gdb/nat/linux-waitpid.c

   1 /* Wrapper implementation for waitpid for GNU/Linux (LWP layer).
   2
   3    Copyright (C) 2001-2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "common-defs.h"
  21
  22 #ifdef GDBSERVER
  23 /* FIXME: server.h is required for the definition of debug_threads
  24    which is used in the gdbserver-specific debug printing in
  25    linux_debug.  This code should be made available to GDB also,
  26    but the lack of a suitable flag to enable it prevents this.  */
  27 #include "server.h"
  28 #endif
  29
  30 #include "linux-nat.h"
  31 #include "linux-waitpid.h"
  32 #include "gdb_wait.h"
  33
  34 /* Print debugging output based on the format string FORMAT and
  35    its parameters.  */
  36
  37 static inline void ATTRIBUTE_PRINTF (1,2)
  38 linux_debug (const char *format, ...)
  39 {
  40 #ifdef GDBSERVER
  41   if (debug_threads)
  42     {
  43       va_list args;
  44       va_start (args, format);
  45       vfprintf (stderr, format, args);
  46       va_end (args);
  47     }
  48 #endif
  49 }
  50
  51 /* Convert wait status STATUS to a string.  Used for printing debug
  52    messages only.  */
  53
  54 char *
  55 status_to_str (int status)
  56 {
  57   static char buf[64];
  58
  59   if (WIFSTOPPED (status))
  60     {
  61       if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
  62         snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
  63                   strsignal (SIGTRAP));
  64       else
  65         snprintf (buf, sizeof (buf), "%s (stopped)",
  66                   strsignal (WSTOPSIG (status)));
  67     }
  68   else if (WIFSIGNALED (status))
  69     snprintf (buf, sizeof (buf), "%s (terminated)",
  70               strsignal (WTERMSIG (status)));
  71   else
  72     snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
  73
  74   return buf;
  75 }
  76
  77 /* See linux-waitpid.h.  */
  78
  79 int
  80 my_waitpid (int pid, int *status, int flags)
  81 {
  82   int ret, out_errno;
  83
  84   linux_debug ("my_waitpid (%d, 0x%x)\n", pid, flags);
  85
  86   do
  87     {
  88       ret = waitpid (pid, status, flags);
  89     }
  90   while (ret == -1 && errno == EINTR);
  91   out_errno = errno;
  92
  93   linux_debug ("my_waitpid (%d, 0x%x): status(%x), %d\n",
  94                pid, flags, (ret > 0 && status != NULL) ? *status : -1, ret);
  95
  96   errno = out_errno;
  97   return ret;
  98 }