# Copyright 2022-2026 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8

PYTHON_COMPAT=( python3_{12..14} )
ROCM_VERSION=6.1
inherit python-single-r1 cmake cuda flag-o-matic prefix rocm

MYPN=pytorch
MYP=${MYPN}-${PV}

# caffe2-2.9.0 depends on future version of composable kernel
# TODO: replace it with DEPEND in the future
CK_COMMIT=7fe50dc3da2069d6645d9deb8c017a876472a977
CK_P=composable_kernel-${CK_COMMIT:0:8}

FLASH_PV=2.7.4
FLASH_PN=flash-attention
FLASH_P=${FLASH_PN}-${FLASH_PV}
FLASH_ATT_URI="https://github.com/Dao-AILab/${FLASH_PN}/archive/refs/tags/v${FLASH_PV}.tar.gz -> ${FLASH_P}.gh.tar.gz"

AOTRITON_PV=0.12b
AOTRITON_PN=aotriton
AOTRITON_P=${AOTRITON_PN}-${AOTRITON_PV}
AOTRITON_tar=${AOTRITON_P}-manylinux_2_28_x86_64-rocm6.4-shared.tar.gz

DESCRIPTION="A deep learning framework"
HOMEPAGE="https://pytorch.org/"
SRC_URI="
	https://github.com/pytorch/${MYPN}/archive/refs/tags/v${PV}.tar.gz -> ${MYP}.tar.gz
	rocm? (
		https://github.com/ROCm/composable_kernel/archive/${CK_COMMIT}.tar.gz
		-> ${CK_P}.tar.gz
	)
	cuda? (
		flash? ( ${FLASH_ATT_URI} )
		memefficient? ( ${FLASH_ATT_URI} )
	)
"

S="${WORKDIR}"/${MYP}

LICENSE="BSD"
SLOT="0"
KEYWORDS="~amd64 ~arm64"
IUSE="cuda cusparselt distributed fbgemm flash gloo kineto memefficient
	mimalloc mkl mpi nccl nnpack +numpy onednn openblas opencl openmp qnnpack
	rocm xnnpack"
RESTRICT="test"
REQUIRED_USE="
	${PYTHON_REQUIRED_USE}
	mpi? ( distributed )
	gloo? ( distributed )
	?? ( cuda rocm )
	rocm? (
		|| ( ${ROCM_REQUIRED_USE} )
		memefficient? ( flash )
	)
	cusparselt? ( || ( cuda rocm ) )
	flash? ( || ( cuda rocm ) )
	memefficient? ( || ( cuda rocm ) )
	nccl? ( rocm )
"

RDEPEND="
	${PYTHON_DEPS}
	dev-cpp/abseil-cpp:=
	dev-cpp/gflags:=
	>=dev-cpp/glog-0.5.0:=
	>=dev-libs/cpuinfo-2025.11.14
	dev-libs/libfmt:=
	dev-libs/protobuf:=
	dev-libs/sleef
	sci-ml/onnx
	virtual/lapack
	cuda? (
		dev-libs/cudnn
		>=sci-ml/cudnn-frontend-1.12.0:=
		>=dev-util/nvidia-cuda-toolkit-12.9:=[profiler]
		cusparselt? ( dev-libs/cusparselt )
	)
	fbgemm? ( >=sci-ml/FBGEMM-1.4 )
	gloo? ( >=sci-ml/gloo-2025.06.04[cuda?,rocm?] )
	kineto? ( ~sci-ml/kineto-0.4.0_p20260323 )
	mimalloc? ( dev-libs/mimalloc )
	mpi? ( virtual/mpi )
	nnpack? (
		sci-ml/NNPACK
		dev-libs/pthreadpool
	)
	numpy? ( $(python_gen_cond_dep '
		dev-python/numpy[${PYTHON_USEDEP}]
	') )
	onednn? ( sci-ml/oneDNN )
	opencl? ( virtual/opencl )
	qnnpack? (
		sci-ml/gemmlowp
		dev-libs/pthreadpool
	)
	rocm? (
		nccl? ( >=dev-libs/rccl-6.3:= <dev-libs/rccl-7.3:= )
		>=dev-util/hip-6.3:=       <dev-util/hip-7.3:=
		>=dev-util/roctracer-6.3:= <dev-util/roctracer-7.3:=
		>=sci-libs/hipBLAS-6.3:=   <sci-libs/hipBLAS-7.3:=[rocsolver(+)]
		>=sci-libs/hipBLASLt-6.3:= <sci-libs/hipBLASLt-7.3:=
		>=sci-libs/hipFFT-6.3:=    <sci-libs/hipFFT-7.3:=
		>=sci-libs/hipRAND-6.3:=   <sci-libs/hipRAND-7.3:=
		>=sci-libs/hipSOLVER-6.3:= <sci-libs/hipSOLVER-7.3:=
		>=sci-libs/hipSPARSE-6.3:= <sci-libs/hipSPARSE-7.3:=
		>=sci-libs/miopen-6.3:=    <sci-libs/miopen-7.3:=
		>=sci-libs/rocBLAS-6.3:=   <sci-libs/rocBLAS-7.3:=
		>=sci-libs/rocRAND-6.3:=   <sci-libs/rocRAND-7.3:=
		>=sci-libs/rocSOLVER-6.3:= <sci-libs/rocSOLVER-7.3:=
		memefficient? ( =sci-libs/aotriton-bin-0.12*:= )
		distributed? ( >=dev-util/rocm-smi-6.3:= <dev-util/rocm-smi-7.3:= )
		cusparselt? ( >=sci-libs/hipsparselt-6.3:= <sci-libs/hipsparselt-7.3:= )
	)
	distributed? (
		!rocm? ( sci-ml/tensorpipe[cuda?] )
		dev-cpp/cpp-httplib:=
	)
	xnnpack? (
		>=sci-ml/XNNPACK-2024.11
		dev-libs/pthreadpool
	)
	mkl? ( sci-libs/mkl )
	openblas? ( sci-libs/openblas )
"

DEPEND="
	${RDEPEND}
	dev-cpp/nlohmann_json
	dev-libs/flatbuffers
	dev-libs/FXdiv
	dev-libs/pocketfft
	dev-libs/psimd
	sci-ml/FP16
	$(python_gen_cond_dep '
		<dev-python/pybind11-3.0.5[${PYTHON_USEDEP}]
		dev-python/pyyaml[${PYTHON_USEDEP}]
		dev-python/typing-extensions[${PYTHON_USEDEP}]
	')
	cuda? ( >=dev-libs/cutlass-3.9.2[tools(+)] )
	onednn? ( sci-ml/ideep )
	rocm? (
		>=sci-libs/hipCUB-6.3:=    <sci-libs/hipCUB-7.3:=
		>=sci-libs/rocPRIM-6.3:=   <sci-libs/rocPRIM-7.3:=
		>=sci-libs/rocThrust-6.3:= <sci-libs/rocThrust-7.3:=
	)
	qnnpack? ( dev-libs/clog )
"

PATCHES=(
	"${FILESDIR}"/${PN}-2.5.1-unbundle_fmt.patch.xz
	"${FILESDIR}"/${PN}-2.5.1-unbundle_kineto.patch.xz
	"${FILESDIR}"/${PN}-2.8.0-unbundle_pocketfft.patch.xz
	"${FILESDIR}"/${PN}-2.5.1-cudnn_include_fix.patch.xz
	"${FILESDIR}"/${PN}-2.4.0-cpp-httplib.patch.xz
	"${FILESDIR}"/${PN}-2.5.1-glog-0.6.0.patch.xz
	"${FILESDIR}"/${PN}-2.7.0-glog-0.7.1.patch.xz
	# 2.13.0 duplicated the "check if glog is initialized" hack into
	# c10/util/Exception.cpp, still calling the internal
	# glog_internal_namespace_::IsGoogleLoggingInitialized(); system glog 0.6.0
	# only exports the public ::google::IsGoogleLoggingInitialized(), so link
	# fails. Mirror the Logging.cpp glog patch here. # verified 2026-07-18
	"${FILESDIR}"/${P}-glog-exception-init.patch.xz
	"${FILESDIR}"/${PN}-2.12.0-aotriton-fixes.patch.xz
	"${FILESDIR}"/${PN}-2.8.0-rocm-minus-flash.patch.xz
	"${FILESDIR}"/${PN}-2.12.0-rocm-distributed-link.patch.xz
	"${FILESDIR}"/${PN}-2.9.1-torch_cpu.patch.xz
	"${FILESDIR}"/${PN}-2.10.0-gentoo.patch.xz
	"${FILESDIR}"/${PN}-2.11.0-mimalloc.patch.xz
	"${FILESDIR}"/${PN}-2.12.0-removekineto-pr178960.patch.xz

	# 2.13.0 moved setup.py's submodule check into cmake/PreBuildSteps.cmake,
	# which FATAL_ERRORs on the (intentionally empty) third_party submodules of
	# a tarball build. Guard the whole block behind a .git check so it no-ops
	# here (deps are system / prestaged). # verified 2026-07-18
	"${FILESDIR}"/${P}-prebuildsteps-tarball-guard.patch.xz

	# 2.13.0's cmake/PostBuildSteps.cmake runs wrap_headers.py via install(CODE)
	# against ${CMAKE_INSTALL_PREFIX}/include with no ${DESTDIR} prefix, so it
	# writes to the live /usr/include instead of the image (sandbox denies it).
	# Prepend $ENV{DESTDIR}. # verified 2026-07-18
	"${FILESDIR}"/${P}-wrap-headers-destdir.patch.xz

	# stuff overlay only: scrub MKL MPI / cluster libs and force GNU
	# OpenMP threading in caffe2::mkl's public link interface so that
	# downstream consumers (vllm, custom torch C++ ext) link cleanly
	# on hosts with the basic intel-oneapi-mkl package (no Cluster
	# Edition, no Intel Compiler / libiomp5). Drop when an equivalent
	# upstream fix lands. # verified 2026-05-08 against 2.11.0;
	# cmake/public/mkl.cmake context identical at 2.12.0 and 2.13.0.
	"${FILESDIR}"/${PN}-2.12.0-mkl-public-scrub.patch.xz
)

src_prepare() {
	# files/*.patch ship xz-compressed to stay under pkgcheck's 50K
	# TotalSizeViolation cap; eapply(1) does not decompress, so expand
	# every files/ patch into ${T} and repoint PATCHES (and the
	# composable-kernel patch below) at the plain-text copies.
	local p b i
	mkdir "${T}"/patches || die
	for p in "${FILESDIR}"/*.patch.xz; do
		b=${p##*/}
		xz -dc "${p}" > "${T}/patches/${b%.xz}" || die
	done
	for i in "${!PATCHES[@]}"; do
		b=${PATCHES[i]##*/}
		PATCHES[i]="${T}/patches/${b%.xz}"
	done

	if use cuda && ( use flash || use memefficient ); then
		mv "${WORKDIR}"/${FLASH_P}/* third_party/${FLASH_PN}/ || die
	fi
	filter-lto #bug 862672

	# Unbundle fmt
	sed -i \
		-e 's|::fmt-header-only||' \
		c10/CMakeLists.txt \
		cmake/Dependencies.cmake \
		torch/CMakeLists.txt \
		|| die

	# tensorpipe is in system, not a build target of caffe2
	sed -e '/target_compile_options_if_supported(tensorpipe/d' -i cmake/Dependencies.cmake || die

	# Drop third_party from CMake tree
	sed -i \
		-e '/add_subdirectory.*third_party/d' \
		CMakeLists.txt \
		cmake/Dependencies.cmake \
		cmake/ProtoBuf.cmake \
		aten/src/ATen/CMakeLists.txt \
		|| die

	# 2.13.0 added FMT_NO_UNIQUE_ADDRESS compile-defs on the bundled fmt /
	# fmt-header-only targets, which no longer exist once fmt is unbundled
	# (system dev-libs/libfmt, add_subdirectory dropped above); drop those two
	# lines (2.12.0 had no such block and built fine). # verified 2026-07-18
	sed -i \
		-e '/target_compile_definitions(fmt.*FMT_NO_UNIQUE_ADDRESS/d' \
		cmake/Dependencies.cmake \
		|| die
	# Change libc10* path
	sed -i \
		-e "/EXPORT/s|DESTINATION lib)|DESTINATION $(get_libdir))|" \
		c10/cuda/CMakeLists.txt \
		c10/CMakeLists.txt \
		c10/hip/CMakeLists.txt \
		|| die

	# Change libaotriton path
	sed -i \
		-e "s|}/lib|}/\${CMAKE_INSTALL_LIBDIR}|g" \
		-e "/set(__AOTRITON_LIB/s|lib/|\${CMAKE_INSTALL_LIBDIR}/|g" \
		cmake/External/aotriton.cmake \
		|| die

	# Noisy warnings from Logging.h
	sed -i 's/-Wextra-semi//' cmake/public/utils.cmake || die

	cmake_src_prepare
	pushd torch/csrc/jit/serialization > /dev/null || die
	flatc --cpp --gen-mutable --scoped-enums mobile_bytecode.fbs || die
	popd > /dev/null || die

	# prefixify the hardcoded paths, after all patches are applied
	hprefixify \
		aten/CMakeLists.txt \
		caffe2/CMakeLists.txt \
		cmake/Metal.cmake \
		cmake/Modules/*.cmake \
		cmake/Modules_CUDA_fix/FindCUDNN.cmake \
		cmake/Modules_CUDA_fix/upstream/FindCUDA/make2cmake.cmake \
		cmake/Modules_CUDA_fix/upstream/FindPackageHandleStandardArgs.cmake \
		cmake/public/LoadHIP.cmake \
		cmake/public/cuda.cmake \
		cmake/Dependencies.cmake \
		torch/CMakeLists.txt \
		CMakeLists.txt

	if use rocm; then
		sed -e "s:/opt/rocm:/usr:" \
			-e "s:lib/cmake:$(get_libdir)/cmake:g" \
			-i cmake/public/LoadHIP.cmake || die

		# TODO: delete, when caffe2 depends on systemwide composable_kernel
		sed -e "s:third_party/composable_kernel:../composable_kernel-${CK_COMMIT}:g" \
			-i aten/src/ATen/CMakeLists.txt || die

		# Bug 959808: fix for gfx101x targets
		pushd "${WORKDIR}/composable_kernel-${CK_COMMIT}" > /dev/null || die
		eapply "${T}"/patches/composable-kernel-7fe50dc-expand-isa.patch
		popd > /dev/null || die

		# Workaround for libc++ issue https://github.com/llvm/llvm-project/issues/100802
		sed -e 's/std::memcpy/memcpy/g' -i torch/headeronly/util/Half.h || die

		ebegin "HIPifying cuda sources"
		FBCODE_BUILD_TOOL="buck" ${EPYTHON} tools/amd_build/build_amd.py || die
		eend $?
	fi
}

src_configure() {
	if use cuda && [[ -z ${TORCH_CUDA_ARCH_LIST} ]]; then
		ewarn "WARNING: caffe2 is being built with its default CUDA compute capabilities: 3.5 and 7.0."
		ewarn "These may not be optimal for your GPU."
		ewarn ""
		ewarn "To configure caffe2 with the CUDA compute capability that is optimal for your GPU,"
		ewarn "set TORCH_CUDA_ARCH_LIST in your make.conf, and re-emerge caffe2."
		ewarn "For example, to use CUDA capability 7.5 & 3.5, add: TORCH_CUDA_ARCH_LIST=7.5 3.5"
		ewarn "For a Maxwell model GPU, an example value would be: TORCH_CUDA_ARCH_LIST=Maxwell"
		ewarn ""
		ewarn "You can look up your GPU's CUDA compute capability at https://developer.nvidia.com/cuda-gpus"
		ewarn "or by running /opt/cuda/extras/demo_suite/deviceQuery | grep 'CUDA Capability'"
	fi

	local mycmakeargs=(
		-DBUILD_CUSTOM_PROTOBUF=OFF
		-DBUILD_TEST=OFF
		-DLIBSHM_INSTALL_LIB_SUBDIR="${EPREFIX}"/usr/$(get_libdir)
		-DPython_EXECUTABLE="${PYTHON}"
		-DTORCH_INSTALL_LIB_DIR="${EPREFIX}"/usr/$(get_libdir)
		-DUSE_CCACHE=OFF
		-DUSE_CUDA=$(usex cuda)
		-DUSE_DISTRIBUTED=$(usex distributed)
		-DUSE_FBGEMM=$(usex fbgemm)
		-DUSE_FLASH_ATTENTION=$(usex flash)
		-DUSE_GFLAGS=ON
		-DUSE_GLOG=ON
		-DUSE_GLOO=$(usex gloo)
		-DUSE_ITT=OFF
		-DUSE_KINETO=$(usex kineto)
		-DUSE_KLEIDIAI=OFF # TODO
		-DUSE_MAGMA=OFF # TODO: In GURU as sci-libs/magma
		-DUSE_MEM_EFF_ATTENTION=$(usex memefficient)
		-DUSE_MIMALLOC=$(usex mimalloc)
		-DUSE_MKLDNN=$(usex onednn)
		-DUSE_MPI=$(usex mpi)
		-DUSE_NCCL=OFF
		-DUSE_NNPACK=$(usex nnpack)
		-DUSE_NUMA=OFF
		-DUSE_NUMPY=$(usex numpy)
		-DUSE_OPENCL=$(usex opencl)
		-DUSE_OPENMP=$(usex openmp)
		-DUSE_PYTORCH_QNNPACK=$(usex qnnpack)
		-DUSE_PYTORCH_METAL=OFF
		-DUSE_ROCM=$(usex rocm)
		-DUSE_SYSTEM_CPUINFO=ON
		-DUSE_SYSTEM_EIGEN_INSTALL=ON
		-DUSE_SYSTEM_FP16=ON
		-DUSE_SYSTEM_FXDIV=ON
		-DUSE_SYSTEM_GLOO=ON
		-DUSE_SYSTEM_NVTX=ON
		-DUSE_SYSTEM_ONNX=ON
		-DUSE_SYSTEM_PSIMD=ON
		-DUSE_SYSTEM_PTHREADPOOL=ON
		-DUSE_SYSTEM_PYBIND11=ON
		-DUSE_SYSTEM_SLEEF=ON
		-DUSE_SYSTEM_XNNPACK=$(usex xnnpack)
		-DUSE_TENSORPIPE=$(usex distributed $(usex !rocm))
		-DUSE_UCC=OFF
		-DUSE_VALGRIND=OFF
		-DUSE_XNNPACK=$(usex xnnpack)
		-DUSE_XPU=OFF
		-Wno-dev
	)

	if use mkl; then
		mycmakeargs+=(-DBLAS=MKL)
	elif use openblas; then
		mycmakeargs+=(-DBLAS=OpenBLAS)
	else
		mycmakeargs+=(-DBLAS=Generic -DBLAS_LIBRARIES=)
	fi

	if use cuda; then
		# bug 867706 926116
		cuda_add_sandbox
		addpredict "/dev/char/"

		mycmakeargs+=(
			-DUSE_CUDNN=ON
			-DTORCH_CUDA_ARCH_LIST="${TORCH_CUDA_ARCH_LIST:-3.5 7.0}"
			-DUSE_NCCL=OFF # TODO: NVIDIA Collective Communication Library
			-DCMAKE_CUDA_FLAGS="$(cuda_gccdir -f | tr -d \")"
			-DUSE_CUSPARSELT=$(usex cusparselt)
		)

		[[ -v CUDACXX ]] && export PYTORCH_NVCC="${CUDACXX}"

		if use flash; then
			export FLASH_ATTENTION_FORCE_BUILD="TRUE"
			export FLASH_ATTN_CUDA_ARCHS="${CUDAARCHS:-${TORCH_CUDA_ARCH_LIST:-3.5 7.0}}"
		fi

	elif use rocm; then
		export PYTORCH_ROCM_ARCH="$(get_amdgpu_flags)"

		# 2.13.0's cmake/public/LoadHIP.cmake switched to CMake-native HIP and
		# defaults the compiler to ${ROCM_PATH}/lib/llvm/bin/clang++ (i.e.
		# /usr/lib/llvm/bin), but Gentoo slots llvm at /usr/lib/llvm/<N>/bin.
		# Point HIP_CLANG_PATH at the real HIP clang. # verified 2026-07-18
		export HIP_CLANG_PATH="$(hipconfig -l)"

		if use memefficient; then
			export AOTRITON_INSTALLED_PREFIX="${ESYSROOT}/usr"
		fi

		mycmakeargs+=(
			-DUSE_NCCL=$(usex nccl)
			-DUSE_SYSTEM_NCCL=ON
			-DCMAKE_REQUIRE_FIND_PACKAGE_HIP=ON
			-DCMAKE_DISABLE_FIND_PACKAGE_hipsparselt=$(usex !cusparselt) # disable automagic
			-DUSE_ROCM_CK_SDPA=OFF # requires flash + aiter, works only on gfx90a/gfx942/gfx950
		)

		# ROCm libraries produce too much warnings
		append-cxxflags -Wno-deprecated-declarations -Wno-unused-result -Wno-unused-value
	fi

	if use onednn; then
		mycmakeargs+=(
			-DMKLDNN_FOUND=ON
			-DMKLDNN_LIBRARIES=dnnl
			-DMKLDNN_INCLUDE_DIR="${ESYSROOT}/usr/include/oneapi/dnnl"
		)
	fi

	cmake_src_configure
}

src_compile() {
	PYTORCH_BUILD_VERSION=${PV} \
	PYTORCH_BUILD_NUMBER=0 \
	cmake_src_compile
}

python_install() {
	python_domodule python/torch
	mkdir "${D}"$(python_get_sitedir)/torch/bin || die
	mkdir "${D}"$(python_get_sitedir)/torch/lib || die
	mkdir "${D}"$(python_get_sitedir)/torch/include || die
	ln -s ../../../../../include/torch \
		"${D}$(python_get_sitedir)"/torch/include/torch || die # bug 923269
	ln -s ../../../../../bin/torch_shm_manager \
		"${D}"/$(python_get_sitedir)/torch/bin/torch_shm_manager || die
	ln -s ../../../../../$(get_libdir)/libtorch_global_deps.so \
		"${D}"/$(python_get_sitedir)/torch/lib/libtorch_global_deps.so || die
}

src_install() {
	cmake_src_install

	# 2.13.0's cmake/External/aotriton.cmake unconditionally bundles the system
	# libaotriton_v2.so* + aotriton.images into DESTINATION "lib" (-> /usr/lib),
	# which trips multilib-strict (64-bit ELF outside libdir) and duplicates
	# sci-libs/aotriton-bin. aotriton is a system dep here (torch_hip links the
	# /usr/$(get_libdir) copy), not bundled, so drop the stray /usr/lib copy.
	# verified 2026-07-18
	if use rocm && use memefficient; then
		rm -rf "${ED}"/usr/lib/libaotriton_v2* "${ED}"/usr/lib/aotriton.images || die
	fi

	# 2.13.0 folds the torch *Python* package install into cmake (torch._C +
	# version.py via DESTINATION "." plus cmake/PackageData.cmake), relative to
	# CMAKE_INSTALL_PREFIX = /usr where upstream assumes the wheel's <root>/torch.
	# So the payload leaks into /usr/ root and drops stray /usr/lib symlinks --
	# /usr/lib/terminfo collides with sys-libs/ncurses and aborts the merge.
	# Keep only the compiled torch._C: 2.13.0 moved its build to cmake and
	# sci-ml/pytorch skips cmake (dontbuildagain patch), so nothing else ships it
	# and `import torch` fails without it. Relocate _C into site-packages/torch
	# (its NEEDED libtorch* resolve from /usr/lib64); the pure-python package is
	# sci-ml/pytorch's, so whitelist the FHS dirs and drop the rest.
	# verified 2026-07-22
	local _c_ext=( "${ED}"/usr/_C.cpython-*.so )
	if [[ -f ${_c_ext[0]} ]]; then
		local _torchdir="${D}$(python_get_sitedir)/torch"
		mkdir -p "${_torchdir}" || die
		cp -p "${_c_ext[0]}" "${_torchdir}/" || die
	fi
	local d
	for d in "${ED}"/usr/*; do
		case ${d##*/} in
			bin|include|lib|lib64|share) ;;
			*) rm -rf "${d}" || die ;;
		esac
	done
	# caffe2 owns nothing directly under /usr/lib but the python site-packages
	# tree (added by python_install below); drop the stray leaked symlinks.
	if [[ -d ${ED}/usr/lib ]]; then
		find "${ED}"/usr/lib -mindepth 1 -maxdepth 1 ! -name 'python*' \
			-exec rm -rf {} + || die
	fi

	# Used by pytorch ebuild
	insinto "/var/lib/${PN}"
	doins "${BUILD_DIR}"/CMakeCache.txt

	rm -rf python
	mkdir -p python/torch || die
	cp torch/version.py python/torch/ || die
	python_install
}