Use spawnve on cygwin.

	* configure.ac (AC_CHECK_HEADERS): Add process.h.
	(checkfuncs): Add dup3, spawnve, spawnvpe; sort the list.
	(AC_CHECK_FUNCS): Add dup3, spawnve, spawnvpe.
	* configure, config.in: Rebuild.
	* pex-unix.c [HAVE_SPAWNVE] (pex_unix_exec_child): New function.
	[HAVE_SPAWNVE] (save_and_install_fd, restore_fd): New functions.

5 files changed, 237 insertions, 13 deletions

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index fa38b09..62c60bd 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,12 @@
+2010-11-04  Richard Henderson  <rth@redhat.com>
+
+	* configure.ac (AC_CHECK_HEADERS): Add process.h.
+	(checkfuncs): Add dup3, spawnve, spawnvpe; sort the list.
+	(AC_CHECK_FUNCS): Add dup3, spawnve, spawnvpe.
+	* configure, config.in: Rebuild.
+	* pex-unix.c [HAVE_SPAWNVE] (pex_unix_exec_child): New function.
+	[HAVE_SPAWNVE] (save_and_install_fd, restore_fd): New functions.
+
 2010-11-02  Ian Lance Taylor  <iant@google.com>
 	    Dave Korn  <dave.korn.cygwin@gmail.com>
 	    Iain Sandoe  <iains@gcc.gnu.org>
diff --git a/libiberty/config.in b/libiberty/config.in
index 0e5f3d2..3febdad 100644
--- a/libiberty/config.in
+++ b/libiberty/config.in
@@ -91,6 +91,9 @@
    don't. */
 #undef HAVE_DECL_VSNPRINTF
 
+/* Define to 1 if you have the `dup3' function. */
+#undef HAVE_DUP3
+
 /* Define to 1 if you have the <fcntl.h> header file. */
 #undef HAVE_FCNTL_H
 
@@ -169,6 +172,9 @@
 /* Define if you have prctl PR_SET_NAME */
 #undef HAVE_PRCTL_SET_NAME
 
+/* Define to 1 if you have the <process.h> header file. */
+#undef HAVE_PROCESS_H
+
 /* Define to 1 if you have the `psignal' function. */
 #undef HAVE_PSIGNAL
 
@@ -208,6 +214,12 @@
 /* Define to 1 if you have the `snprintf' function. */
 #undef HAVE_SNPRINTF
 
+/* Define to 1 if you have the `spawnve' function. */
+#undef HAVE_SPAWNVE
+
+/* Define to 1 if you have the `spawnvpe' function. */
+#undef HAVE_SPAWNVPE
+
 /* Define to 1 if you have the <stdint.h> header file. */
 #undef HAVE_STDINT_H
 
diff --git a/libiberty/configure b/libiberty/configure
index 3d7ba30..c16ced9 100755
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -4895,7 +4895,7 @@ host_makefile_frag=${frag}
 # It's OK to check for header files.  Although the compiler may not be
 # able to link anything, it had better be able to at least compile
 # something.
-for ac_header in sys/file.h sys/param.h limits.h stdlib.h malloc.h string.h unistd.h strings.h sys/time.h time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h alloca.h sys/pstat.h sys/sysmp.h sys/sysinfo.h machine/hal_sysinfo.h sys/table.h sys/sysctl.h sys/systemcfg.h stdint.h stdio_ext.h
+for ac_header in sys/file.h sys/param.h limits.h stdlib.h malloc.h string.h unistd.h strings.h sys/time.h time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h alloca.h sys/pstat.h sys/sysmp.h sys/sysinfo.h machine/hal_sysinfo.h sys/table.h sys/sysctl.h sys/systemcfg.h stdint.h stdio_ext.h process.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_preproc "$LINENO" "$ac_header" "$as_ac_Header"
@@ -5293,9 +5293,10 @@ funcs="$funcs setproctitle"
 
 vars="sys_errlist sys_nerr sys_siglist"
 
-checkfuncs="getrusage on_exit psignal strerror strsignal sysconf times sbrk gettimeofday"
-checkfuncs="$checkfuncs realpath canonicalize_file_name pstat_getstatic pstat_getdynamic sysmp"
-checkfuncs="$checkfuncs getsysinfo table sysctl wait3 wait4 __fsetlocking"
+checkfuncs="__fsetlocking canonicalize_file_name dup3 getrusage getsysinfo \
+ gettimeofday on_exit psignal pstat_getdynamic pstat_getstatic realpath \
+ sbrk spawnve spawnvpe strerror strsignal sysconf sysctl sysmp table \
+ times wait3 wait4"
 
 # These are neither executed nor required, but they help keep
 # autoheader happy without adding a bunch of text to acconfig.h.
@@ -5303,6 +5304,7 @@ if test "x" = "y"; then
   for ac_func in asprintf atexit \
     basename bcmp bcopy bsearch bzero \
     calloc canonicalize_file_name clock \
+    dup3 \
     ffs __fsetlocking \
     getcwd getpagesize getrusage getsysinfo gettimeofday \
     index insque \
@@ -5310,8 +5312,8 @@ if test "x" = "y"; then
     on_exit \
     psignal pstat_getdynamic pstat_getstatic putenv \
     random realpath rename rindex \
-    sbrk setenv setproctitle sigsetmask snprintf stpcpy stpncpy strcasecmp strchr \
-    strdup \
+    sbrk setenv setproctitle sigsetmask snprintf spawnve spawnvpe \
+     stpcpy stpncpy strcasecmp strchr strdup \
      strerror strncasecmp strndup strrchr strsignal strstr strtod strtol \
      strtoul strverscmp sysconf sysctl sysmp \
     table times tmpnam \
diff --git a/libiberty/configure.ac b/libiberty/configure.ac
index 8136f25..d9ecfdd 100644
--- a/libiberty/configure.ac
+++ b/libiberty/configure.ac
@@ -246,7 +246,7 @@ AC_SUBST_FILE(host_makefile_frag)
 # It's OK to check for header files.  Although the compiler may not be
 # able to link anything, it had better be able to at least compile
 # something.
-AC_CHECK_HEADERS(sys/file.h sys/param.h limits.h stdlib.h malloc.h string.h unistd.h strings.h sys/time.h time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h alloca.h sys/pstat.h sys/sysmp.h sys/sysinfo.h machine/hal_sysinfo.h sys/table.h sys/sysctl.h sys/systemcfg.h stdint.h stdio_ext.h)
+AC_CHECK_HEADERS(sys/file.h sys/param.h limits.h stdlib.h malloc.h string.h unistd.h strings.h sys/time.h time.h sys/resource.h sys/stat.h sys/mman.h fcntl.h alloca.h sys/pstat.h sys/sysmp.h sys/sysinfo.h machine/hal_sysinfo.h sys/table.h sys/sysctl.h sys/systemcfg.h stdint.h stdio_ext.h process.h)
 AC_HEADER_SYS_WAIT
 AC_HEADER_TIME
 
@@ -358,9 +358,10 @@ funcs="$funcs setproctitle"
 
 vars="sys_errlist sys_nerr sys_siglist"
 
-checkfuncs="getrusage on_exit psignal strerror strsignal sysconf times sbrk gettimeofday"
-checkfuncs="$checkfuncs realpath canonicalize_file_name pstat_getstatic pstat_getdynamic sysmp"
-checkfuncs="$checkfuncs getsysinfo table sysctl wait3 wait4 __fsetlocking"
+checkfuncs="__fsetlocking canonicalize_file_name dup3 getrusage getsysinfo \
+ gettimeofday on_exit psignal pstat_getdynamic pstat_getstatic realpath \
+ sbrk spawnve spawnvpe strerror strsignal sysconf sysctl sysmp table \
+ times wait3 wait4"
 
 # These are neither executed nor required, but they help keep
 # autoheader happy without adding a bunch of text to acconfig.h.
@@ -368,6 +369,7 @@ if test "x" = "y"; then
   AC_CHECK_FUNCS(asprintf atexit \
     basename bcmp bcopy bsearch bzero \
     calloc canonicalize_file_name clock \
+    dup3 \
     ffs __fsetlocking \
     getcwd getpagesize getrusage getsysinfo gettimeofday \
     index insque \
@@ -375,8 +377,8 @@ if test "x" = "y"; then
     on_exit \
     psignal pstat_getdynamic pstat_getstatic putenv \
     random realpath rename rindex \
-    sbrk setenv setproctitle sigsetmask snprintf stpcpy stpncpy strcasecmp strchr \
-    strdup \
+    sbrk setenv setproctitle sigsetmask snprintf spawnve spawnvpe \
+     stpcpy stpncpy strcasecmp strchr strdup \
      strerror strncasecmp strndup strrchr strsignal strstr strtod strtol \
      strtoul strverscmp sysconf sysctl sysmp \
     table times tmpnam \
diff --git a/libiberty/pex-unix.c b/libiberty/pex-unix.c
index 85733a6..c4a69ad 100644
--- a/libiberty/pex-unix.c
+++ b/libiberty/pex-unix.c
@@ -55,7 +55,9 @@ extern int errno;
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
-
+#ifdef HAVE_PROCESS_H
+#include <process.h>
+#endif
 
 #ifdef vfork /* Autoconf may define this to fork for us. */
 # define VFORK_STRING "fork"
@@ -387,6 +389,202 @@ pex_child_error (struct pex_obj *obj, const char *executable,
 
 extern char **environ;
 
+#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;
+}
+
+#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,
@@ -521,6 +719,7 @@ pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
       return pid;
     }
 }
+#endif /* SPAWN */
 
 /* Wait for a child process to complete.  */