1 files changed, 57 insertions, 41 deletions

diff --git a/gl/m4/include_next.m4 b/gl/m4/include_next.m4
index d6101fe3..c7e0672f 100644
--- a/gl/m4/include_next.m4
+++ b/gl/m4/include_next.m4
@@ -1,5 +1,5 @@
-# include_next.m4 serial 12
-dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
+# include_next.m4 serial 14
+dnl Copyright (C) 2006-2010 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.
@@ -104,10 +104,16 @@ EOF
 # For each arg foo.h, if #include_next works, define NEXT_FOO_H to be
 # '<foo.h>'; otherwise define it to be
 # '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
+# Also, if #include_next works as first preprocessing directive in a file,
+# define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be '<foo.h>'; otherwise define it to
+# be
+# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
 # That way, a header file with the following line:
-#       #@INCLUDE_NEXT@ @NEXT_FOO_H@
+#       #@INCLUDE_NEXT@ @NEXT_FOO_H@
+# or
+#       #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@
 # behaves (after sed substitution) as if it contained
-#       #include_next <foo.h>
+#       #include_next <foo.h>
 # even if the compiler does not support include_next.
 # The three "///" are to pacify Sun C 5.8, which otherwise would say
 # "warning: #include of /usr/include/... may be non-portable".
@@ -123,49 +129,59 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS],
 
   m4_foreach_w([gl_HEADER_NAME], [$1],
     [AS_VAR_PUSHDEF([gl_next_header],
-                    [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME])))
+                    [gl_cv_next_]m4_defn([gl_HEADER_NAME]))
      if test $gl_cv_have_include_next = yes; then
        AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
      else
        AC_CACHE_CHECK(
-         [absolute name of <]m4_quote(m4_defn([gl_HEADER_NAME]))[>],
-         m4_quote(m4_defn([gl_next_header])),
-         [AS_VAR_PUSHDEF([gl_header_exists],
-                         [ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME])))
-          if test AS_VAR_GET(gl_header_exists) = yes; then
-            AC_LANG_CONFTEST(
-              [AC_LANG_SOURCE(
-                 [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
-               )])
-            dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
-            dnl that contain only a #include of other header files and no
-            dnl non-comment tokens of their own. This leads to a failure to
-            dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
-            dnl and others. The workaround is to force preservation of comments
-            dnl through option -C. This ensures all necessary #line directives
-            dnl are present. GCC supports option -C as well.
-            case "$host_os" in
-              aix*) gl_absname_cpp="$ac_cpp -C" ;;
-              *)    gl_absname_cpp="$ac_cpp" ;;
-            esac
-            dnl eval is necessary to expand gl_absname_cpp.
-            dnl Ultrix and Pyramid sh refuse to redirect output of eval,
-            dnl so use subshell.
-            AS_VAR_SET([gl_next_header],
-              ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
-               sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{
-                 s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1#
-                 s#^/[^/]#//&#
-                 p
-                 q
-               }'`'"'])
-          else
-            AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
-          fi
-          AS_VAR_POPDEF([gl_header_exists])])
+         [absolute name of <]m4_defn([gl_HEADER_NAME])[>],
+         m4_defn([gl_next_header]),
+         [AS_VAR_PUSHDEF([gl_header_exists],
+                         [ac_cv_header_]m4_defn([gl_HEADER_NAME]))
+          if test AS_VAR_GET(gl_header_exists) = yes; then
+            AC_LANG_CONFTEST(
+              [AC_LANG_SOURCE(
+                 [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
+               )])
+            dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
+            dnl that contain only a #include of other header files and no
+            dnl non-comment tokens of their own. This leads to a failure to
+            dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
+            dnl and others. The workaround is to force preservation of comments
+            dnl through option -C. This ensures all necessary #line directives
+            dnl are present. GCC supports option -C as well.
+            case "$host_os" in
+              aix*) gl_absname_cpp="$ac_cpp -C" ;;
+              *)    gl_absname_cpp="$ac_cpp" ;;
+            esac
+            dnl eval is necessary to expand gl_absname_cpp.
+            dnl Ultrix and Pyramid sh refuse to redirect output of eval,
+            dnl so use subshell.
+            AS_VAR_SET([gl_next_header],
+              ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
+               sed -n '\#/]m4_defn([gl_HEADER_NAME])[#{
+                 s#.*"\(.*/]m4_defn([gl_HEADER_NAME])[\)".*#\1#
+                 s#^/[^/]#//&#
+                 p
+                 q
+               }'`'"'])
+          else
+            AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
+          fi
+          AS_VAR_POPDEF([gl_header_exists])])
      fi
      AC_SUBST(
-       AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))),
+       AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])),
        [AS_VAR_GET([gl_next_header])])
+     if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
+       gl_next_as_first_directive='<'gl_HEADER_NAME'>'
+     else
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
+       gl_next_as_first_directive=AS_VAR_GET([gl_next_header])
+     fi
+     AC_SUBST(
+       AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_defn([gl_HEADER_NAME])),
+       [$gl_next_as_first_directive])
      AS_VAR_POPDEF([gl_next_header])])
 ])