> Date: Mon, 30 Jun 2014 05:49:52 +0300
> From: Eli Zaretskii <e...@gnu.org>
> Cc: m...@netris.org, guile-devel@gnu.org
Ping! I've been waiting for comments from Mark, but those never came.
Meanwhile I implemented the changes requested by Ludo, see the updated
patch below.
I hope this will be finally admitted into the repo.
TIA
>
> > From: l...@gnu.org (Ludovic Courtès)
> > Cc: Mark H Weaver <m...@netris.org>, guile-devel@gnu.org
> > Date: Sun, 29 Jun 2014 22:21:28 +0200
> >
> > > +#ifdef __MINGW32__
> > > +
> > > +#include <c-strcase.h>
> > > +
> > > +# define WEXITSTATUS(stat_val) ((stat_val) & 255)
> > > +# define WIFEXITED(stat_val) (((stat_val) & 0xC0000000) == 0)
> > > +# define WIFSIGNALED(stat_val) (((stat_val) & 0xC0000000) == 0xC0000000)
> > > +# define WTERMSIG(stat_val) win32_status_to_termsig (stat_val)
> > > +/* The funny conditional avoids a compiler warning in status:stop_sig.
> > > */
> > > +# define WIFSTOPPED(stat_val) ((stat_val) == (stat_val) ? 0 : 0)
> > > +# define WSTOPSIG(stat_var) (0)
> >
> > I think this was raised in the previous discussion: it looks a bit like
> > black magic, so there should be a comment explaining why this is needed,
> > how the constants were chosen, etc.
>
> Most of the magic is gone in this version. I will add a comment about
> 0xC0000000.
>
> > > +# include <process.h>
> > > +# define HAVE_WAITPID 1
> > > + static int win32_status_to_termsig (DWORD);
> > > + static int win32_signal_to_status (int);
> > > +# define getuid() (500) /* Local Administrator */
> > > +# define getgid() (513) /* None */
> > > +# define setuid(u) (0)
> > > +# define setgid(g) (0)
> > > +# define WIN32_LEAN_AND_MEAN
> > > +# include <windows.h>
> > > +# define WNOHANG 1
> > > + int waitpid (intptr_t, int *, int);
> > > +# include "win32-proc.c"
> >
> > ... what would you think of putting all this in a Gnulib module? It
> > would benefit all GNU packages and probably get more testing.
>
> Gnulib already has such a module, but its design and implementation is
> based on wrong premises. We've been through that with Mark back in
> February.
>
> And my experience with Gnulib responsiveness hasn't changed much since
> then: 2 tiny patches I submitted were accepted, but a larger patch to
> nl_langinfo, which is very important for Guile, was left without a
> comment for the past 3 weeks.
>
> > > -#ifdef HAVE_SETEGID
> > > SCM_DEFINE (scm_setegid, "setegid", 1, 0, 0,
> > > (SCM id),
> > > "Sets the effective group ID to the integer @var{id}, provided the
> > > process\n"
> >
> > This should be a separate change, and it’s dubious since there could be
> > platforms without setegid.
>
> Which ones?
>
> > > exec_argv = scm_i_allocate_string_pointers (args);
> > >
> > > - execv (exec_file, exec_argv);
> > > + execv (exec_file, (char const * const *)exec_argv);
> >
> > This should be a separate change (if at all needed.)
>
> It fixes a compiler warning.
>
> > > - if (reading)
> > > + if (reading)
> > > {
> > > close (c2p[1]);
> > > - read_port = scm_fdes_to_port (c2p[0], "r0", sym_read_pipe);
> > > + read_port = scm_fdes_to_port (c2p[0], "r", sym_read_pipe);
> > > + scm_setvbuf (read_port, scm_from_int (_IONBF), SCM_UNDEFINED);
> > > }
> > > if (writing)
> > > {
> > > close (p2c[0]);
> > > - write_port = scm_fdes_to_port (p2c[1], "w0", sym_write_pipe);
> > > + write_port = scm_fdes_to_port (p2c[1], "w", sym_write_pipe);
> > > + scm_setvbuf (write_port, scm_from_int (_IONBF), SCM_UNDEFINED);
> >
> > This reverts a43fa1b. Could you explain why it’s needed, and make it a
> > separate patch?
>
> Ignore this, I wasn't aware a change was made there.
>
> > > --- /dev/null 1970-01-01 02:00:00 +0200
> > > +++ libguile/win32-proc.c 2014-06-29 11:26:08 +0300
> >
> > Please call it “w32-proc.c” or “woe32-proc.c”
>
> I was just following the example of win32-uname.c.
>
> Thanks for the other feedback.
Here's the updated patch:
--- libguile/posix.c.~1~ 2014-02-28 22:01:27.000000000 +0200
+++ libguile/posix.c 2014-08-08 17:27:50.339267200 +0300
@@ -84,6 +84,42 @@
#if HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
+#ifdef __MINGW32__
+
+#include <c-strcase.h>
+
+# define WEXITSTATUS(stat_val) ((stat_val) & 255)
+/* MS-Windows programs that crash due to a fatal exception exit with
+ an exit code whose 2 MSB bits are set. */
+# define WIFEXITED(stat_val) (((stat_val) & 0xC0000000) == 0)
+# define WIFSIGNALED(stat_val) (((stat_val) & 0xC0000000) == 0xC0000000)
+# define WTERMSIG(stat_val) w32_status_to_termsig (stat_val)
+/* The funny conditional avoids a compiler warning in status:stop_sig. */
+# define WIFSTOPPED(stat_val) ((stat_val) == (stat_val) ? 0 : 0)
+# define WSTOPSIG(stat_var) (0)
+# include <process.h>
+# define HAVE_WAITPID 1
+ static int w32_status_to_termsig (DWORD);
+ static int w32_signal_to_status (int);
+# define getuid() (500) /* Local Administrator */
+# define getgid() (513) /* None */
+# define setuid(u) (0)
+# define setgid(g) (0)
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# define WNOHANG 1
+ int waitpid (intptr_t, int *, int);
+
+ typedef DWORD_PTR cpu_set_t;
+
+#define CPU_ZERO(s) memset(s,0,sizeof(*s))
+#define CPU_ISSET(b,s) ((*s) & (1U << (b))) != 0
+#define CPU_SET(b,s) (*s) |= (1U << (b))
+#define CPU_SETSIZE (8*sizeof(DWORD_PTR))
+
+# include "w32-proc.c"
+#endif /* __MINGW32__ */
+
#ifndef WEXITSTATUS
# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
#endif
@@ -659,7 +695,7 @@ SCM_DEFINE (scm_kill, "kill", 2, 0, 0,
#else
/* Mingw has raise(), but not kill(). (Other raw DOS environments might
be similar.) Use raise() when the requested pid is our own process,
- otherwise bomb. */
+ otherwise TerminateProcess. */
if (scm_to_int (pid) == getpid ())
{
if (raise (scm_to_int (sig)) != 0)
@@ -673,6 +709,25 @@ SCM_DEFINE (scm_kill, "kill", 2, 0, 0,
goto err;
}
}
+#ifdef __MINGW32__
+ else
+ {
+ HANDLE ph = OpenProcess (PROCESS_TERMINATE, 0, scm_to_int (pid));
+ int s = scm_to_int (sig);
+
+ if (!ph)
+ {
+ errno = EPERM;
+ goto err;
+ }
+ if (!TerminateProcess (ph, w32_signal_to_status (s)))
+ {
+ errno = EINVAL;
+ goto err;
+ }
+ CloseHandle (ph);
+ }
+#endif /* __MINGW32__ */
#endif
return SCM_UNSPECIFIED;
}
@@ -735,7 +790,6 @@ SCM_DEFINE (scm_waitpid, "waitpid", 1, 1
#undef FUNC_NAME
#endif /* HAVE_WAITPID */
-#ifndef __MINGW32__
SCM_DEFINE (scm_status_exit_val, "status:exit-val", 1, 0, 0,
(SCM status),
"Return the exit status value, as would be set if a process\n"
@@ -786,7 +840,6 @@ SCM_DEFINE (scm_status_stop_sig, "status
return SCM_BOOL_F;
}
#undef FUNC_NAME
-#endif /* __MINGW32__ */
#ifdef HAVE_GETPPID
SCM_DEFINE (scm_getppid, "getppid", 0, 0, 0,
@@ -801,7 +854,6 @@ SCM_DEFINE (scm_getppid, "getppid", 0, 0
#endif /* HAVE_GETPPID */
-#ifndef __MINGW32__
SCM_DEFINE (scm_getuid, "getuid", 0, 0, 0,
(),
"Return an integer representing the current real user ID.")
@@ -905,10 +957,8 @@ SCM_DEFINE (scm_seteuid, "seteuid", 1, 0
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
-#endif /* __MINGW32__ */
-#ifdef HAVE_SETEGID
SCM_DEFINE (scm_setegid, "setegid", 1, 0, 0,
(SCM id),
"Sets the effective group ID to the integer @var{id}, provided the
process\n"
@@ -931,7 +981,6 @@ SCM_DEFINE (scm_setegid, "setegid", 1, 0
}
#undef FUNC_NAME
-#endif
#ifdef HAVE_GETPGRP
@@ -1141,7 +1190,7 @@ SCM_DEFINE (scm_execl, "execl", 1, 0, 1,
exec_argv = scm_i_allocate_string_pointers (args);
- execv (exec_file, exec_argv);
+ execv (exec_file, (char const * const *)exec_argv);
SCM_SYSERROR;
/* not reached. */
@@ -1170,7 +1219,7 @@ SCM_DEFINE (scm_execlp, "execlp", 1, 0,
exec_argv = scm_i_allocate_string_pointers (args);
- execvp (exec_file, exec_argv);
+ execvp (exec_file, (char const * const *)exec_argv);
SCM_SYSERROR;
/* not reached. */
@@ -1204,7 +1253,8 @@ SCM_DEFINE (scm_execle, "execle", 2, 0,
exec_argv = scm_i_allocate_string_pointers (args);
exec_env = scm_i_allocate_string_pointers (env);
- execve (exec_file, exec_argv, exec_env);
+ execve (exec_file, (char const * const *)exec_argv,
+ (char const * const *)exec_env);
SCM_SYSERROR;
/* not reached. */
@@ -1246,6 +1296,7 @@ SCM_DEFINE (scm_fork, "primitive-fork",
return scm_from_int (pid);
}
#undef FUNC_NAME
+#endif /* HAVE_FORK */
/* Since Guile uses threads, we have to be very careful to avoid calling
functions that are not async-signal-safe in the child. That's why
@@ -1262,7 +1313,9 @@ scm_open_process (SCM mode, SCM prog, SC
int pid;
char *exec_file;
char **exec_argv;
+#ifdef HAVE_FORK
int max_fd = 1024;
+#endif
exec_file = scm_to_locale_string (prog);
exec_argv = scm_i_allocate_string_pointers (scm_cons (prog, args));
@@ -1319,12 +1372,28 @@ scm_open_process (SCM mode, SCM prog, SC
}
#endif
+#ifdef HAVE_FORK
pid = fork ();
+#elif defined(__MINGW32__)
+ if (!reading)
+ c2p[1] = out;
+ if (!writing)
+ p2c[0] = in;
+ pid = start_child (exec_file, exec_argv, reading, c2p, writing, p2c, err);
+#else
+ close (c2p[0]);
+ close (c2p[1]);
+ close (p2c[0]);
+ close (p2c[1]);
+ free (exec_file);
+ errno = ENOSYS;
+ SCM_SYSERROR;
+#endif /* HAVE_FORK */
if (pid == -1)
{
int errno_save = errno;
- free (exec_file);
+
if (reading)
{
close (c2p[0]);
@@ -1336,6 +1405,8 @@ scm_open_process (SCM mode, SCM prog, SC
close (p2c[1]);
}
errno = errno_save;
+
+ free (exec_file);
SCM_SYSERROR;
}
@@ -1361,7 +1432,8 @@ scm_open_process (SCM mode, SCM prog, SC
return scm_values
(scm_list_3 (read_port, write_port, scm_from_int (pid)));
}
-
+
+#ifdef HAVE_FORK
/* The child. */
if (reading)
close (c2p[0]);
@@ -1410,16 +1482,16 @@ scm_open_process (SCM mode, SCM prog, SC
if (err > 0)
{
char *msg = strerror (errno);
- fprintf (fdopen (err, "a"), "In execlp of %s: %s\n",
+ fprintf (fdopen (err, "a"), "In execvp of %s: %s\n",
exec_file, msg);
}
_exit (EXIT_FAILURE);
+#endif /* HAVE_FORK */
/* Not reached. */
return SCM_BOOL_F;
}
#undef FUNC_NAME
-#endif /* HAVE_FORK */
#ifdef __MINGW32__
# include "win32-uname.h"
--- /dev/null 1970-01-01 02:00:00 +0200
+++ libguile/w32-proc.c 2014-06-29 11:26:08 +0300
@@ -0,0 +1,563 @@
+/* Run a child process with redirected standard handles, without
+ redirecting standard handles of the parent. This is required in
+ multithreaded programs, where redirecting a standard handle affects
+ all threads. */
+
+#include <stdlib.h>
+#include <string.h>
+
+/* Prepare a possibly redirected file handle to be passed to a child
+ process. The handle is for the file/device open on file descriptor
+ FD; if FD is invalid, use the null device instead.
+
+ USE_STD non-zero means we have been passed the descriptor used by
+ the parent.
+
+ ACCESS is the Windows access mode for opening the null device.
+
+ Returns the Win32 handle to be passed to CreateProcess. */
+static HANDLE
+prepare_child_handle (int fd, int use_std, DWORD access)
+{
+ HANDLE htem, hret;
+ DWORD err = 0;
+
+ /* Start with the descriptor, if specified by the caller and valid,
+ otherwise open the null device. */
+ if (fd < 0)
+ htem = INVALID_HANDLE_VALUE;
+ else
+ htem = (HANDLE)_get_osfhandle (fd);
+
+ /* Duplicate the handle and make it inheritable. */
+ if (DuplicateHandle (GetCurrentProcess (),
+ htem,
+ GetCurrentProcess (),
+ &hret,
+ 0,
+ TRUE,
+ DUPLICATE_SAME_ACCESS) == FALSE)
+ {
+ /* If the original standard handle was invalid (happens, e.g.,
+ in GUI programs), open the null device instead. */
+ if ((err = GetLastError ()) == ERROR_INVALID_HANDLE
+ && use_std)
+ {
+ htem = CreateFile ("NUL", access,
+ FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+ OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+ if (htem != INVALID_HANDLE_VALUE
+ && DuplicateHandle (GetCurrentProcess (),
+ htem,
+ GetCurrentProcess (),
+ &hret,
+ 0,
+ TRUE,
+ DUPLICATE_SAME_ACCESS) == FALSE)
+ {
+ err = GetLastError ();
+ CloseHandle (htem);
+ hret = INVALID_HANDLE_VALUE;
+ }
+ }
+ }
+
+ if (hret == INVALID_HANDLE_VALUE)
+ {
+ switch (err)
+ {
+ case ERROR_NO_MORE_FILES:
+ errno = EMFILE;
+ break;
+ case ERROR_INVALID_HANDLE:
+ default:
+ errno = EBADF;
+ break;
+ }
+ }
+
+ return hret;
+}
+
+/* A comparison function for sorting the environment. */
+static int
+compenv (const void *a1, const void *a2)
+{
+ return stricmp (*((char**)a1), *((char**)a2));
+}
+
+/* Convert the program's 'environ' array to a block of environment
+ variables suitable to be passed to CreateProcess. This is needed
+ to ensure the child process inherits the up-to-date environment of
+ the parent, including any variables inserted by the parent. */
+static void
+prepare_envblk (char **envp, char **envblk)
+{
+ char **tmp;
+ int size_needed;
+ int envcnt;
+ char *ptr;
+
+ for (envcnt = 0; envp[envcnt]; envcnt++)
+ ;
+
+ tmp = scm_calloc ((envcnt + 1) * sizeof (*tmp));
+
+ for (envcnt = size_needed = 0; envp[envcnt]; envcnt++)
+ {
+ tmp[envcnt] = envp[envcnt];
+ size_needed += strlen (envp[envcnt]) + 1;
+ }
+ size_needed++;
+
+ /* Windows likes its environment variables sorted. */
+ qsort ((void *) tmp, (size_t) envcnt, sizeof (char *), compenv);
+
+ /* CreateProcess needs the environment block as a linear array,
+ where each variable is terminated by a null character, and the
+ last one is terminated by 2 null characters. */
+ ptr = *envblk = scm_calloc (size_needed);
+
+ for (envcnt = 0; tmp[envcnt]; envcnt++)
+ {
+ strcpy (ptr, tmp[envcnt]);
+ ptr += strlen (tmp[envcnt]) + 1;
+ }
+
+ free (tmp);
+}
+
+/* Find an executable PROGRAM on PATH, return result in malloc'ed
+ storage. If PROGRAM is /bin/sh, and no sh.exe was found on PATH,
+ fall back on the Windows shell and set BIN_SH_REPLACED to non-zero. */
+static char *
+lookup_cmd (const char *program, int *bin_sh_replaced)
+{
+ static const char *extensions[] = {
+ ".exe", ".cmd", ".bat", "", ".com", NULL
+ };
+ int bin_sh_requested = 0;
+ const char *path;
+ char abs_name[MAX_PATH];
+ DWORD abs_namelen;
+ int i;
+
+ /* If they ask for the Unix system shell, try to find it on PATH. */
+ if (c_strcasecmp (program, "/bin/sh") == 0)
+ {
+ bin_sh_requested = 1;
+ program = "sh.exe";
+ }
+
+ /* If PROGRAM includes leading directories, the caller already did
+ our job. */
+ if (strchr (program, '/') != NULL
+ || strchr (program, '\\') != NULL)
+ return scm_strdup (program);
+
+ /* Note: It is OK for getenv below to return NULL -- in that case,
+ SearchPath will search in the directories whose list is specified
+ by the system Registry. */
+ path = getenv ("PATH");
+ for (i = 0; extensions[i]; i++)
+ {
+ abs_namelen = SearchPath (path, program, extensions[i],
+ MAX_PATH, abs_name, NULL);
+ if (0 < abs_namelen && abs_namelen <= MAX_PATH) /* found! */
+ break;
+ }
+
+ /* If they asked for /bin/sh and we didn't find it, fall back on the
+ default Windows shell. */
+ if (abs_namelen <= 0 && bin_sh_requested)
+ {
+ const char *shell = getenv ("ComSpec");
+
+ if (!shell)
+ shell = "C:\\Windows\\system32\\cmd.exe";
+
+ *bin_sh_replaced = 1;
+ strcpy (abs_name, shell);
+ abs_namelen = strlen (abs_name);
+ }
+
+ /* If not found, return the original PROGRAM name. */
+ if (abs_namelen <= 0 || abs_namelen > MAX_PATH)
+ return scm_strdup (program);
+
+ return scm_strndup (abs_name, abs_namelen);
+}
+
+/* Concatenate command-line arguments in argv[] into a single
+ command-line string, while quoting arguments as needed. The result
+ is malloc'ed. */
+static char *
+prepare_cmdline (const char *cmd, const char * const *argv, int
bin_sh_replaced)
+{
+ /* These characters should include anything that is special to _any_
+ program, including both Windows and Unixy shells, and the
+ widlcard expansion in startup code of a typical Windows app. */
+ const char need_quotes[] = " \t#;\"\'*?[]&|<>(){}$`^";
+ size_t cmdlen = 1; /* for terminating null */
+ char *cmdline = scm_malloc (cmdlen);
+ char *dst = cmdline;
+ int cmd_exe_quoting = 0;
+ int i;
+ const char *p;
+
+ /* Are we constructing a command line for cmd.exe? */
+ if (bin_sh_replaced)
+ cmd_exe_quoting = 1;
+ else
+ {
+ for (p = cmd + strlen (cmd);
+ p > cmd && p[-1] != '/' && p[-1] != '\\' && p[-1] != ':';
+ p--)
+ ;
+ if (c_strcasecmp (p, "cmd.exe") == 0
+ || c_strcasecmp (p, "cmd") == 0)
+ cmd_exe_quoting = 1;
+ }
+
+ /* Initialize the command line to empty. */
+ *dst = '\0';
+
+ /* Append arguments, if any, from argv[]. */
+ for (i = 0; argv[i]; i++)
+ {
+ const char *src = argv[i];
+ size_t len;
+ int quote_this = 0, n_backslashes = 0;
+ int j;
+
+ /* Append the blank separator. We don't do that for argv[0]
+ because that is the command name (will end up in child's
+ argv[0]), and is only recognized as such if there're no
+ blanks before it. */
+ if (i > 0)
+ *dst++ = ' ';
+ len = dst - cmdline;
+
+ /* How much space is required for this argument? */
+ cmdlen += strlen (argv[i]) + 1; /* 1 for a blank separator */
+ /* cmd.exe needs a different style of quoting: all the arguments
+ beyond the /c switch are enclosed in an extra pair of quotes,
+ and not otherwise quoted/escaped. */
+ if (cmd_exe_quoting)
+ {
+ if (i == 2)
+ cmdlen += 2;
+ }
+ else if (strpbrk (argv[i], need_quotes))
+ {
+ quote_this = 1;
+ cmdlen += 2;
+ for ( ; *src; src++)
+ {
+ /* An embedded quote needs to be escaped by a backslash.
+ Any backslashes immediately preceding that quote need
+ each one to be escaped by another backslash. */
+ if (*src == '\"')
+ cmdlen += n_backslashes + 1;
+ if (*src == '\\')
+ n_backslashes++;
+ else
+ n_backslashes = 0;
+ }
+ /* If the closing quote we will add is preceded by
+ backslashes, those backslashes need to be escaped. */
+ cmdlen += n_backslashes;
+ }
+
+ /* Enlarge the command-line string as needed. */
+ cmdline = scm_realloc (cmdline, cmdlen);
+ dst = cmdline + len;
+
+ if (i == 0
+ && c_strcasecmp (argv[0], "/bin/sh") == 0
+ && bin_sh_replaced)
+ {
+ strcpy (dst, "cmd.exe");
+ dst += sizeof ("cmd.exe") - 1;
+ continue;
+ }
+ if (i == 1 && bin_sh_replaced && strcmp (argv[1], "-c") == 0)
+ {
+ *dst++ = '/';
+ *dst++ = 'c';
+ *dst = '\0';
+ continue;
+ }
+
+ /* Add this argument, possibly quoted, to the command line. */
+ if (quote_this || (i == 2 && cmd_exe_quoting))
+ *dst++ = '\"';
+ for (src = argv[i]; *src; src++)
+ {
+ if (quote_this)
+ {
+ if (*src == '\"')
+ for (j = n_backslashes + 1; j > 0; j--)
+ *dst++ = '\\';
+ if (*src == '\\')
+ n_backslashes++;
+ else
+ n_backslashes = 0;
+ }
+ *dst++ = *src;
+ }
+ if (quote_this)
+ {
+ for (j = n_backslashes; j > 0; j--)
+ *dst++ = '\\';
+ *dst++ = '\"';
+ }
+ *dst = '\0';
+ }
+
+ if (cmd_exe_quoting && i > 2)
+ {
+ /* One extra slot was already reserved when we enlarged cmdlen
+ by 2 in the "if (cmd_exe_quoting)" clause above. So we can
+ safely append a closing quote. */
+ *dst++ = '\"';
+ *dst = '\0';
+ }
+
+ return cmdline;
+}
+
+/* Start a child process running the program in EXEC_FILE with its
+ standard input and output optionally redirected to a pipe. ARGV is
+ the array of command-line arguments to pass to the child. P2C and
+ C2P are 2 pipes for communicating with the child, and ERRFD is the
+ standard error file descriptor to be inherited by the child.
+ READING and WRITING, if non-zero, mean that the corresponding pipe
+ will be used.
+
+ Return the PID of the child process, or -1 if couldn't start a
+ process. */
+static intptr_t
+start_child (const char *exec_file, char **argv,
+ int reading, int c2p[2], int writing, int p2c[2], int errfd)
+{
+ HANDLE hin = INVALID_HANDLE_VALUE, hout = INVALID_HANDLE_VALUE;
+ HANDLE herr = INVALID_HANDLE_VALUE;
+ STARTUPINFO si;
+ char *env_block = NULL;
+ char *cmdline = NULL;
+ PROCESS_INFORMATION pi;
+ char *progfile, *p;
+ int errno_save;
+ intptr_t pid;
+ int bin_sh_replaced = 0;
+
+ /* Prepare standard handles to be passed to the child process. */
+ hin = prepare_child_handle (p2c[0], !writing, GENERIC_READ);
+ if (hin == INVALID_HANDLE_VALUE)
+ return -1;
+ hout = prepare_child_handle (c2p[1], !reading, GENERIC_WRITE);
+ if (hout == INVALID_HANDLE_VALUE)
+ return -1;
+ herr = prepare_child_handle (errfd, 1, GENERIC_WRITE);
+ if (herr == INVALID_HANDLE_VALUE)
+ return -1;
+
+ /* Make sure the parent side of both pipes is not inherited. This
+ is required because gnulib's 'pipe' creates pipes whose both ends
+ are inheritable, which is traditional on Posix (where pipe
+ descriptors are implicitly duplicated by 'fork'), but wrong on
+ Windows (where pipe handles need to be explicitly
+ duplicated). */
+ if (writing)
+ SetHandleInformation ((HANDLE)_get_osfhandle (p2c[1]),
+ HANDLE_FLAG_INHERIT, 0);
+ if (reading)
+ {
+ SetHandleInformation ((HANDLE)_get_osfhandle (c2p[0]),
+ HANDLE_FLAG_INHERIT, 0);
+ /* Gnulib's 'pipe' opens the pipe in binary mode, but we don't
+ want to read text-mode input of subprocesses in binary more,
+ because then we will get the ^M (a.k.a. "CR") characters we
+ don't expect. */
+ _setmode (c2p[0], _O_TEXT);
+ }
+
+ /* Set up the startup info for the child, using the parent's as the
+ starting point, and specify in it the redirected handles. */
+ GetStartupInfo (&si);
+ si.dwFlags = STARTF_USESTDHANDLES;
+ si.lpReserved = 0;
+ si.cbReserved2 = 0;
+ si.lpReserved2 = 0;
+ si.hStdInput = hin;
+ si.hStdOutput = hout;
+ si.hStdError = herr;
+
+ /* Create the environment block for the child. This is needed
+ because the environment we have in 'environ' is not in the format
+ expected by CreateProcess. */
+ prepare_envblk (environ, &env_block);
+
+ /* CreateProcess doesn't search PATH, so we must do that for it. */
+ progfile = lookup_cmd (exec_file, &bin_sh_replaced);
+
+ /* CreateProcess doesn't like forward slashes in the application
+ file name. */
+ for (p = progfile; *p; p++)
+ if (*p == '/')
+ *p = '\\';
+
+ /* Construct the command line. */
+ cmdline = prepare_cmdline (exec_file, (const char * const *)argv,
+ bin_sh_replaced);
+
+ /* All set and ready to fly. Launch the child process. */
+ if (!CreateProcess (progfile, cmdline, NULL, NULL, TRUE, 0, env_block, NULL,
+ &si, &pi))
+ {
+ pid = -1;
+
+ /* Since we use Win32 APIs directly, we need to translate their
+ errors to errno values by hand. */
+ switch (GetLastError ())
+ {
+ case ERROR_FILE_NOT_FOUND:
+ case ERROR_PATH_NOT_FOUND:
+ case ERROR_INVALID_DRIVE:
+ case ERROR_BAD_PATHNAME:
+ errno = ENOENT;
+ break;
+ case ERROR_ACCESS_DENIED:
+ errno = EACCES;
+ break;
+ case ERROR_BAD_ENVIRONMENT:
+ errno = E2BIG;
+ break;
+ case ERROR_BROKEN_PIPE:
+ errno = EPIPE;
+ break;
+ case ERROR_INVALID_HANDLE:
+ errno = EBADF;
+ break;
+ case ERROR_MAX_THRDS_REACHED:
+ errno = EAGAIN;
+ break;
+ case ERROR_BAD_EXE_FORMAT:
+ case ERROR_BAD_FORMAT:
+ default:
+ errno = ENOEXEC;
+ break;
+ }
+ }
+ else
+ pid = (intptr_t)pi.hProcess;
+
+ errno_save = errno;
+
+ /* Free resources. */
+ free (progfile);
+ free (cmdline);
+ free (env_block);
+ CloseHandle (hin);
+ CloseHandle (hout);
+ CloseHandle (herr);
+ CloseHandle (pi.hThread);
+
+ /* Posix requires to call the shell if execvp fails to invoke EXEC_FILE. */
+ if (errno_save == ENOEXEC || errno_save == ENOENT)
+ {
+ const char *shell = getenv ("ComSpec");
+
+ if (!shell)
+ shell = "cmd.exe";
+
+ if (c_strcasecmp (exec_file, shell) != 0)
+ {
+ argv[0] = (char *)exec_file;
+ return start_child (shell, argv, reading, c2p, writing, p2c, errfd);
+ }
+ }
+
+ errno = errno_save;
+ return pid;
+}
+
+
+/* Emulation of waitpid which only supports WNOHANG, since _cwait doesn't. */
+int
+waitpid (intptr_t pid, int *status, int options)
+{
+ if ((options & WNOHANG) != 0)
+ {
+ DWORD st;
+
+ if (!GetExitCodeProcess ((HANDLE)pid, &st))
+ {
+ errno = ECHILD;
+ return -1;
+ }
+ if (st == STILL_ACTIVE)
+ return 0;
+ if (status)
+ *status = st;
+ return (int)pid;
+ }
+
+ return (int)_cwait (status, pid, WAIT_CHILD);
+}
+
+
+/* Translate abnormal exit status of Windows programs into the signal
+ that terminated the program. This is required to support scm_kill
+ and WTERMSIG. */
+
+struct signal_and_status {
+ int sig;
+ DWORD status;
+};
+
+static const struct signal_and_status sigtbl[] = {
+ {SIGSEGV, 0xC0000005}, /* access to invalid address */
+ {SIGSEGV, 0xC0000008}, /* invalid handle */
+ {SIGILL, 0xC000001D}, /* illegal instruction */
+ {SIGILL, 0xC0000025}, /* non-continuable instruction */
+ {SIGSEGV, 0xC000008C}, /* array bounds exceeded */
+ {SIGFPE, 0xC000008D}, /* float denormal */
+ {SIGFPE, 0xC000008E}, /* float divide by zero */
+ {SIGFPE, 0xC000008F}, /* float inexact */
+ {SIGFPE, 0xC0000090}, /* float invalid operation */
+ {SIGFPE, 0xC0000091}, /* float overflow */
+ {SIGFPE, 0xC0000092}, /* float stack check */
+ {SIGFPE, 0xC0000093}, /* float underflow */
+ {SIGFPE, 0xC0000094}, /* integer divide by zero */
+ {SIGFPE, 0xC0000095}, /* integer overflow */
+ {SIGILL, 0xC0000096}, /* privileged instruction */
+ {SIGSEGV, 0xC00000FD}, /* stack overflow */
+ {SIGTERM, 0xC000013A}, /* Ctrl-C exit */
+ {SIGINT, 0xC000013A}
+};
+
+static int
+w32_signal_to_status (int sig)
+{
+ int i;
+
+ for (i = 0; i < sizeof (sigtbl) / sizeof (sigtbl[0]); i++)
+ if (sig == sigtbl[i].sig)
+ return sigtbl[i].status;
+
+ return (int)0xC000013A;
+}
+
+static int
+w32_status_to_termsig (DWORD status)
+{
+ int i;
+
+ for (i = 0; i < sizeof (sigtbl) / sizeof (sigtbl[0]); i++)
+ if (status == sigtbl[i].status)
+ return sigtbl[i].sig;
+
+ return SIGTERM;
+}
