2009-07-19 Bruno Haible <bruno@clisp.org>
+ Fix handling of closed stdin/stdout/stderr on mingw.
+ * lib/w32spawn.h: Include unistd.h.
+ (dup_noinherit): Return -1 if the old handle is invalid. Allocate new
+ file descriptor with O_NOINHERIT flag.
+ (fd_safer_noinherit): New function, based on fd-safer.c.
+ (dup_safer_noinherit): New function, based on dup-safer.c.
+ (undup_safer_noinherit): New function.
+ * lib/execute.c (execute) [WIN32]: Use dup_safer_noinherit instead of
+ dup_noinherit. Use undup_safer_noinherit instead of dup2 and close.
+ * lib/pipe.c (create_pipe) [WIN32]: Likewise. Use fd_safer_noinherit
+ instead of fd_safer.
+ * tests/test-pipe.c: Include <windows.h>.
+ (child_main) [WIN32]: Test the handle of STDERR_FILENO, not its close() result.
+
* tests/test-pipe.c (child_main, parent_main): New functions, extracted
from main.
(test_pipe): Pass an extra argument for disambiguation.
/* Save standard file handles of parent process. */
if (null_stdin)
- orig_stdin = dup_noinherit (STDIN_FILENO);
+ orig_stdin = dup_safer_noinherit (STDIN_FILENO);
if (null_stdout)
- orig_stdout = dup_noinherit (STDOUT_FILENO);
+ orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
if (null_stderr)
- orig_stderr = dup_noinherit (STDERR_FILENO);
+ orig_stderr = dup_safer_noinherit (STDERR_FILENO);
exitcode = -1;
/* Create standard file handles of child process. */
/* Restore standard file handles of parent process. */
if (null_stderr)
- dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
+ undup_safer_noinherit (orig_stderr, STDERR_FILENO);
if (null_stdout)
- dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
+ undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
if (null_stdin)
- dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
+ undup_safer_noinherit (orig_stdin, STDIN_FILENO);
if (termsigp != NULL)
*termsigp = 0;
if (pipe_stdout)
if (_pipe (ifd, 4096, O_BINARY | O_NOINHERIT) < 0
- || (ifd[0] = fd_safer (ifd[0])) < 0
- || (ifd[1] = fd_safer (ifd[1])) < 0)
+ || (ifd[0] = fd_safer_noinherit (ifd[0])) < 0
+ || (ifd[1] = fd_safer_noinherit (ifd[1])) < 0)
error (EXIT_FAILURE, errno, _("cannot create pipe"));
if (pipe_stdin)
if (_pipe (ofd, 4096, O_BINARY | O_NOINHERIT) < 0
- || (ofd[0] = fd_safer (ofd[0])) < 0
- || (ofd[1] = fd_safer (ofd[1])) < 0)
+ || (ofd[0] = fd_safer_noinherit (ofd[0])) < 0
+ || (ofd[1] = fd_safer_noinherit (ofd[1])) < 0)
error (EXIT_FAILURE, errno, _("cannot create pipe"));
/* Data flow diagram:
*
/* Save standard file handles of parent process. */
if (pipe_stdin || prog_stdin != NULL)
- orig_stdin = dup_noinherit (STDIN_FILENO);
+ orig_stdin = dup_safer_noinherit (STDIN_FILENO);
if (pipe_stdout || prog_stdout != NULL)
- orig_stdout = dup_noinherit (STDOUT_FILENO);
+ orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
if (null_stderr)
- orig_stderr = dup_noinherit (STDERR_FILENO);
+ orig_stderr = dup_safer_noinherit (STDERR_FILENO);
child = -1;
/* Create standard file handles of child process. */
/* Restore standard file handles of parent process. */
if (null_stderr)
- dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
+ undup_safer_noinherit (orig_stderr, STDERR_FILENO);
if (pipe_stdout || prog_stdout != NULL)
- dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
+ undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
if (pipe_stdin || prog_stdin != NULL)
- dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
+ undup_safer_noinherit (orig_stdin, STDIN_FILENO);
if (pipe_stdin)
close (ofd[0]);
/* Auxiliary functions for the creation of subprocesses. Native Woe32 API.
- Copyright (C) 2003, 2006-2009 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2003, 2004-2009 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
This program is free software: you can redistribute it and/or modify
#include <stdbool.h>
#include <string.h>
+#include <unistd.h>
#include <errno.h>
#include "xalloc.h"
-/* Duplicates a file handle, making the copy uninheritable. */
+/* Duplicates a file handle, making the copy uninheritable.
+ Returns -1 for a file handle that is equivalent to closed. */
static int
dup_noinherit (int fd)
{
HANDLE new_handle;
int nfd;
+ if (old_handle == INVALID_HANDLE_VALUE)
+ /* fd is closed, or is open to no handle at all.
+ We cannot duplicate fd in this case, because _open_osfhandle fails for
+ an INVALID_HANDLE_VALUE argument. */
+ return -1;
+
if (!DuplicateHandle (curr_process, /* SourceProcessHandle */
old_handle, /* SourceHandle */
curr_process, /* TargetProcessHandle */
error (EXIT_FAILURE, 0, _("DuplicateHandle failed with error code 0x%08x"),
(unsigned int) GetLastError ());
- nfd = _open_osfhandle ((long) new_handle, O_BINARY);
+ nfd = _open_osfhandle ((long) new_handle, O_BINARY | O_NOINHERIT);
if (nfd < 0)
error (EXIT_FAILURE, errno, _("_open_osfhandle failed"));
return nfd;
}
+/* Returns a file descriptor equivalent to FD, except that the resulting file
+ descriptor is none of STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO.
+ FD must be open and non-inheritable. The result will be non-inheritable as
+ well.
+ If FD < 0, FD itself is returned. */
+static int
+fd_safer_noinherit (int fd)
+{
+ if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
+ {
+ /* The recursion depth is at most 3. */
+ int nfd = fd_safer_noinherit (dup_noinherit (fd));
+ int saved_errno = errno;
+ close (fd);
+ errno = saved_errno;
+ return nfd;
+ }
+ return fd;
+}
+
+/* Duplicates a file handle, making the copy uninheritable and ensuring the
+ result is none of STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO.
+ Returns -1 for a file handle that is equivalent to closed. */
+static int
+dup_safer_noinherit (int fd)
+{
+ return fd_safer_noinherit (dup_noinherit (fd));
+}
+
+/* Undoes the effect of TEMPFD = dup_safer_noinherit (ORIGFD); */
+static void
+undup_safer_noinherit (int tempfd, int origfd)
+{
+ if (tempfd >= 0)
+ {
+ if (dup2 (tempfd, origfd) < 0)
+ error (EXIT_FAILURE, errno, _("cannot restore fd %d: dup2 failed"),
+ origfd);
+ close (tempfd);
+ }
+ else
+ {
+ /* origfd was closed or open to no handle at all. Set it to a closed
+ state. This is (nearly) equivalent to the original state. */
+ close (origfd);
+ }
+}
+
/* Prepares an argument vector before calling spawn().
Note that spawn() does not by itself call the command interpreter
(getenv ("COMSPEC") != NULL ? getenv ("COMSPEC") :
#include "pipe.h"
#include "wait-process.h"
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions. */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
child_main (int argc, char *argv[])
{
char buffer[1];
- int i;
int fd;
ASSERT (argc == 3);
buffer[0]++;
ASSERT (write (STDOUT_FILENO, buffer, 1) == 1);
- errno = 0;
-#ifdef F_GETFL
- /* Try to keep stderr open for better diagnostics. */
- i = fcntl (STDERR_FILENO, F_GETFL);
-#else
- /* But allow compilation on mingw. You might need to disable this code for
- debugging failures. */
- i = close (STDERR_FILENO);
-#endif
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ /* On Win32, the initial state of unassigned standard file descriptors is
+ that they are open but point to an INVALID_HANDLE_VALUE. Thus
+ close (STDERR_FILENO) would always succeed. */
switch (atoi (argv[2]))
{
case 0:
- /* Expect fd 2 was open. */
- ASSERT (i >= 0);
+ /* Expect fd 2 is open to a valid handle. */
+ ASSERT ((HANDLE) _get_osfhandle (STDERR_FILENO) != INVALID_HANDLE_VALUE);
break;
case 1:
- /* Expect fd 2 was closed. */
- ASSERT (i < 0);
- ASSERT (errno == EBADF);
+ /* Expect fd 2 is pointing to INVALID_HANDLE_VALUE. */
+ ASSERT ((HANDLE) _get_osfhandle (STDERR_FILENO) == INVALID_HANDLE_VALUE);
break;
default:
ASSERT (false);
}
+#elif defined F_GETFL
+ /* On Unix, the initial state of unassigned standard file descriptors is
+ that they are closed. */
+ {
+ int ret;
+ errno = 0;
+ ret = fcntl (STDERR_FILENO, F_GETFL);
+ switch (atoi (argv[2]))
+ {
+ case 0:
+ /* Expect fd 2 is open. */
+ ASSERT (ret >= 0);
+ break;
+ case 1:
+ /* Expect fd 2 is closed. */
+ ASSERT (ret < 0);
+ ASSERT (errno == EBADF);
+ break;
+ default:
+ ASSERT (false);
+ }
+ }
+#endif
for (fd = 3; fd < 7; fd++)
{
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