blob: 30cd9040d967d85d51c0f91142d4af782de197ad [file] [log] [blame]
/* Common code for executing a program in a sub-process.
Copyright (C) 2005-2020 Free Software Foundation, Inc.
Written by Ian Lance Taylor <ian@airs.com>.
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., 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "config.h"
#include "libiberty.h"
#include "pex-common.h"
#include <stdio.h>
#include <errno.h>
#ifdef NEED_DECLARATION_ERRNO
extern int errno;
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
extern int mkstemps (char *, int);
/* This file contains subroutines for the program execution routines
(pex_init, pex_run, etc.). This file is compiled on all
systems. */
static void pex_add_remove (struct pex_obj *, const char *, int);
static int pex_get_status_and_time (struct pex_obj *, int, const char **,
int *);
/* Initialize a pex_obj structure. */
struct pex_obj *
pex_init_common (int flags, const char *pname, const char *tempbase,
const struct pex_funcs *funcs)
{
struct pex_obj *obj;
obj = XNEW (struct pex_obj);
obj->flags = flags;
obj->pname = pname;
obj->tempbase = tempbase;
obj->next_input = STDIN_FILE_NO;
obj->next_input_name = NULL;
obj->next_input_name_allocated = 0;
obj->stderr_pipe = -1;
obj->count = 0;
obj->children = NULL;
obj->status = NULL;
obj->time = NULL;
obj->number_waited = 0;
obj->input_file = NULL;
obj->read_output = NULL;
obj->read_err = NULL;
obj->remove_count = 0;
obj->remove = NULL;
obj->funcs = funcs;
obj->sysdep = NULL;
return obj;
}
/* Add a file to be removed when we are done. */
static void
pex_add_remove (struct pex_obj *obj, const char *name, int allocated)
{
char *add;
++obj->remove_count;
obj->remove = XRESIZEVEC (char *, obj->remove, obj->remove_count);
if (allocated)
add = (char *) name;
else
add = xstrdup (name);
obj->remove[obj->remove_count - 1] = add;
}
/* Generate a temporary file name based on OBJ, FLAGS, and NAME.
Return NULL if we were unable to reserve a temporary filename.
If non-NULL, the result is either allocated with malloc, or the
same pointer as NAME. */
static char *
temp_file (struct pex_obj *obj, int flags, char *name)
{
if (name == NULL)
{
if (obj->tempbase == NULL)
{
name = make_temp_file (NULL);
}
else
{
int len = strlen (obj->tempbase);
int out;
if (len >= 6
&& strcmp (obj->tempbase + len - 6, "XXXXXX") == 0)
name = xstrdup (obj->tempbase);
else
name = concat (obj->tempbase, "XXXXXX", NULL);
out = mkstemps (name, 0);
if (out < 0)
{
free (name);
return NULL;
}
/* This isn't obj->funcs->close because we got the
descriptor from mkstemps, not from a function in
obj->funcs. Calling close here is just like what
make_temp_file does. */
close (out);
}
}
else if ((flags & PEX_SUFFIX) != 0)
{
if (obj->tempbase == NULL)
name = make_temp_file (name);
else
name = concat (obj->tempbase, name, NULL);
}
return name;
}
/* As for pex_run (), but permits the environment for the child process
to be specified. */
const char *
pex_run_in_environment (struct pex_obj *obj, int flags, const char *executable,
char * const * argv, char * const * env,
const char *orig_outname, const char *errname,
int *err)
{
const char *errmsg;
int in, out, errdes;
char *outname;
int outname_allocated;
int p[2];
int toclose;
pid_t pid;
in = -1;
out = -1;
errdes = -1;
outname = (char *) orig_outname;
outname_allocated = 0;
/* If the user called pex_input_file, close the file now. */
if (obj->input_file)
{
if (fclose (obj->input_file) == EOF)
{
errmsg = "closing pipeline input file";
goto error_exit;
}
obj->input_file = NULL;
}
/* Set IN. */
if (obj->next_input_name != NULL)
{
/* We have to make sure that the previous process has completed
before we try to read the file. */
if (!pex_get_status_and_time (obj, 0, &errmsg, err))
goto error_exit;
in = obj->funcs->open_read (obj, obj->next_input_name,
(flags & PEX_BINARY_INPUT) != 0);
if (in < 0)
{
*err = errno;
errmsg = "open temporary file";
goto error_exit;
}
if (obj->next_input_name_allocated)
{
free (obj->next_input_name);
obj->next_input_name_allocated = 0;
}
obj->next_input_name = NULL;
}
else
{
in = obj->next_input;
if (in < 0)
{
*err = 0;
errmsg = "pipeline already complete";
goto error_exit;
}
}
/* Set OUT and OBJ->NEXT_INPUT/OBJ->NEXT_INPUT_NAME. */
if ((flags & PEX_LAST) != 0)
{
if (outname == NULL)
out = STDOUT_FILE_NO;
else if ((flags & PEX_SUFFIX) != 0)
{
outname = concat (obj->tempbase, outname, NULL);
outname_allocated = 1;
}
obj->next_input = -1;
}
else if ((obj->flags & PEX_USE_PIPES) == 0)
{
outname = temp_file (obj, flags, outname);
if (! outname)
{
*err = 0;
errmsg = "could not create temporary file";
goto error_exit;
}
if (outname != orig_outname)
outname_allocated = 1;
if ((obj->flags & PEX_SAVE_TEMPS) == 0)
{
pex_add_remove (obj, outname, outname_allocated);
outname_allocated = 0;
}
/* Hand off ownership of outname to the next stage. */
obj->next_input_name = outname;
obj->next_input_name_allocated = outname_allocated;
outname_allocated = 0;
}
else
{
if (obj->funcs->pipe (obj, p, (flags & PEX_BINARY_OUTPUT) != 0) < 0)
{
*err = errno;
errmsg = "pipe";
goto error_exit;
}
out = p[WRITE_PORT];
obj->next_input = p[READ_PORT];
}
if (out < 0)
{
out = obj->funcs->open_write (obj, outname,
(flags & PEX_BINARY_OUTPUT) != 0,
(flags & PEX_STDOUT_APPEND) != 0);
if (out < 0)
{
*err = errno;
errmsg = "open temporary output file";
goto error_exit;
}
}
if (outname_allocated)
{
free (outname);
outname_allocated = 0;
}
/* Set ERRDES. */
if (errname != NULL && (flags & PEX_STDERR_TO_PIPE) != 0)
{
*err = 0;
errmsg = "both ERRNAME and PEX_STDERR_TO_PIPE specified.";
goto error_exit;
}
if (obj->stderr_pipe != -1)
{
*err = 0;
errmsg = "PEX_STDERR_TO_PIPE used in the middle of pipeline";
goto error_exit;
}
if (errname == NULL)
{
if (flags & PEX_STDERR_TO_PIPE)
{
if (obj->funcs->pipe (obj, p, (flags & PEX_BINARY_ERROR) != 0) < 0)
{
*err = errno;
errmsg = "pipe";
goto error_exit;
}
errdes = p[WRITE_PORT];
obj->stderr_pipe = p[READ_PORT];
}
else
{
errdes = STDERR_FILE_NO;
}
}
else
{
errdes = obj->funcs->open_write (obj, errname,
(flags & PEX_BINARY_ERROR) != 0,
(flags & PEX_STDERR_APPEND) != 0);
if (errdes < 0)
{
*err = errno;
errmsg = "open error file";
goto error_exit;
}
}
/* If we are using pipes, the child process has to close the next
input pipe. */
if ((obj->flags & PEX_USE_PIPES) == 0)
toclose = -1;
else
toclose = obj->next_input;
/* Run the program. */
pid = obj->funcs->exec_child (obj, flags, executable, argv, env,
in, out, errdes, toclose, &errmsg, err);
if (pid < 0)
goto error_exit;
++obj->count;
obj->children = XRESIZEVEC (pid_t, obj->children, obj->count);
obj->children[obj->count - 1] = pid;
return NULL;
error_exit:
if (in >= 0 && in != STDIN_FILE_NO)
obj->funcs->close (obj, in);
if (out >= 0 && out != STDOUT_FILE_NO)
obj->funcs->close (obj, out);
if (errdes >= 0 && errdes != STDERR_FILE_NO)
obj->funcs->close (obj, errdes);
if (outname_allocated)
free (outname);
return errmsg;
}
/* Run a program. */
const char *
pex_run (struct pex_obj *obj, int flags, const char *executable,
char * const * argv, const char *orig_outname, const char *errname,
int *err)
{
return pex_run_in_environment (obj, flags, executable, argv, NULL,
orig_outname, errname, err);
}
/* Return a FILE pointer for a temporary file to fill with input for
the pipeline. */
FILE *
pex_input_file (struct pex_obj *obj, int flags, const char *in_name)
{
char *name = (char *) in_name;
FILE *f;
/* This must be called before the first pipeline stage is run, and
there must not have been any other input selected. */
if (obj->count != 0
|| (obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
|| obj->next_input_name)
{
errno = EINVAL;
return NULL;
}
name = temp_file (obj, flags, name);
if (! name)
return NULL;
f = fopen (name, (flags & PEX_BINARY_OUTPUT) ? "wb" : "w");
if (! f)
{
free (name);
return NULL;
}
obj->input_file = f;
obj->next_input_name = name;
obj->next_input_name_allocated = (name != in_name);
return f;
}
/* Return a stream for a pipe connected to the standard input of the
first stage of the pipeline. */
FILE *
pex_input_pipe (struct pex_obj *obj, int binary)
{
int p[2];
FILE *f;
/* You must call pex_input_pipe before the first pex_run or pex_one. */
if (obj->count > 0)
goto usage_error;
/* You must be using pipes. Implementations that don't support
pipes clear this flag before calling pex_init_common. */
if (! (obj->flags & PEX_USE_PIPES))
goto usage_error;
/* If we have somehow already selected other input, that's a
mistake. */
if ((obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
|| obj->next_input_name)
goto usage_error;
if (obj->funcs->pipe (obj, p, binary != 0) < 0)
return NULL;
f = obj->funcs->fdopenw (obj, p[WRITE_PORT], binary != 0);
if (! f)
{
int saved_errno = errno;
obj->funcs->close (obj, p[READ_PORT]);
obj->funcs->close (obj, p[WRITE_PORT]);
errno = saved_errno;
return NULL;
}
obj->next_input = p[READ_PORT];
return f;
usage_error:
errno = EINVAL;
return NULL;
}
/* Return a FILE pointer for the output of the last program
executed. */
FILE *
pex_read_output (struct pex_obj *obj, int binary)
{
if (obj->next_input_name != NULL)
{
const char *errmsg;
int err;
/* We have to make sure that the process has completed before we
try to read the file. */
if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
{
errno = err;
return NULL;
}
obj->read_output = fopen (obj->next_input_name, binary ? "rb" : "r");
if (obj->next_input_name_allocated)
{
free (obj->next_input_name);
obj->next_input_name_allocated = 0;
}
obj->next_input_name = NULL;
}
else
{
int o;
o = obj->next_input;
if (o < 0 || o == STDIN_FILE_NO)
return NULL;
obj->read_output = obj->funcs->fdopenr (obj, o, binary);
obj->next_input = -1;
}
return obj->read_output;
}
FILE *
pex_read_err (struct pex_obj *obj, int binary)
{
int o;
o = obj->stderr_pipe;
if (o < 0 || o == STDIN_FILE_NO)
return NULL;
obj->read_err = obj->funcs->fdopenr (obj, o, binary);
obj->stderr_pipe = -1;
return obj->read_err;
}
/* Get the exit status and, if requested, the resource time for all
the child processes. Return 0 on failure, 1 on success. */
static int
pex_get_status_and_time (struct pex_obj *obj, int done, const char **errmsg,
int *err)
{
int ret;
int i;
if (obj->number_waited == obj->count)
return 1;
obj->status = XRESIZEVEC (int, obj->status, obj->count);
if ((obj->flags & PEX_RECORD_TIMES) != 0)
obj->time = XRESIZEVEC (struct pex_time, obj->time, obj->count);
ret = 1;
for (i = obj->number_waited; i < obj->count; ++i)
{
if (obj->funcs->wait (obj, obj->children[i], &obj->status[i],
obj->time == NULL ? NULL : &obj->time[i],
done, errmsg, err) < 0)
ret = 0;
}
obj->number_waited = i;
return ret;
}
/* Get exit status of executed programs. */
int
pex_get_status (struct pex_obj *obj, int count, int *vector)
{
if (obj->status == NULL)
{
const char *errmsg;
int err;
if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
return 0;
}
if (count > obj->count)
{
memset (vector + obj->count, 0, (count - obj->count) * sizeof (int));
count = obj->count;
}
memcpy (vector, obj->status, count * sizeof (int));
return 1;
}
/* Get process times of executed programs. */
int
pex_get_times (struct pex_obj *obj, int count, struct pex_time *vector)
{
if (obj->status == NULL)
{
const char *errmsg;
int err;
if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
return 0;
}
if (obj->time == NULL)
return 0;
if (count > obj->count)
{
memset (vector + obj->count, 0,
(count - obj->count) * sizeof (struct pex_time));
count = obj->count;
}
memcpy (vector, obj->time, count * sizeof (struct pex_time));
return 1;
}
/* Free a pex_obj structure. */
void
pex_free (struct pex_obj *obj)
{
/* Close pipe file descriptors corresponding to child's stdout and
stderr so that the child does not hang trying to output something
while we're waiting for it. */
if (obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
obj->funcs->close (obj, obj->next_input);
if (obj->stderr_pipe >= 0 && obj->stderr_pipe != STDIN_FILE_NO)
obj->funcs->close (obj, obj->stderr_pipe);
if (obj->read_output != NULL)
fclose (obj->read_output);
if (obj->read_err != NULL)
fclose (obj->read_err);
/* If the caller forgot to wait for the children, we do it here, to
avoid zombies. */
if (obj->status == NULL)
{
const char *errmsg;
int err;
obj->flags &= ~ PEX_RECORD_TIMES;
pex_get_status_and_time (obj, 1, &errmsg, &err);
}
if (obj->next_input_name_allocated)
free (obj->next_input_name);
free (obj->children);
free (obj->status);
free (obj->time);
if (obj->remove_count > 0)
{
int i;
for (i = 0; i < obj->remove_count; ++i)
{
remove (obj->remove[i]);
free (obj->remove[i]);
}
free (obj->remove);
}
if (obj->funcs->cleanup != NULL)
obj->funcs->cleanup (obj);
free (obj);
}