1# serial 7 2# Determine whether getcwd aborts when the length of the working directory 3# name is unusually large. Any length between 4k and 16k trigger the bug 4# when using glibc-2.4.90-9 or older. 5 6# Copyright (C) 2006, 2009-2012 Free Software Foundation, Inc. 7# This file is free software; the Free Software Foundation 8# gives unlimited permission to copy and/or distribute it, 9# with or without modifications, as long as this notice is preserved. 10 11# From Jim Meyering 12 13# gl_FUNC_GETCWD_ABORT_BUG([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) 14AC_DEFUN([gl_FUNC_GETCWD_ABORT_BUG], 15[ 16 AC_CHECK_DECLS_ONCE([getcwd]) 17 AC_CHECK_HEADERS_ONCE([unistd.h]) 18 AC_REQUIRE([gl_PATHMAX_SNIPPET_PREREQ]) 19 AC_CHECK_FUNCS([getpagesize]) 20 AC_CACHE_CHECK([whether getcwd aborts when 4k < cwd_length < 16k], 21 gl_cv_func_getcwd_abort_bug, 22 [# Remove any remnants of a previous test. 23 rm -rf confdir-14B--- 24 # Arrange for deletion of the temporary directory this test creates. 25 ac_clean_files="$ac_clean_files confdir-14B---" 26 dnl Please keep this in sync with tests/test-getcwd.c. 27 AC_RUN_IFELSE( 28 [AC_LANG_SOURCE( 29 [[ 30#include <stdlib.h> 31#if HAVE_UNISTD_H 32# include <unistd.h> 33#else /* on Windows with MSVC */ 34# include <direct.h> 35#endif 36#include <string.h> 37#include <sys/stat.h> 38 39]gl_PATHMAX_SNIPPET[ 40 41/* Don't get link errors because mkdir is redefined to rpl_mkdir. */ 42#undef mkdir 43 44#ifndef S_IRWXU 45# define S_IRWXU 0700 46#endif 47 48/* FIXME: skip the run-test altogether on systems without getpagesize. */ 49#if ! HAVE_GETPAGESIZE 50# define getpagesize() 0 51#endif 52 53/* This size is chosen to be larger than PATH_MAX (4k), yet smaller than 54 the 16kB pagesize on ia64 linux. Those conditions make the code below 55 trigger a bug in glibc's getcwd implementation before 2.4.90-10. */ 56#define TARGET_LEN (5 * 1024) 57 58int 59main () 60{ 61 char const *dir_name = "confdir-14B---"; 62 char *cwd; 63 size_t initial_cwd_len; 64 int fail = 0; 65 size_t desired_depth; 66 size_t d; 67 68 /* The bug is triggered when PATH_MAX < getpagesize (), so skip 69 this relatively expensive and invasive test if that's not true. */ 70 if (getpagesize () <= PATH_MAX) 71 return 0; 72 73 cwd = getcwd (NULL, 0); 74 if (cwd == NULL) 75 return 2; 76 77 initial_cwd_len = strlen (cwd); 78 free (cwd); 79 desired_depth = ((TARGET_LEN - 1 - initial_cwd_len) 80 / (1 + strlen (dir_name))); 81 for (d = 0; d < desired_depth; d++) 82 { 83 if (mkdir (dir_name, S_IRWXU) < 0 || chdir (dir_name) < 0) 84 { 85 fail = 3; /* Unable to construct deep hierarchy. */ 86 break; 87 } 88 } 89 90 /* If libc has the bug in question, this invocation of getcwd 91 results in a failed assertion. */ 92 cwd = getcwd (NULL, 0); 93 if (cwd == NULL) 94 fail = 4; /* getcwd failed: it refuses to return a string longer 95 than PATH_MAX. */ 96 free (cwd); 97 98 /* Call rmdir first, in case the above chdir failed. */ 99 rmdir (dir_name); 100 while (0 < d--) 101 { 102 if (chdir ("..") < 0) 103 { 104 fail = 5; 105 break; 106 } 107 rmdir (dir_name); 108 } 109 110 return fail; 111} 112 ]])], 113 [gl_cv_func_getcwd_abort_bug=no], 114 [dnl An abort will provoke an exit code of something like 134 (128 + 6). 115 dnl An exit code of 4 can also occur (in OpenBSD 4.9, NetBSD 5.1 for 116 dnl example): getcwd (NULL, 0) fails rather than returning a string 117 dnl longer than PATH_MAX. This may be POSIX compliant (in some 118 dnl interpretations of POSIX). But gnulib's getcwd module wants to 119 dnl provide a non-NULL value in this case. 120 ret=$? 121 if test $ret -ge 128 || test $ret = 4; then 122 gl_cv_func_getcwd_abort_bug=yes 123 else 124 gl_cv_func_getcwd_abort_bug=no 125 fi], 126 [gl_cv_func_getcwd_abort_bug=yes]) 127 ]) 128 AS_IF([test $gl_cv_func_getcwd_abort_bug = yes], [$1], [$2]) 129]) 130