m4: Rely less on internal symbols

* gettext-runtime/m4/gettext.m4 (AM_GNU_GETTEXT): Skip checks for the
internal symbols _nl_msg_cat_cntr, _nl_domain_bindings, and
_nl_expand_alias, if __GNU_GETTEXT_SUPPORTED_REVISION is defined.
Problem reported and fix suggested by Masanori Ogino in:
https://lists.gnu.org/archive/html/bug-gettext/2016-04/msg00000.html
The rationale behind this is: (1) those symbol checks are for detecting
certain broken implementations, namely NetBSD and Solaris 7, and
(2) __GNU_GETTEXT_SUPPORTED_REVISION is not defined in those
implementations, while it is defined on compatible implementations, such
as musl-libc which doesn't have those internal symbols.

diff --git a/gettext-runtime/m4/gettext.m4 b/gettext-runtime/m4/gettext.m4
index 1f6979a531dc107411c9e7819b3a97d8340dde5e..eef5073b32cbbb94d33cd34075cf12d6e2703f16 100644 (file)
--- a/gettext-runtime/m4/gettext.m4
+++ b/gettext-runtime/m4/gettext.m4
@@ -1,4 +1,4 @@
-# gettext.m4 serial 67 (gettext-0.19.6)
+# gettext.m4 serial 68 (gettext-0.19.8)
 dnl Copyright (C) 1995-2014, 2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -161,13 +161,18 @@ changequote([,])dnl
             [AC_LANG_PROGRAM(
                [[
 #include <libintl.h>
-$gt_revision_test_code
+#ifndef __GNU_GETTEXT_SUPPORTED_REVISION
 extern int _nl_msg_cat_cntr;
 extern int *_nl_domain_bindings;
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION (_nl_msg_cat_cntr + *_nl_domain_bindings)
+#else
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION 0
+#endif
+$gt_revision_test_code
                ]],
                [[
 bindtextdomain ("", "");
-return * gettext ("")$gt_expression_test_code + _nl_msg_cat_cntr + *_nl_domain_bindings
+return * gettext ("")$gt_expression_test_code + __GNU_GETTEXT_SYMBOL_EXPRESSION
                ]])],
             [eval "$gt_func_gnugettext_libc=yes"],
             [eval "$gt_func_gnugettext_libc=no"])])
@@ -193,17 +198,22 @@ return * gettext ("")$gt_expression_test_code + _nl_msg_cat_cntr + *_nl_domain_b
               [AC_LANG_PROGRAM(
                  [[
 #include <libintl.h>
-$gt_revision_test_code
+#ifndef __GNU_GETTEXT_SUPPORTED_REVISION
 extern int _nl_msg_cat_cntr;
 extern
 #ifdef __cplusplus
 "C"
 #endif
 const char *_nl_expand_alias (const char *);
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION (_nl_msg_cat_cntr + *_nl_expand_alias (""))
+#else
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION 0
+#endif
+$gt_revision_test_code
                  ]],
                  [[
 bindtextdomain ("", "");
-return * gettext ("")$gt_expression_test_code + _nl_msg_cat_cntr + *_nl_expand_alias ("")
+return * gettext ("")$gt_expression_test_code + __GNU_GETTEXT_SYMBOL_EXPRESSION
                  ]])],
               [eval "$gt_func_gnugettext_libintl=yes"],
               [eval "$gt_func_gnugettext_libintl=no"])
@@ -214,17 +224,22 @@ return * gettext ("")$gt_expression_test_code + _nl_msg_cat_cntr + *_nl_expand_a
                 [AC_LANG_PROGRAM(
                    [[
 #include <libintl.h>
-$gt_revision_test_code
+#ifndef __GNU_GETTEXT_SUPPORTED_REVISION
 extern int _nl_msg_cat_cntr;
 extern
 #ifdef __cplusplus
 "C"
 #endif
 const char *_nl_expand_alias (const char *);
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION (_nl_msg_cat_cntr + *_nl_expand_alias (""))
+#else
+#define __GNU_GETTEXT_SYMBOL_EXPRESSION 0
+#endif
+$gt_revision_test_code
                    ]],
                    [[
 bindtextdomain ("", "");
-return * gettext ("")$gt_expression_test_code + _nl_msg_cat_cntr + *_nl_expand_alias ("")
+return * gettext ("")$gt_expression_test_code + __GNU_GETTEXT_SYMBOL_EXPRESSION
                    ]])],
                 [LIBINTL="$LIBINTL $LIBICONV"
                  LTLIBINTL="$LTLIBINTL $LTLIBICONV"