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-rw-r--r--m4/getcwd.m4168
1 files changed, 168 insertions, 0 deletions
diff --git a/m4/getcwd.m4 b/m4/getcwd.m4
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+++ b/m4/getcwd.m4
@@ -0,0 +1,168 @@
+# getcwd.m4 - check for working getcwd that is compatible with glibc
+
+# Copyright (C) 2001, 2003-2007, 2009-2023 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.
+
+# Written by Paul Eggert.
+# serial 20
+
+AC_DEFUN([gl_FUNC_GETCWD_NULL],
+ [
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CHECK_HEADERS_ONCE([unistd.h])
+ AC_CACHE_CHECK([whether getcwd (NULL, 0) allocates memory for result],
+ [gl_cv_func_getcwd_null],
+ [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+# include <stdlib.h>
+# if HAVE_UNISTD_H
+# include <unistd.h>
+# else /* on Windows with MSVC */
+# include <direct.h>
+# endif
+ ]GL_MDA_DEFINES[
+# ifndef getcwd
+ char *getcwd ();
+# endif
+]], [[
+#if defined _WIN32 && ! defined __CYGWIN__
+/* mingw cwd does not start with '/', but _getcwd does allocate.
+ However, mingw fails to honor non-zero size. */
+#else
+ if (chdir ("/") != 0)
+ return 1;
+ else
+ {
+ char *f = getcwd (NULL, 0);
+ if (! f)
+ return 2;
+ if (f[0] != '/')
+ { free (f); return 3; }
+ if (f[1] != '\0')
+ { free (f); return 4; }
+ free (f);
+ return 0;
+ }
+#endif
+ ]])],
+ [gl_cv_func_getcwd_null=yes],
+ [gl_cv_func_getcwd_null=no],
+ [[case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu* | gnu*) gl_cv_func_getcwd_null="guessing yes";;
+ # Guess yes on musl systems.
+ *-musl*) gl_cv_func_getcwd_null="guessing yes";;
+ # Guess yes on systems that emulate the Linux system calls.
+ midipix*) gl_cv_func_getcwd_null="guessing yes";;
+ # Guess yes on Cygwin.
+ cygwin*) gl_cv_func_getcwd_null="guessing yes";;
+ # If we don't know, obey --enable-cross-guesses.
+ *) gl_cv_func_getcwd_null="$gl_cross_guess_normal";;
+ esac
+ ]])])
+])
+
+AC_DEFUN([gl_FUNC_GETCWD_SIGNATURE],
+[
+ AC_CACHE_CHECK([for getcwd with POSIX signature],
+ [gl_cv_func_getcwd_posix_signature],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+ ]GL_MDA_DEFINES],
+ [[extern
+ #ifdef __cplusplus
+ "C"
+ #endif
+ char *getcwd (char *, size_t);
+ ]])
+ ],
+ [gl_cv_func_getcwd_posix_signature=yes],
+ [gl_cv_func_getcwd_posix_signature=no])
+ ])
+])
+
+dnl Guarantee that getcwd will malloc with a NULL first argument. Assumes
+dnl that either the system getcwd is robust, or that calling code is okay
+dnl with spurious failures when run from a directory with an absolute name
+dnl larger than 4k bytes.
+dnl
+dnl Assumes that getcwd exists; if you are worried about obsolete
+dnl platforms that lacked getcwd(), then you need to use the GPL module.
+AC_DEFUN([gl_FUNC_GETCWD_LGPL],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([gl_FUNC_GETCWD_NULL])
+ AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
+
+ case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_posix_signature in
+ *yes,yes) ;;
+ *)
+ dnl Minimal replacement lib/getcwd-lgpl.c.
+ REPLACE_GETCWD=1
+ ;;
+ esac
+])
+
+dnl Check for all known getcwd bugs; useful for a program likely to be
+dnl executed from an arbitrary location.
+AC_DEFUN([gl_FUNC_GETCWD],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([gl_FUNC_GETCWD_NULL])
+ AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+ gl_abort_bug=no
+ case "$host_os" in
+ mingw*)
+ gl_cv_func_getcwd_path_max=yes
+ ;;
+ *)
+ gl_FUNC_GETCWD_PATH_MAX
+ case "$gl_cv_func_getcwd_null" in
+ *yes)
+ gl_FUNC_GETCWD_ABORT_BUG([gl_abort_bug=yes])
+ ;;
+ esac
+ ;;
+ esac
+ dnl Define HAVE_MINIMALLY_WORKING_GETCWD and HAVE_PARTLY_WORKING_GETCWD
+ dnl if appropriate.
+ case "$gl_cv_func_getcwd_path_max" in
+ *"no" | *"no, it has the AIX bug") ;;
+ *)
+ AC_DEFINE([HAVE_MINIMALLY_WORKING_GETCWD], [1],
+ [Define to 1 if getcwd minimally works, that is, its result can be
+ trusted when it succeeds.])
+ ;;
+ esac
+ case "$gl_cv_func_getcwd_path_max" in
+ *"no, but it is partly working")
+ AC_DEFINE([HAVE_PARTLY_WORKING_GETCWD], [1],
+ [Define to 1 if getcwd works, except it sometimes fails when it
+ shouldn't, setting errno to ERANGE, ENAMETOOLONG, or ENOENT.])
+ ;;
+ *"yes, but with shorter paths")
+ AC_DEFINE([HAVE_GETCWD_SHORTER], [1],
+ [Define to 1 if getcwd works, but with shorter paths
+ than is generally tested with the replacement.])
+ ;;
+ esac
+
+ if { case "$gl_cv_func_getcwd_null" in *yes) false;; *) true;; esac; } \
+ || test $gl_cv_func_getcwd_posix_signature != yes \
+ || { case "$gl_cv_func_getcwd_path_max" in *yes*) false;; *) true;; esac; } \
+ || test $gl_abort_bug = yes; then
+ REPLACE_GETCWD=1
+ fi
+])
+
+# Prerequisites of lib/getcwd.c, when full replacement is in effect.
+AC_DEFUN([gl_PREREQ_GETCWD],
+[
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+ AC_REQUIRE([gl_CHECK_TYPE_STRUCT_DIRENT_D_INO])
+ :
+])