Add new build option to enable WASM support.

Remove redundant Emscripten build option for pre-generating the system libraries because newer Emscripten version has fixed the cache lock issue.

CMake/Modules/UrhoCommon.cmake

@@ -297,7 +297,7 @@ if (EMSCRIPTEN)     # CMAKE_CROSSCOMPILING is always true for Emscripten
     set (EMSCRIPTEN_TOTAL_MEMORY ${EMSCRIPTEN_TOTAL_MEMORY} CACHE STRING "Specify the total size of memory to be used (Emscripten only); default to 128 MB, this option is ignored when EMSCRIPTEN_ALLOW_MEMORY_GROWTH=1")
     option (EMSCRIPTEN_SHARE_DATA "Enable sharing data file support (Emscripten only)")
     cmake_dependent_option (EMSCRIPTEN_SHARE_JS "Share the same JS file responsible to load the shared data file (Emscripten only and when enabling sharing data file support only)" FALSE EMSCRIPTEN_SHARE_DATA FALSE)
-    set (EMSCRIPTEN_SYSTEM_LIBS "" CACHE STRING "Specify a semicolon-separated list of additional system libraries that should be pre-built using embuilder.py, by default 'dlmalloc', 'libc', 'libcxxabi', and 'gl' will be pre-built, so they should not be listed again (Emscripten only); when using CMake CLI on Unix-like host systems, the semicolon may need to be properly escaped; see usage of embuilder.py to get the full list of supported system libraries")
+    cmake_dependent_option (EMSCRIPTEN_WASM "Enable Binaryen support to generate output to WASM (WebAssembly) format (Emscripten only)" FALSE "NOT EMSCRIPTEN_EMCC_VERSION VERSION_LESS 1.37.3" FALSE)
 endif ()
 # Constrain the build option values in cmake-gui, if applicable
 set_property (CACHE URHO3D_LIB_TYPE PROPERTY STRINGS STATIC SHARED)
@@ -634,7 +634,10 @@ else ()
                 else ()
                     set (MEMORY_LINKER_FLAGS "-s TOTAL_MEMORY=${EMSCRIPTEN_TOTAL_MEMORY}")
                 endif ()
-                set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${MEMORY_LINKER_FLAGS} -s NO_EXIT_RUNTIME=1 -s ERROR_ON_UNDEFINED_SYMBOLS=1")
+                if (EMSCRIPTEN_WASM)
+                    set (WASM "-s WASM=1")
+                endif ()
+                set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${MEMORY_LINKER_FLAGS} -s NO_EXIT_RUNTIME=1 -s ERROR_ON_UNDEFINED_SYMBOLS=1 ${WASM}")
                 set (CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -O3 -s AGGRESSIVE_VARIABLE_ELIMINATION=1")     # Remove variables to make the -O3 regalloc easier
                 set (CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} -g4")     # Preserve LLVM debug information, show line number debug comments, and generate source maps
                 if (URHO3D_TESTING)

CMakeLists.txt

@@ -158,6 +158,8 @@ elseif (ARM_ABI_FLAGS)
     string (REGEX REPLACE .*- - CPU_NAME "${CPU_NAME}")
     string (TOUPPER "${CPU_NAME}" CPU_NAME)
     set (CPACK_SYSTEM_NAME ${CPACK_SYSTEM_NAME}${CPU_NAME})
+elseif (EMSCRIPTEN_WASM)
+    set (CPACK_SYSTEM_NAME ${CPACK_SYSTEM_NAME}-WASM)
 endif ()
 if (NOT DEFINED ENV{RELEASE_TAG})
     set (CPACK_SYSTEM_NAME ${CPACK_SYSTEM_NAME}-snapshot)

Docs/GettingStarted.dox

@@ -166,8 +166,8 @@ A number of build options can be defined when invoking the build scripts or when
 |EMSCRIPTEN_TOTAL_MEMORY|*|Specify the total size of memory to be used (Emscripten only); default to 128 MB, this option is ignored when EMSCRIPTEN_ALLOW_MEMORY_GROWTH=1|
 |EMSCRIPTEN_SHARE_DATA|0|Enable sharing data file support (Emscripten only)|
 |EMSCRIPTEN_SHARE_JS  |0|Share the same JS file responsible to load the shared data file (Emscripten only and when enabling sharing data file support only)|
+|EMSCRIPTEN_WASM      |0|Enable Binaryen support to generate output to WASM (WebAssembly) format (Emscripten only)|
 |EMSCRIPTEN_EMRUN_BROWSER|firefox|Specify the particular browser to be spawned by emrun during testing (Emscripten only), use 'emrun --list_browsers' command to get the list of possible values|
-|EMSCRIPTEN_SYSTEM_LIBS|-|Specify a semicolon-separated list of additional system libraries that should be pre-built using embuilder.py, by default 'dlmalloc', 'libc', 'libcxxabi', and 'gl' will be pre-built, so they should not be listed again (Emscripten only); when using CMake CLI on Unix-like host systems, the semicolon may need to be properly escaped; see usage of embuilder.py to get the full list of supported system libraries|
 
 Note that the specified build option values are cached by CMake after the initial configuration step. The cached values will be used by CMake in the subsequent configuration. The same build options are not required to be specified again and again. But once a non-default build option value is being cached, it can only be reverted back to its default value by explicitly resetting it. That is, simply by not passing the corresponding build option would not revert it back to its default. One way to revert all the build options to their default values is by clearing the CMake cache by executing cmake_clean.bat or cmake_clean.sh with the location of the build tree as the first argument or by executing it in the build tree itself.
 

Rakefile

@@ -54,7 +54,7 @@ task :cmake do
   platform = 'native'
   build_options = ''
   # TODO: Need to find a way to automatically populate the array with all the Urho3D supported build options, at the moment it only contains those being used in CI
-  ['URHO3D_64BIT', 'URHO3D_LIB_TYPE', 'URHO3D_STATIC_RUNTIME', 'URHO3D_PCH', 'URHO3D_BINDINGS', 'URHO3D_OPENGL', 'URHO3D_D3D11', 'URHO3D_TESTING', 'URHO3D_TEST_TIMEOUT', 'URHO3D_UPDATE_SOURCE_TREE', 'URHO3D_TOOLS', 'URHO3D_DEPLOYMENT_TARGET', 'URHO3D_USE_LIB64_RPM', 'CMAKE_BUILD_TYPE', 'CMAKE_OSX_DEPLOYMENT_TARGET', 'IOS', 'IPHONEOS_DEPLOYMENT_TARGET', 'WIN32', 'MINGW', 'ANDROID', 'ANDROID_ABI', 'ANDROID_NATIVE_API_LEVEL', 'ANDROID_TOOLCHAIN_NAME', 'RPI', 'RPI_ABI', 'ARM', 'ARM_ABI_FLAGS', 'WEB', 'EMSCRIPTEN_SHARE_DATA', 'EMSCRIPTEN_SHARE_JS', 'EMSCRIPTEN_EMRUN_BROWSER'].each { |var|
+  ['URHO3D_64BIT', 'URHO3D_LIB_TYPE', 'URHO3D_STATIC_RUNTIME', 'URHO3D_PCH', 'URHO3D_BINDINGS', 'URHO3D_OPENGL', 'URHO3D_D3D11', 'URHO3D_TESTING', 'URHO3D_TEST_TIMEOUT', 'URHO3D_UPDATE_SOURCE_TREE', 'URHO3D_TOOLS', 'URHO3D_DEPLOYMENT_TARGET', 'URHO3D_USE_LIB64_RPM', 'CMAKE_BUILD_TYPE', 'CMAKE_OSX_DEPLOYMENT_TARGET', 'IOS', 'IPHONEOS_DEPLOYMENT_TARGET', 'WIN32', 'MINGW', 'ANDROID', 'ANDROID_ABI', 'ANDROID_NATIVE_API_LEVEL', 'ANDROID_TOOLCHAIN_NAME', 'RPI', 'RPI_ABI', 'ARM', 'ARM_ABI_FLAGS', 'WEB', 'EMSCRIPTEN_SHARE_DATA', 'EMSCRIPTEN_SHARE_JS', 'EMSCRIPTEN_WASM', 'EMSCRIPTEN_EMRUN_BROWSER'].each { |var|
     ARGV << "#{var}=\"#{ENV[var]}\"" if ENV[var] && !ARGV.find { |arg| /#{var}=/ =~ arg }
   }
   ARGV.each { |option|

Source/Urho3D/CMakeLists.txt

@@ -149,22 +149,12 @@ if (TARGET LuaJIT_universal)
         WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
     list (APPEND SYMBOLIC_SOURCES ${LuaJIT_universal_symbolic})
 endif ()
+set_source_files_properties (${SYMBOLIC_SOURCES} PROPERTIES SYMBOLIC TRUE)
 add_custom_command (OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/librevision.h
     COMMAND ${CMAKE_COMMAND} -DFILENAME=${CMAKE_CURRENT_BINARY_DIR}/librevision.h -P CMake/Modules/GetUrho3DRevision.cmake
     DEPENDS ${URHO3D_DEPS} ${CMAKE_SOURCE_DIR}/CMake/Modules/GetUrho3DRevision.cmake
     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
     COMMENT "Generating GIT revision number (tag + last commit SHA-1)")
-if (EMSCRIPTEN)
-    # Emscripten will attempt to generate system libraries in LLVM bitcode (libcxxabi, gl, libc, and dlmalloc) when linking for the very first time
-    # However, currently it does so without any locking resulting in potentially multiple same generation with build system that supports concurrent build processes such as ours
-    # Workaround that by calling Emscripten builder to generate all the required system libraries (in case it is the very first time) ahead of time in an orderly fashion
-    set (EMBUILDER_SYSTEM_LIBS_symbolic EMBUILDER_SYSTEM_LIBS_symbolic)
-    list (APPEND EMSCRIPTEN_SYSTEM_LIBS dlmalloc libc libcxxabi gl)
-    add_custom_command (OUTPUT ${EMBUILDER_SYSTEM_LIBS_symbolic}
-        COMMAND ${EMBUILDER} build ${EMSCRIPTEN_SYSTEM_LIBS})
-    list (APPEND SYMBOLIC_SOURCES ${EMBUILDER_SYSTEM_LIBS_symbolic})
-endif ()
-set_source_files_properties (${SYMBOLIC_SOURCES} PROPERTIES SYMBOLIC TRUE)
 
 # Use the AutoBinder tool to generate source files for binding script subsystems
 if (URHO3D_BINDINGS)