]> sjero.net Git - wget/blobdiff - md5/m4/include_next.m4
Moved md5 stuff out into separate md5/ dir.
[wget] / md5 / m4 / include_next.m4
diff --git a/md5/m4/include_next.m4 b/md5/m4/include_next.m4
new file mode 100644 (file)
index 0000000..7ce472b
--- /dev/null
@@ -0,0 +1,107 @@
+# include_next.m4 serial 4
+dnl Copyright (C) 2006, 2007 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.
+
+dnl From Paul Eggert and Derek Price.
+
+AC_DEFUN([gl_INCLUDE_NEXT],
+[
+  AC_LANG_PREPROC_REQUIRE()
+  AC_CACHE_CHECK([whether the preprocessor supports include_next],
+    [gl_cv_have_include_next],
+    [rm -rf conftestd1 conftestd2
+     mkdir conftestd1 conftestd2
+     cat <<EOF > conftestd1/conftest.h
+#define DEFINED_IN_CONFTESTD1
+#include_next <conftest.h>
+#ifdef DEFINED_IN_CONFTESTD2
+int foo;
+#else
+#error "include_next doesn't work"
+#endif
+EOF
+     cat <<EOF > conftestd2/conftest.h
+#ifndef DEFINED_IN_CONFTESTD1
+#error "include_next test doesn't work"
+#endif
+#define DEFINED_IN_CONFTESTD2
+EOF
+     save_CPPFLAGS="$CPPFLAGS"
+     CPPFLAGS="$CPPFLAGS -Iconftestd1 -Iconftestd2"
+     AC_COMPILE_IFELSE([#include <conftest.h>],
+       [gl_cv_have_include_next=yes],
+       [gl_cv_have_include_next=no])
+     CPPFLAGS="$save_CPPFLAGS"
+     rm -rf conftestd1 conftestd2
+    ])
+  if test $gl_cv_have_include_next = yes; then
+
+    dnl FIXME: Remove HAVE_INCLUDE_NEXT and update everything that uses it
+    dnl to use @INCLUDE_NEXT@ instead.
+    AC_DEFINE([HAVE_INCLUDE_NEXT], 1,
+             [Define if your compiler supports the #include_next directive.])
+
+    INCLUDE_NEXT=include_next
+  else
+    INCLUDE_NEXT=include
+  fi
+  AC_SUBST([INCLUDE_NEXT])
+])
+
+# gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...)
+# ------------------------------------------
+# 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.
+# That way, a header file with the following line:
+#      #@INCLUDE_NEXT@ @NEXT_FOO_H@
+# behaves (after sed substitution) as if it contained
+#      #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".
+# Use `""', not `<>', so that the /// cannot be confused with a C99 comment.
+AC_DEFUN([gl_CHECK_NEXT_HEADERS],
+[
+  AC_REQUIRE([gl_INCLUDE_NEXT])
+  AC_CHECK_HEADERS_ONCE([$1])
+
+  AC_FOREACH([gl_HEADER_NAME], [$1],
+    [AS_VAR_PUSHDEF([gl_next_header],
+                   [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME])))
+     if test $gl_cv_have_include_next = yes; then
+       AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
+     else
+       AC_CACHE_CHECK(
+        [absolute name of <]m4_quote(m4_defn([gl_HEADER_NAME]))[>],
+        m4_quote(m4_defn([gl_next_header])),
+        [AS_VAR_PUSHDEF([gl_header_exists],
+                        [ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME])))
+         if test AS_VAR_GET(gl_header_exists) = yes; then
+           AC_LANG_CONFTEST(
+             [AC_LANG_SOURCE(
+                [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
+              )])
+           dnl eval is necessary to expand ac_cpp.
+           dnl Ultrix and Pyramid sh refuse to redirect output of eval,
+           dnl so use subshell.
+           AS_VAR_SET([gl_next_header],
+             ['"'`(eval "$ac_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])])
+     fi
+     AC_SUBST(
+       AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))),
+       [AS_VAR_GET([gl_next_header])])
+     AS_VAR_POPDEF([gl_next_header])])
+])