Add the crashpad_handler executable

handler/mac/main.cc

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <getopt.h>
+#include <libgen.h>
+#include <stdlib.h>
+
+#include <string>
+
+#include "tools/tool_support.h"
+#include "handler/mac/exception_handler_server.h"
+#include "util/mach/child_port_handshake.h"
+#include "util/posix/close_stdio.h"
+#include "util/stdlib/string_number_conversion.h"
+
+namespace crashpad {
+namespace {
+
+void Usage(const std::string& me) {
+  fprintf(stderr,
+"Usage: %s [OPTION]...\n"
+"Crashpad's exception handler server.\n"
+"\n"
+"  -h, --handshake-fd=FD  establish communication with the client over FD\n"

[Robert Sesek, 2014/12/29 16:17:08]

Since this is never meant to be run by users, I'm not sure you need a short arg.

+"      --help             display this help and exit\n"
+"      --version          output version information and exit\n",
+          me.c_str());
+  ToolSupport::UsageTail(me);
+}
+
+int HandlerMain(int argc, char* argv[]) {
+  const std::string me(basename(argv[0]));
+
+  enum OptionFlags {
+    // “Short” (single-character) options.
+    kOptionHandshakeFD = 'h',
+
+    // Long options without short equivalents.
+    kOptionLastChar = 255,
+
+    // Standard options.
+    kOptionHelp = -2,
+    kOptionVersion = -3,
+  };
+
+  struct {
+    int handshake_fd;
+  } options = {};
+  options.handshake_fd = -1;
+
+  const struct option long_options[] = {
+      {"handshake-fd", required_argument, nullptr, kOptionHandshakeFD},
+      {"help", no_argument, nullptr, kOptionHelp},
+      {"version", no_argument, nullptr, kOptionVersion},
+      {nullptr, 0, nullptr, 0},
+  };
+
+  int opt;
+  while ((opt = getopt_long(argc, argv, "h:", long_options, nullptr)) != -1) {
+    switch (opt) {
+      case kOptionHandshakeFD:
+        if (!StringToNumber(optarg, &options.handshake_fd) ||
+            options.handshake_fd < 0) {
+          ToolSupport::UsageHint(me, "-h requires a file descriptor");
+          return EXIT_FAILURE;
+        }
+        break;
+      case kOptionHelp:
+        Usage(me);
+        return EXIT_SUCCESS;
+      case kOptionVersion:
+        ToolSupport::Version(me);
+        return EXIT_SUCCESS;
+      default:
+        ToolSupport::UsageHint(me, nullptr);
+        return EXIT_FAILURE;
+    }
+  }
+  argc -= optind;
+  argv += optind;
+
+  if (options.handshake_fd < 0) {

[Robert Sesek, 2014/12/29 16:17:08]

This is done above on line 74, too. This one is needed for the lack of a -h, but
you could remove the one above.

[Mark Mentovai, 2014/12/29 17:08:07]

Robert Sesek wrote:
The first one comes into play when you give a bad argument, and the second when
you don’t give it at all. I think it’s useful to distinguish. The other tools do
when converting a string argument to a number.

+    ToolSupport::UsageHint(me, "-h is required");
+    return EXIT_FAILURE;
+  }
+
+  if (argc) {
+    ToolSupport::UsageHint(me, nullptr);
+    return EXIT_FAILURE;
+  }
+
+  CloseStdinAndStdout();
+
+  ExceptionHandlerServer exception_handler_server;
+
+  ChildPortHandshake::RunClient(options.handshake_fd,
+                                exception_handler_server.receive_port(),
+                                MACH_MSG_TYPE_MAKE_SEND);
+
+  exception_handler_server.Run();
+
+  return EXIT_SUCCESS;
+}
+
+}  // namespace
+}  // namespace crashpad
+
+int main(int argc, char* argv[]) {
+  return crashpad::HandlerMain(argc, argv);
+}