/* Utilities to execute a program in a subprocess (possibly linked by pipes
with other subprocesses), and wait for it. Generic Unix version
(also used for UWIN and VMS).
- Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005
- Free Software Foundation, Inc.
+ Copyright (C) 1996-2024 Free Software Foundation, Inc.
This file is part of the libiberty library.
Libiberty is free software; you can redistribute it and/or
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. */
+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 "environ.h"
#include <stdio.h>
+#include <signal.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
-#ifdef HAVE_STDLIB_H
-#include <stdlib.h>
+
+#include <sys/types.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
-
-#ifndef HAVE_WAITPID
-#define waitpid(pid, status, flags) wait(status)
+#ifdef HAVE_GETRUSAGE
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#ifdef HAVE_PROCESS_H
+#include <process.h>
+#endif
+#ifdef HAVE_SPAWN_H
+#include <spawn.h>
#endif
#ifdef vfork /* Autoconf may define this to fork for us. */
#ifdef HAVE_VFORK_H
#include <vfork.h>
#endif
-#ifdef VMS
-#define vfork() (decc$$alloc_vfork_blocks() >= 0 ? \
- lib$get_current_invo_context(decc$$get_vfork_jmpbuf()) : -1)
-#endif /* VMS */
-
-/* Execute a program, possibly setting up pipes to programs executed
- via other calls to this function.
-
- This version of the function uses vfork. In general vfork is
- similar to setjmp/longjmp, in that any variable which is modified by
- the child process has an indeterminate value in the parent process.
- We follow a safe approach here by not modifying any variables at
- all in the child process (with the possible exception of variables
- modified by xstrerror if exec fails, but this is unlikely to be
- detectable).
-
- We work a little bit harder to avoid gcc warnings. gcc will warn
- about any automatic variable which is live at the time of the
- vfork, which is non-volatile, and which is either set more than
- once or is an argument to the function. This warning isn't quite
- right, since what we really care about is whether the variable is
- live at the time of the vfork and set afterward by the child
- process, but gcc only checks whether the variable is set more than
- once. To avoid this warning, we ensure that any variable which is
- live at the time of the vfork (i.e., used after the vfork) is set
- exactly once and is not an argument, or is marked volatile. */
-
-int
-pexecute (const char *program, char * const *argv, const char *this_pname,
- const char *temp_base ATTRIBUTE_UNUSED,
- char **errmsg_fmt, char **errmsg_arg, int flagsarg)
-{
- int pid;
- int pdes[2];
- int out;
- int input_desc, output_desc;
- int flags;
- /* We declare these to be volatile to avoid warnings from gcc about
- them being clobbered by vfork. */
- volatile int 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 defined(VMS) && defined (__LONG_POINTERS)
+#ifndef __CHAR_PTR32
+typedef char * __char_ptr32
+__attribute__ ((mode (SI)));
+#endif
+
+typedef __char_ptr32 *__char_ptr_char_ptr32
+__attribute__ ((mode (SI)));
+
+/* Return a 32 bit pointer to an array of 32 bit pointers
+ given a 64 bit pointer to an array of 64 bit pointers. */
+
+static __char_ptr_char_ptr32
+to_ptr32 (char **ptr64)
+{
+ int argc;
+ __char_ptr_char_ptr32 short_argv;
+
+ /* Count number of arguments. */
+ for (argc = 0; ptr64[argc] != NULL; argc++)
+ ;
+
+ /* Reallocate argv with 32 bit pointers. */
+ short_argv = (__char_ptr_char_ptr32) decc$malloc
+ (sizeof (__char_ptr32) * (argc + 1));
+
+ for (argc = 0; ptr64[argc] != NULL; argc++)
+ short_argv[argc] = (__char_ptr32) decc$strdup (ptr64[argc]);
+
+ short_argv[argc] = (__char_ptr32) 0;
+ return short_argv;
+
+}
+#else
+#define to_ptr32(argv) argv
+#endif
+
+/* File mode to use for private and world-readable files. */
+
+#if defined (S_IRUSR) && defined (S_IWUSR) && defined (S_IRGRP) && defined (S_IWGRP) && defined (S_IROTH) && defined (S_IWOTH)
+#define PUBLIC_MODE \
+ (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
+#else
+#define PUBLIC_MODE 0666
+#endif
+
+/* Get the exit status of a particular process, and optionally get the
+ time that it took. This is simple if we have wait4, slightly
+ harder if we have waitpid, and is a pain if we only have wait. */
+
+static pid_t pex_wait (struct pex_obj *, pid_t, int *, struct pex_time *);
+
+#ifdef HAVE_WAIT4
+
+static pid_t
+pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
+ struct pex_time *time)
+{
+ pid_t ret;
+ struct rusage r;
+
+#ifdef HAVE_WAITPID
+ if (time == NULL)
+ return waitpid (pid, status, 0);
+#endif
+
+ ret = wait4 (pid, status, 0, &r);
+
+ if (time != NULL)
+ {
+ time->user_seconds = r.ru_utime.tv_sec;
+ time->user_microseconds= r.ru_utime.tv_usec;
+ time->system_seconds = r.ru_stime.tv_sec;
+ time->system_microseconds= r.ru_stime.tv_usec;
+ }
+
+ return ret;
+}
+
+#else /* ! defined (HAVE_WAIT4) */
+
+#ifdef HAVE_WAITPID
+
+#ifndef HAVE_GETRUSAGE
+
+static pid_t
+pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
+ struct pex_time *time)
+{
+ if (time != NULL)
+ memset (time, 0, sizeof (struct pex_time));
+ return waitpid (pid, status, 0);
+}
+
+#else /* defined (HAVE_GETRUSAGE) */
+
+static pid_t
+pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
+ struct pex_time *time)
+{
+ struct rusage r1, r2;
+ pid_t ret;
+
+ if (time == NULL)
+ return waitpid (pid, status, 0);
+
+ getrusage (RUSAGE_CHILDREN, &r1);
+
+ ret = waitpid (pid, status, 0);
+ if (ret < 0)
+ return ret;
+
+ getrusage (RUSAGE_CHILDREN, &r2);
+
+ time->user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
+ time->user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
+ if (r2.ru_utime.tv_usec < r1.ru_utime.tv_usec)
+ {
+ --time->user_seconds;
+ time->user_microseconds += 1000000;
+ }
+
+ time->system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
+ time->system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
+ if (r2.ru_stime.tv_usec < r1.ru_stime.tv_usec)
+ {
+ --time->system_seconds;
+ time->system_microseconds += 1000000;
+ }
+
+ return ret;
+}
+
+#endif /* defined (HAVE_GETRUSAGE) */
+
+#else /* ! defined (HAVE_WAITPID) */
+
+struct status_list
+{
+ struct status_list *next;
+ pid_t pid;
+ int status;
+ struct pex_time time;
+};
+
+static pid_t
+pex_wait (struct pex_obj *obj, pid_t pid, int *status, struct pex_time *time)
+{
+ struct status_list **pp;
+
+ for (pp = (struct status_list **) &obj->sysdep;
+ *pp != NULL;
+ pp = &(*pp)->next)
+ {
+ if ((*pp)->pid == pid)
+ {
+ struct status_list *p;
+
+ p = *pp;
+ *status = p->status;
+ if (time != NULL)
+ *time = p->time;
+ *pp = p->next;
+ free (p);
+ return pid;
+ }
+ }
+
+ while (1)
+ {
+ pid_t cpid;
+ struct status_list *psl;
+ struct pex_time pt;
+#ifdef HAVE_GETRUSAGE
+ struct rusage r1, r2;
+#endif
+
+ if (time != NULL)
+ {
+#ifdef HAVE_GETRUSAGE
+ getrusage (RUSAGE_CHILDREN, &r1);
+#else
+ memset (&pt, 0, sizeof (struct pex_time));
+#endif
+ }
+
+ cpid = wait (status);
+
+#ifdef HAVE_GETRUSAGE
+ if (time != NULL && cpid >= 0)
+ {
+ getrusage (RUSAGE_CHILDREN, &r2);
+
+ pt.user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
+ pt.user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
+ if (pt.user_microseconds < 0)
+ {
+ --pt.user_seconds;
+ pt.user_microseconds += 1000000;
+ }
+
+ pt.system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
+ pt.system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
+ if (pt.system_microseconds < 0)
+ {
+ --pt.system_seconds;
+ pt.system_microseconds += 1000000;
+ }
+ }
+#endif
+
+ if (cpid < 0 || cpid == pid)
+ {
+ if (time != NULL)
+ *time = pt;
+ return cpid;
+ }
+
+ psl = XNEW (struct status_list);
+ psl->pid = cpid;
+ psl->status = *status;
+ if (time != NULL)
+ psl->time = pt;
+ psl->next = (struct status_list *) obj->sysdep;
+ obj->sysdep = (void *) psl;
+ }
+}
+
+#endif /* ! defined (HAVE_WAITPID) */
+#endif /* ! defined (HAVE_WAIT4) */
+
+static int pex_unix_open_read (struct pex_obj *, const char *, int);
+static int pex_unix_open_write (struct pex_obj *, const char *, int, int);
+static pid_t pex_unix_exec_child (struct pex_obj *, int, const char *,
+ char * const *, char * const *,
+ int, int, int, int,
+ const char **, int *);
+static int pex_unix_close (struct pex_obj *, int);
+static pid_t pex_unix_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
+ int, const char **, int *);
+static int pex_unix_pipe (struct pex_obj *, int *, int);
+static FILE *pex_unix_fdopenr (struct pex_obj *, int, int);
+static FILE *pex_unix_fdopenw (struct pex_obj *, int, int);
+static void pex_unix_cleanup (struct pex_obj *);
+
+/* The list of functions we pass to the common routines. */
+
+const struct pex_funcs funcs =
+{
+ pex_unix_open_read,
+ pex_unix_open_write,
+ pex_unix_exec_child,
+ pex_unix_close,
+ pex_unix_wait,
+ pex_unix_pipe,
+ pex_unix_fdopenr,
+ pex_unix_fdopenw,
+ pex_unix_cleanup
+};
+
+/* Return a newly initialized pex_obj structure. */
+
+struct pex_obj *
+pex_init (int flags, const char *pname, const char *tempbase)
+{
+ return pex_init_common (flags, pname, tempbase, &funcs);
+}
+
+/* Open a file for reading. */
+
+static int
+pex_unix_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
+ int binary ATTRIBUTE_UNUSED)
+{
+ return open (name, O_RDONLY);
+}
+
+/* Open a file for writing. */
+
+static int
+pex_unix_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
+ int binary ATTRIBUTE_UNUSED, int append)
+{
+ /* Note that we can't use O_EXCL here because gcc may have already
+ created the temporary file via make_temp_file. */
+ return open (name, O_WRONLY | O_CREAT
+ | (append ? O_APPEND : O_TRUNC), PUBLIC_MODE);
+}
+
+/* Close a file. */
+
+static int
+pex_unix_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd)
+{
+ return close (fd);
+}
+
+/* Execute a child. */
+
+#if defined(HAVE_SPAWNVE) && defined(HAVE_SPAWNVPE)
+/* Implementation of pex->exec_child using the Cygwin spawn operation. */
+
+/* Subroutine of pex_unix_exec_child. Move OLD_FD to a new file descriptor
+ to be stored in *PNEW_FD, save the flags in *PFLAGS, and arrange for the
+ saved copy to be close-on-exec. Move CHILD_FD into OLD_FD. If CHILD_FD
+ is -1, OLD_FD is to be closed. Return -1 on error. */
+
+static int
+save_and_install_fd(int *pnew_fd, int *pflags, int old_fd, int child_fd)
+{
+ int new_fd, flags;
+
+ flags = fcntl (old_fd, F_GETFD);
+
+ /* If we could not retrieve the flags, then OLD_FD was not open. */
+ if (flags < 0)
+ {
+ new_fd = -1, flags = 0;
+ if (child_fd >= 0 && dup2 (child_fd, old_fd) < 0)
+ return -1;
+ }
+ /* If we wish to close OLD_FD, just mark it CLOEXEC. */
+ else if (child_fd == -1)
+ {
+ new_fd = old_fd;
+ if ((flags & FD_CLOEXEC) == 0 && fcntl (old_fd, F_SETFD, FD_CLOEXEC) < 0)
+ return -1;
+ }
+ /* Otherwise we need to save a copy of OLD_FD before installing CHILD_FD. */
+ else
+ {
+#ifdef F_DUPFD_CLOEXEC
+ new_fd = fcntl (old_fd, F_DUPFD_CLOEXEC, 3);
+ if (new_fd < 0)
+ return -1;
+#else
+ /* Prefer F_DUPFD over dup in order to avoid getting a new fd
+ in the range 0-2, right where a new stderr fd might get put. */
+ new_fd = fcntl (old_fd, F_DUPFD, 3);
+ if (new_fd < 0)
+ return -1;
+ if (fcntl (new_fd, F_SETFD, FD_CLOEXEC) < 0)
+ return -1;
+#endif
+ if (dup2 (child_fd, old_fd) < 0)
+ return -1;
+ }
+
+ *pflags = flags;
+ if (pnew_fd)
+ *pnew_fd = new_fd;
+ else if (new_fd != old_fd)
+ abort ();
+
+ return 0;
+}
+
+/* Subroutine of pex_unix_exec_child. Move SAVE_FD back to OLD_FD
+ restoring FLAGS. If SAVE_FD < 0, OLD_FD is to be closed. */
+
+static int
+restore_fd(int old_fd, int save_fd, int flags)
+{
+ /* For SAVE_FD < 0, all we have to do is restore the
+ "closed-ness" of the original. */
+ if (save_fd < 0)
+ return close (old_fd);
+
+ /* For SAVE_FD == OLD_FD, all we have to do is restore the
+ original setting of the CLOEXEC flag. */
+ if (save_fd == old_fd)
+ {
+ if (flags & FD_CLOEXEC)
+ return 0;
+ return fcntl (old_fd, F_SETFD, flags);
+ }
+
+ /* Otherwise we have to move the descriptor back, restore the flags,
+ and close the saved copy. */
+#ifdef HAVE_DUP3
+ if (flags == FD_CLOEXEC)
+ {
+ if (dup3 (save_fd, old_fd, O_CLOEXEC) < 0)
+ return -1;
+ }
+ else
+#endif
+ {
+ if (dup2 (save_fd, old_fd) < 0)
+ return -1;
+ if (flags != 0 && fcntl (old_fd, F_SETFD, flags) < 0)
+ return -1;
+ }
+ return close (save_fd);
+}
+
+static pid_t
+pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED,
+ int flags, const char *executable,
+ char * const * argv, char * const * env,
+ int in, int out, int errdes, int toclose,
+ const char **errmsg, int *err)
+{
+ int fl_in = 0, fl_out = 0, fl_err = 0, fl_tc = 0;
+ int save_in = -1, save_out = -1, save_err = -1;
+ int max, retries;
+ pid_t pid;
+
+ if (flags & PEX_STDERR_TO_STDOUT)
+ errdes = out;
+
+ /* We need the three standard file descriptors to be set up as for
+ the child before we perform the spawn. The file descriptors for
+ the parent need to be moved and marked for close-on-exec. */
+ if (in != STDIN_FILE_NO
+ && save_and_install_fd (&save_in, &fl_in, STDIN_FILE_NO, in) < 0)
+ goto error_dup2;
+ if (out != STDOUT_FILE_NO
+ && save_and_install_fd (&save_out, &fl_out, STDOUT_FILE_NO, out) < 0)
+ goto error_dup2;
+ if (errdes != STDERR_FILE_NO
+ && save_and_install_fd (&save_err, &fl_err, STDERR_FILE_NO, errdes) < 0)
+ goto error_dup2;
+ if (toclose >= 0
+ && save_and_install_fd (NULL, &fl_tc, toclose, -1) < 0)
+ goto error_dup2;
+
+ /* Now that we've moved the file descriptors for the child into place,
+ close the originals. Be careful not to close any of the standard
+ file descriptors that we just set up. */
+ max = -1;
+ if (errdes >= 0)
+ max = STDERR_FILE_NO;
+ else if (out >= 0)
+ max = STDOUT_FILE_NO;
+ else if (in >= 0)
+ max = STDIN_FILE_NO;
+ if (in > max)
+ close (in);
+ if (out > max)
+ close (out);
+ if (errdes > max && errdes != out)
+ close (errdes);
+
+ /* If we were not given an environment, use the global environment. */
+ if (env == NULL)
+ env = environ;
+
+ /* Launch the program. If we get EAGAIN (normally out of pid's), try
+ again a few times with increasing backoff times. */
+ retries = 0;
+ while (1)
+ {
+ typedef const char * const *cc_cp;
+
+ if (flags & PEX_SEARCH)
+ pid = spawnvpe (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
+ else
+ pid = spawnve (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
+
+ if (pid > 0)
+ break;
+
+ *err = errno;
+ *errmsg = "spawn";
+ if (errno != EAGAIN || ++retries == 4)
+ return (pid_t) -1;
+ sleep (1 << retries);
+ }
+
+ /* Success. Restore the parent's file descriptors that we saved above. */
+ if (toclose >= 0
+ && restore_fd (toclose, toclose, fl_tc) < 0)
+ goto error_dup2;
+ if (in != STDIN_FILE_NO
+ && restore_fd (STDIN_FILE_NO, save_in, fl_in) < 0)
+ goto error_dup2;
+ if (out != STDOUT_FILE_NO
+ && restore_fd (STDOUT_FILE_NO, save_out, fl_out) < 0)
+ goto error_dup2;
+ if (errdes != STDERR_FILE_NO
+ && restore_fd (STDERR_FILE_NO, save_err, fl_err) < 0)
+ goto error_dup2;
+
+ return pid;
+
+ error_dup2:
+ *err = errno;
+ *errmsg = "dup2";
+ return (pid_t) -1;
+}
+
+#elif defined(HAVE_POSIX_SPAWN) && defined(HAVE_POSIX_SPAWNP)
+/* Implementation of pex->exec_child using posix_spawn. */
+
+static pid_t
+pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED,
+ int flags, const char *executable,
+ char * const * argv, char * const * env,
+ int in, int out, int errdes,
+ int toclose, const char **errmsg, int *err)
+{
+ int ret;
+ pid_t pid = -1;
+ posix_spawnattr_t attr;
+ posix_spawn_file_actions_t actions;
+ int attr_initialized = 0, actions_initialized = 0;
+
+ *err = 0;
+
+ ret = posix_spawnattr_init (&attr);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawnattr_init";
+ goto exit;
+ }
+ attr_initialized = 1;
+
+ /* Use vfork() on glibc <=2.24. */
+#ifdef POSIX_SPAWN_USEVFORK
+ ret = posix_spawnattr_setflags (&attr, POSIX_SPAWN_USEVFORK);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawnattr_setflags";
+ goto exit;
+ }
+#endif
+
+ ret = posix_spawn_file_actions_init (&actions);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_init";
+ goto exit;
+ }
+ actions_initialized = 1;
+
+ if (in != STDIN_FILE_NO)
+ {
+ ret = posix_spawn_file_actions_adddup2 (&actions, in, STDIN_FILE_NO);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_adddup2";
+ goto exit;
+ }
+
+ ret = posix_spawn_file_actions_addclose (&actions, in);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_addclose";
+ goto exit;
+ }
+ }
+
+ if (out != STDOUT_FILE_NO)
+ {
+ ret = posix_spawn_file_actions_adddup2 (&actions, out, STDOUT_FILE_NO);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_adddup2";
+ goto exit;
+ }
+
+ ret = posix_spawn_file_actions_addclose (&actions, out);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_addclose";
+ goto exit;
+ }
+ }
+
+ if (errdes != STDERR_FILE_NO)
+ {
+ ret = posix_spawn_file_actions_adddup2 (&actions, errdes, STDERR_FILE_NO);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_adddup2";
+ goto exit;
+ }
- flags = flagsarg;
+ ret = posix_spawn_file_actions_addclose (&actions, errdes);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_addclose";
+ goto exit;
+ }
+ }
- /* If this is the first process, initialize. */
- if (flags & PEXECUTE_FIRST)
- last_pipe_input = STDIN_FILE_NO;
+ if (toclose >= 0)
+ {
+ ret = posix_spawn_file_actions_addclose (&actions, toclose);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_addclose";
+ goto exit;
+ }
+ }
- input_desc = last_pipe_input;
+ if ((flags & PEX_STDERR_TO_STDOUT) != 0)
+ {
+ ret = posix_spawn_file_actions_adddup2 (&actions, STDOUT_FILE_NO, STDERR_FILE_NO);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn_file_actions_adddup2";
+ goto exit;
+ }
+ }
- /* 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 ((flags & PEX_SEARCH) != 0)
{
- if (pipe (pdes) < 0)
+ ret = posix_spawnp (&pid, executable, &actions, &attr, argv, env ? env : environ);
+ if (ret)
{
- *errmsg_fmt = "pipe";
- *errmsg_arg = NULL;
- return -1;
+ *err = ret;
+ *errmsg = "posix_spawnp";
+ pid = -1; /* The value of pid is unspecified on failure. */
+ goto exit;
}
- out = pdes[WRITE_PORT];
- last_pipe_input = pdes[READ_PORT];
}
else
{
- /* Last process. */
- out = STDOUT_FILE_NO;
- last_pipe_input = STDIN_FILE_NO;
+ ret = posix_spawn (&pid, executable, &actions, &attr, argv, env ? env : environ);
+ if (ret)
+ {
+ *err = ret;
+ *errmsg = "posix_spawn";
+ pid = -1;
+ goto exit;
+ }
+ }
+
+exit:
+ if (actions_initialized)
+ posix_spawn_file_actions_destroy (&actions);
+ if (attr_initialized)
+ posix_spawnattr_destroy (&attr);
+
+ if (!*err && in != STDIN_FILE_NO)
+ if (close (in))
+ *errmsg = "close", *err = errno, pid = -1;
+ if (!*err && out != STDOUT_FILE_NO)
+ if (close (out))
+ *errmsg = "close", *err = errno, pid = -1;
+ if (!*err && errdes != STDERR_FILE_NO)
+ if (close (errdes))
+ *errmsg = "close", *err = errno, pid = -1;
+
+ return pid;
+}
+#else
+/* Implementation of pex->exec_child using standard vfork + exec. */
+
+static pid_t
+pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
+ char * const * argv, char * const * env,
+ int in, int out, int errdes,
+ int toclose, const char **errmsg, int *err)
+{
+ pid_t pid = -1;
+ /* Tuple to communicate error from child to parent. We can safely
+ transfer string literal pointers as both run with identical
+ address mappings. */
+ struct fn_err
+ {
+ const char *fn;
+ int err;
+ };
+ volatile int do_pipe = 0;
+ volatile int pipes[2]; /* [0]:reader,[1]:writer. */
+#ifdef O_CLOEXEC
+ do_pipe = 1;
+#endif
+ if (do_pipe)
+ {
+#ifdef HAVE_PIPE2
+ if (pipe2 ((int *)pipes, O_CLOEXEC))
+ do_pipe = 0;
+#else
+ if (pipe ((int *)pipes))
+ do_pipe = 0;
+ else
+ {
+ if (fcntl (pipes[1], F_SETFD, FD_CLOEXEC) == -1)
+ {
+ close (pipes[0]);
+ close (pipes[1]);
+ do_pipe = 0;
+ }
+ }
+#endif
}
- output_desc = out;
+ /* We declare these to be volatile to avoid warnings from gcc about
+ them being clobbered by vfork. */
+ volatile int sleep_interval = 1;
+ volatile int retries;
+
+ /* We vfork and then set environ in the child before calling execvp.
+ This clobbers the parent's environ so we need to restore it.
+ It would be nice to use one of the exec* functions that takes an
+ environment as a parameter, but that may have portability
+ issues. It is marked volatile so the child doesn't consider it a
+ dead variable and therefore clobber where ever it is stored. */
+ char **volatile save_environ = environ;
- /* Fork a subprocess; wait and retry if it fails. */
- sleep_interval = 1;
- pid = -1;
- for (retries = 0; retries < 4; retries++)
+ for (retries = 0; retries < 4; ++retries)
{
pid = vfork ();
if (pid >= 0)
switch (pid)
{
case -1:
- *errmsg_fmt = "fork";
- *errmsg_arg = NULL;
- return -1;
-
- case 0: /* child */
- /* Move the input and output pipes into place, if necessary. */
- if (input_desc != STDIN_FILE_NO)
+ if (do_pipe)
{
- 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 (pipes[0]);
+ close (pipes[1]);
}
+ *err = errno;
+ *errmsg = VFORK_STRING;
+ return (pid_t) -1;
- /* Close the parent's descs that aren't wanted here. */
- if (last_pipe_input != STDIN_FILE_NO)
- close (last_pipe_input);
+ case 0:
+ /* Child process. */
+ {
+ struct fn_err failed;
+ failed.fn = NULL;
- /* Exec the program. */
- if (flags & PEXECUTE_SEARCH)
- execvp (program, argv);
- else
- execv (program, argv);
-
- /* We don't want to call fprintf after vfork. */
-#define writeerr(s) write (STDERR_FILE_NO, s, strlen (s))
- writeerr (this_pname);
- writeerr (": ");
- writeerr ("installation problem, cannot exec '");
- writeerr (program);
- writeerr ("': ");
- writeerr (xstrerror (errno));
- writeerr ("\n");
- _exit (-1);
+ if (do_pipe)
+ close (pipes[0]);
+ if (!failed.fn && in != STDIN_FILE_NO)
+ {
+ if (dup2 (in, STDIN_FILE_NO) < 0)
+ failed.fn = "dup2", failed.err = errno;
+ else if (close (in) < 0)
+ failed.fn = "close", failed.err = errno;
+ }
+ if (!failed.fn && out != STDOUT_FILE_NO)
+ {
+ if (dup2 (out, STDOUT_FILE_NO) < 0)
+ failed.fn = "dup2", failed.err = errno;
+ else if (close (out) < 0)
+ failed.fn = "close", failed.err = errno;
+ }
+ if (!failed.fn && errdes != STDERR_FILE_NO)
+ {
+ if (dup2 (errdes, STDERR_FILE_NO) < 0)
+ failed.fn = "dup2", failed.err = errno;
+ else if (close (errdes) < 0)
+ failed.fn = "close", failed.err = errno;
+ }
+ if (!failed.fn && toclose >= 0)
+ {
+ if (close (toclose) < 0)
+ failed.fn = "close", failed.err = errno;
+ }
+ if (!failed.fn && (flags & PEX_STDERR_TO_STDOUT) != 0)
+ {
+ if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0)
+ failed.fn = "dup2", failed.err = errno;
+ }
+ if (!failed.fn)
+ {
+ if (env)
+ /* NOTE: In a standard vfork implementation this clobbers
+ the parent's copy of environ "too" (in reality there's
+ only one copy). This is ok as we restore it below. */
+ environ = (char**) env;
+ if ((flags & PEX_SEARCH) != 0)
+ {
+ execvp (executable, to_ptr32 (argv));
+ failed.fn = "execvp", failed.err = errno;
+ }
+ else
+ {
+ execv (executable, to_ptr32 (argv));
+ failed.fn = "execv", failed.err = errno;
+ }
+ }
+
+ /* Something failed, report an error. We don't use stdio
+ routines, because we might be here due to a vfork call. */
+ ssize_t retval = 0;
+
+ if (!do_pipe
+ || write (pipes[1], &failed, sizeof (failed)) != sizeof (failed))
+ {
+ /* The parent will not see our scream above, so write to
+ stdout. */
+#define writeerr(s) (retval |= write (STDERR_FILE_NO, s, strlen (s)))
+ writeerr (obj->pname);
+ writeerr (": error trying to exec '");
+ writeerr (executable);
+ writeerr ("': ");
+ writeerr (failed.fn);
+ writeerr (": ");
+ writeerr (xstrerror (failed.err));
+ writeerr ("\n");
+#undef writeerr
+ }
+
+ /* Exit with -2 if the error output failed, too. */
+ _exit (retval < 0 ? -2 : -1);
+ }
/* NOTREACHED */
- return 0;
+ return (pid_t) -1;
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. */
+ /* Parent process. */
+ {
+ /* Restore environ. Note that the parent either doesn't run
+ until the child execs/exits (standard vfork behaviour), or
+ if it does run then vfork is behaving more like fork. In
+ either case we needn't worry about clobbering the child's
+ copy of environ. */
+ environ = save_environ;
+
+ struct fn_err failed;
+ failed.fn = NULL;
+ if (do_pipe)
+ {
+ close (pipes[1]);
+ ssize_t len = read (pipes[0], &failed, sizeof (failed));
+ if (len < 0)
+ failed.fn = NULL;
+ close (pipes[0]);
+ }
+
+ if (!failed.fn && in != STDIN_FILE_NO)
+ if (close (in) < 0)
+ failed.fn = "close", failed.err = errno;
+ if (!failed.fn && out != STDOUT_FILE_NO)
+ if (close (out) < 0)
+ failed.fn = "close", failed.err = errno;
+ if (!failed.fn && errdes != STDERR_FILE_NO)
+ if (close (errdes) < 0)
+ failed.fn = "close", failed.err = errno;
+
+ if (failed.fn)
+ {
+ *err = failed.err;
+ *errmsg = failed.fn;
+ return (pid_t) -1;
+ }
+ }
return pid;
}
}
+#endif /* SPAWN */
-int
-pwait (int pid, int *status, int flags ATTRIBUTE_UNUSED)
+/* Wait for a child process to complete. */
+
+static pid_t
+pex_unix_wait (struct pex_obj *obj, pid_t pid, int *status,
+ struct pex_time *time, int done, const char **errmsg,
+ int *err)
{
- /* ??? Here's an opportunity to canonicalize the values in STATUS.
- Needed? */
- pid = waitpid (pid, status, 0);
- return pid;
+ /* If we are cleaning up when the caller didn't retrieve process
+ status for some reason, encourage the process to go away. */
+ if (done)
+ kill (pid, SIGTERM);
+
+ if (pex_wait (obj, pid, status, time) < 0)
+ {
+ *err = errno;
+ *errmsg = "wait";
+ return -1;
+ }
+
+ return 0;
+}
+
+/* Create a pipe. */
+
+static int
+pex_unix_pipe (struct pex_obj *obj ATTRIBUTE_UNUSED, int *p,
+ int binary ATTRIBUTE_UNUSED)
+{
+ return pipe (p);
+}
+
+/* Get a FILE pointer to read from a file descriptor. */
+
+static FILE *
+pex_unix_fdopenr (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
+ int binary ATTRIBUTE_UNUSED)
+{
+ return fdopen (fd, "r");
+}
+
+static FILE *
+pex_unix_fdopenw (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
+ int binary ATTRIBUTE_UNUSED)
+{
+ if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0)
+ return NULL;
+ return fdopen (fd, "w");
+}
+
+static void
+pex_unix_cleanup (struct pex_obj *obj ATTRIBUTE_UNUSED)
+{
+#if !defined (HAVE_WAIT4) && !defined (HAVE_WAITPID)
+ while (obj->sysdep != NULL)
+ {
+ struct status_list *this;
+ struct status_list *next;
+
+ this = (struct status_list *) obj->sysdep;
+ next = this->next;
+ free (this);
+ obj->sysdep = (void *) next;
+ }
+#endif
}
projects / thirdparty / gcc.git / blobdiff