binutils-gdb/gdb/gnulib/import/fchdir.c
Sergio Durigan Junior 6ec2e0f5bd Import "glob" and "getcwd" modules from gnulib
These two modules are necessary because of the rework that will be
done in the "change directory" logic on GDB/gdbserver in the next
commits.

First, we will get rid of the "gdb_dirbuf" global variable and instead
rely on the fact that "getcwd (NULL, 0)", which is a GNU extension,
returns a heap-allocated string with the necessary bytes to hold the
full path.  This is a good practice not only because globals are not
ideal but also because there is no good way to know beforehand the
size of the full pathname allowed in the filesystem ("PATH_MAX" is not
portable and does not reflect all the possible filesystems out there).

We will also have a way to "cd" to a directory also on gdbserver, but
in order to do that uniformly, there must be a way to do tilde
expansion on directories provided by the user.  Currently, GDB uses
"tilde_expand" from readline to do that, but gdbserver doesn't link
against readline and therefore cannot use this function.  The solution
is to use "glob" instead, which can perform tilde expansion as a GNU
extension.  Therefore, we need gnulib's version of "glob".

A special note is necessary for gdb/ser-tcp.c.  It defines "close" as
"closesocket" on Win32 targets.  If we leave the code as is, this
would conflict with gnulib's definition of "close".  Therefore, in
order to keep the same code path from before this import, I decided to
"#undef close" first, and then let the original (re)definition of it
take place.

gdb/ChangeLog:
2017-09-22  Sergio Durigan Junior  <sergiodj@redhat.com>

	* gnulib/aclocal.m4: Regenerate.
	* gnulib/config.in: Regenerate.
	* gnulib/configure: Regenerate.
	* gnulib/import/Makefile.am: Regenerate.
	* gnulib/import/Makefile.in: Regenerate.
	* gnulib/import/assure.h: New file.
	* gnulib/import/at-func.c: Likewise
	* gnulib/import/chdir-long.c: New file.
	* gnulib/import/chdir-long.h: New file.
	* gnulib/import/cloexec.c: New file.
	* gnulib/import/cloexec.h: New file.
	* gnulib/import/close.c: New file.
	* gnulib/import/closedir.c: New file.
	* gnulib/import/dirent-private.h: New file.
	* gnulib/import/dup-safer.c: New file.
	* gnulib/import/dup.c: New file.
	* gnulib/import/dup2.c: New file.
	* gnulib/import/error.c: New file.
	* gnulib/import/error.h: New file.
	* gnulib/import/exitfail.c: New file.
	* gnulib/import/exitfail.h: New file.
	* gnulib/import/fchdir.c: New file.
	* gnulib/import/fcntl.c: New file.
	* gnulib/import/fcntl.in.h: New file.
	* gnulib/import/fd-hook.c: New file.
	* gnulib/import/fd-hook.h: New file.
	* gnulib/import/fd-safer.c: New file.
	* gnulib/import/fdopendir.c: New file.
	* gnulib/import/filename.h: New file.
	* gnulib/import/filenamecat-lgpl.c: New file.
	* gnulib/import/filenamecat.h: New file.
	* gnulib/import/fstat.c: New file.
	* gnulib/import/fstatat.c: New file.
	* gnulib/import/getcwd-lgpl.c: New file.
	* gnulib/import/getcwd.c: New file.
	* gnulib/import/getdtablesize.c: New file.
	* gnulib/import/getlogin_r.c: New file.
	* gnulib/import/getprogname.c: New file.
	* gnulib/import/getprogname.h: New file.
	* gnulib/import/gettext.h: New file.
	* gnulib/import/glob-libc.h: New file.
	* gnulib/import/glob.c: New file.
	* gnulib/import/glob.in.h: New file.
	* gnulib/import/intprops.h: New file.
	* gnulib/import/m4/chdir-long.m4: New file.
	* gnulib/import/m4/close.m4: New file.
	* gnulib/import/m4/closedir.m4: New file.
	* gnulib/import/m4/d-ino.m4: New file.
	* gnulib/import/m4/d-type.m4: New file.
	* gnulib/import/m4/dup.m4: New file.
	* gnulib/import/m4/dup2.m4: New file.
	* gnulib/import/m4/error.m4: New file.
	* gnulib/import/m4/fchdir.m4: New file.
	* gnulib/import/m4/fcntl.m4: New file.
	* gnulib/import/m4/fcntl_h.m4: New file.
	* gnulib/import/m4/fdopendir.m4: New file.
	* gnulib/import/m4/filenamecat.m4: New file.
	* gnulib/import/m4/fstat.m4: New file.
	* gnulib/import/m4/fstatat.m4: New file.
	* gnulib/import/m4/getcwd-abort-bug.m4: New file.
	* gnulib/import/m4/getcwd-path-max.m4: New file.
	* gnulib/import/m4/getcwd.m4: New file.
	* gnulib/import/m4/getdtablesize.m4: New file.
	* gnulib/import/m4/getlogin_r.m4: New file.
	* gnulib/import/m4/getprogname.m4: New file.
	* gnulib/import/m4/glob.m4: New file.
	* gnulib/import/m4/gnulib-cache.m4: Regenerate.
	* gnulib/import/m4/gnulib-comp.m4: Regenerate.
	* gnulib/import/m4/mempcpy.m4: New file.
	* gnulib/import/m4/memrchr.m4: New file.
	* gnulib/import/m4/mode_t.m4: New file.
	* gnulib/import/m4/msvc-inval.m4: New file.
	* gnulib/import/m4/msvc-nothrow.m4: New file.
	* gnulib/import/m4/open.m4: New file.
	* gnulib/import/m4/openat.m4: New file.
	* gnulib/import/m4/opendir.m4: New file.
	* gnulib/import/m4/readdir.m4: New file.
	* gnulib/import/m4/realloc.m4: New file.
	* gnulib/import/m4/rewinddir.m4: New file.
	* gnulib/import/m4/save-cwd.m4: New file.
	* gnulib/import/m4/strdup.m4: New file.
	* gnulib/import/m4/strerror.m4: New file.
	* gnulib/import/m4/unistd-safer.m4: New file.
	* gnulib/import/mempcpy.c: New file.
	* gnulib/import/memrchr.c: New file.
	* gnulib/import/msvc-inval.c: New file.
	* gnulib/import/msvc-inval.h: New file.
	* gnulib/import/msvc-nothrow.c: New file.
	* gnulib/import/msvc-nothrow.h: New file.
	* gnulib/import/open.c: New file.
	* gnulib/import/openat-die.c: New file.
	* gnulib/import/openat-priv.h: New file.
	* gnulib/import/openat-proc.c: New file.
	* gnulib/import/openat.c: New file.
	* gnulib/import/openat.h: New file.
	* gnulib/import/opendir.c: New file.
	* gnulib/import/pipe-safer.c: New file.
	* gnulib/import/readdir.c: New file.
	* gnulib/import/realloc.c: New file.
	* gnulib/import/rewinddir.c: New file.
	* gnulib/import/save-cwd.c: New file.
	* gnulib/import/save-cwd.h: New file.
	* gnulib/import/strdup.c: New file.
	* gnulib/import/strerror-override.c: New file.
	* gnulib/import/strerror-override.h: New file.
	* gnulib/import/strerror.c: New file.
	* gnulib/import/unistd--.h: New file.
	* gnulib/import/unistd-safer.h: New file.
	* gnulib/update-gnulib.sh (IMPORTED_GNULIB_MODULES): Add
	"getcwd" and "glob".
	* ser-tcp.c: Undefine "close" before redefining it.
2017-09-22 13:28:03 -04:00

209 lines
5.7 KiB
C

/* fchdir replacement.
Copyright (C) 2006-2016 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "assure.h"
#include "dosname.h"
#include "filenamecat.h"
#ifndef REPLACE_OPEN_DIRECTORY
# define REPLACE_OPEN_DIRECTORY 0
#endif
/* This replacement assumes that a directory is not renamed while opened
through a file descriptor.
FIXME: On mingw, this would be possible to enforce if we were to
also open a HANDLE to each directory currently visited by a file
descriptor, since mingw refuses to rename any in-use file system
object. */
/* Array of file descriptors opened. If REPLACE_OPEN_DIRECTORY or if it points
to a directory, it stores info about this directory. */
typedef struct
{
char *name; /* Absolute name of the directory, or NULL. */
/* FIXME - add a DIR* member to make dirfd possible on mingw? */
} dir_info_t;
static dir_info_t *dirs;
static size_t dirs_allocated;
/* Try to ensure dirs has enough room for a slot at index fd; free any
contents already in that slot. Return false and set errno to
ENOMEM on allocation failure. */
static bool
ensure_dirs_slot (size_t fd)
{
if (fd < dirs_allocated)
free (dirs[fd].name);
else
{
size_t new_allocated;
dir_info_t *new_dirs;
new_allocated = 2 * dirs_allocated + 1;
if (new_allocated <= fd)
new_allocated = fd + 1;
new_dirs =
(dirs != NULL
? (dir_info_t *) realloc (dirs, new_allocated * sizeof *dirs)
: (dir_info_t *) malloc (new_allocated * sizeof *dirs));
if (new_dirs == NULL)
return false;
memset (new_dirs + dirs_allocated, 0,
(new_allocated - dirs_allocated) * sizeof *dirs);
dirs = new_dirs;
dirs_allocated = new_allocated;
}
return true;
}
/* Return an absolute name of DIR in malloc'd storage. */
static char *
get_name (char const *dir)
{
char *cwd;
char *result;
int saved_errno;
if (IS_ABSOLUTE_FILE_NAME (dir))
return strdup (dir);
/* We often encounter "."; treat it as a special case. */
cwd = getcwd (NULL, 0);
if (!cwd || (dir[0] == '.' && dir[1] == '\0'))
return cwd;
result = mfile_name_concat (cwd, dir, NULL);
saved_errno = errno;
free (cwd);
errno = saved_errno;
return result;
}
/* Hook into the gnulib replacements for open() and close() to keep track
of the open file descriptors. */
/* Close FD, cleaning up any fd to name mapping if fd was visiting a
directory. */
void
_gl_unregister_fd (int fd)
{
if (fd >= 0 && fd < dirs_allocated)
{
free (dirs[fd].name);
dirs[fd].name = NULL;
}
}
/* Mark FD as visiting FILENAME. FD must be non-negative, and refer
to an open file descriptor. If REPLACE_OPEN_DIRECTORY is non-zero,
this should only be called if FD is visiting a directory. Close FD
and return -1 if there is insufficient memory to track the
directory name; otherwise return FD. */
int
_gl_register_fd (int fd, const char *filename)
{
struct stat statbuf;
assure (0 <= fd);
if (REPLACE_OPEN_DIRECTORY
|| (fstat (fd, &statbuf) == 0 && S_ISDIR (statbuf.st_mode)))
{
if (!ensure_dirs_slot (fd)
|| (dirs[fd].name = get_name (filename)) == NULL)
{
int saved_errno = errno;
close (fd);
errno = saved_errno;
return -1;
}
}
return fd;
}
/* Mark NEWFD as a duplicate of OLDFD; useful from dup, dup2, dup3,
and fcntl. Both arguments must be valid and distinct file
descriptors. Close NEWFD and return -1 if OLDFD is tracking a
directory, but there is insufficient memory to track the same
directory in NEWFD; otherwise return NEWFD. */
int
_gl_register_dup (int oldfd, int newfd)
{
assure (0 <= oldfd && 0 <= newfd && oldfd != newfd);
if (oldfd < dirs_allocated && dirs[oldfd].name)
{
/* Duplicated a directory; must ensure newfd is allocated. */
if (!ensure_dirs_slot (newfd)
|| (dirs[newfd].name = strdup (dirs[oldfd].name)) == NULL)
{
int saved_errno = errno;
close (newfd);
errno = saved_errno;
newfd = -1;
}
}
else if (newfd < dirs_allocated)
{
/* Duplicated a non-directory; ensure newfd is cleared. */
free (dirs[newfd].name);
dirs[newfd].name = NULL;
}
return newfd;
}
/* If FD is currently visiting a directory, then return the name of
that directory. Otherwise, return NULL and set errno. */
const char *
_gl_directory_name (int fd)
{
if (0 <= fd && fd < dirs_allocated && dirs[fd].name != NULL)
return dirs[fd].name;
/* At this point, fd is either invalid, or open but not a directory.
If dup2 fails, errno is correctly EBADF. */
if (0 <= fd)
{
if (dup2 (fd, fd) == fd)
errno = ENOTDIR;
}
else
errno = EBADF;
return NULL;
}
/* Implement fchdir() in terms of chdir(). */
int
fchdir (int fd)
{
const char *name = _gl_directory_name (fd);
return name ? chdir (name) : -1;
}