master e387371 1/2: Revert "Use posix_spawn if possible."

[Eli Zaretskii]

branch: master
commit e387371497d313f05b94e3bf42fe6685184605d1
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Revert "Use posix_spawn if possible."
    
    This reverts commit 2c79a8f9210db01c86b0e5f236adeb0509519d30.
    It breaks the MinGW build in too many ways, and should be
    first tested on a branch.
---
 src/Makefile.in |   4 +-
 src/callproc.c  | 148 +-------------------------------------------------------
 2 files changed, 2 insertions(+), 150 deletions(-)

diff --git a/src/Makefile.in b/src/Makefile.in
index aa93b60..39c0f12 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -239,8 +239,6 @@ LCMS2_CFLAGS = @LCMS2_CFLAGS@
 
 LIBZ = @LIBZ@
 
-LIB_POSIX_SPAWN = @LIB_POSIX_SPAWN@
-
 ## system-specific libs for dynamic modules, else empty
 LIBMODULES = @LIBMODULES@
 ## dynlib.o emacs-module.o if modules enabled, else empty
@@ -537,7 +535,7 @@ LIBES = $(LIBS) $(W32_LIBS) $(LIBS_GNUSTEP) $(LIBX_BASE) 
$(LIBIMAGE) \
    $(FREETYPE_LIBS) $(FONTCONFIG_LIBS) $(HARFBUZZ_LIBS) $(LIBOTF_LIBS) 
$(M17N_FLT_LIBS) \
    $(LIBGNUTLS_LIBS) $(LIB_PTHREAD) $(GETADDRINFO_A_LIBS) $(LCMS2_LIBS) \
    $(NOTIFY_LIBS) $(LIB_MATH) $(LIBZ) $(LIBMODULES) $(LIBSYSTEMD_LIBS) \
-   $(JSON_LIBS) $(LIBGMP) $(LIB_POSIX_SPAWN)
+   $(JSON_LIBS) $(LIBGMP)
 
 ## FORCE it so that admin/unidata can decide whether this file is
 ## up-to-date.  Although since charprop depends on bootstrap-emacs,
diff --git a/src/callproc.c b/src/callproc.c
index a505653..3ecd688 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -27,7 +27,6 @@ along with GNU Emacs.  If not, see 
<https://www.gnu.org/licenses/>.  */
 
 #include <sys/file.h>
 #include <fcntl.h>
-#include <spawn.h>
 
 #include "lisp.h"
 
@@ -1229,156 +1228,12 @@ int
 emacs_spawn (pid_t *newpid, int std_in, int std_out, int std_err,
              char **argv, char **envp, const char *cwd, const char *pty)
 {
-  /* `posix_spawn' is available on all Unix systems, either natively
-     or through Gnulib.  Gnulib defines `posix_spawn' on Windows as
-     well, but doesn't implement it yet.  So we fall back to our own
-     code on Windows.  Because Gnulib always defines `posix_spawn', we
-     don't need to use conditional compilation here.  */
-
-#ifdef DOS_NT
-  enum { can_use_posix_spawn = false };
-#else
-  enum { can_use_posix_spawn = true };
-#endif
-
-  /* `posix_spawn' doesn't yet support setting up pseudoterminals, so
-     we fall back to `vfork' if we're supposed to use a
-     pseudoterminal.  */
-
-  bool use_posix_spawn = can_use_posix_spawn && pty == NULL;
-
-  posix_spawn_file_actions_t actions;
-  posix_spawnattr_t attributes;
-
-  if (use_posix_spawn)
-    {
-      /* Initialize optional attributes before blocking. */
-      bool destroy_actions = false;
-      bool destroy_attributes = false;
-
-      int error = posix_spawn_file_actions_init (&actions);
-      if (error != 0)
-        goto posix_spawn_init_failed;
-      destroy_actions = true;
-
-      error = posix_spawnattr_init (&attributes);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-      destroy_attributes = true;
-
-      error = posix_spawn_file_actions_adddup2 (&actions, std_in,
-                                                STDIN_FILENO);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      error = posix_spawn_file_actions_adddup2 (&actions, std_out,
-                                                STDOUT_FILENO);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      error = posix_spawn_file_actions_adddup2 (&actions,
-                                                std_err < 0 ? std_out
-                                                            : std_err,
-                                                STDERR_FILENO);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      error = posix_spawn_file_actions_addchdir (&actions, cwd);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      error = posix_spawnattr_setflags (&attributes,
-                                        POSIX_SPAWN_SETPGROUP
-                                          | POSIX_SPAWN_SETSIGDEF
-                                          | POSIX_SPAWN_SETSIGMASK);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      error = posix_spawnattr_setpgroup (&attributes, 0);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      sigset_t sigdefault;
-      sigemptyset (&sigdefault);
-
-#ifdef DARWIN_OS
-      /* Work around a macOS bug, where SIGCHLD is apparently
-        delivered to a vforked child instead of to its parent.  See:
-        https://lists.gnu.org/r/emacs-devel/2017-05/msg00342.html
-      */
-      sigaddset (&sigdefault, SIGCHLD);
-#endif
-
-      sigaddset (&sigdefault, SIGINT);
-      sigaddset (&sigdefault, SIGQUIT);
-#ifdef SIGPROF
-      sigaddset (&sigdefault, SIGPROF);
-#endif
-
-      /* Emacs ignores SIGPIPE, but the child should not.  */
-      sigaddset (&sigdefault, SIGPIPE);
-      /* Likewise for SIGPROF.  */
-#ifdef SIGPROF
-      sigaddset (&sigdefault, SIGPROF);
-#endif
-
-      error
-        = posix_spawnattr_setsigdefault (&attributes, &sigdefault);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      /* Stop blocking SIGCHLD in the child.  */
-      sigset_t oldset;
-      error = pthread_sigmask (SIG_SETMASK, NULL, &oldset);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-      error = posix_spawnattr_setsigmask (&attributes, &oldset);
-      if (error != 0)
-       goto posix_spawn_init_failed;
-
-      goto next;
-
-    posix_spawn_init_failed:
-      if (destroy_actions)
-       posix_spawn_file_actions_destroy (&actions);
-      if (destroy_attributes)
-       posix_spawnattr_destroy (&attributes);
-      eassert (0 < error);
-      return error;
-    }
-
   sigset_t oldset;
   int pid;
-  int vfork_error;
 
- next:
   block_input ();
   block_child_signal (&oldset);
 
-  if (use_posix_spawn)
-    {
-      vfork_error = posix_spawn (&pid, argv[0], &actions, &attributes,
-                                 argv, envp);
-      if (vfork_error != 0)
-       pid = -1;
-
-      int error = posix_spawn_file_actions_destroy (&actions);
-      if (error != 0)
-       {
-         errno = error;
-         emacs_perror ("posix_spawn_file_actions_destroy");
-       }
-
-      error = posix_spawnattr_destroy (&attributes);
-      if (error != 0)
-       {
-         errno = error;
-         emacs_perror ("posix_spawnattr_destroy");
-       }
-
-      goto fork_done;
-    }
-
 #ifndef WINDOWSNT
   /* vfork, and prevent local vars from being clobbered by the vfork.  */
   pid_t *volatile newpid_volatile = newpid;
@@ -1520,9 +1375,8 @@ emacs_spawn (pid_t *newpid, int std_in, int std_out, int 
std_err,
 
   /* Back in the parent process.  */
 
-  vfork_error = pid < 0 ? errno : 0;
+  int vfork_error = pid < 0 ? errno : 0;
 
- fork_done:
   /* Stop blocking in the parent.  */
   unblock_child_signal (&oldset);
   unblock_input ();