m4/libunistring.m4

   1 # libunistring.m4
   2 # serial 13
   3 dnl Copyright (C) 2009-2024 Free Software Foundation, Inc.
   4 dnl This file is free software; the Free Software Foundation
   5 dnl gives unlimited permission to copy and/or distribute it,
   6 dnl with or without modifications, as long as this notice is preserved.
   7 dnl This file is offered as-is, without any warranty.
   8
   9 AC_PREREQ([2.64])
  10
  11 dnl gl_LIBUNISTRING
  12 dnl Searches for an installed libunistring.
  13 dnl If found, it sets and AC_SUBSTs HAVE_LIBUNISTRING=yes and the LIBUNISTRING
  14 dnl and LTLIBUNISTRING variables, sets the LIBUNISTRING_VERSION variable, and
  15 dnl augments the CPPFLAGS variable, and #defines HAVE_LIBUNISTRING to 1.
  16 dnl Otherwise, it sets and AC_SUBSTs HAVE_LIBUNISTRING=no and LIBUNISTRING and
  17 dnl LTLIBUNISTRING to empty.
  18
  19 dnl Define gl_LIBUNISTRING using AC_DEFUN_ONCE, in order dnl to avoid warnings
  20 dnl like
  21 dnl "warning: AC_REQUIRE: `gl_LIBUNISTRING' was expanded before it was required".
  22 dnl This is tricky because of the way 'aclocal' is implemented:
  23 dnl - It requires defining an auxiliary macro whose name ends in AC_DEFUN.
  24 dnl   Otherwise aclocal's initial scan pass would miss the macro definition.
  25 dnl - It requires a line break inside the AC_DEFUN_ONCE and AC_DEFUN expansions.
  26 dnl   Otherwise aclocal would emit many "Use of uninitialized value $1"
  27 dnl   warnings.
  28 AC_DEFUN_ONCE([gl_LIBUNISTRING],
  29 [
  30   AC_BEFORE([$0], [gl_LIBUNISTRING_MODULE])
  31   AC_BEFORE([$0], [gl_LIBUNISTRING_LIBHEADER])
  32   AC_BEFORE([$0], [gl_LIBUNISTRING_LIB_PREPARE])
  33
  34   m4_ifdef([gl_LIBUNISTRING_OPTIONAL],
  35     [
  36       AC_MSG_CHECKING([whether included libunistring is requested])
  37       AC_ARG_WITH([included-libunistring],
  38         [  --with-included-libunistring  use the libunistring parts included here],
  39         [gl_libunistring_force_included=$withval],
  40         [gl_libunistring_force_included=no])
  41       AC_MSG_RESULT([$gl_libunistring_force_included])
  42       gl_libunistring_use_included="$gl_libunistring_force_included"
  43       if test "$gl_libunistring_use_included" = yes; then
  44         dnl Assume that libunistring is not installed until some other macro
  45         dnl explicitly invokes gl_LIBUNISTRING_CORE.
  46         if test -z "$HAVE_LIBUNISTRING"; then
  47           HAVE_LIBUNISTRING=no
  48         fi
  49         LIBUNISTRING=
  50         LTLIBUNISTRING=
  51       else
  52         gl_LIBUNISTRING_CORE
  53         if test $HAVE_LIBUNISTRING = no; then
  54           gl_libunistring_use_included=yes
  55           LIBUNISTRING=
  56           LTLIBUNISTRING=
  57         fi
  58       fi
  59     ],
  60     [gl_LIBUNISTRING_CORE])
  61 ])
  62
  63 AC_DEFUN([gl_LIBUNISTRING_CORE],
  64 [
  65   AC_REQUIRE([AM_ICONV])
  66   if test -n "$LIBICONV"; then
  67     dnl First, try to link without -liconv. libunistring often depends on
  68     dnl libiconv, but we don't know (and often don't need to know) where
  69     dnl libiconv is installed.
  70     AC_LIB_HAVE_LINKFLAGS([unistring], [],
  71       [#include <uniconv.h>], [u8_strconv_from_locale((char*)0);],
  72       [no, trying again together with libiconv])
  73     if test "$ac_cv_libunistring" != yes; then
  74       dnl Second try, with -liconv.
  75       dnl We have to erase the cached result of the first AC_LIB_HAVE_LINKFLAGS
  76       dnl invocation, otherwise the second one will not be run.
  77       unset ac_cv_libunistring
  78       glus_saved_LIBS="$LIBS"
  79       LIBS="$LIBS $LIBICONV"
  80       AC_LIB_HAVE_LINKFLAGS([unistring], [],
  81         [#include <uniconv.h>], [u8_strconv_from_locale((char*)0);],
  82         [no, consider installing GNU libunistring])
  83       if test -n "$LIBUNISTRING"; then
  84         LIBUNISTRING="$LIBUNISTRING $LIBICONV"
  85         LTLIBUNISTRING="$LTLIBUNISTRING $LTLIBICONV"
  86       fi
  87       LIBS="$glus_saved_LIBS"
  88     fi
  89   else
  90     AC_LIB_HAVE_LINKFLAGS([unistring], [],
  91       [#include <uniconv.h>], [u8_strconv_from_locale((char*)0);],
  92       [no, consider installing GNU libunistring])
  93   fi
  94   if test $HAVE_LIBUNISTRING = yes; then
  95     dnl Determine the installed version.
  96     AC_CACHE_CHECK([for libunistring version], [gl_cv_libunistring_version],
  97       [AC_COMPUTE_INT([gl_libunistring_hexversion],
  98                       [_LIBUNISTRING_VERSION],
  99                       [#include <unistring/version.h>])
 100        dnl Versions <= 0.9.3 had a hexversion of 0x0009.
 101        dnl Use other tests to distinguish them.
 102        if test $gl_libunistring_hexversion = 9; then
 103          dnl Version 0.9.2 introduced the header <unistring/cdefs.h>.
 104          AC_COMPILE_IFELSE(
 105            [AC_LANG_PROGRAM([[#include <unistring/cdefs.h>]], [[]])],
 106            [gl_cv_libunistring_version092=true],
 107            [gl_cv_libunistring_version092=false])
 108          if $gl_cv_libunistring_version092; then
 109            dnl Version 0.9.3 changed a comment in <unistr.h>.
 110            gl_ABSOLUTE_HEADER_ONE([unistr.h])
 111            if test -n "$gl_cv_absolute_unistr_h" \
 112               && grep 'Copy no more than N units of SRC to DEST.  Return a pointer' $gl_cv_absolute_unistr_h > /dev/null; then
 113              dnl Detected version 0.9.3.
 114              gl_libunistring_hexversion=2307
 115            else
 116              dnl Detected version 0.9.2.
 117              gl_libunistring_hexversion=2306
 118            fi
 119          else
 120            dnl Version 0.9.1 introduced the type casing_suffix_context_t.
 121            AC_COMPILE_IFELSE(
 122              [AC_LANG_PROGRAM(
 123                 [[#include <unicase.h>
 124                   casing_suffix_context_t ct;]],
 125                 [[]])],
 126              [gl_cv_libunistring_version091=true],
 127              [gl_cv_libunistring_version091=false])
 128            if $gl_cv_libunistring_version091; then
 129              dnl Detected version 0.9.1.
 130              gl_libunistring_hexversion=2305
 131            else
 132              dnl Detected version 0.9.
 133              gl_libunistring_hexversion=2304
 134            fi
 135          fi
 136        fi
 137        dnl Transform into the usual major.minor.subminor notation.
 138        gl_libunistring_major=`expr $gl_libunistring_hexversion / 65536`
 139        gl_libunistring_minor=`expr $gl_libunistring_hexversion / 256 % 256`
 140        gl_libunistring_subminor=`expr $gl_libunistring_hexversion % 256`
 141        gl_cv_libunistring_version="$gl_libunistring_major.$gl_libunistring_minor.$gl_libunistring_subminor"
 142       ])
 143     LIBUNISTRING_VERSION="$gl_cv_libunistring_version"
 144   fi
 145 ])