have-lib: more tweaks for GNOME libraries

[Bruno Haible]

GNOME libraries often have their include files in subdirectories of
$prefix/include. The default INC${NAME} flags set by AC_LIB_LINKFLAGS
don't help in this case. The invoking macro needs to know the $prefix
so it can synthesize the right INC${NAME} flags itself. (If $prefix
is /usr or /usr/local, INC${NAME} might come out empty, giving no
information about $prefix.)

2006-11-12  Bruno Haible  <address@hidden>

        * m4/lib-link.m4 (AC_LIB_LINKFLAGS, AC_LIB_HAVE_LINKFLAGS,
        AC_LIB_LINKFLAGS_BODY): Also set a LIB${NAME}_PREFIX variable. Needed
        for GNOME libraries, for which the include files are installed in
        subdirectories of $prefix/include.

*** m4/lib-link.m4      Thu Oct 26 00:06:11 2006
--- m4/lib-link.m4      Sun Nov 12 17:25:29 2006
***************
*** 1,4 ****
! # lib-link.m4 serial 9 (gettext-0.16)
  dnl Copyright (C) 2001-2006 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # lib-link.m4 serial 10 (gettext-0.16.1)
  dnl Copyright (C) 2001-2006 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
***************
*** 12,17 ****
--- 12,19 ----
  dnl the libraries corresponding to explicit and implicit dependencies.
  dnl Sets and AC_SUBSTs the LIB${NAME} and LTLIB${NAME} variables and
  dnl augments the CPPFLAGS variable.
+ dnl Sets and AC_SUBSTs the LIB${NAME}_PREFIX variable to nonempty if libname
+ dnl was found in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
  AC_DEFUN([AC_LIB_LINKFLAGS],
  [
    AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
***************
*** 24,36 ****
--- 26,41 ----
      ac_cv_lib[]Name[]_libs="$LIB[]NAME"
      ac_cv_lib[]Name[]_ltlibs="$LTLIB[]NAME"
      ac_cv_lib[]Name[]_cppflags="$INC[]NAME"
+     ac_cv_lib[]Name[]_prefix="$LIB[]NAME[]_PREFIX"
    ])
    LIB[]NAME="$ac_cv_lib[]Name[]_libs"
    LTLIB[]NAME="$ac_cv_lib[]Name[]_ltlibs"
    INC[]NAME="$ac_cv_lib[]Name[]_cppflags"
+   LIB[]NAME[]_PREFIX="$ac_cv_lib[]Name[]_prefix"
    AC_LIB_APPENDTOVAR([CPPFLAGS], [$INC]NAME)
    AC_SUBST([LIB]NAME)
    AC_SUBST([LTLIB]NAME)
+   AC_SUBST([LIB]NAME[_PREFIX])
    dnl Also set HAVE_LIB[]NAME so that AC_LIB_HAVE_LINKFLAGS can reuse the
    dnl results of this search when this library appears as a dependency.
    HAVE_LIB[]NAME=yes
***************
*** 46,51 ****
--- 51,58 ----
  dnl LTLIB${NAME} variables and augments the CPPFLAGS variable, and
  dnl #defines HAVE_LIB${NAME} to 1. Otherwise, it sets and AC_SUBSTs
  dnl HAVE_LIB${NAME}=no and LIB${NAME} and LTLIB${NAME} to empty.
+ dnl Sets and AC_SUBSTs the LIB${NAME}_PREFIX variable to nonempty if libname
+ dnl was found in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
  AC_DEFUN([AC_LIB_HAVE_LINKFLAGS],
  [
    AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
***************
*** 82,91 ****
--- 89,100 ----
      CPPFLAGS="$ac_save_CPPFLAGS"
      LIB[]NAME=
      LTLIB[]NAME=
+     LIB[]NAME[]_PREFIX=
    fi
    AC_SUBST([HAVE_LIB]NAME)
    AC_SUBST([LIB]NAME)
    AC_SUBST([LTLIB]NAME)
+   AC_SUBST([LIB]NAME[_PREFIX])
    undefine([Name])
    undefine([NAME])
  ])
***************
*** 124,129 ****
--- 133,140 ----
  dnl AC_LIB_LINKFLAGS_BODY(name [, dependencies]) searches for libname and
  dnl the libraries corresponding to explicit and implicit dependencies.
  dnl Sets the LIB${NAME}, LTLIB${NAME} and INC${NAME} variables.
+ dnl Also, sets the LIB${NAME}_PREFIX variable to nonempty if libname was found
+ dnl in ${LIB${NAME}_PREFIX}/$acl_libdirstem.
  AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
  [
    AC_REQUIRE([AC_LIB_PREPARE_MULTILIB])
***************
*** 158,163 ****
--- 169,175 ----
    LIB[]NAME=
    LTLIB[]NAME=
    INC[]NAME=
+   LIB[]NAME[]_PREFIX=
    rpathdirs=
    ltrpathdirs=
    names_already_handled=
***************
*** 351,356 ****
--- 363,369 ----
              case "$found_dir" in
                */$acl_libdirstem | */$acl_libdirstem/)
                  basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e 
"s,/$acl_libdirstem/"'*$,,'`
+                 LIB[]NAME[]_PREFIX="$basedir"
                  additional_includedir="$basedir/include"
                  ;;
              esac