Import posix_spawn from Gnulib.

posix_spawn is less error-prone than vfork + exec, and can make use of
system-specific optimizations like `clone' on Linux.  Import Gnulib
replacement so that we can use recent additions like
`posix_spawn_file_actions_addchdir'.

The only manual change are to admin/merge-gnulib and .gitignore.  All
other changes are due to rerunning merge-gnulib.

* admin/merge-gnulib (GNULIB_MODULES): Add posix_spawn-related
modules.
* .gitignore: Add new generated files.

1 files changed, 144 insertions, 0 deletions

diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 0971636c33d..e2a44efe621 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -139,6 +139,18 @@ AC_DEFUN([gl_EARLY],
   # Code from module openat-h:
   # Code from module pathmax:
   # Code from module pipe2:
+  # Code from module posix_spawn:
+  # Code from module posix_spawn-internal:
+  # Code from module posix_spawn_file_actions_addchdir:
+  # Code from module posix_spawn_file_actions_adddup2:
+  # Code from module posix_spawn_file_actions_destroy:
+  # Code from module posix_spawn_file_actions_init:
+  # Code from module posix_spawnattr_destroy:
+  # Code from module posix_spawnattr_init:
+  # Code from module posix_spawnattr_setflags:
+  # Code from module posix_spawnattr_setpgroup:
+  # Code from module posix_spawnattr_setsigdefault:
+  # Code from module posix_spawnattr_setsigmask:
   # Code from module pselect:
   # Code from module pthread_sigmask:
   # Code from module qcopy-acl:
@@ -147,7 +159,9 @@ AC_DEFUN([gl_EARLY],
   # Code from module readlinkat:
   # Code from module regex:
   # Code from module root-uid:
+  # Code from module sched:
   # Code from module scratch_buffer:
+  # Code from module sh-filename:
   # Code from module sig2str:
   # Code from module sigdescr_np:
   # Code from module signal-h:
@@ -156,6 +170,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module snippet/c++defs:
   # Code from module snippet/warn-on-use:
   # Code from module socklen:
+  # Code from module spawn:
   # Code from module ssize_t:
   # Code from module stat-time:
   # Code from module std-gnu11:
@@ -165,6 +180,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module stdio:
   # Code from module stdlib:
   # Code from module stpcpy:
+  # Code from module strchrnul:
   # Code from module string:
   # Code from module strnlen:
   # Code from module strtoimax:
@@ -403,6 +419,61 @@ AC_DEFUN([gl_INIT],
   gl_PATHMAX
   gl_FUNC_PIPE2
   gl_UNISTD_MODULE_INDICATOR([pipe2])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawn])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawn])
+  gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR = 0 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR = 1; then
+    AC_LIBOBJ([spawn_faction_addchdir])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_addchdir])
+  gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2 = 1; then
+    AC_LIBOBJ([spawn_faction_adddup2])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_adddup2])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawn_faction_destroy])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_destroy])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawn_faction_init])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawn_file_actions_init])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_destroy])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_destroy])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_init])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_init])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_setflags])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setflags])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_setpgroup])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setpgroup])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_setdefault])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setsigdefault])
+  gl_POSIX_SPAWN
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    AC_LIBOBJ([spawnattr_setsigmask])
+  fi
+  gl_SPAWN_MODULE_INDICATOR([posix_spawnattr_setsigmask])
   gl_FUNC_PSELECT
   if test $HAVE_PSELECT = 0 || test $REPLACE_PSELECT = 1; then
     AC_LIBOBJ([pselect])
@@ -430,6 +501,7 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([regex])
     gl_PREREQ_REGEX
   fi
+  gl_SCHED_H
   gl_FUNC_SIG2STR
   if test $ac_cv_func_sig2str = no; then
     AC_LIBOBJ([sig2str])
@@ -442,6 +514,7 @@ AC_DEFUN([gl_INIT],
   gl_STRING_MODULE_INDICATOR([sigdescr_np])
   gl_SIGNAL_H
   gl_TYPE_SOCKLEN_T
+  gl_SPAWN_H
   gt_TYPE_SSIZE_T
   gl_STAT_TIME
   gl_STAT_BIRTHTIME
@@ -528,9 +601,12 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_open=false
   gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
+  gl_gnulib_enabled_332607f759618fb73dfc3076748afea7=false
   gl_gnulib_enabled_rawmemchr=false
   gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
   gl_gnulib_enabled_scratch_buffer=false
+  gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70=false
+  gl_gnulib_enabled_strchrnul=false
   gl_gnulib_enabled_strtoll=false
   gl_gnulib_enabled_utimens=false
   gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
@@ -685,6 +761,20 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=true
     fi
   }
+  func_gl_gnulib_m4code_332607f759618fb73dfc3076748afea7 ()
+  {
+    if ! $gl_gnulib_enabled_332607f759618fb73dfc3076748afea7; then
+      gl_POSIX_SPAWN
+      if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+        AC_LIBOBJ([spawni])
+        gl_PREREQ_POSIX_SPAWN_INTERNAL
+      fi
+      gl_gnulib_enabled_332607f759618fb73dfc3076748afea7=true
+      func_gl_gnulib_m4code_open
+      func_gl_gnulib_m4code_cdeb0f2aaf9d280baa6526bfa1b07f70
+      func_gl_gnulib_m4code_strchrnul
+    fi
+  }
   func_gl_gnulib_m4code_rawmemchr ()
   {
     if ! $gl_gnulib_enabled_rawmemchr; then
@@ -709,6 +799,28 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_scratch_buffer=true
     fi
   }
+  func_gl_gnulib_m4code_cdeb0f2aaf9d280baa6526bfa1b07f70 ()
+  {
+    if ! $gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70; then
+      gl_SH_FILENAME
+      gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70=true
+    fi
+  }
+  func_gl_gnulib_m4code_strchrnul ()
+  {
+    if ! $gl_gnulib_enabled_strchrnul; then
+      gl_FUNC_STRCHRNUL
+      if test $HAVE_STRCHRNUL = 0 || test $REPLACE_STRCHRNUL = 1; then
+        AC_LIBOBJ([strchrnul])
+        gl_PREREQ_STRCHRNUL
+      fi
+      gl_STRING_MODULE_INDICATOR([strchrnul])
+      gl_gnulib_enabled_strchrnul=true
+      if test $HAVE_STRCHRNUL = 0 || test $REPLACE_STRCHRNUL = 1; then
+        func_gl_gnulib_m4code_rawmemchr
+      fi
+    fi
+  }
   func_gl_gnulib_m4code_strtoll ()
   {
     if ! $gl_gnulib_enabled_strtoll; then
@@ -791,6 +903,12 @@ AC_DEFUN([gl_INIT],
   if case $host_os in mingw*) false;; *) test $HAVE_GETRANDOM = 0 || test $REPLACE_GETRANDOM = 1;; esac; then
     func_gl_gnulib_m4code_open
   fi
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1; then
+    func_gl_gnulib_m4code_332607f759618fb73dfc3076748afea7
+  fi
+  if test $HAVE_POSIX_SPAWN = 0 || test $REPLACE_POSIX_SPAWN = 1 || test $REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2 = 1; then
+    func_gl_gnulib_m4code_getdtablesize
+  fi
   if test $HAVE_READLINKAT = 0 || test $REPLACE_READLINKAT = 1; then
     func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b
   fi
@@ -830,9 +948,12 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_open], [$gl_gnulib_enabled_open])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_332607f759618fb73dfc3076748afea7], [$gl_gnulib_enabled_332607f759618fb73dfc3076748afea7])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_rawmemchr], [$gl_gnulib_enabled_rawmemchr])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_scratch_buffer], [$gl_gnulib_enabled_scratch_buffer])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_cdeb0f2aaf9d280baa6526bfa1b07f70], [$gl_gnulib_enabled_cdeb0f2aaf9d280baa6526bfa1b07f70])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_strchrnul], [$gl_gnulib_enabled_strchrnul])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_strtoll], [$gl_gnulib_enabled_strtoll])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_utimens], [$gl_gnulib_enabled_utimens])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_682e609604ccaac6be382e4ee3a4eaec], [$gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec])
@@ -1113,6 +1234,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/regex_internal.h
   lib/regexec.c
   lib/root-uid.h
+  lib/sched.in.h
   lib/scratch_buffer.h
   lib/set-permissions.c
   lib/sha1.c
@@ -1125,6 +1247,20 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/sig2str.h
   lib/sigdescr_np.c
   lib/signal.in.h
+  lib/spawn.c
+  lib/spawn.in.h
+  lib/spawn_faction_addchdir.c
+  lib/spawn_faction_adddup2.c
+  lib/spawn_faction_destroy.c
+  lib/spawn_faction_init.c
+  lib/spawn_int.h
+  lib/spawnattr_destroy.c
+  lib/spawnattr_init.c
+  lib/spawnattr_setdefault.c
+  lib/spawnattr_setflags.c
+  lib/spawnattr_setpgroup.c
+  lib/spawnattr_setsigmask.c
+  lib/spawni.c
   lib/stat-time.c
   lib/stat-time.h
   lib/stdalign.in.h
@@ -1135,6 +1271,8 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/stdlib.in.h
   lib/stpcpy.c
   lib/str-two-way.h
+  lib/strchrnul.c
+  lib/strchrnul.valgrind
   lib/strftime.h
   lib/string.in.h
   lib/strnlen.c
@@ -1248,12 +1386,16 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/pathmax.m4
   m4/pid_t.m4
   m4/pipe2.m4
+  m4/posix_spawn.m4
+  m4/posix_spawn_faction_addchdir.m4
   m4/pselect.m4
   m4/pthread_sigmask.m4
   m4/rawmemchr.m4
   m4/readlink.m4
   m4/readlinkat.m4
   m4/regex.m4
+  m4/sched_h.m4
+  m4/sh-filename.m4
   m4/sha1.m4
   m4/sha256.m4
   m4/sha512.m4
@@ -1261,6 +1403,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/sigdescr_np.m4
   m4/signal_h.m4
   m4/socklen.m4
+  m4/spawn_h.m4
   m4/ssize_t.m4
   m4/stat-time.m4
   m4/std-gnu11.m4
@@ -1270,6 +1413,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/stdio_h.m4
   m4/stdlib_h.m4
   m4/stpcpy.m4
+  m4/strchrnul.m4
   m4/string_h.m4
   m4/strnlen.m4
   m4/strtoimax.m4