New module 'libunistring-optional'.

1 files changed, 87 insertions, 4 deletions

diff --git a/m4/libunistring.m4 b/m4/libunistring.m4
index 0faedb9476..7a10efec79 100644
--- a/m4/libunistring.m4
+++ b/m4/libunistring.m4
@@ -1,4 +1,4 @@
-# libunistring.m4 serial 5
+# libunistring.m4 serial 6
 dnl Copyright (C) 2009-2010 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,12 +7,48 @@ dnl with or without modifications, as long as this notice is preserved.
 dnl gl_LIBUNISTRING
 dnl Searches for an installed libunistring.
 dnl If found, it sets and AC_SUBSTs HAVE_LIBUNISTRING=yes and the LIBUNISTRING
-dnl and LTLIBUNISTRING variables and augments the CPPFLAGS variable, and
-dnl #defines HAVE_LIBUNISTRING to 1. Otherwise, it sets and AC_SUBSTs
-dnl HAVE_LIBUNISTRING=no and LIBUNISTRING and LTLIBUNISTRING to empty.
+dnl and LTLIBUNISTRING variables, sets the LIBUNISTRING_VERSION variable, and
+dnl augments the CPPFLAGS variable, and #defines HAVE_LIBUNISTRING to 1.
+dnl Otherwise, it sets and AC_SUBSTs HAVE_LIBUNISTRING=no and LIBUNISTRING and
+dnl LTLIBUNISTRING to empty.
 
 AC_DEFUN([gl_LIBUNISTRING],
 [
+  AC_BEFORE([$0], [gl_LIBUNISTRING_LIBSOURCE])
+  AC_BEFORE([$0], [gl_LIBUNISTRING_LIBHEADER])
+  AC_BEFORE([$0], [gl_LIBUNISTRING_LIB_PREPARE])
+
+  m4_ifdef([gl_LIBUNISTRING_OPTIONAL],
+    [
+      AC_MSG_CHECKING([whether included libunistring is requested])
+      AC_ARG_WITH([included-libunistring],
+        [  --with-included-libunistring  use the libunistring parts included here],
+        [gl_libunistring_force_included=$withval],
+        [gl_libunistring_force_included=no])
+      AC_MSG_RESULT([$gl_libunistring_force_included])
+      gl_libunistring_use_included="$gl_libunistring_force_included"
+      if test "$gl_libunistring_use_included" = yes; then
+        dnl Assume that libunistring is not installed until some other macro
+        dnl explicitly invokes gl_LIBUNISTRING_CORE.
+        if test -z "$HAVE_LIBUNISTRING"; then
+          HAVE_LIBUNISTRING=no
+        fi
+        LIBUNISTRING=
+        LTLIBUNISTRING=
+      else
+        gl_LIBUNISTRING_CORE
+        if test $HAVE_LIBUNISTRING = no; then
+          gl_libunistring_use_included=yes
+          LIBUNISTRING=
+          LTLIBUNISTRING=
+        fi
+      fi
+    ],
+    [gl_LIBUNISTRING_CORE])
+])
+
+AC_DEFUN([gl_LIBUNISTRING_CORE],
+[
   AC_REQUIRE([AM_ICONV])
   if test -n "$LIBICONV"; then
     dnl First, try to link without -liconv. libunistring often depends on
@@ -42,4 +78,51 @@ AC_DEFUN([gl_LIBUNISTRING],
       [#include <uniconv.h>], [u8_strconv_from_locale((char*)0);],
       [no, consider installing GNU libunistring])
   fi
+  if test $HAVE_LIBUNISTRING = yes; then
+    dnl Determine the installed version.
+    AC_CACHE_CHECK([for libunistring version], [gl_cv_libunistring_version],
+      [AC_COMPUTE_INT([gl_libunistring_hexversion],
+                      [_LIBUNISTRING_VERSION],
+                      [#include <unistring/version.h>])
+       dnl Versions <= 0.9.3 had a hexversion of 0x0009.
+       dnl Use other tests to distinguish them.
+       if test $gl_libunistring_hexversion = 9; then
+         dnl Version 0.9.2 introduced the header <unistring/cdefs.h>.
+         AC_TRY_COMPILE([#include <unistring/cdefs.h>], ,
+           [gl_cv_libunistring_version092=true],
+           [gl_cv_libunistring_version092=false]);
+         if $gl_cv_libunistring_version092; then
+           dnl Version 0.9.3 changed a comment in <unistr.h>.
+           gl_ABSOLUTE_HEADER_ONE([unistr.h])
+           if test -n "$gl_cv_absolute_unistr_h" \
+              && grep 'Copy no more than N units of SRC to DEST.  Return a pointer' $gl_cv_absolute_unistr_h > /dev/null; then
+             dnl Detected version 0.9.3.
+             gl_libunistring_hexversion=2307
+           else
+             dnl Detected version 0.9.2.
+             gl_libunistring_hexversion=2306
+           fi
+         else
+           dnl Version 0.9.1 introduced the type casing_suffix_context_t.
+           AC_TRY_COMPILE([#include <unicase.h>
+                           casing_suffix_context_t ct;], ,
+             [gl_cv_libunistring_version091=true],
+             [gl_cv_libunistring_version091=false])
+           if $gl_cv_libunistring_version091; then
+             dnl Detected version 0.9.1.
+             gl_libunistring_hexversion=2305
+           else
+             dnl Detected version 0.9.
+             gl_libunistring_hexversion=2304
+           fi
+         fi
+       fi
+       dnl Transform into the usual major.minor.subminor notation.
+       gl_libunistring_major=`expr $gl_libunistring_hexversion / 65536`
+       gl_libunistring_minor=`expr $gl_libunistring_hexversion / 256 % 256`
+       gl_libunistring_subminor=`expr $gl_libunistring_hexversion % 256`
+       gl_cv_libunistring_version="$gl_libunistring_major.$gl_libunistring_minor.$gl_libunistring_subminor"
+      ])
+    LIBUNISTRING_VERSION="$gl_cv_libunistring_version"
+  fi
 ])