| # serial 25 |
| # Check for several getcwd bugs with long file names. |
| # If so, arrange to compile the wrapper function. |
| |
| # This is necessary for at least GNU libc on linux-2.4.19 and 2.4.20. |
| # I've heard that this is due to a Linux kernel bug, and that it has |
| # been fixed between 2.4.21-pre3 and 2.4.21-pre4. |
| |
| # Copyright (C) 2003-2007, 2009-2021 Free Software Foundation, Inc. |
| # This file is free software; the Free Software Foundation |
| # gives unlimited permission to copy and/or distribute it, |
| # with or without modifications, as long as this notice is preserved. |
| |
| # From Jim Meyering |
| |
| AC_DEFUN([gl_FUNC_GETCWD_PATH_MAX], |
| [ |
| AC_CHECK_DECLS_ONCE([getcwd]) |
| AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) |
| AC_CHECK_HEADERS_ONCE([unistd.h]) |
| AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ]) |
| AC_CACHE_CHECK([whether getcwd handles long file names properly], |
| [gl_cv_func_getcwd_path_max], |
| [# Arrange for deletion of the temporary directory this test creates. |
| ac_clean_files="$ac_clean_files confdir3" |
| dnl Please keep this in sync with tests/test-getcwd.c. |
| AC_RUN_IFELSE( |
| [AC_LANG_SOURCE( |
| [[ |
| #include <errno.h> |
| #include <stdlib.h> |
| #if HAVE_UNISTD_H |
| # include <unistd.h> |
| #else |
| # include <direct.h> |
| #endif |
| #include <string.h> |
| #include <limits.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <fcntl.h> |
| |
| ]gl_PATHMAX_SNIPPET[ |
| |
| #ifndef AT_FDCWD |
| # define AT_FDCWD 0 |
| #endif |
| #ifdef ENAMETOOLONG |
| # define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG) |
| #else |
| # define is_ENAMETOOLONG(x) 0 |
| #endif |
| |
| /* Use the getcwd function, not any macro. */ |
| #undef getcwd |
| |
| ]GL_MDA_DEFINES[ |
| |
| #ifndef S_IRWXU |
| # define S_IRWXU 0700 |
| #endif |
| |
| /* The length of this name must be 8. */ |
| #define DIR_NAME "confdir3" |
| #define DIR_NAME_LEN 8 |
| #define DIR_NAME_SIZE (DIR_NAME_LEN + 1) |
| |
| /* The length of "../". */ |
| #define DOTDOTSLASH_LEN 3 |
| |
| /* Leftover bytes in the buffer, to work around library or OS bugs. */ |
| #define BUF_SLOP 20 |
| |
| int |
| main () |
| { |
| #ifndef PATH_MAX |
| /* The Hurd doesn't define this, so getcwd can't exhibit the bug -- |
| at least not on a local file system. And if we were to start worrying |
| about remote file systems, we'd have to enable the wrapper function |
| all of the time, just to be safe. That's not worth the cost. */ |
| exit (0); |
| #elif ((INT_MAX / (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) \ |
| - DIR_NAME_SIZE - BUF_SLOP) \ |
| <= PATH_MAX) |
| /* FIXME: Assuming there's a system for which this is true, |
| this should be done in a compile test. */ |
| exit (0); |
| #else |
| char buf[PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN + 1) |
| + DIR_NAME_SIZE + BUF_SLOP]; |
| char *cwd = getcwd (buf, PATH_MAX); |
| size_t initial_cwd_len; |
| size_t cwd_len; |
| int fail = 0; |
| size_t n_chdirs = 0; |
| |
| if (cwd == NULL) |
| exit (10); |
| |
| cwd_len = initial_cwd_len = strlen (cwd); |
| |
| while (1) |
| { |
| size_t dotdot_max = PATH_MAX * (DIR_NAME_SIZE / DOTDOTSLASH_LEN); |
| char *c = NULL; |
| |
| cwd_len += DIR_NAME_SIZE; |
| /* If mkdir or chdir fails, it could be that this system cannot create |
| any file with an absolute name longer than PATH_MAX, such as cygwin. |
| If so, leave fail as 0, because the current working directory can't |
| be too long for getcwd if it can't even be created. On Linux with |
| the 9p file system, mkdir fails with error EINVAL when cwd_len gets |
| too long; ignore this failure because the getcwd() system call |
| produces good results whereas the gnulib substitute calls getdents64 |
| which fails with error EPROTO. |
| For other errors, be pessimistic and consider that as a failure, |
| too. */ |
| if (mkdir (DIR_NAME, S_IRWXU) < 0 || chdir (DIR_NAME) < 0) |
| { |
| if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) |
| #ifdef __linux__ |
| if (! (errno == EINVAL)) |
| #endif |
| fail = 20; |
| break; |
| } |
| |
| if (PATH_MAX <= cwd_len && cwd_len < PATH_MAX + DIR_NAME_SIZE) |
| { |
| struct stat sb; |
| |
| c = getcwd (buf, PATH_MAX); |
| if (!c && errno == ENOENT) |
| { |
| fail = 11; |
| break; |
| } |
| if (c) |
| { |
| fail = 31; |
| break; |
| } |
| if (! (errno == ERANGE || is_ENAMETOOLONG (errno))) |
| { |
| fail = 21; |
| break; |
| } |
| |
| /* Our replacement needs to be able to stat() long ../../paths, |
| so generate a path larger than PATH_MAX to check, |
| avoiding the replacement if we can't stat(). */ |
| c = getcwd (buf, cwd_len + 1); |
| if (c && !AT_FDCWD && stat (c, &sb) != 0 && is_ENAMETOOLONG (errno)) |
| { |
| fail = 32; |
| break; |
| } |
| } |
| |
| if (dotdot_max <= cwd_len - initial_cwd_len) |
| { |
| if (dotdot_max + DIR_NAME_SIZE < cwd_len - initial_cwd_len) |
| break; |
| c = getcwd (buf, cwd_len + 1); |
| if (!c) |
| { |
| if (! (errno == ERANGE || errno == ENOENT |
| || is_ENAMETOOLONG (errno))) |
| { |
| fail = 22; |
| break; |
| } |
| if (AT_FDCWD || errno == ERANGE || errno == ENOENT) |
| { |
| fail = 12; |
| break; |
| } |
| } |
| } |
| |
| if (c && strlen (c) != cwd_len) |
| { |
| fail = 23; |
| break; |
| } |
| ++n_chdirs; |
| } |
| |
| /* Leaving behind such a deep directory is not polite. |
| So clean up here, right away, even though the driving |
| shell script would also clean up. */ |
| { |
| size_t i; |
| |
| /* Try rmdir first, in case the chdir failed. */ |
| rmdir (DIR_NAME); |
| for (i = 0; i <= n_chdirs; i++) |
| { |
| if (chdir ("..") < 0) |
| break; |
| if (rmdir (DIR_NAME) != 0) |
| break; |
| } |
| } |
| |
| exit (fail); |
| #endif |
| } |
| ]])], |
| [gl_cv_func_getcwd_path_max=yes], |
| [case $? in |
| 10|11|12) gl_cv_func_getcwd_path_max='no, but it is partly working';; |
| 31) gl_cv_func_getcwd_path_max='no, it has the AIX bug';; |
| 32) gl_cv_func_getcwd_path_max='yes, but with shorter paths';; |
| *) gl_cv_func_getcwd_path_max=no;; |
| esac], |
| [# Cross-compilation guesses: |
| case "$host_os" in |
| aix*) # On AIX, it has the AIX bug. |
| gl_cv_func_getcwd_path_max='guessing no, it has the AIX bug' ;; |
| gnu*) # On Hurd, it is 'yes'. |
| gl_cv_func_getcwd_path_max='guessing yes' ;; |
| linux* | kfreebsd*) |
| # On older Linux+glibc it's 'no, but it is partly working', |
| # on newer Linux+glibc it's 'yes'. |
| # On Linux+musl libc, it's 'no, but it is partly working'. |
| # On kFreeBSD+glibc, it's 'no, but it is partly working'. |
| gl_cv_func_getcwd_path_max='guessing no, but it is partly working' ;; |
| *) # If we don't know, obey --enable-cross-guesses. |
| gl_cv_func_getcwd_path_max="$gl_cross_guess_normal" ;; |
| esac |
| ]) |
| ]) |
| ]) |
