build: Split out core logic from libpng detection.

[liblbx.git] / m4 / libpng.m4

diff --git a/m4/libpng.m4 b/m4/libpng.m4
index da3bac90a0bb4bc2f175b43c75c0307636f2a14f..52db43ef22eea544eec69cb0321a520c2095c9db 100644 (file)
--- a/m4/libpng.m4
+++ b/m4/libpng.m4
@@ -4,104 +4,49 @@ dnl are permitted in any medium without royalty provided the copyright
 dnl notice and this notice are preserved.  This file is offered as-is,
 dnl without any warranty.
 
-dnl _LIBPNG_TRY_VERSION(min-version)
-AC_DEFUN([_LIBPNG_TRY_VERSION], [dnl
-shead='s/@<:@0-9@:>@@<:@0-9@:>@*/<<<&>>>/'
-sbody='s/.*<<<\(.*\)>>>.*/\1/;t'
-stail='s/.*/0/'
-png_min_major=`printf   '%s' '$1' | sed -e "$shead"1 -e "$sbody" -e "$stail"`
-png_min_minor=`printf   '%s' '$1' | sed -e "$shead"2 -e "$sbody" -e "$stail"`
-png_min_release=`printf '%s' '$1' | sed -e "$shead"3 -e "$sbody" -e "$stail"`
-png_min_build=`printf   '%s' '$1' | sed -e "$shead"4 -e "$sbody" -e "$stail"`
-png_min_status=`printf  '%s' '$1' | sed '
-       t
-       s/.*alpha.*/PNG_LIBPNG_BUILD_ALPHA/
-       t
-       s/.*beta.*/PNG_LIBPNG_BUILD_BETA/
-       t
-       s/.*rc.*/PNG_LIBPNG_BUILD_RC/
-       t
-       s/.*/PNG_LIBPNG_BUILD_STABLE/
-'`
-
-AC_CACHE_CHECK([for libpng version at least $1],
-       [libpng_cv_sufficient_ver],
-       [AC_LINK_IFELSE([AC_LANG_PROGRAM([dnl
+dnl _DX_LIBPNG_TEST_PROGRAM(major, minor, release)
+AC_DEFUN([_DX_LIBPNG_TEST_PROGRAM], [AC_LANG_PROGRAM([dnl
 #include <png.h>
-#if PNG_LIBPNG_VER_MAJOR < $png_min_major
+ifelse([$1], [], [], [dnl
+#if PNG_LIBPNG_VER_MAJOR < $1
 #  error Invalid libpng major version
-#elif PNG_LIBPNG_VER_MAJOR == $png_min_major
-#  if PNG_LIBPNG_VER_MINOR < $png_min_minor
+ifelse([$2], [], [], [dnl
+#elif PNG_LIBPNG_VER_MAJOR == $1
+#  if PNG_LIBPNG_VER_MINOR < $2
 #    error Invalid libpng minor version
-#  elif PNG_LIBPNG_VER_MINOR == $png_min_minor
-#    if PNG_LIBPNG_VER_RELEASE < $png_min_release
+ifelse([$3], [], [], [dnl
+#  elif PNG_LIBPNG_VER_MINOR == $2
+#    if PNG_LIBPNG_VER_RELEASE < $3
 #      error Invalid libpng release
-#    elif PNG_LIBPNG_VER_RELEASE == $png_min_release
-#      if PNG_LIBPNG_BUILD_BASE_TYPE < $png_min_status
-#        error Invalid libpng release status
-#      elif PNG_LIBPNG_BUILD_BASE_TYPE == $png_min_status
-#        if PNG_LIBPNG_VER_BUILD < $png_min_build
-#          error Invalid libpng build
-#        endif
-#      endif
 #    endif
+])dnl
 #  endif
+])dnl
 #endif
+])dnl
 ], [dnl
 png_structp png  = png_create_read_struct("", 0, 0, 0);
 png_infop   info = png_create_info_struct(png);
-])], [libpng_cv_sufficient_ver=yes], [libpng_cv_sufficient_ver=no])])
-])
-
-dnl CHECK_LIBPNG([min-version], [action-if-ok], [action-if-fail])
-AC_DEFUN([CHECK_LIBPNG],
-[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
-AC_ARG_VAR([LIBPNG_CFLAGS], [C compiler flags for libpng])dnl
-AC_ARG_VAR([LIBPNG_LIBS],   [linker flags for libpng])dnl
-
-if test x"$PKG_CONFIG" != x; then
-       AC_MSG_CHECKING([pkg-config database for libpng])
-       _PKG_CONFIG([libpng_cflags], [cflags], [libpng])
-       _PKG_CONFIG([libpng_libs],   [libs],   [libpng])
-       if test x$pkg_failed = xyes; then
-               errors=`$PKG_CONFIG --errors-to-stdout --print-errors libpng`
-               echo "$errors" >&AS_MESSAGE_LOG_FD
-               AC_MSG_RESULT([no])
-       else
-               if test x"$LIBPNG_CFLAGS" = x; then
-                       LIBPNG_CFLAGS=$pkg_cv_libpng_cflags
-               fi
-               if test x"$LIBPNG_LIBS" = x; then
-                       LIBPNG_LIBS=$pkg_cv_libpng_libs
-               fi
-
-               AC_MSG_RESULT([yes])
-       fi
-fi
-
-if test x"$LIBPNG_LIBS" = x; then
-       LIBPNG_LIBS=-lpng
-fi
-
-AC_LANG_PUSH([C])
-old_cflags=$CFLAGS
-old_libs=$LIBS
-CFLAGS="$LIBPNG_CFLAGS $CFLAGS"
-LIBS="$LIBPNG_LIBS $LIBS"
-
-_LIBPNG_TRY_VERSION(ifelse([$1], [], [1.0], [$1]))
-
-CFLAGS=$old_cflags
-LIBS=$old_libs
-AC_LANG_POP([C])
-
-if test x"$libpng_cv_sufficient_ver" = x"yes"; then
-       AC_SUBST([LIBPNG_CFLAGS])
-       AC_SUBST([LIBPNG_LIBS])
-       ifelse([$2], [], [true], [$2])
+])])
+
+dnl DX_CHECK_LIBPNG([min-version], [action-if-ok], [action-if-fail])
+AC_DEFUN([DX_CHECK_LIBPNG],
+[DX_PKG_CONFIG([libpng], [libpng], [libpng])
+
+DX_CHECK_LIB([libpng],
+       [for libpng[]ifelse([$1], [], [], [ version at least $1])],
+       [m4_apply([_DX_LIBPNG_TEST_PROGRAM], m4_split([$1], [\.]))], [dnl
+               [[$LIBPNG_CFLAGS], [$LIBPNG_LIBS]],
+               [[$pkg_cv_libpng_cflags], [$pkg_cv_libpng_libs],
+                       [test ! x"$pkg_failed" = x"yes"]],
+               [[], [-lpng]],
+               ])
+
+if test x"$dx_cv_libpng_found" = x"yes"; then
+       ifelse([$2], [], [:], [$2])
 else
        ifelse([$3], [], [AC_MSG_FAILURE([dnl
-libpng version >= ifelse([$1], [], [1.0], [$1]) is required.  The latest
+libpng[]ifelse([$1], [], [], [ version at least $1]) is required.  The latest
 version can be obtained from http://libpng.org/pub/png/libpng.html.
 
 If libpng is installed but was not found by this configure script,