Improve error handling in the process library.

runtime/bin/process_linux.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 66 matching lines @@
 }
 
 
 static void SetChildOsErrorMessage(char* os_error_message,
                                    int os_error_message_len) {
   SafeStrNCpy(os_error_message, strerror(errno), os_error_message_len);
 }
 
 
 void ExitHandler(int process_signal, siginfo_t* siginfo, void* tmp) {
-  assert(process_signal == SIGCHLD);
+  ASSERT(process_signal == SIGCHLD);
   struct sigaction act;
   bzero(&act, sizeof(act));
   act.sa_handler = SIG_IGN;
   act.sa_flags = SA_NOCLDSTOP | SA_SIGINFO;
   if (sigaction(SIGCHLD, &act, 0) != 0) {
     perror("Process start: disabling signal handler failed");
   }
   ProcessInfo* process = LookupProcess(siginfo->si_pid);
   if (process != NULL) {
     intptr_t message[2] = { siginfo->si_pid, siginfo->si_status };
@@ skipping 231 matching lines @@
   if (result == -1) {
     return false;
   }
   return true;
 }
 
 
 void Process::Exit(intptr_t id) {
   RemoveProcess(id);
 }