CMake: generate skia.h and skia_{compile|link}_arguments.txt

cmake/CMakeLists.txt

Index: cmake/CMakeLists.txt
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index f87b5f836b276868974cf1060ee525f9ebe8ccc6..5f0049bdad609443a0267329c49a88c8b6eda028 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -8,17 +8,6 @@ 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)
 
@@ -39,6 +28,7 @@ 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})
+set (userconfig_directory ${CMAKE_BINARY_DIR}/include)
 list (APPEND public_includes ${userconfig_directory})
 
 # These guys are third_party but provided by a Skia checkout.
@@ -215,7 +205,6 @@ 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()
@@ -260,6 +249,59 @@ file(GLOB c_headers "../include/c/*.h")
 install(FILES ${c_headers} DESTINATION include)
 install(TARGETS skia DESTINATION lib)
 
+# SkUserConfig.h
+set (userconfig_path ${userconfig_directory}/SkUserConfig.h)
+file(WRITE ${userconfig_path} "// SkUserConfig generated by CMake.\n")
+file(APPEND ${userconfig_path} "#ifndef SkUserConfig_DEFINED\n")
+file(APPEND ${userconfig_path} "#define SkUserConfig_DEFINED\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 ()
+if (OSMESA_LIBRARIES AND OSMESA_INCLUDE_DIRS)
+  file (APPEND ${userconfig_path} "#define SK_MESA 1\n")
+endif()
+file(APPEND ${userconfig_path} "#endif  // SkUserConfig_DEFINED\n")
+
+# skia_link_arguments.txt
+set (link_arguments ${CMAKE_BINARY_DIR}/skia_link_arguments.txt)
+file (WRITE ${link_arguments} "-L${CMAKE_BINARY_DIR}\n")
+file (APPEND ${link_arguments} "-lskia\n")
+file (APPEND ${link_arguments} "-Wl,-rpath,${CMAKE_BINARY_DIR}\n")
+
+# skia_compile_arguments.txt
+set (compile_arguments ${CMAKE_BINARY_DIR}/skia_compile_arguments.txt)
+file (WRITE ${compile_arguments} "--std=c++11\n")
+foreach (include ${public_includes})
+  get_filename_component (abs_include ${include} ABSOLUTE)
+  file (APPEND ${compile_arguments} "-I${abs_include}\n")
+endforeach()
+
+# cmake .
+# cmake --build . --target skia
+# c++ -c @skia_compile_arguments.txt example.cpp
+# c++ example.o @skia_link_arguments.txt
+
+# skia.h
+set (skia_h_path ${userconfig_directory}/skia.h)
+file (WRITE ${skia_h_path} "// skia.h generated by CMake.\n")
+file(APPEND ${skia_h_path} "#ifndef skia_DEFINED\n")
+file(APPEND ${skia_h_path} "#define skia_DEFINED\n")
+foreach (include ${public_includes})
+  if (NOT include STREQUAL userconfig_directory)
+    file (APPEND ${skia_h_path} "\n")
+    file (GLOB all_public_headers ${include}/*.h)
+    foreach (public_header ${all_public_headers})
+      get_filename_component (filename_component ${public_header} NAME)
+      file (APPEND ${skia_h_path} "#include \"${filename_component}\"\n")
+    endforeach()
+  endif()
+endforeach()
+file(APPEND ${skia_h_path} "\n#endif  // skia_DEFINED\n")
+
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})