Using Booth from CMake

Booth builds with its own Makefile; there is no CMake build of the compiler itself. What this gives you is the other direction, a CMake project consuming an installed Booth to compile kernels as part of its build.

Installing

make
sudo make install                 # /usr/local by default
make install PREFIX=$HOME/.local  # or wherever

That puts kath in <prefix>/bin, the --lang catalogues in <prefix>/share/booth/lang, and the package config in <prefix>/lib/cmake/Booth. DESTDIR is honoured for staged installs.

Finding it

find_package(Booth 0.5 REQUIRED)

If the prefix is not one CMake already searches, point it there with -DCMAKE_PREFIX_PATH=<prefix>.

While Booth is on 0.x the minor version has to match, so asking for 0.5 is satisfied by 0.5.2 but not by 0.6. That is deliberate: 0.x is where things are still allowed to move, and a package config that quietly accepted 0.6 would be promising something Booth is not ready to promise. From 1.0 the usual same-major rule takes over.

You get Booth_VERSION, Booth_EXECUTABLE, Booth_LANG_DIR, and a Booth::kath imported target.

Compiling a kernel

booth_add_kernel(vadd_amd
    SOURCE  vadd.cu
    BACKEND amdgpu-bin
    ARCH    gfx942)

That adds a target vadd_amd that runs kath at build time. The output path comes back two ways, as a BOOTH_KERNEL_OUTPUT target property and as a vadd_amd_OUTPUT variable in the calling scope:

add_custom_command(TARGET app POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy ${vadd_amd_OUTPUT} $<TARGET_FILE_DIR:app>)

The cpu and rv64 backends emit ordinary relocatable objects, so those can go straight into a target:

booth_add_kernel(vadd_host SOURCE vadd.cu BACKEND cpu)
add_executable(app main.c)
add_dependencies(app vadd_host)
target_link_libraries(app PRIVATE ${vadd_host_OUTPUT})

Arguments

SOURCE	The one input file. kath compiles a single file per run, so a kernel is one source.
BACKEND	amdgpu, amdgpu-bin, nvidia-ptx, tensix, rv-elf, cpu, rv64, metal, intel-spirv.
LANGUAGE	CUDA (default), HIP, or TRITON. .hip files pick HIP up on their own.
ARCH	gfx90a, gfx942, gfx1030…gfx1201, or xe-lpg/xe-hpg/xe-hpc/xe2.
TT_CHIP	blackhole or wormhole.
OUTPUT	Output path. Defaults to <name> in the build dir with a suffix picked from the backend.
INCLUDE_DIRECTORIES	Passed through as -I.
COMPILE_DEFINITIONS	Passed through as -D.
OPTIONS	Any other flags, handed to kath untouched.
DEPENDS	Extra files to rebuild on.
EXCLUDE_FROM_ALL	Build only when something asks for it.

Two things to know

kath writes no depfile, so editing a header the kernel includes will not retrigger a build on its own. List those headers in DEPENDS if you need it.

The tensix backend emits a whole Metalium program rather than one file: the compute kernel at OUTPUT, plus reader, writer and host sources and their ELFs alongside it. Those are declared as byproducts, so clean reaches them, but BOOTH_KERNEL_OUTPUT names only the compute kernel.