diff options
Diffstat (limited to 'src/dired.c')
| -rw-r--r-- | src/dired.c | 166 |
1 files changed, 113 insertions, 53 deletions
diff --git a/src/dired.c b/src/dired.c index 5ea00fb8db4..239b1acd1fb 100644 --- a/src/dired.c +++ b/src/dired.c @@ -15,7 +15,7 @@ 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 GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ +along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include <config.h> @@ -51,7 +51,8 @@ extern int is_slow_fs (const char *); #endif static ptrdiff_t scmp (const char *, const char *, ptrdiff_t); -static Lisp_Object file_attributes (int, char const *, Lisp_Object); +static Lisp_Object file_attributes (int, char const *, Lisp_Object, + Lisp_Object, Lisp_Object); /* Return the number of bytes in DP's name. */ static ptrdiff_t @@ -64,6 +65,21 @@ dirent_namelen (struct dirent *dp) #endif } +#ifndef HAVE_STRUCT_DIRENT_D_TYPE +enum { DT_UNKNOWN, DT_DIR, DT_LNK }; +#endif + +/* Return the file type of DP. */ +static int +dirent_type (struct dirent *dp) +{ +#ifdef HAVE_STRUCT_DIRENT_D_TYPE + return dp->d_type; +#else + return DT_UNKNOWN; +#endif +} + static DIR * open_directory (Lisp_Object dirname, int *fdp) { @@ -146,7 +162,7 @@ read_dirent (DIR *dir, Lisp_Object dirname) /* Function shared by Fdirectory_files and Fdirectory_files_and_attributes. If not ATTRS, return a list of directory filenames; if ATTRS, return a list of directory filenames and their attributes. - In the latter case, ID_FORMAT is passed to Ffile_attributes. */ + In the latter case, pass ID_FORMAT to file_attributes. */ Lisp_Object directory_files_internal (Lisp_Object directory, Lisp_Object full, @@ -210,7 +226,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full, if (attrs) { /* Do this only once to avoid doing it (in w32.c:stat) for each - file in the directory, when we call Ffile_attributes below. */ + file in the directory, when we call file_attributes below. */ record_unwind_protect (directory_files_internal_w32_unwind, Vw32_get_true_file_attributes); w32_save = Vw32_get_true_file_attributes; @@ -289,7 +305,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full, if (attrs) { Lisp_Object fileattrs - = file_attributes (fd, dp->d_name, id_format); + = file_attributes (fd, dp->d_name, directory, name, id_format); list = Fcons (Fcons (finalname, fileattrs), list); } else @@ -336,7 +352,7 @@ If NOSORT is non-nil, the list is not sorted--its order is unpredictable. return call5 (handler, Qdirectory_files, directory, full, match, nosort); - return directory_files_internal (directory, full, match, nosort, 0, Qnil); + return directory_files_internal (directory, full, match, nosort, false, Qnil); } DEFUN ("directory-files-and-attributes", Fdirectory_files_and_attributes, @@ -364,7 +380,8 @@ which see. */) return call6 (handler, Qdirectory_files_and_attributes, directory, full, match, nosort, id_format); - return directory_files_internal (directory, full, match, nosort, 1, id_format); + return directory_files_internal (directory, full, match, nosort, + true, id_format); } @@ -434,7 +451,7 @@ is matched against file and directory names relative to DIRECTORY. */) return file_name_completion (file, directory, 1, Qnil); } -static int file_name_completion_stat (int, struct dirent *, struct stat *); +static bool file_name_completion_dirp (int, struct dirent *, ptrdiff_t); static Lisp_Object file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, @@ -448,7 +465,6 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, Lisp_Object bestmatch, tem, elt, name; Lisp_Object encoded_file; Lisp_Object encoded_dir; - struct stat st; bool directoryp; /* If not INCLUDEALL, exclude files in completion-ignored-extensions as well as "." and "..". Until shown otherwise, assume we can't exclude @@ -512,10 +528,21 @@ file_name_completion (Lisp_Object file, Lisp_Object dirname, bool all_flag, >= 0)) continue; - if (file_name_completion_stat (fd, dp, &st) < 0) - continue; + switch (dirent_type (dp)) + { + case DT_DIR: + directoryp = true; + break; + + case DT_LNK: case DT_UNKNOWN: + directoryp = file_name_completion_dirp (fd, dp, len); + break; + + default: + directoryp = false; + break; + } - directoryp = S_ISDIR (st.st_mode) != 0; tem = Qnil; /* If all_flag is set, always include all. It would not actually be helpful to the user to ignore any possible @@ -781,32 +808,18 @@ scmp (const char *s1, const char *s2, ptrdiff_t len) return len - l; } -static int -file_name_completion_stat (int fd, struct dirent *dp, struct stat *st_addr) +/* Return true if in the directory FD the directory entry DP, whose + string length is LEN, is that of a subdirectory that can be searched. */ +static bool +file_name_completion_dirp (int fd, struct dirent *dp, ptrdiff_t len) { - int value; - -#ifdef MSDOS - /* Some fields of struct stat are *very* expensive to compute on MS-DOS, - but aren't required here. Avoid computing the following fields: - st_inode, st_size and st_nlink for directories, and the execute bits - in st_mode for non-directory files with non-standard extensions. */ - - unsigned short save_djstat_flags = _djstat_flags; - - _djstat_flags = _STAT_INODE | _STAT_EXEC_MAGIC | _STAT_DIRSIZE; -#endif /* MSDOS */ - - /* We want to return success if a link points to a nonexistent file, - but we want to return the status for what the link points to, - in case it is a directory. */ - value = fstatat (fd, dp->d_name, st_addr, AT_SYMLINK_NOFOLLOW); - if (value == 0 && S_ISLNK (st_addr->st_mode)) - fstatat (fd, dp->d_name, st_addr, 0); -#ifdef MSDOS - _djstat_flags = save_djstat_flags; -#endif /* MSDOS */ - return value; + USE_SAFE_ALLOCA; + char *subdir_name = SAFE_ALLOCA (len + 2); + memcpy (subdir_name, dp->d_name, len); + strcpy (subdir_name + len, "/"); + bool dirp = faccessat (fd, subdir_name, F_OK, AT_EACCESS) == 0; + SAFE_FREE (); + return dirp; } static char * @@ -912,14 +925,17 @@ so last access time will always be midnight of that day. */) } encoded = ENCODE_FILE (filename); - return file_attributes (AT_FDCWD, SSDATA (encoded), id_format); + return file_attributes (AT_FDCWD, SSDATA (encoded), Qnil, filename, + id_format); } static Lisp_Object -file_attributes (int fd, char const *name, Lisp_Object id_format) +file_attributes (int fd, char const *name, + Lisp_Object dirname, Lisp_Object filename, + Lisp_Object id_format) { + ptrdiff_t count = SPECPDL_INDEX (); struct stat s; - int lstat_result; /* An array to hold the mode string generated by filemodestring, including its terminating space and null byte. */ @@ -927,22 +943,67 @@ file_attributes (int fd, char const *name, Lisp_Object id_format) char *uname = NULL, *gname = NULL; -#ifdef WINDOWSNT - /* We usually don't request accurate owner and group info, because - it can be very expensive on Windows to get that, and most callers - of 'lstat' don't need that. But here we do want that information - to be accurate. */ - w32_stat_get_owner_group = 1; -#endif + int err = EINVAL; - lstat_result = fstatat (fd, name, &s, AT_SYMLINK_NOFOLLOW); +#ifdef O_PATH + int namefd = openat (fd, name, O_PATH | O_CLOEXEC | O_NOFOLLOW); + if (namefd < 0) + err = errno; + else + { + record_unwind_protect_int (close_file_unwind, namefd); + if (fstat (namefd, &s) != 0) + { + err = errno; + /* The Linux kernel before version 3.6 does not support + fstat on O_PATH file descriptors. Handle this error like + missing support for O_PATH. */ + if (err == EBADF) + err = EINVAL; + } + else + { + err = 0; + fd = namefd; + name = ""; + } + } +#endif + if (err == EINVAL) + { #ifdef WINDOWSNT - w32_stat_get_owner_group = 0; + /* We usually don't request accurate owner and group info, + because it can be expensive on Windows to get that, and most + callers of 'lstat' don't need that. But here we do want that + information to be accurate. */ + w32_stat_get_owner_group = 1; #endif + if (fstatat (fd, name, &s, AT_SYMLINK_NOFOLLOW) == 0) + err = 0; +#ifdef WINDOWSNT + w32_stat_get_owner_group = 0; +#endif + } - if (lstat_result < 0) - return Qnil; + if (err != 0) + return unbind_to (count, Qnil); + + Lisp_Object file_type; + if (S_ISLNK (s.st_mode)) + { + /* On systems lacking O_PATH support there is a race if the + symlink is replaced between the call to fstatat and the call + to emacs_readlinkat. Detect this race unless the replacement + is also a symlink. */ + file_type = emacs_readlinkat (fd, name); + if (NILP (file_type)) + return unbind_to (count, Qnil); + } + else + file_type = S_ISDIR (s.st_mode) ? Qt : Qnil; + + unbind_to (count, Qnil); if (!(NILP (id_format) || EQ (id_format, Qinteger))) { @@ -953,8 +1014,7 @@ file_attributes (int fd, char const *name, Lisp_Object id_format) filemodestring (&s, modes); return CALLN (Flist, - (S_ISLNK (s.st_mode) ? emacs_readlinkat (fd, name) - : S_ISDIR (s.st_mode) ? Qt : Qnil), + file_type, make_number (s.st_nlink), (uname ? DECODE_SYSTEM (build_unibyte_string (uname)) |