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Diffstat (limited to '')
| -rw-r--r-- | m4/readlink.m4 | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/m4/readlink.m4 b/m4/readlink.m4 new file mode 100644 index 0000000..f1d41d2 --- /dev/null +++ b/m4/readlink.m4 @@ -0,0 +1,120 @@ +# readlink.m4 serial 17 +dnl Copyright (C) 2003, 2007, 2009-2023 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN([gl_FUNC_READLINK], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CHECK_FUNCS_ONCE([readlink]) + if test $ac_cv_func_readlink = no; then + HAVE_READLINK=0 + else + AC_CACHE_CHECK([whether readlink signature is correct], + [gl_cv_decl_readlink_works], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <unistd.h> + /* Cause compilation failure if original declaration has wrong type. */ + ssize_t readlink (const char *, char *, size_t);]])], + [gl_cv_decl_readlink_works=yes], [gl_cv_decl_readlink_works=no])]) + dnl Solaris 9 ignores trailing slash. + dnl FreeBSD 7.2 dereferences only one level of links with trailing slash. + AC_CACHE_CHECK([whether readlink handles trailing slash correctly], + [gl_cv_func_readlink_trailing_slash], + [# We have readlink, so assume ln -s works. + ln -s conftest.no-such conftest.link + ln -s conftest.link conftest.lnk2 + AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include <unistd.h> +]], [[char buf[20]; + return readlink ("conftest.lnk2/", buf, sizeof buf) != -1;]])], + [gl_cv_func_readlink_trailing_slash=yes], + [gl_cv_func_readlink_trailing_slash=no], + [case "$host_os" in + # Guess yes on Linux or glibc systems. + linux-* | linux | *-gnu* | gnu*) + gl_cv_func_readlink_trailing_slash="guessing yes" ;; + # Guess yes on systems that emulate the Linux system calls. + midipix*) + gl_cv_func_readlink_trailing_slash="guessing yes" ;; + # Guess no on AIX or HP-UX. + aix* | hpux*) + gl_cv_func_readlink_trailing_slash="guessing no" ;; + # If we don't know, obey --enable-cross-guesses. + *) + gl_cv_func_readlink_trailing_slash="$gl_cross_guess_normal" ;; + esac + ]) + rm -f conftest.link conftest.lnk2]) + case "$gl_cv_func_readlink_trailing_slash" in + *yes) + if test "$gl_cv_decl_readlink_works" != yes; then + REPLACE_READLINK=1 + fi + ;; + *) + AC_DEFINE([READLINK_TRAILING_SLASH_BUG], [1], [Define to 1 if readlink + fails to recognize a trailing slash.]) + REPLACE_READLINK=1 + ;; + esac + + AC_CACHE_CHECK([whether readlink truncates results correctly], + [gl_cv_func_readlink_truncate], + [# We have readlink, so assume ln -s works. + ln -s ab conftest.link + AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include <unistd.h> +]], [[char c; + return readlink ("conftest.link", &c, 1) != 1;]])], + [gl_cv_func_readlink_truncate=yes], + [gl_cv_func_readlink_truncate=no], + [case "$host_os" in + # Guess yes on Linux or glibc systems. + linux-* | linux | *-gnu* | gnu*) + gl_cv_func_readlink_truncate="guessing yes" ;; + # Guess yes on systems that emulate the Linux system calls. + midipix*) + gl_cv_func_readlink_truncate="guessing yes" ;; + # Guess no on AIX or HP-UX. + aix* | hpux*) + gl_cv_func_readlink_truncate="guessing no" ;; + # If we don't know, obey --enable-cross-guesses. + *) + gl_cv_func_readlink_truncate="$gl_cross_guess_normal" ;; + esac + ]) + rm -f conftest.link conftest.lnk2]) + case $gl_cv_func_readlink_truncate in + *yes) + if test "$gl_cv_decl_readlink_works" != yes; then + REPLACE_READLINK=1 + fi + ;; + *) + AC_DEFINE([READLINK_TRUNCATE_BUG], [1], [Define to 1 if readlink + sets errno instead of truncating a too-long link.]) + REPLACE_READLINK=1 + ;; + esac + fi +]) + +# Like gl_FUNC_READLINK, except prepare for separate compilation +# (no REPLACE_READLINK, no AC_LIBOBJ). +AC_DEFUN([gl_FUNC_READLINK_SEPARATE], +[ + AC_CHECK_FUNCS_ONCE([readlink]) + gl_PREREQ_READLINK +]) + +# Prerequisites of lib/readlink.c. +AC_DEFUN([gl_PREREQ_READLINK], +[ + : +]) |