Disable skia from configure

Implement suggestion by Adrian Johnson to comment out skia in
configure.ac to avoid presenting it as an option to users.  This was
discussed on the Cairo mailing list in September 2017.

Skia is not API stable and is not available in packaged+versioned forms,
resulting in it being a continually moving target.  I.e. it's pretty
much always unusably out of date.  The last update to the skia backend
was in 2014, and had not been updated very regularly prior to that.

We'll simply disable it for now.  If no one complains by the next Cairo
snapshot release, we'll assume no one is needing it and will drop the
code entirely.

Meanwhile, if anyone does need it, it can be uncommented and used.

(The changes to the win32 build config appear to be automatically
generated as a result of disabling the feature in configure.  I'm
committing them to avoid confusion.)

6 files changed, 24 insertions, 52 deletions

diff --git a/boilerplate/Makefile.win32.features b/boilerplate/Makefile.win32.features
index abb198dee..178d5b650 100644
--- a/boilerplate/Makefile.win32.features
+++ b/boilerplate/Makefile.win32.features
@@ -151,18 +151,6 @@ enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_win32_font_cxx_sour
 enabled_cairo_boilerplate_sources += $(cairo_boilerplate_win32_font_sources)
 endif
 
-unsupported_cairo_boilerplate_headers += $(cairo_boilerplate_skia_headers)
-all_cairo_boilerplate_headers += $(cairo_boilerplate_skia_headers)
-all_cairo_boilerplate_private += $(cairo_boilerplate_skia_private)
-all_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_skia_cxx_sources)
-all_cairo_boilerplate_sources += $(cairo_boilerplate_skia_sources)
-ifeq ($(CAIRO_HAS_SKIA_SURFACE),1)
-enabled_cairo_boilerplate_headers += $(cairo_boilerplate_skia_headers)
-enabled_cairo_boilerplate_private += $(cairo_boilerplate_skia_private)
-enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_skia_cxx_sources)
-enabled_cairo_boilerplate_sources += $(cairo_boilerplate_skia_sources)
-endif
-
 unsupported_cairo_boilerplate_headers += $(cairo_boilerplate_os2_headers)
 all_cairo_boilerplate_headers += $(cairo_boilerplate_os2_headers)
 all_cairo_boilerplate_private += $(cairo_boilerplate_os2_private)
diff --git a/build/Makefile.win32.features b/build/Makefile.win32.features
index 7f62d975e..b15c4488f 100644
--- a/build/Makefile.win32.features
+++ b/build/Makefile.win32.features
@@ -11,7 +11,6 @@ CAIRO_HAS_QUARTZ_FONT=0
 CAIRO_HAS_QUARTZ_IMAGE_SURFACE=0
 CAIRO_HAS_WIN32_SURFACE=1
 CAIRO_HAS_WIN32_FONT=1
-CAIRO_HAS_SKIA_SURFACE=0
 CAIRO_HAS_OS2_SURFACE=0
 CAIRO_HAS_BEOS_SURFACE=0
 CAIRO_HAS_DRM_SURFACE=0
diff --git a/build/Makefile.win32.features-h b/build/Makefile.win32.features-h
index 2825f0c3c..5759b48a3 100644
--- a/build/Makefile.win32.features-h
+++ b/build/Makefile.win32.features-h
@@ -38,9 +38,6 @@ endif
 ifeq ($(CAIRO_HAS_WIN32_FONT),1)
 	@echo "#define CAIRO_HAS_WIN32_FONT 1" >> $(top_srcdir)/src/cairo-features.h
 endif
-ifeq ($(CAIRO_HAS_SKIA_SURFACE),1)
-	@echo "#define CAIRO_HAS_SKIA_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
-endif
 ifeq ($(CAIRO_HAS_OS2_SURFACE),1)
 	@echo "#define CAIRO_HAS_OS2_SURFACE 1" >> $(top_srcdir)/src/cairo-features.h
 endif
diff --git a/build/configure.ac.features b/build/configure.ac.features
index aa48652f2..e0a46069c 100644
--- a/build/configure.ac.features
+++ b/build/configure.ac.features
@@ -369,7 +369,7 @@ AC_DEFUN([CAIRO_REPORT],
 	echo "  Mime:          yes (always builtin)"
 	echo "  Tee:           $use_tee"
 	echo "  XML:           $use_xml"
-	echo "  Skia:          $use_skia"
+	#echo "  Skia:          $use_skia"
 	echo "  Xlib:          $use_xlib"
 	echo "  Xlib Xrender:  $use_xlib_xrender"
 	echo "  Qt:            $use_qt"
diff --git a/configure.ac b/configure.ac
index fb8b6b698..d78b2ed41 100644
--- a/configure.ac
+++ b/configure.ac
@@ -249,24 +249,28 @@ AM_CONDITIONAL(CAIRO_CAN_TEST_WIN32_PRINTING_SURFACE, test "x$test_win32_printin
 
 dnl ===========================================================================
 
-CAIRO_ENABLE_SURFACE_BACKEND(skia, Skia, no, [
-  AC_ARG_WITH([skia],
-	      [AS_HELP_STRING([--with-skia=/path/to/skia],
-			      [directory to find compiled skia sources])],
-	      [skia_DIR="$withval"],
-	      [skia_DIR="`pwd`/../skia"])
-  AC_ARG_WITH([skia-build-type],
-	      [AS_HELP_STRING([--with-skia-build-type=(Release|Debug)]
-			      [build of skia to link with, default is Release])],
-	      [skia_BUILD_TYPE="$withval"],
-	      [skia_BUILD_TYPE="Release"])
-  skia_NONPKGCONFIG_CFLAGS="-I$skia_DIR/include/config -I$skia_DIR/include/core -I$skia_DIR/include/effects"
-  if test "x$skia_BUILD_TYPE" = "xRelease"; then
-  	skia_NONPKGCONFIG_CFLAGS="-DSK_RELEASE -DSK_CAN_USE_FLOAT $skia_NONPKGCONFIG_CFLAGS"
-  fi
-  skia_NONPKGCONFIG_LIBS="-L$skia_DIR/out/$skia_BUILD_TYPE/lib.target/ -lskia -lstdc++"
-  AC_SUBST(skia_DIR)
-])
+dnl NOTE: We're temporarily disabiling this backend to see if anyone
+dnl       is actually using it.  If you are, please mention on the cairo
+dnl       mailing list.
+
+dnl CAIRO_ENABLE_SURFACE_BACKEND(skia, Skia, no, [
+dnl   AC_ARG_WITH([skia],
+dnl 	      [AS_HELP_STRING([--with-skia=/path/to/skia],
+dnl 			      [directory to find compiled skia sources])],
+dnl 	      [skia_DIR="$withval"],
+dnl 	      [skia_DIR="`pwd`/../skia"])
+dnl   AC_ARG_WITH([skia-build-type],
+dnl 	      [AS_HELP_STRING([--with-skia-build-type=(Release|Debug)]
+dnl 			      [build of skia to link with, default is Release])],
+dnl 	      [skia_BUILD_TYPE="$withval"],
+dnl 	      [skia_BUILD_TYPE="Release"])
+dnl   skia_NONPKGCONFIG_CFLAGS="-I$skia_DIR/include/config -I$skia_DIR/include/core -I$skia_DIR/include/effects"
+dnl   if test "x$skia_BUILD_TYPE" = "xRelease"; then
+dnl   	skia_NONPKGCONFIG_CFLAGS="-DSK_RELEASE -DSK_CAN_USE_FLOAT $skia_NONPKGCONFIG_CFLAGS"
+dnl   fi
+dnl   skia_NONPKGCONFIG_LIBS="-L$skia_DIR/out/$skia_BUILD_TYPE/lib.target/ -lskia -lstdc++"
+dnl   AC_SUBST(skia_DIR)
+dnl ])
 
 dnl ===========================================================================
 
@@ -869,7 +873,7 @@ dnl ===========================================================================
 
 dnl Extra stuff we need to do when building C++ code
 need_cxx="no"
-AS_IF([test "x$use_skia" = "xyes"], [need_cxx="yes"])
+dnl AS_IF([test "x$use_skia" = "xyes"], [need_cxx="yes"])
 AS_IF([test "x$use_qt" = "xyes"], [need_cxx="yes"])
 AS_IF([test "x$use_beos" = "xyes"], [need_cxx="yes"])
 
diff --git a/src/Makefile.win32.features b/src/Makefile.win32.features
index e8be9f748..377d6dd12 100644
--- a/src/Makefile.win32.features
+++ b/src/Makefile.win32.features
@@ -197,22 +197,6 @@ ifeq ($(CAIRO_HAS_WIN32_FONT),1)
 enabled_cairo_pkgconf += cairo-win32-font.pc
 endif
 
-unsupported_cairo_headers += $(cairo_skia_headers)
-all_cairo_headers += $(cairo_skia_headers)
-all_cairo_private += $(cairo_skia_private)
-all_cairo_cxx_sources += $(cairo_skia_cxx_sources)
-all_cairo_sources += $(cairo_skia_sources)
-ifeq ($(CAIRO_HAS_SKIA_SURFACE),1)
-enabled_cairo_headers += $(cairo_skia_headers)
-enabled_cairo_private += $(cairo_skia_private)
-enabled_cairo_cxx_sources += $(cairo_skia_cxx_sources)
-enabled_cairo_sources += $(cairo_skia_sources)
-endif
-all_cairo_pkgconf += cairo-skia.pc
-ifeq ($(CAIRO_HAS_SKIA_SURFACE),1)
-enabled_cairo_pkgconf += cairo-skia.pc
-endif
-
 unsupported_cairo_headers += $(cairo_os2_headers)
 all_cairo_headers += $(cairo_os2_headers)
 all_cairo_private += $(cairo_os2_private)