assimp/contrib/draco/cmake/draco_emscripten.cmake

233 lines
8.0 KiB
CMake

# Copyright 2021 The Draco Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
if(DRACO_CMAKE_DRACO_EMSCRIPTEN_CMAKE_)
return()
endif() # DRACO_CMAKE_DRACO_EMSCRIPTEN_CMAKE_
# Checks environment for Emscripten prerequisites.
macro(draco_check_emscripten_environment)
if(NOT PYTHONINTERP_FOUND)
message(
FATAL_ERROR
"Python required for Emscripten builds, but cmake cannot find it.")
endif()
if(NOT EXISTS "$ENV{EMSCRIPTEN}")
message(
FATAL_ERROR
"The EMSCRIPTEN environment variable must be set. See README.md.")
endif()
endmacro()
# Obtains the required Emscripten flags for Draco targets.
macro(draco_get_required_emscripten_flags)
set(em_FLAG_LIST_VAR_COMPILER)
set(em_FLAG_LIST_VAR_LINKER)
set(em_flags)
set(em_single_arg_opts FLAG_LIST_VAR_COMPILER FLAG_LIST_VAR_LINKER)
set(em_multi_arg_opts)
cmake_parse_arguments(em "${em_flags}" "${em_single_arg_opts}"
"${em_multi_arg_opts}" ${ARGN})
if(NOT em_FLAG_LIST_VAR_COMPILER)
message(
FATAL
"draco_get_required_emscripten_flags: FLAG_LIST_VAR_COMPILER required")
endif()
if(NOT em_FLAG_LIST_VAR_LINKER)
message(
FATAL
"draco_get_required_emscripten_flags: FLAG_LIST_VAR_LINKER required")
endif()
if(DRACO_JS_GLUE)
unset(required_flags)
# TODO(tomfinegan): Revisit splitting of compile/link flags for Emscripten,
# and drop -Wno-unused-command-line-argument. Emscripten complains about
# what are supposedly link-only flags sent with compile commands, but then
# proceeds to produce broken code if the warnings are heeded.
list(APPEND ${em_FLAG_LIST_VAR_COMPILER}
"-Wno-unused-command-line-argument")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-Wno-almost-asm")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "--memory-init-file" "0")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-fno-omit-frame-pointer")
# According to Emscripten the following flags are linker only, but sending
# these flags (en masse) to only the linker results in a broken Emscripten
# build with an empty DracoDecoderModule.
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sALLOW_MEMORY_GROWTH=1")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sMODULARIZE=1")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sFILESYSTEM=0")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER}
"-sEXPORTED_FUNCTIONS=[\"_free\",\"_malloc\"]")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sPRECISE_F32=1")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sNODEJS_CATCH_EXIT=0")
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sNODEJS_CATCH_REJECTION=0")
if(DRACO_FAST)
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "--llvm-lto" "1")
endif()
# The WASM flag is reported as linker only.
if(DRACO_WASM)
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sWASM=1")
else()
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sWASM=0")
endif()
# The LEGACY_VM_SUPPORT flag is reported as linker only.
if(DRACO_IE_COMPATIBLE)
list(APPEND ${em_FLAG_LIST_VAR_COMPILER} "-sLEGACY_VM_SUPPORT=1")
endif()
endif()
endmacro()
# Macro for generating C++ glue code from IDL for Emscripten targets. Executes
# python to generate the C++ binding, and establishes dendency: $OUTPUT_PATH.cpp
# on $INPUT_IDL.
macro(draco_generate_emscripten_glue)
set(glue_flags)
set(glue_single_arg_opts INPUT_IDL OUTPUT_PATH)
set(glue_multi_arg_opts)
cmake_parse_arguments(glue "${glue_flags}" "${glue_single_arg_opts}"
"${glue_multi_arg_opts}" ${ARGN})
if(DRACO_VERBOSE GREATER 1)
message(
"--------- draco_generate_emscripten_glue -----------\n"
"glue_INPUT_IDL=${glue_INPUT_IDL}\n"
"glue_OUTPUT_PATH=${glue_OUTPUT_PATH}\n"
"----------------------------------------------------\n")
endif()
if(NOT glue_INPUT_IDL OR NOT glue_OUTPUT_PATH)
message(
FATAL_ERROR
"draco_generate_emscripten_glue: INPUT_IDL and OUTPUT_PATH required.")
endif()
# Generate the glue source.
execute_process(
COMMAND ${PYTHON_EXECUTABLE} $ENV{EMSCRIPTEN}/tools/webidl_binder.py
${glue_INPUT_IDL} ${glue_OUTPUT_PATH})
if(NOT EXISTS "${glue_OUTPUT_PATH}.cpp")
message(FATAL_ERROR "JS glue generation failed for ${glue_INPUT_IDL}.")
endif()
# Create a dependency so that it regenerated on edits.
add_custom_command(
OUTPUT "${glue_OUTPUT_PATH}.cpp"
COMMAND ${PYTHON_EXECUTABLE} $ENV{EMSCRIPTEN}/tools/webidl_binder.py
${glue_INPUT_IDL} ${glue_OUTPUT_PATH}
DEPENDS ${draco_js_dec_idl}
COMMENT "Generating ${glue_OUTPUT_PATH}.cpp."
WORKING_DIRECTORY ${draco_build}
VERBATIM)
endmacro()
# Wrapper for draco_add_executable() that handles the extra work necessary for
# emscripten targets when generating JS glue:
#
# ~~~
# - Set source level dependency on the C++ binding.
# - Pre/Post link emscripten magic.
#
# Required args:
# - GLUE_PATH: Base path for glue file. Used to generate .cpp and .js files.
# - PRE_LINK_JS_SOURCES: em_link_pre_js() source files.
# - POST_LINK_JS_SOURCES: em_link_post_js() source files.
# Optional args:
# - FEATURES:
# ~~~
macro(draco_add_emscripten_executable)
unset(emexe_NAME)
unset(emexe_FEATURES)
unset(emexe_SOURCES)
unset(emexe_DEFINES)
unset(emexe_INCLUDES)
unset(emexe_LINK_FLAGS)
set(optional_args)
set(single_value_args NAME GLUE_PATH)
set(multi_value_args
SOURCES
DEFINES
FEATURES
INCLUDES
LINK_FLAGS
PRE_LINK_JS_SOURCES
POST_LINK_JS_SOURCES)
cmake_parse_arguments(emexe "${optional_args}" "${single_value_args}"
"${multi_value_args}" ${ARGN})
if(NOT
(emexe_GLUE_PATH
AND emexe_POST_LINK_JS_SOURCES
AND emexe_PRE_LINK_JS_SOURCES))
message(FATAL
"draco_add_emscripten_executable: GLUE_PATH PRE_LINK_JS_SOURCES "
"POST_LINK_JS_SOURCES args required.")
endif()
if(DRACO_VERBOSE GREATER 1)
message(
"--------- draco_add_emscripten_executable ---------\n"
"emexe_NAME=${emexe_NAME}\n"
"emexe_SOURCES=${emexe_SOURCES}\n"
"emexe_DEFINES=${emexe_DEFINES}\n"
"emexe_INCLUDES=${emexe_INCLUDES}\n"
"emexe_LINK_FLAGS=${emexe_LINK_FLAGS}\n"
"emexe_GLUE_PATH=${emexe_GLUE_PATH}\n"
"emexe_FEATURES=${emexe_FEATURES}\n"
"emexe_PRE_LINK_JS_SOURCES=${emexe_PRE_LINK_JS_SOURCES}\n"
"emexe_POST_LINK_JS_SOURCES=${emexe_POST_LINK_JS_SOURCES}\n"
"----------------------------------------------------\n")
endif()
# The Emscripten linker needs the C++ flags in addition to whatever has been
# passed in with the target.
list(APPEND emexe_LINK_FLAGS ${DRACO_CXX_FLAGS})
if(DRACO_GLTF_BITSTREAM)
# Add "_gltf" suffix to target output name.
draco_add_executable(
NAME ${emexe_NAME}
OUTPUT_NAME ${emexe_NAME}_gltf
SOURCES ${emexe_SOURCES}
DEFINES ${emexe_DEFINES}
INCLUDES ${emexe_INCLUDES}
LINK_FLAGS ${emexe_LINK_FLAGS})
else()
draco_add_executable(
NAME ${emexe_NAME}
SOURCES ${emexe_SOURCES}
DEFINES ${emexe_DEFINES}
INCLUDES ${emexe_INCLUDES}
LINK_FLAGS ${emexe_LINK_FLAGS})
endif()
foreach(feature ${emexe_FEATURES})
draco_enable_feature(FEATURE ${feature} TARGETS ${emexe_NAME})
endforeach()
set_property(
SOURCE ${emexe_SOURCES}
APPEND
PROPERTY OBJECT_DEPENDS "${emexe_GLUE_PATH}.cpp")
em_link_pre_js(${emexe_NAME} ${emexe_PRE_LINK_JS_SOURCES})
em_link_post_js(${emexe_NAME} "${emexe_GLUE_PATH}.js"
${emexe_POST_LINK_JS_SOURCES})
endmacro()