CMake: generate SkUserConfig.h

cmake/CMakeLists.txt

 # Boilerplate.
 cmake_minimum_required (VERSION 3.1)   # First version with CMAKE_CXX_STANDARD.
 project (skimake)
 set (CMAKE_CXX_STANDARD 11)
 
 # Default to Release mode.  We're mainly targeting Skia users, not Skia developers.
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE Release)
 endif ()
 
+set (userconfig_directory ${CMAKE_BINARY_DIR}/include)
+set (userconfig_path ${userconfig_directory}/SkUserConfig.h)
+file(WRITE ${userconfig_path} "// SkUserConfig generated by CMake.\n")
+if (CMAKE_BUILD_TYPE STREQUAL Release)
+  file(APPEND ${userconfig_path} "#define SK_RELEASE\n")
+  file(APPEND ${userconfig_path} "#undef SK_DEBUG\n")
+else ()
+  file(APPEND ${userconfig_path} "#define SK_DEBUG\n")
+  file(APPEND ${userconfig_path} "#undef SK_RELEASE\n")
+endif ()
+
 # To first approximation, the Skia library comprises all .cpp files under src/.
 file (GLOB_RECURSE srcs ../src/*.cpp)
 
 function (find_include_dirs out)
     file (GLOB_RECURSE headers ${ARGN})
     foreach (path ${headers})
         get_filename_component (dir ${path} PATH)
         list (APPEND include_dirs ${dir})
     endforeach()
     list (REMOVE_DUPLICATES include_dirs)
     set (${out} ${include_dirs} PARENT_SCOPE)
 endfunction()
 
 # We need src/ directories and include/private on our path when building Skia.
 # Users should be able to use Skia with only include/ directories that are not include/private.
 find_include_dirs(private_includes ../src/*.h ../include/private/*.h)
 find_include_dirs(public_includes ../include/*.h)
 list (REMOVE_ITEM public_includes ${private_includes})  # Easiest way to exclude private.
+file (GLOB default_include_config "../include/config")
+list (REMOVE_ITEM public_includes ${default_include_config})
+list (APPEND public_includes ${userconfig_directory})
 
 # These guys are third_party but provided by a Skia checkout.
 list (APPEND srcs             ../third_party/etc1/etc1.cpp ../third_party/ktx/ktx.cpp)
 list (APPEND private_includes ../third_party/etc1          ../third_party/ktx)
 
 function (remove_srcs)
     file (GLOB_RECURSE to_remove ${ARGN})
     list (REMOVE_ITEM srcs ${to_remove})
     set (srcs ${srcs} PARENT_SCOPE)
 endfunction()
@@ skipping 155 matching lines @@
 
 if (APPLE)
     find_library(APPLICATION_SERVICES_FRAMEWORK ApplicationServices REQUIRED)
     list (APPEND libs ${APPLICATION_SERVICES_FRAMEWORK})
 endif()
 
 if (OSMESA_LIBRARIES AND OSMESA_INCLUDE_DIRS)
     list (APPEND libs             ${OSMESA_LIBRARIES})
     list (APPEND private_includes ${OSMESA_INCLUDE_DIRS})
     list (APPEND public_defines   "-DSK_MESA=1")
+    file (APPEND ${userconfig_path} "#define SK_MESA 1\n")
 else()
     remove_srcs(../src/gpu/gl/mesa/*)
 endif()
 
 if (WIN32)
     list (APPEND libs FontSub.lib Usp10.lib)
 endif()
 
 find_package(OpenGL REQUIRED)
 list (APPEND libs  ${OPENGL_LIBRARIES})
@@ skipping 27 matching lines @@
     VISIBILITY_INLINES_HIDDEN true)
 
 # Experimental C API install:
 file(GLOB c_headers "../include/c/*.h")
 install(FILES ${c_headers} DESTINATION include)
 install(TARGETS skia DESTINATION lib)
 
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})