CMake Build Guide

Requirements: CMake 3.26+, Ninja (recommended), C++20 compiler (MSVC/Clang/GCC).

Quick Start

cmake -S . -B build -G Ninja -D CMAKE_BUILD_TYPE=Release
cmake --build build
cmake --install build --prefix dist

Platform specifics:

Linux:

export CC=clang-20 CXX=clang++-20
cmake -S . -B build -G Ninja -D CMAKE_BUILD_TYPE=Release

macOS:

export PATH="$PATH:/opt/homebrew/opt/llvm/bin"
export CC=/opt/homebrew/opt/llvm/bin/clang
export CXX=/opt/homebrew/opt/llvm/bin/clang++
export SDKROOT=$(xcrun --show-sdk-path)
cmake -S . -B build -G Ninja -D CMAKE_BUILD_TYPE=Release

Windows: Requires VS Developer Command Prompt. Or use Python bootstrap:

import bootstrap
bootstrap.prepare_msvc_environment()

scripts/agent_windows_cmake.py

One-shot configure + build + verify on Windows using the repository defaults.

# Full pipeline: configure → build → verify
python scripts/agent_windows_cmake.py

# Individual steps
python scripts/agent_windows_cmake.py --config          # configure only
python scripts/agent_windows_cmake.py --build           # build only
python scripts/agent_windows_cmake.py --verify          # check key .lib/.dll outputs
python scripts/agent_windows_cmake.py --clean           # clear CMake cache

# Options
python scripts/agent_windows_cmake.py --type Debug      # Debug build
python scripts/agent_windows_cmake.py -j 8              # limit parallel jobs
python scripts/agent_windows_cmake.py --clean --config  # clean re-configure

Auto-finds cmake and ninja (PATH → .deps/ → pip). Auto-prepares MSVC environment via vswhere. Verifies: SPIRV-Tools-opt.lib, SPIRV-Tools.lib, luisa-ast.dll, luisa-core.dll.

Build Options

LUISA_COMPUTE_USE_SYSTEM_* options exist for STL, GLFW, LMDB, REPROC, SPDLOG, XXHASH, YYJSON, MAGIC_ENUM, and MARL (CMakeLists.txt:180-188; STL defaults to ON, the rest follow LUISA_COMPUTE_USE_SYSTEM_LIBS).

LUISA_COMPUTE_ENABLE_SCCACHE and LUISA_COMPUTE_ENABLE_LTO are declared in scripts/setup_compilation.cmake:60,76 (not the root file); LTO only sets CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE / _RELWITHDEBINFO / _MINSIZEREL.

The two Vulkan SPIR-V codegen options are mutually exclusive: CMakeLists.txt:160-164 and src/backends/CMakeLists.txt:3-8 raise a FATAL_ERROR if both are ON. The LLVM path also builds/links the common luisa-compute-spirv support library (STATIC, src/backends/common/spirv/CMakeLists.txt:18) because the Vulkan backend still uses its disassembler/validation utilities and its target-feature reconciliation (reconcile_spirv_target_features, src/backends/common/spirv/spirv_codegen/optimizer.cpp:657) in that configuration (src/backends/vk/CMakeLists.txt:143-148).

Minimal build (no GPU/fallback backends):

cmake -S . -B build -G Ninja -D CMAKE_BUILD_TYPE=Release \
  -D LUISA_COMPUTE_ENABLE_CUDA=OFF \
  -D LUISA_COMPUTE_ENABLE_VULKAN=OFF \
  -D LUISA_COMPUTE_ENABLE_FALLBACK=OFF
cmake --build build

CI jobs are defined in .github/workflows/build-cmake.yml: all three platforms configure with -G Ninja -D LUISA_COMPUTE_ENABLE_PACKAGE_DISTRIBUTION=<ON|OFF> -D CMAKE_BUILD_TYPE=<Release|Debug>, and the macOS job additionally passes -D LUISA_COMPUTE_ENABLE_VULKAN=OFF -D LUISA_COMPUTE_ENABLE_UNITY_BUILD=OFF. Release jobs then run cmake --build build --target luisa-compute-package-e2e (cmake/LuisaComputeCPack.cmake:78).

Target Naming

Module Hierarchy

luisa-compute-include (INTERFACE, header-only)
  → luisa-compute-ext (INTERFACE, third-party deps)
    → luisa-compute-core
      → luisa-compute-ast
        → luisa-compute-xir
      → luisa-compute-runtime (links ast; PRIVATE luisa-compute-vstl)
        → luisa-compute-dsl, luisa-compute-gui (gui links runtime + dsl)
luisa-compute-backends (INTERFACE aggregator: each luisa_compute_add_backend target links ast/runtime/gui/dsl and registers itself via add_dependencies)

These libraries follow BUILD_SHARED_LIBS: ordinary desktop builds force it ON, while iOS forces it OFF so the signed app contains static core/runtime/XIR and backend slices.

The umbrella target is compute, aliased as luisa::compute (src/CMakeLists.txt:55-75); it links luisa-compute-core, -tile, -ast, -xir, -dsl, -osl, -runtime, -gui, -backends, -coro, -clangcxx, plus luisa-compute-cuda-ext-lcub when LUISA_COMPUTE_ENABLE_CUDA_EXT_LCUB is ON. luisa-compute-vstl is an OBJECT helper (src/vstl/CMakeLists.txt:11) linked PRIVATE by luisa-compute-runtime (src/runtime/CMakeLists.txt:44-46), not by compute.

Custom CMake Functions

luisa_compute_add_backend(name [SOURCES <srcs...>] [SUPPORT_DIR dir] [BUILTIN_DIR dir])

File: src/backends/CMakeLists.txt:11. Creates a backend MODULE target named luisa-compute-backend-<name> on desktop platforms and a STATIC target on iOS (CMAKE_SYSTEM_NAME STREQUAL "iOS"). It links luisa-compute-ast, luisa-compute-runtime, luisa-compute-gui, and (when LUISA_COMPUTE_ENABLE_DSL is ON) luisa-compute-dsl. Desktop output is named luisa-backend-<name> (OUTPUT_NAME, EXPORT_NAME backend_<name>) and runtime artifacts are installed to bin/. If SUPPORT_DIR is given, its contents are copied next to the runtime outputs ($<TARGET_FILE_DIR:luisa-compute-core>) and installed to bin/. A BUILTIN_DIR keyword is parsed but currently unused by the function body.

luisa_compute_add_backend(cuda SOURCES ${LUISA_COMPUTE_CUDA_SOURCES})          # src/backends/cuda/CMakeLists.txt:53
luisa_compute_add_backend(dx SOURCES ${LC_BACKEND_DX_SOURCES} SUPPORT_DIR ${LUISA_COMPUTE_DX_SDK_DIR})

luisa_compute_install(target [SOURCES <srcs...>])

File: src/CMakeLists.txt:14. Installs luisa-compute-<target> into the LuisaComputeTargets export with LIBRARY/ARCHIVE → ${CMAKE_INSTALL_LIBDIR} and RUNTIME → ${CMAKE_INSTALL_BINDIR}. The SOURCES keyword is accepted by the call sites but ignored by the function.

luisa_compute_install(core SOURCES ${LUISA_COMPUTE_CORE_SOURCES})

luisa_compute_add_executable(name [sources...])

File: src/CMakeLists.txt:77. Wraps add_executable(${name} ${ARGN}) (extra arguments are the sources) and links luisa::compute PRIVATE.

luisa_compute_add_executable(test_basic_traits unit/core/test_basic_traits.cpp)

luisa_compute_add_test(name source [LABELS ...] [ARGS ...])

File: src/tests/CMakeLists.txt:19. Builds one standalone executable per source (via luisa_compute_add_executable) and adds ./ and ./common to its include paths. With LABELS, registers a CTest entry; ARGS becomes the test's argv, used to pin a backend for a GPU integration test (e.g. ARGS metal4, ARGS simd). Without LABELS, it just builds the binary and any device test is invoked manually with a backend argument.

luisa_compute_add_test(test_basic_traits unit/core/test_basic_traits.cpp LABELS "unit;unit_core")
luisa_compute_add_test(test_vk_cuda_kernel_launch integration/runtime/test_vk_cuda_kernel_launch.cpp)  # no CTest
luisa_compute_add_test(test_tile_xir_runtime_gpu_dx unit/tile/bridge/test_xir_runtime_gpu.cpp LABELS "integration;integration_tile_xir;integration_dx" ARGS dx)

luisa_compute_add_example(name [sources...] [MIRROR_AS_TEST])

File: examples/CMakeLists.txt:1. Builds the <name> executable (call sites pass names already prefixed with example_) and, when MIRROR_AS_TEST is set, additionally builds a mirror executable whose name is <name> with the leading example_ replaced by test_ (only if that target does not already exist), recording it in the LUISA_TEST_MIRROR target property. Reserved for auto-checkable examples (reference-image comparison, deterministic sims, headless compute). GUI/interop demos must omit the flag.

luisa_compute_add_example(example_path_tracing rendering/path_tracing.cpp MIRROR_AS_TEST)
luisa_compute_add_example(example_swapchain_qt gui/swapchain_qt.cpp)  # no mirror

luisa_example_pair_link(name <link-args>)

File: examples/CMakeLists.txt:16. Companion to luisa_compute_add_example. Calls target_link_libraries on <name> and, if its LUISA_TEST_MIRROR property is set, on that mirror too. Use whenever an example needs extra libs.

luisa_compute_add_example(example_cuda_lcub extension/cuda_lcub.cpp)
luisa_example_pair_link(example_cuda_lcub PRIVATE CUDA::cudart CUDA::cuda_driver)

Backend Plugin Build

Desktop backends are built as MODULE runtime-loadable libraries:

luisa_compute_add_backend(cuda SOURCES ${LUISA_COMPUTE_CUDA_SOURCES})

Key: output renamed to luisa-backend-<name>, installed to bin/. Device-lib embedding is done by each backend's own CMakeLists.txt through the luisa_embed_device_lib host tool (utils/CMakeLists.txt:2; e.g. src/backends/cuda/CMakeLists.txt:6-11) — luisa_compute_add_backend itself does not embed anything.

On iOS, the same helper emits a static backend. A signed Metal4 AIR device app also requires static arm64 iPhoneOS LLVM 22 archives; an arm64 macOS LLVM build is not platform-compatible. Prefer the checked scripts so local and CI options remain identical:

scripts/build_ios_llvm.sh \
  --host-llvm-prefix "$(brew --prefix llvm@22)"
scripts/build_ios_metal4.sh \
  --llvm-dir cmake-build-llvm22-ios/lib/cmake/llvm \
  --team <team-id> --mode all

# CI/link closure only; these bundles are not installable.
scripts/build_ios_metal4.sh \
  --llvm-dir cmake-build-llvm22-ios/lib/cmake/llvm \
  --mode all --unsigned
scripts/audit_ios_bundles.sh \
  --bin-dir cmake-build-ios-metal4-device-air-xcode/bin/Release

build_ios_llvm.sh downloads the official LLVM 22.1.8 source when needed and uses CMake/Ninja with arm64-apple-ios<deployment> host/default triples. The application script uses CMake's Xcode generator only because provisioning and automatic signing are Xcode workflows. --mode examples, tests, or all maps to luisa-ios-rendering-examples, luisa-ios-device-tests, or both.

Metal4 user shaders and fixed runtime builtins are LLVM/AIR. BC6H/BC7 fixed support sources are compiled to target-specific metallibs by xcrun metal and metallib at build time; the runtime embeds and loads only their binary bytes.

Third-Party Extension Pattern

Each src/ext/<lib>/ (pattern from src/ext/CMakeLists.txt:283-310):

if (LUISA_COMPUTE_USE_SYSTEM_<LIB>)
    find_package(<LIB> REQUIRED)
    target_link_libraries(luisa-compute-ext INTERFACE <target>)
    target_compile_definitions(luisa-compute-ext INTERFACE LUISA_USE_SYSTEM_<LIB>=1)
else()
    add_subdirectory(<lib>)
    target_link_libraries(luisa-compute-ext INTERFACE <target>)
    luisa_compute_install_extension(<target> INCLUDE <lib>/include/<LIB>)
endif()

luisa_compute_install_extension(target [INCLUDE dir] [INCLUDES dirs...] [HEADER_FILES files...] [HEADER_DESTINATION dir]) is defined in src/ext/CMakeLists.txt:243 and installs the target plus its headers to ${CMAKE_INSTALL_INCLUDEDIR}/luisa/ext.

Output & RPATH

${CMAKE_BINARY_DIR}/bin  → Runtime + library outputs (DLLs/.so/.dylib, executables)
${CMAKE_BINARY_DIR}/lib  → Archive outputs (static libs, import libs, PDBs)

Per scripts/setup_output_dirs.cmake:1-14; multi-config generators (e.g. Xcode, VS) write bin/<config> and lib/<config> instead.

Install layout: headers → ${CMAKE_INSTALL_INCLUDEDIR}/luisa (CMakeLists.txt:323-326), libraries → ${CMAKE_INSTALL_LIBDIR} and runtime binaries → ${CMAKE_INSTALL_BINDIR} (luisa_compute_install, src/CMakeLists.txt:14-20), CMake package files (LuisaComputeConfig.cmake, LuisaComputeTargets.cmake) → LUISA_COMPUTE_INSTALL_CMAKEDIR, which defaults to ${CMAKE_INSTALL_LIBDIR}/cmake/LuisaCompute (CMakeLists.txt:267-270, 367-381). RPATH is set from CMakeLists.txt:244-249.

• macOS: @loader_path, @loader_path/../bin, @loader_path/../lib
• Linux: $ORIGIN, $ORIGIN/../bin, $ORIGIN/../lib