/* Utilities to execute a program in a subprocess (possibly linked by pipes
   with other subprocesses), and wait for it.
   Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.

This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

Libiberty is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with libiberty; see the file COPYING.LIB.  If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* This file exports two functions: pexecute and pwait.  */

/* This file lives in at least two places: libiberty and gcc.
   Don't change one without the other.  */

#ifdef IN_GCC
#include "config.h"
#endif

#include <stdio.h>
#include <errno.h>

#include "rts-config.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef STDC_HEADERS
#include <string.h>
#endif

#include "pexecute.h"

/* stdin file number.  */
#define STDIN_FILE_NO 0

/* stdout file number.  */
#define STDOUT_FILE_NO 1

/* value of `pipe': port index for reading.  */
#define READ_PORT 0

/* value of `pipe': port index for writing.  */
#define WRITE_PORT 1

static char *install_error_msg = "installation problem, cannot exec `%s'";

#ifdef __MSDOS__

/* MSDOS doesn't multitask, but for the sake of a consistent interface
   the code behaves like it does.  pexecute runs the program, tucks the
   exit code away, and returns a "pid".  pwait must be called to fetch the
   exit code.  */

#include <process.h>

/* For communicating information from pexecute to pwait.  */
static int last_pid = 0;
static int last_status = 0;
static int last_reaped = 0;

int
pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
     const char *program;
     char * const *argv;
     const char *this_pname;
     const char *temp_base;
     char **errmsg_fmt, **errmsg_arg;
     int flags;
{
  int rc;

  last_pid++;
  if (last_pid < 0)
    last_pid = 1;

  if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
    abort ();

#ifdef __GO32__
  /* ??? What are the possible return values from spawnv?  */
  rc = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
#else
  char *scmd, *rf;
  FILE *argfile;
  int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;

  scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
  rf = scmd + strlen(program) + 2 + el;
  sprintf (scmd, "%s%s @%s.gp", program,
	   (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
  argfile = fopen (rf, "w");
  if (argfile == 0)
    {
      int errno_save = errno;
      free (scmd);
      errno = errno_save;
      *errmsg_fmt = "cannot open `%s.gp'";
      *errmsg_arg = temp_base;
      return -1;
    }

  for (i=1; argv[i]; i++)
    {
      char *cp;
      for (cp = argv[i]; *cp; cp++)
	{
	  if (*cp == '"' || *cp == '\'' || *cp == '\\' || isspace (*cp))
	    fputc ('\\', argfile);
	  fputc (*cp, argfile);
	}
      fputc ('\n', argfile);
    }
  fclose (argfile);

  rc = system (scmd);

  {
    int errno_save = errno;
    remove (rf);
    free (scmd);
    errno = errno_save;
  }
#endif

  if (rc == -1)
    {
      *errmsg_fmt = install_error_msg;
      *errmsg_arg = (char *) program;
      return -1;
    }

  /* Tuck the status away for pwait, and return a "pid".  */
  last_status = rc << 8;
  return last_pid;
}

int
pwait (pid, status, flags)
     int pid;
     int *status;
     int flags;
{
  /* On MSDOS each pexecute must be followed by it's associated pwait.  */
  if (pid != last_pid
      /* Called twice for the same child?  */
      || pid == last_reaped)
    {
      /* ??? ECHILD would be a better choice.  Can we use it here?  */
      errno = EINVAL;
      return -1;
    }
  /* ??? Here's an opportunity to canonicalize the values in STATUS.
     Needed?  */
  *status = last_status;
  last_reaped = last_pid;
  return last_pid;
}

#endif /* MSDOS */

#if defined (_WIN32)

#include <process.h>
#include <signal.h>
extern int _spawnv ();
extern int _spawnvp ();

#ifdef __CYGWIN32__

#define fix_argv(argvec) (argvec)

#else

/* This is a kludge to get around the Microsoft C spawn functions' propensity
   to remove the outermost set of double quotes from all arguments.  */

char * const *
fix_argv (argvec)
     char **argvec;
{
  int i;

  for (i = 1; argvec[i] != 0; i++)
    {
      int len, j;
      char *temp, *newtemp;

      temp = argvec[i];
      len = strlen (temp);
      for (j = 0; j < len; j++)
        {
          if (temp[j] == '"')
            {
              newtemp = (char *) xmalloc (len + 2);
              strncpy (newtemp, temp, j);
              newtemp [j] = '\\';
              strncpy (&newtemp [j+1], &temp [j], len-j);
              newtemp [len+1] = 0;
              temp = newtemp;
              len++;
              j++;
            }
        }

        argvec[i] = temp;
      }

  return (char * const *) argvec;
}

#endif /* ! defined (__CYGWIN32__) */

int
pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
     const char *program;
     char * const *argv;
     const char *this_pname;
     const char *temp_base;
     char **errmsg_fmt;
     char **errmsg_arg;
     int flags;
{
  int pid;

  if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
    abort ();
  pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
    (_P_NOWAIT, program, fix_argv (argv));
  if (pid == -1)
    {
      *errmsg_fmt = install_error_msg;
      *errmsg_arg = program;
      return -1;
    }
  return pid;
}

int
pwait (pid, status, flags)
     int pid;
     int *status;
     int flags;
{
  int termstat;

  pid = cwait (&termstat, pid, WAIT_CHILD);

  /* ??? Here's an opportunity to canonicalize the values in STATUS.
     Needed?  */

  /* cwait returns the child process exit code in termstat.
     A value of 3 indicates that the child caught a signal, but not
     which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
     report SIGABRT.  */
  if (termstat == 3)
    *status = SIGABRT;
  else
    *status = (((termstat) & 0xff) << 8);

  return pid;
}

#endif /* _WIN32 */

#ifdef OS2

/* ??? Does OS2 have process.h?  */
extern int spawnv ();
extern int spawnvp ();

int
pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
     const char *program;
     char * const *argv;
     const char *this_pname;
     const char *temp_base;
     char **errmsg_fmt, **errmsg_arg;
     int flags;
{
  int pid;

  if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
    abort ();
  /* ??? Presumably 1 == _P_NOWAIT.  */
  pid = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
  if (pid == -1)
    {
      *errmsg_fmt = install_error_msg;
      *errmsg_arg = program;
      return -1;
    }
  return pid;
}

int
pwait (pid, status, flags)
     int pid;
     int *status;
     int flags;
{
  /* ??? Here's an opportunity to canonicalize the values in STATUS.
     Needed?  */
  int pid = wait (status);
  return pid;
}

#endif /* OS2 */

#ifdef MPW

/* MPW pexecute doesn't actually run anything; instead, it writes out
   script commands that, when run, will do the actual executing.

   For example, in GCC's case, GCC will write out several script commands:

   cpp ...
   cc1 ...
   as ...
   ld ...

   and then exit.  None of the above programs will have run yet.  The task
   that called GCC will then execute the script and cause cpp,etc. to run.
   The caller must invoke pfinish before calling exit.  This adds
   the finishing touches to the generated script.  */

static int first_time = 1;

int
pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
     const char *program;
     char * const *argv;
     const char *this_pname;
     const char *temp_base;
     char **errmsg_fmt, **errmsg_arg;
     int flags;
{
  char tmpprogram[255];
  char *cp, *tmpname;
  int i;

  mpwify_filename (program, tmpprogram);
  if (first_time)
    {
      printf ("Set Failed 0\n");
      first_time = 0;
    }

  fputs ("If {Failed} == 0\n", stdout);
  /* If being verbose, output a copy of the command.  It should be
     accurate enough and escaped enough to be "clickable".  */
  if (flags & PEXECUTE_VERBOSE)
    {
      fputs ("\tEcho ", stdout);
      fputc ('\'', stdout);
      fputs (tmpprogram, stdout);
      fputc ('\'', stdout);
      fputc (' ', stdout);
      for (i=1; argv[i]; i++)
	{
	  fputc ('\'', stdout);
	  /* See if we have an argument that needs fixing.  */
	  if (strchr(argv[i], '/'))
	    {
	      tmpname = (char *) xmalloc (256);
	      mpwify_filename (argv[i], tmpname);
	      argv[i] = tmpname;
	    }
	  for (cp = argv[i]; *cp; cp++)
	    {
	      /* Write an Option-d escape char in front of special chars.  */
	      if (strchr("'+", *cp))
		fputc ('\266', stdout);
	      fputc (*cp, stdout);
	    }
	  fputc ('\'', stdout);
	  fputc (' ', stdout);
	}
      fputs ("\n", stdout);
    }
  fputs ("\t", stdout);
  fputs (tmpprogram, stdout);
  fputc (' ', stdout);

  for (i=1; argv[i]; i++)
    {
      /* See if we have an argument that needs fixing.  */
      if (strchr(argv[i], '/'))
	{
	  tmpname = (char *) xmalloc (256);
	  mpwify_filename (argv[i], tmpname);
	  argv[i] = tmpname;
	}
      if (strchr (argv[i], ' '))
	fputc ('\'', stdout);
      for (cp = argv[i]; *cp; cp++)
	{
	  /* Write an Option-d escape char in front of special chars.  */
	  if (strchr("'+", *cp))
	    fputc ('\266', stdout);
	  fputc (*cp, stdout);
	}
      if (strchr (argv[i], ' '))
	fputc ('\'', stdout);
      fputc (' ', stdout);
    }

  fputs ("\n", stdout);

  /* Output commands that arrange to clean up and exit if a failure occurs.
     We have to be careful to collect the status from the program that was
     run, rather than some other script command.  Also, we don't exit
     immediately, since necessary cleanups are at the end of the script.  */
  fputs ("\tSet TmpStatus {Status}\n", stdout);
  fputs ("\tIf {TmpStatus} != 0\n", stdout);
  fputs ("\t\tSet Failed {TmpStatus}\n", stdout);
  fputs ("\tEnd\n", stdout);
  fputs ("End\n", stdout);

  /* We're just composing a script, can't fail here.  */
  return 0;
}

int
pwait (pid, status, flags)
     int pid;
     int *status;
     int flags;
{
  *status = 0;
  return 0;
}

/* Write out commands that will exit with the correct error code
   if something in the script failed.  */

void
pfinish ()
{
  printf ("\tExit \"{Failed}\"\n");
}

#endif /* MPW */

/* include for Unix-like environments but not for Dos-like environments */
#if ! defined (__MSDOS__) && ! defined (OS2) && ! defined (MPW) \
    && ! defined (_WIN32)

#ifdef VMS
#define vfork() (decc$$alloc_vfork_blocks() >= 0 ? \
               lib$get_current_invo_context(decc$$get_vfork_jmpbuf()) : -1)
#else
#ifdef USG
#define vfork fork
#endif
#endif

extern int execv ();
extern int execvp ();

int
pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
     const char *program;
     char * const *argv;
     const char *this_pname;
     const char *temp_base;
     char **errmsg_fmt, **errmsg_arg;
     int flags;
{
  int (*volatile func)() = (flags & PEXECUTE_SEARCH ? execvp : execv);
  int pid = 0;
  int pdes[2];
  int input_desc;
  volatile int output_desc, retries, sleep_interval;
  /* Pipe waiting from last process, to be used as input for the next one.
     Value is STDIN_FILE_NO if no pipe is waiting
     (i.e. the next command is the first of a group).  */
  static int last_pipe_input;

  /* If this is the first process, initialize.  */
  if (flags & PEXECUTE_FIRST)
    last_pipe_input = STDIN_FILE_NO;

  input_desc = last_pipe_input;

  /* If this isn't the last process, make a pipe for its output,
     and record it as waiting to be the input to the next process.  */
  if (! (flags & PEXECUTE_LAST))
    {
      if (pipe (pdes) < 0)
	{
	  *errmsg_fmt = "pipe";
	  *errmsg_arg = NULL;
	  return -1;
	}
      output_desc = pdes[WRITE_PORT];
      last_pipe_input = pdes[READ_PORT];
    }
  else
    {
      /* Last process.  */
      output_desc = STDOUT_FILE_NO;
      last_pipe_input = STDIN_FILE_NO;
    }

  /* Fork a subprocess; wait and retry if it fails.  */
  sleep_interval = 1;
  for (retries = 0; retries < 4; retries++)
    {
      pid = vfork ();
      if (pid >= 0)
	break;
      sleep (sleep_interval);
      sleep_interval *= 2;
    }

  switch (pid)
    {
    case -1:
      {
#ifdef vfork
	*errmsg_fmt = "fork";
#else
	*errmsg_fmt = "vfork";
#endif
	*errmsg_arg = NULL;
	return -1;
      }

    case 0: /* child */
      /* Move the input and output pipes into place, if necessary.  */
      if (input_desc != STDIN_FILE_NO)
	{
	  close (STDIN_FILE_NO);
	  dup (input_desc);
	  close (input_desc);
	}
      if (output_desc != STDOUT_FILE_NO)
	{
	  close (STDOUT_FILE_NO);
	  dup (output_desc);
	  close (output_desc);
	}

      /* Close the parent's descs that aren't wanted here.  */
      if (last_pipe_input != STDIN_FILE_NO)
	close (last_pipe_input);

      /* Exec the program.  */
      (*func) (program, argv);

      /* Note: Calling fprintf and exit here doesn't seem right for vfork.  */
      fprintf (stderr, "%s: ", this_pname);
      fprintf (stderr, install_error_msg, program);
#ifdef IN_GCC
      fprintf (stderr, ": %s\n", my_strerror (errno));
#else
      fprintf (stderr, ": %s\n", strerror (errno));
#endif
      exit (-1);
      /* NOTREACHED */
      return 0;

    default:
      /* In the parent, after forking.
	 Close the descriptors that we made for this child.  */
      if (input_desc != STDIN_FILE_NO)
	close (input_desc);
      if (output_desc != STDOUT_FILE_NO)
	close (output_desc);

      /* Return child's process number.  */
      return pid;
    }
}

int
pwait (pid, status, flags)
     int pid;
     int *status;
     int flags;
{
  /* ??? Here's an opportunity to canonicalize the values in STATUS.
     Needed?  */
#ifdef VMS
  pid = waitpid (-1, status, 0);
#else
  pid = wait (status);
#endif
  return pid;
}

#endif /* ! __MSDOS__ && ! OS2 && ! MPW && ! _WIN32 */
