_buf;
+  stream.avail_out = compressed_bufsize;
+
+  do
+    {
+      r = lzma_code (&stream, LZMA_FINISH);
+      if (r != LZMA_OK && r != LZMA_STREAM_END)
+	{
+	  fprintf (stderr, "lzma_code failed: %d\n", r);
+	  goto fail;
+	}
+    }
+  while (r != LZMA_STREAM_END);
+
+  compressed_bufsize = stream.total_out;
+
+  if (!backtrace_uncompress_lzma (state, (unsigned char *) compressed_buf,
+				  compressed_bufsize,
+				  error_callback_compress, NULL,
+				  &uncompressed_buf, &uncompressed_bufsize))
+    {
+      fprintf (stderr, "lzma large: backtrace_uncompress_lzma failed\n");
+      goto fail;
+    }
+
+  if (uncompressed_bufsize != orig_bufsize)
+    {
+      fprintf (stderr,
+	       "lzma large: got uncompressed length %zu, want %zu\n",
+	       uncompressed_bufsize, orig_bufsize);
+      goto fail;
+    }
+
+  if (memcmp (uncompressed_buf, orig_buf, uncompressed_bufsize) != 0)
+    {
+      fprintf (stderr, "lzma large: uncompressed data mismatch\n");
+      goto fail;
+    }
+
+  printf ("PASS: lzma large\n");
+
+  spare_buf = malloc (orig_bufsize);
+  if (spare_buf == NULL)
+    {
+      perror ("malloc");
+      goto fail;
+    }
+
+  for (i = 0; i < trials; ++i)
+    {
+      cid = LIBLZMA_CLOCK_GETTIME_ARG;
+      if (clock_gettime (cid, &ts1) < 0)
+	{
+	  if (errno == EINVAL)
+	    return;
+	  perror ("clock_gettime");
+	  return;
+	}
+
+      if (!backtrace_uncompress_lzma (state,
+				      (unsigned char *) compressed_buf,
+				      compressed_bufsize,
+				      error_callback_compress, NULL,
+				      &uncompressed_buf,
+				      &uncompressed_bufsize))
+	{
+	  fprintf (stderr,
+		   ("lzma large: "
+		    "benchmark backtrace_uncompress_lzma failed\n"));
+	  return;
+	}
+
+      if (clock_gettime (cid, &ts2) < 0)
+	{
+	  perror ("clock_gettime");
+	  return;
+	}
+
+      ctime = (ts2.tv_sec - ts1.tv_sec) * 1000000000;
+      ctime += ts2.tv_nsec - ts1.tv_nsec;
+      ctimes[i] = ctime;
+
+      stream = initial_stream;
+
+      r = lzma_auto_decoder (&stream, UINT64_MAX, 0);
+      if (r != LZMA_OK)
+	{
+	  fprintf (stderr, "lzma_stream_decoder failed: %d\n", r);
+	  goto fail;
+	}
+
+      stream.next_in = compressed_buf;
+      stream.avail_in = compressed_bufsize;
+      stream.next_out = spare_buf;
+      stream.avail_out = orig_bufsize;
+
+      if (clock_gettime (cid, &ts1) < 0)
+	{
+	  perror("clock_gettime");
+	  return;
+	}
+
+      do
+	{
+	  r = lzma_code (&stream, LZMA_FINISH);
+	  if (r != LZMA_OK && r != LZMA_STREAM_END)
+	    {
+	      fprintf (stderr, "lzma_code failed: %d\n", r);
+	      goto fail;
+	    }
+	}
+      while (r != LZMA_STREAM_END);
+
+      if (clock_gettime (cid, &ts2) < 0)
+	{
+	  perror ("clock_gettime");
+	  return;
+	}
+
+      ztime = (ts2.tv_sec - ts1.tv_sec) * 1000000000;
+      ztime += ts2.tv_nsec - ts1.tv_nsec;
+      ztimes[i] = ztime;
+    }
+
+  /* Toss the highest and lowest times and average the rest.  */
+  ctime = average_time (ctimes, trials);
+  ztime = average_time (ztimes, trials);
+
+  printf ("backtrace: %zu ns\n", ctime);
+  printf ("liblzma  : %zu ns\n", ztime);
+  printf ("ratio    : %g\n", (double) ztime / (double) ctime);
+
+  return;
+
+ fail:
+  printf ("FAIL: lzma large\n");
+  ++failures;
+
+  if (orig_buf != NULL)
+    free (orig_buf);
+  if (compressed_buf != NULL)
+    free (compressed_buf);
+  if (uncompressed_buf != NULL)
+    free (uncompressed_buf);
+
+#else /* !HAVE_LIBLZMA */
+
+ printf ("UNSUPPORTED: lzma large\n");
+
+#endif /* !HAVE_LIBLZMA */
+}
+
+int
+main (int argc ATTRIBUTE_UNUSED, char **argv)
+{
+  struct backtrace_state *state;
+
+  state = backtrace_create_state (argv[0], BACKTRACE_SUPPORTS_THREADS,
+				  error_callback_create, NULL);
+
+  test_samples (state);
+  test_large (state);
+
+  exit (failures != 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+}