getcwd-lgpl: new module

[pspp] / m4 / getcwd.m4

diff --git a/m4/getcwd.m4 b/m4/getcwd.m4
index 0c7e20c2e06f6f08cb844f522f1827b2d3443338..55f937222bc2549da5491ff556c53bd1e7564f16 100644 (file)
--- a/m4/getcwd.m4
+++ b/m4/getcwd.m4
@@ -6,10 +6,11 @@
 # with or without modifications, as long as this notice is preserved.
 
 # Written by Paul Eggert.
-# serial 4
+# serial 5
 
 AC_DEFUN([gl_FUNC_GETCWD_NULL],
   [
+   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
    AC_CACHE_CHECK([whether getcwd (NULL, 0) allocates memory for result],
      [gl_cv_func_getcwd_null],
      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
@@ -52,6 +53,29 @@ AC_DEFUN([gl_FUNC_GETCWD_NULL],
         ]])])
 ])
 
+
+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])
+
+  case $gl_cv_func_getcwd_null in
+  *yes) ;;
+  *)
+    dnl Minimal replacement
+    REPLACE_GETCWD=1
+    AC_LIBOBJ([getcwd-lgpl])
+    ;;
+  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],
@@ -72,13 +96,14 @@ AC_DEFUN([gl_FUNC_GETCWD],
   case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_path_max,$gl_abort_bug in
   *yes,yes,no) ;;
   *)
+    dnl Full replacement, overrides LGPL replacement.
     REPLACE_GETCWD=1
     AC_LIBOBJ([getcwd])
     gl_PREREQ_GETCWD;;
   esac
 ])
 
-# Prerequisites of lib/getcwd.c.
+# Prerequisites of lib/getcwd.c, when full replacement is in effect.
 AC_DEFUN([gl_PREREQ_GETCWD],
 [
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])