Forgot to add file for the previous change...

Add InstallFailureSignalHandler().  The function installs a signal handler that will dump useful information when the program crashes on certain signals such as SIGSEGV.


git-svn-id: https://google-glog.googlecode.com/svn/trunk@12 eb4d4688-79bd-11dd-afb4-1d65580434c0

m4/ac_have_sync_val_compare_and_swap.m4

+AC_DEFUN([AX_C___SYNC_VAL_COMPARE_AND_SWAP], [
+  AC_MSG_CHECKING(for __sync_val_compare_and_swap)
+  AC_CACHE_VAL(ac_cv___sync_val_compare_and_swap, [
+    AC_TRY_LINK(
+      [int main() { int a; if (__sync_val_compare_and_swap(&a, 0, 1)) return 1; return 0; }],
+      [],
+      ac_cv___sync_val_compare_and_swap=yes,
+      ac_cv___sync_val_compare_and_swap=no
+    )])
+  if test "$ac_cv___sync_val_compare_and_swap" = "yes"; then
+    AC_DEFINE(HAVE___SYNC_VAL_COMPARE_AND_SWAP, 1, [define if your compiler has __sync_val_compare_and_swap])
+  fi
+  AC_MSG_RESULT($ac_cv___sync_val_compare_and_swap)
+])

src/signalhandler_unittest.cc

+// Copyright 2008 Google Inc. All Rights Reserved.
+// Author: satorux@google.com (Satoru Takabayashi)
+//
+// This is a helper binary for testing signalhandler.cc.  The actual test
+// is done in signalhandler_unittest.sh.
+
+#include "utilities.h"
+
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string>
+#include "glog/logging.h"
+
+using namespace GOOGLE_NAMESPACE;
+
+void* DieInThread(void*) {
+  fprintf(stderr, "0x%lx is dying\n", pthread_self());
+  // Use volatile to prevent from these to be optimized away.
+  volatile int a = 0;
+  volatile int b = 1 / a;
+}
+
+void WriteToStdout(const char* data, int size) {
+  write(STDOUT_FILENO, data, size);
+}
+
+int main(int argc, char **argv) {
+#ifdef HAVE_STACKTRACE
+  InitGoogleLogging(argv[0]);
+  InstallFailureSignalHandler();
+  const std::string command = argc > 1 ? argv[1] : "none";
+  if (command == "segv") {
+    // We assume 0xDEAD is not writable.
+    int *a = (int*)0xDEAD;
+    *a = 0;
+  } else if (command == "loop") {
+    fprintf(stderr, "looping\n");
+    while (true);
+  } else if (command == "die_in_thread") {
+    pthread_t thread;
+    pthread_create(&thread, NULL, &DieInThread, NULL);
+    pthread_join(thread, NULL);
+  } else if (command == "dump_to_stdout") {
+    InstallFailureWriter(WriteToStdout);
+    abort();
+  } else {
+    // Tell the shell script
+    puts("OK");
+  }
+#endif
+  return 0;
+}

src/signalhandler_unittest.sh

+#! /bin/sh
+# Copyright 2008 Google, Inc.  All Rights Reserved.
+# Author: Satoru Takabayashi
+#
+# Unit tests for signalhandler.cc.
+
+die () {
+    echo $1
+    exit 1
+}
+
+BINDIR=".libs"
+LIBGLOG="$BINDIR/libglog.so"
+
+BINARY="$BINDIR/signalhandler_unittest"
+
+# Remove temporary files.
+rm -f signalhandler.out*
+
+if test -e "$BINARY"; then
+  # We need shared object.
+  export LD_LIBRARY_PATH=$BINDIR
+  export DYLD_LIBRARY_PATH=$BINDIR
+else
+  # For windows
+  BINARY="./signalhandler_unittest.exe"
+  if ! test -e "$BINARY"; then
+    echo "We coundn't find demangle_unittest binary."
+    exit 1
+  fi
+fi
+
+if [ x`$BINARY` != 'xOK' ]; then
+  echo "PASS (No stacktrace support. We don't run this test.)"
+  exit 0
+fi
+
+# Test for a case the program kills itself by SIGSEGV.
+$BINARY segv 2> signalhandler.out1
+for pattern in SIGSEGV 0xdead main "Aborted at [0-9]"; do
+  if ! grep --quiet "$pattern" signalhandler.out1; then
+    die "'$pattern' should appear in the output"
+  fi
+done
+
+# Test for a case the program is killed by this shell script.
+# $! = the process id of the last command run in the background.
+# $$ = the process id of this shell.
+$BINARY loop 2> signalhandler.out2 &
+# Wait until "looping" is written in the file.  This indicates the program
+# is ready to accept signals.
+while true; do
+  if grep --quiet looping signalhandler.out2; then
+    break
+  fi
+done
+kill -TERM $!
+wait $!
+
+from_pid=''
+# Only linux has the process ID of the signal sender.
+if [ x`uname` = "xLinux" ]; then
+  from_pid="from PID $$"
+fi
+for pattern in SIGTERM "by PID $!" "$from_pid" main "Aborted at [0-9]"; do
+  if ! grep --quiet "$pattern" signalhandler.out2; then
+    die "'$pattern' should appear in the output"
+  fi
+done
+
+# Test for a case the program dies in a non-main thread.
+$BINARY die_in_thread 2> signalhandler.out3
+EXPECTED_TID="`sed 's/ .*//' signalhandler.out3`"
+
+for pattern in SIGFPE DieInThread "TID $EXPECTED_TID" "Aborted at [0-9]"; do
+  if ! grep --quiet "$pattern" signalhandler.out3; then
+    die "'$pattern' should appear in the output"
+  fi
+done
+
+# Test for a case the program installs a custom failure writer that writes
+# stuff to stdout instead of stderr.
+$BINARY dump_to_stdout 1> signalhandler.out4
+for pattern in SIGABRT main "Aborted at [0-9]"; do
+  if ! grep --quiet "$pattern" signalhandler.out4; then
+    die "'$pattern' should appear in the output"
+  fi
+done
+
+echo PASS