NEWS.stable: log cherry-pick [a0d9972]->[21d1619] freopen: Don't crash if the filenam...

[gnulib.git] / m4 / canonicalize.m4

diff --git a/m4/canonicalize.m4 b/m4/canonicalize.m4
index b488bb5..ba7a38b 100644 (file)
--- a/m4/canonicalize.m4
+++ b/m4/canonicalize.m4
@@ -1,19 +1,101 @@
-#serial 11
+# canonicalize.m4 serial 23
 
-# Copyright (C) 2003, 2004, 2005, 2006 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.
+dnl Copyright (C) 2003-2007, 2009-2011 Free Software Foundation, Inc.
 
-# Written by Jim Meyering.
+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([AC_FUNC_CANONICALIZE_FILE_NAME],
-  [
-    AC_LIBOBJ([canonicalize])
+# Provides canonicalize_file_name and canonicalize_filename_mode, but does
+# not provide or fix realpath.
+AC_DEFUN([gl_FUNC_CANONICALIZE_FILENAME_MODE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+  elif test "$gl_cv_func_realpath_works" != yes; then
+    REPLACE_CANONICALIZE_FILE_NAME=1
+  fi
+])
 
-    AC_CHECK_HEADERS_ONCE([sys/param.h])
-    AC_CHECK_DECLS_ONCE([canonicalize_file_name])
-    AC_CHECK_FUNCS_ONCE([canonicalize_file_name resolvepath])
-    AC_DEFINE([PROVIDE_CANONICALIZE_FILENAME_MODE], 1,
-      [Define to 1 to provide canonicalize_filename_mode.])
+# Provides canonicalize_file_name and realpath.
+AC_DEFUN([gl_CANONICALIZE_LGPL],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_REQUIRE([gl_CANONICALIZE_LGPL_SEPARATE])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+    if test $ac_cv_func_realpath = no; then
+      HAVE_REALPATH=0
+    elif test "$gl_cv_func_realpath_works" != yes; then
+      REPLACE_REALPATH=1
+    fi
+  elif test "$gl_cv_func_realpath_works" != yes; then
+    REPLACE_CANONICALIZE_FILE_NAME=1
+    REPLACE_REALPATH=1
+  fi
+])
+
+# Like gl_CANONICALIZE_LGPL, except prepare for separate compilation
+# (no REPLACE_CANONICALIZE_FILE_NAME, no REPLACE_REALPATH, no AC_LIBOBJ).
+AC_DEFUN([gl_CANONICALIZE_LGPL_SEPARATE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name getcwd readlink])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  AC_CHECK_HEADERS_ONCE([sys/param.h])
+])
+
+# Check whether realpath works.  Assume that if a platform has both
+# realpath and canonicalize_file_name, but the former is broken, then
+# so is the latter.
+AC_DEFUN([gl_FUNC_REALPATH_WORKS],
+[
+  AC_CHECK_FUNCS_ONCE([realpath])
+  AC_CACHE_CHECK([whether realpath works], [gl_cv_func_realpath_works], [
+    touch conftest.a
+    mkdir conftest.d
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        ]GL_NOCRASH[
+        #include <stdlib.h>
+        #include <string.h>
+      ]], [[
+        int result = 0;
+        {
+          char *name = realpath ("conftest.a", NULL);
+          if (!(name && *name == '/'))
+            result |= 1;
+        }
+        {
+          char *name = realpath ("conftest.b/../conftest.a", NULL);
+          if (name != NULL)
+            result |= 2;
+        }
+        {
+          char *name = realpath ("conftest.a/", NULL);
+          if (name != NULL)
+            result |= 4;
+        }
+        {
+          char *name1 = realpath (".", NULL);
+          char *name2 = realpath ("conftest.d//./..", NULL);
+          if (strcmp (name1, name2) != 0)
+            result |= 8;
+        }
+        return result;
+      ]])
+    ], [gl_cv_func_realpath_works=yes], [gl_cv_func_realpath_works=no],
+       [gl_cv_func_realpath_works="guessing no"])
+    rm -rf conftest.a conftest.d
   ])
+  if test "$gl_cv_func_realpath_works" = yes; then
+    AC_DEFINE([FUNC_REALPATH_WORKS], [1], [Define to 1 if realpath()
+      can malloc memory, always gives an absolute path, and handles
+      trailing slash correctly.])
+  fi
+])