Add support for always-builtin features in the build system

Like image surface and user fonts.

build/configure.ac.enable

@@ -21,9 +21,10 @@ dnl		"font" for font backends
 dnl		"functions" for set of functions
 dnl		"" for private configurations
 dnl	DEFAULT is the default state of the feature:
-dnl		"no" for experimental backends, eg. your favorite new backend
-dnl		"yes" for mandatory backends, eg. png
-dnl		"auto" for other supported backends, eg. xlib
+dnl		"no" for experimental features, eg. your favorite new backend
+dnl		"yes" for recommended features, eg. png functions
+dnl		"auto" for other supported features, eg. xlib surface backend
+dnl		"always" for mandatory features (can't be disabled), eg. image surface backend
 dnl	COMMANDS are run to check whether the feature can be enabled.  Their
 dnl		result may be cached, so user should not count on them being run.
 dnl		They should set use_$(ID) to something other than yes if the
@@ -56,13 +57,19 @@ AC_DEFUN([_CAIRO_ENABLE],
 		[no],,
 		[yes],,
 		[auto],,
+		[always],,
 		[m4_fatal([Invalid default value `]cr_feature_default[' for feature `]cr_feature['])]
 	)
 
-	AC_ARG_ENABLE(cr_feature_arg,
-		      AS_HELP_STRING([--enable-]cr_feature_arg[=@<:@no/auto/yes@:>@],
-				     [Enable cairo's ]cr_feature_name[ feature @<:@default=]cr_feature_default[@:>@]),
-		      enable_$1=$enableval, enable_$1=cr_feature_default)
+	m4_if(cr_feature_default, [always],
+	[
+		enable_$1=yes
+	],[
+		AC_ARG_ENABLE(cr_feature_arg,
+			      AS_HELP_STRING([--enable-]cr_feature_arg[=@<:@no/auto/yes@:>@],
+					     [Enable cairo's ]cr_feature_name[ feature @<:@default=]cr_feature_default[@:>@]),
+			      enable_$1=$enableval, enable_$1=cr_feature_default)
+	])
 	case $enable_$1 in
 	no)
 		use_$1="no (disabled, use --enable-cr_feature_arg to enable)"
@@ -120,7 +127,12 @@ AC_DEFUN([_CAIRO_ENABLE],
 
 		AS_IF([test "x$enable_$1" = "xyes" -a "x$use_$1" != xyes],
 		[
-			AC_MSG_ERROR([requested ]cr_feature_name[ feature could not be enabled])
+			AC_MSG_ERROR(
+				m4_case(cr_feature_default,
+					[always],	[mandatory],
+					[yes],		[recommended],
+					,		[requested]
+				) cr_feature_name[ feature could not be enabled])
 		])
 	;;
 	*)
@@ -236,9 +248,10 @@ dnl
 dnl	cr_feature expands to the feature id, eg "ft"
 dnl	cr_feature_name	expands to the human-readable name of the feature, eg. "FreeType font"
 dnl	cr_feature_default expands to the default state of the feature:
-dnl		"no" for experimental backends, eg. your favorite new backend
-dnl		"yes" for mandatory backends, eg. png
-dnl		"auto" for other supported backends, eg. xlib
+dnl		"no" for experimental features, eg. your favorite new backend
+dnl		"yes" for recommended features, eg. png functions
+dnl		"auto" for other supported features, eg. xlib surface backend
+dnl		"always" for mandatory features (can't be disabled), eg. image surface backend
 dnl	cr_what expands to the type of feature:
 dnl		"surface" for surface backends
 dnl		"font" for font backends
@@ -487,8 +500,8 @@ CAIRO_FEATURE_VARS_REGISTER([REQUIRES BASE])
 CAIRO_FEATURE_VARS_REGISTER([CFLAGS NONPKGCONFIG_CFLAGS])
 CAIRO_FEATURE_VARS_REGISTER([LIBS NONPKGCONFIG_LIBS], [$LIBS])
 
-dnl Generate .pc files for enabled public features
-CAIRO_FEATURE_HOOK_REGISTER(yes,*,!,
+dnl Generate .pc files for enabled non-builtin public features
+CAIRO_FEATURE_HOOK_REGISTER(yes,!always,!,
 [
 	AC_CONFIG_FILES(src/cr_feature_pc:src/cairo-features.pc.in,
 	[
@@ -510,8 +523,8 @@ CAIRO_FEATURE_HOOK_REGISTER(yes,*,!,
 	])
 ])
 
-dnl Generate -uninstalled.pc files for enabled public features
-CAIRO_FEATURE_HOOK_REGISTER(yes,*,!,
+dnl Generate -uninstalled.pc files for enabled non-builtin public features
+CAIRO_FEATURE_HOOK_REGISTER(yes,!always,!,
 [
 	AC_CONFIG_FILES(cr_feature_uninstalled_pc:src/cairo-features-uninstalled.pc.in,
 	[

configure.ac

@@ -57,7 +57,7 @@ CAIRO_ENABLE_SURFACE_BACKEND(xlib_xrender, Xlib Xrender, auto, [
 		       CPPFLAGS="$CPPFLAGS $xlib_CFLAGS $xlib_NONPKGCONFIG_CFLAGS"
 		       AC_CHECK_HEADER(X11/extensions/Xrender.h,
 				       [xlib_xrender_NONPKGCONFIG_LIBS="-lXrender"],
-				       [use_xlib_xrender="no (requires Xrender http://freedesktop.org/Software/xlibs)"])
+				       [use_xlib_xrender="no (requires $xlib_xrender_REQUIRES http://freedesktop.org/Software/xlibs)"])
 		       CPPFLAGS=$old_CPPFLAGS
 		      ])
   fi
@@ -68,17 +68,17 @@ dnl ===========================================================================
 CAIRO_ENABLE_SURFACE_BACKEND(xcb, XCB, no, [
   xcb_REQUIRES="xcb >= 0.9.92 xcb-render >= 0.9.92 xcb-renderutil"
   PKG_CHECK_MODULES(xcb, $xcb_REQUIRES, , [AC_MSG_RESULT(no)
-  use_xcb="no (requires XCB http://xcb.freedesktop.org)"])
+  use_xcb="no (requires $xcb_REQUIRES http://xcb.freedesktop.org)"])
 ])
 
 dnl ===========================================================================
 
 CAIRO_ENABLE_SURFACE_BACKEND(quartz, Quartz, auto, [
   dnl There is no pkgconfig for quartz; lets do a header check
-  AC_CHECK_HEADER(ApplicationServices/ApplicationServices.h, , [use_quartz="no (ApplicationServices framework not found)"])
+  AC_CHECK_HEADER(ApplicationServices/ApplicationServices.h, , [use_quartz="no (requires ApplicationServices framework)"])
   if test "x$use_quartz" != "xyes" ; then
     dnl check for CoreGraphics as a separate framework
-    AC_CHECK_HEADER(CoreGraphics/CoreGraphics.h, , [use_quartz="no (CoreGraphics framework not found)"])
+    AC_CHECK_HEADER(CoreGraphics/CoreGraphics.h, , [use_quartz="no (requires CoreGraphics framework)"])
     quartz_LIBS="-Xlinker -framework -Xlinker CoreGraphics"
   else
     quartz_LIBS="-Xlinker -framework -Xlinker ApplicationServices"
@@ -180,7 +180,7 @@ GLITZ_MIN_VERSION=0.5.1
 CAIRO_ENABLE_SURFACE_BACKEND(glitz, glitz, no, [
   glitz_REQUIRES="glitz >= $GLITZ_MIN_VERSION"
   PKG_CHECK_MODULES(glitz, $glitz_REQUIRES, , [AC_MSG_RESULT(no)
-  use_glitz="no (requires glitz http://freedesktop.org/Software/glitz)"])
+  use_glitz="no (requires $glitz_REQUIRES http://freedesktop.org/Software/glitz)"])
 ])
 
 if test "x$use_glitz" = "xyes";then
@@ -217,7 +217,7 @@ dnl ===========================================================================
 CAIRO_ENABLE_SURFACE_BACKEND(directfb, directfb, no, [
   directfb_REQUIRES=directfb
   PKG_CHECK_MODULES(directfb, $directfb_REQUIRES, , AC_MSG_RESULT(no)
-		    [use_directfb="no (requires directfb http://www.directfb.org)"])
+		    [use_directfb="no (requires $directfb_REQUIRES http://www.directfb.org)"])
 ])
 
 dnl ===========================================================================
@@ -245,7 +245,7 @@ FREETYPE_MIN_VERSION=9.7.3
 CAIRO_ENABLE_FONT_BACKEND(ft, FreeType, auto, [
   ft_REQUIRES="fontconfig"
   PKG_CHECK_MODULES(FONTCONFIG, $ft_REQUIRES,,
-		    [AC_MSG_RESULT(no); use_ft="no (requires fontconfig)"])
+		    [AC_MSG_RESULT(no); use_ft="no (requires $ft_REQUIRES)"])
 
   if test "x$use_ft" = "xyes"; then
 
@@ -414,15 +414,15 @@ CAIRO_ENABLE(test_surfaces, test surfaces, no)
 
 dnl ===========================================================================
 
-PIXMAN_VERSION="0.11.2"
-PIXMAN_REQUIRES="pixman-1 >= $PIXMAN_VERSION"
-PKG_CHECK_MODULES(pixman, $PIXMAN_REQUIRES, ,
-	[AC_MSG_ERROR([pixman >= $PIXMAN_VERSION is required
-(http://cairographics.org/releases/)])])
+CAIRO_ENABLE_SURFACE_BACKEND(image, image, always, [
+  pixman_REQUIRES="pixman-1 >= 0.11.2"
+  PKG_CHECK_MODULES(pixman, $pixman_REQUIRES, , [AC_MSG_RESULT(no)
+  use_image="no (requires $pixman_REQUIRES http://cairographics.org/releases/)"])
+])
 
-CAIRO_REQUIRES="$PIXMAN_REQUIRES $CAIRO_REQUIRES"
-CAIRO_CFLAGS="$pixman_CFLAGS $CAIRO_CFLAGS"
-CAIRO_LIBS="$pixman_LIBS $CAIRO_LIBS"
+dnl ===========================================================================
+
+CAIRO_ENABLE_FONT_BACKEND(user, user, always)
 
 dnl ===========================================================================
 dnl Build the external converter if we have any of the test backends

doc/public/cairo-sections.txt

@@ -34,6 +34,7 @@ cairo_quartz_font_face_create_for_atsu_font_id
 <SECTION>
 <FILE>cairo-user-fonts</FILE>
 <TITLE>user-font</TITLE>
+CAIRO_HAS_USER_FONT
 cairo_user_scaled_font_init_func_t
 cairo_user_scaled_font_render_glyph_func_t
 cairo_user_scaled_font_text_to_glyphs_func_t
@@ -52,6 +53,7 @@ cairo_user_font_face_get_text_to_glyphs_func
 <SECTION>
 <FILE>cairo-image</FILE>
 <TITLE>image-surface</TITLE>
+CAIRO_HAS_IMAGE_SURFACE
 cairo_format_t
 cairo_format_stride_for_width
 cairo_image_surface_create

doc/public/tmpl/cairo-image.sgml

@@ -21,6 +21,17 @@ image formats are those defined in #cairo_format_t.
 <!-- ##### SECTION Stability_Level ##### -->
 
 
+<!-- ##### MACRO CAIRO_HAS_IMAGE_SURFACE ##### -->
+<para>
+Defined if the image surface backend is available.
+The image surface backend is always built in.
+This macro was added for completeness in cairo 1.8.
+</para>
+
+@Since: 1.8
+
+
+
 <!-- ##### ENUM cairo_format_t ##### -->
 <para>
 

doc/public/tmpl/cairo-user-fonts.sgml

@@ -22,6 +22,18 @@ other application to draw "funky" fonts.
 <!-- ##### SECTION Stability_Level ##### -->
 
 
+<!-- ##### MACRO CAIRO_HAS_USER_FONT ##### -->
+<para>
+Defined if the user font backend is available.
+This macro can be used to conditionally compile backend-specific code.
+The user font backend is always built in versions of cairo that support
+this feature (1.8 and later).
+</para>
+
+@Since: 1.8
+
+
+
 <!-- ##### USER_FUNCTION cairo_user_scaled_font_init_func_t ##### -->
 <para>