chrome/app/chrome_exe_main_mac.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // The entry point for all Mac Chromium processes, including the outer app
   6 // bundle (browser) and helper app (renderer, plugin, and friends).
   7
   8 #if defined(ADDRESS_SANITIZER)
   9 #include <crt_externs.h>  // for _NSGetArgc, _NSGetArgv
  10 #endif  // ADDRESS_SANITIZER
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #if defined(ADDRESS_SANITIZER)
  15 // NaCl requires its own SEGV handler, so we need to add handle_segv=0 to
  16 // ASAN_OPTIONS. This is done by injecting __asan_default_options into the
  17 // executable.
  18 // Because there's no distinct NaCl executable on OSX, we have to look at the
  19 // command line arguments to understand whether the process is a NaCl loader.
  20
  21 static const char kNaClDefaultOptions[] = "handle_segv=0";
  22 static const char kNaClFlag[] = "--type=nacl-loader";
  23
  24 extern "C"
  25 // __asan_default_options() is called at ASan initialization, so it must
  26 // not be instrumented with ASan -- thus the "no_sanitize_address" attribute.
  27 __attribute__((no_sanitize_address))
  28 // The function isn't referenced from the executable itself. Make sure it isn't
  29 // stripped by the linker.
  30 __attribute__((used))
  31 __attribute__((visibility("default")))
  32 const char* __asan_default_options()  {
  33   char*** argvp = _NSGetArgv();
  34   int* argcp = _NSGetArgc();
  35   if (!argvp || !argcp) return NULL;
  36   char** argv = *argvp;
  37   int argc = *argcp;
  38   for (int i = 0; i < argc; ++i) {
  39     if (strcmp(argv[i], kNaClFlag) == 0) {
  40       return kNaClDefaultOptions;
  41     }
  42   }
  43   return NULL;
  44 }
  45 #endif  // ADDRESS_SANITIZER
  46
  47 extern "C" {
  48 int ChromeMain(int argc, char** argv);
  49 }  // extern "C"
  50
  51 __attribute__((visibility("default")))
  52 int main(int argc, char* argv[]) {
  53   int rv = ChromeMain(argc, argv);
  54
  55   // exit, don't return from main, to avoid the apparent removal of main from
  56   // stack backtraces under tail call optimization.
  57   exit(rv);
  58 }