test: Move util/test to its own top-level directory, test

util/test/multiprocess_exec_test_child.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 <errno.h>
-#include <limits.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-
-#include <algorithm>
-
-#if defined(__APPLE__) || defined(__linux__)
-#define OS_POSIX 1
-#elif defined(_WIN32)
-#define OS_WIN 1
-#endif
-
-#if defined(OS_POSIX)
-#include <unistd.h>
-#elif defined(OS_WIN)
-#include <windows.h>
-#endif
-
-int main(int argc, char* argv[]) {
-#if defined(OS_POSIX)
-  // Make sure that there’s nothing open at any FD higher than 3. All FDs other
-  // than stdin, stdout, and stderr should have been closed prior to or at
-  // exec().
-  int max_fd = std::max(static_cast<int>(sysconf(_SC_OPEN_MAX)), OPEN_MAX);
-  max_fd = std::max(max_fd, getdtablesize());
-  for (int fd = STDERR_FILENO + 1; fd < max_fd; ++fd) {
-    if (close(fd) == 0 || errno != EBADF) {
-      abort();
-    }
-  }
-
-  // Read a byte from stdin, expecting it to be a specific value.
-  char c;
-  ssize_t rv = read(STDIN_FILENO, &c, 1);
-  if (rv != 1 || c != 'z') {
-    abort();
-  }
-
-  // Write a byte to stdout.
-  c = 'Z';
-  rv = write(STDOUT_FILENO, &c, 1);
-  if (rv != 1) {
-    abort();
-  }
-#elif defined(OS_WIN)
-  // TODO(scottmg): Verify that only the handles we expect to be open, are.
-
-  // Read a byte from stdin, expecting it to be a specific value.
-  char c;
-  DWORD bytes_read;
-  HANDLE stdin_handle = GetStdHandle(STD_INPUT_HANDLE);
-  if (!ReadFile(stdin_handle, &c, 1, &bytes_read, nullptr) ||
-      bytes_read != 1 || c != 'z') {
-    abort();
-  }
-
-  // Write a byte to stdout.
-  c = 'Z';
-  DWORD bytes_written;
-  if (!WriteFile(
-          GetStdHandle(STD_OUTPUT_HANDLE), &c, 1, &bytes_written, nullptr) ||
-      bytes_written != 1) {
-    abort();
-  }
-#endif  // OS_POSIX
-
-  return 0;
-}