Using CMake

See Getting Started for environment setup.

Create CMakeLists.txt.

cmake

cmake_minimum_required(VERSION 3.13)

project(emnapiexample)

add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/node_modules/emnapi")

add_executable(hello hello.c)

target_link_libraries(hello emnapi)
if(CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
  target_link_options(hello PRIVATE
    "-sEXPORTED_FUNCTIONS=['_napi_register_wasm_v1','_node_api_module_get_api_version_v1','_malloc','_free']"
  )
elseif(CMAKE_SYSTEM_NAME STREQUAL "WASI")
  set_target_properties(hello PROPERTIES SUFFIX ".wasm")
  target_link_options(hello PRIVATE
    "-mexec-model=reactor"
    "-Wl,--export=napi_register_wasm_v1"
    "-Wl,--export-if-defined=node_api_module_get_api_version_v1"
    "-Wl,--initial-memory=16777216,--export-dynamic,--export=malloc,--export=free,--import-undefined,--export-table"
  )
elseif((CMAKE_C_COMPILER_TARGET STREQUAL "wasm32") OR (CMAKE_C_COMPILER_TARGET STREQUAL "wasm32-unknown-unknown"))
  set_target_properties(hello PROPERTIES SUFFIX ".wasm")
  target_link_options(hello PRIVATE
    "-nostdlib"
    "-Wl,--export=napi_register_wasm_v1"
    "-Wl,--export-if-defined=node_api_module_get_api_version_v1"
    "-Wl,--no-entry"
    "-Wl,--initial-memory=16777216,--export-dynamic,--export=malloc,--export=free,--import-undefined,--export-table"
  )
  target_link_libraries(hello dlmalloc)
  # target_link_libraries(hello emmalloc)
endif()

cmake_minimum_required(VERSION 3.13)

project(emnapiexample)

add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/node_modules/emnapi")

add_executable(hello hello.c)

target_link_libraries(hello emnapi)
if(CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
  target_link_options(hello PRIVATE
    "-sEXPORTED_FUNCTIONS=['_napi_register_wasm_v1','_node_api_module_get_api_version_v1','_malloc','_free']"
  )
elseif(CMAKE_SYSTEM_NAME STREQUAL "WASI")
  set_target_properties(hello PROPERTIES SUFFIX ".wasm")
  target_link_options(hello PRIVATE
    "-mexec-model=reactor"
    "-Wl,--export=napi_register_wasm_v1"
    "-Wl,--export-if-defined=node_api_module_get_api_version_v1"
    "-Wl,--initial-memory=16777216,--export-dynamic,--export=malloc,--export=free,--import-undefined,--export-table"
  )
elseif((CMAKE_C_COMPILER_TARGET STREQUAL "wasm32") OR (CMAKE_C_COMPILER_TARGET STREQUAL "wasm32-unknown-unknown"))
  set_target_properties(hello PROPERTIES SUFFIX ".wasm")
  target_link_options(hello PRIVATE
    "-nostdlib"
    "-Wl,--export=napi_register_wasm_v1"
    "-Wl,--export-if-defined=node_api_module_get_api_version_v1"
    "-Wl,--no-entry"
    "-Wl,--initial-memory=16777216,--export-dynamic,--export=malloc,--export=free,--import-undefined,--export-table"
  )
  target_link_libraries(hello dlmalloc)
  # target_link_libraries(hello emmalloc)
endif()

Building with emcmake, output build/hello.js and build/hello.wasm.

If you use node-addon-api, you can use -DEMNAPI_FIND_NODE_ADDON_API=ON or manually add node-addon-api directory to the include dir via include_directories() or target_include_directories().

bash

mkdir build

# emscripten
emcmake cmake -DCMAKE_BUILD_TYPE=Release \
              -DEMNAPI_FIND_NODE_ADDON_API=ON \
              -G Ninja -H. -Bbuild

# wasi-sdk
cmake -DCMAKE_TOOLCHAIN_FILE=$WASI_SDK_PATH/share/cmake/wasi-sdk.cmake \
      -DWASI_SDK_PREFIX=$WASI_SDK_PATH \
      -DEMNAPI_FIND_NODE_ADDON_API=ON \
      -DCMAKE_BUILD_TYPE=Release \
      -G Ninja -H. -Bbuild

# wasm32
cmake -DCMAKE_TOOLCHAIN_FILE=node_modules/emnapi/cmake/wasm32.cmake \
      -DLLVM_PREFIX=$WASI_SDK_PATH \
      -DCMAKE_BUILD_TYPE=Release \
      -G Ninja -H. -Bbuild

cmake --build build

mkdir build

# emscripten
emcmake cmake -DCMAKE_BUILD_TYPE=Release \
              -DEMNAPI_FIND_NODE_ADDON_API=ON \
              -G Ninja -H. -Bbuild

# wasi-sdk
cmake -DCMAKE_TOOLCHAIN_FILE=$WASI_SDK_PATH/share/cmake/wasi-sdk.cmake \
      -DWASI_SDK_PREFIX=$WASI_SDK_PATH \
      -DEMNAPI_FIND_NODE_ADDON_API=ON \
      -DCMAKE_BUILD_TYPE=Release \
      -G Ninja -H. -Bbuild

# wasm32
cmake -DCMAKE_TOOLCHAIN_FILE=node_modules/emnapi/cmake/wasm32.cmake \
      -DLLVM_PREFIX=$WASI_SDK_PATH \
      -DCMAKE_BUILD_TYPE=Release \
      -G Ninja -H. -Bbuild

cmake --build build

Using CMake ​

Using CMake