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

EAPI=8

PYTHON_COMPAT=( python3_{12..15} )

# *.bc / *.dll under llvm_zluda/src/device-libs are git-lfs blobs; llvm_zluda's
# build.rs panics on lfs stubs. GitHub tag tarballs don't carry resolved LFS
# blobs, so git-r3 + EGIT_LFS=yes is the only viable fetch path even for tags.
EGIT_LFS=yes

inherit git-r3 python-any-r1

DESCRIPTION="Drop-in replacement for CUDA on AMD GPUs"
HOMEPAGE="https://github.com/vosen/ZLUDA"

EGIT_REPO_URI="https://github.com/vosen/ZLUDA.git"
# Pin to the upstream release tag; bump = rename the .ebuild. The substitution
# maps PV to the tag: 6 -> v6, 6_pre79 -> v6-preview.79. v6 (2026-06-29) is
# upstream's first stable release, same commit as the v6-preview.79 tag.
EGIT_COMMIT="v${PV/_pre/-preview.}"
EGIT_SUBMODULES=( '*' )

# Dual-licensed; LLVM submodule (used at build time) is Apache-2.0 with the
# LLVM linking exception.
LICENSE="|| ( Apache-2.0 MIT ) Apache-2.0-with-LLVM-exceptions"
SLOT="0"
KEYWORDS="~amd64"

# cargo fetches deps at build time and git-r3 pulls submodules + LFS blobs;
# both need the network. PROPERTIES=live marks the binary non-deterministic
# between rebuilds despite the tag-pinned source revision.
PROPERTIES="live"
RESTRICT="network-sandbox test"

# build deps: no CRATES — fetches crates online, matching upstream's
# "cargo xtask --release" flow (edition 2024). cmake + python3 + C++ are
# documented build requirements for the LLVM submodule build.
BDEPEND="
	|| ( >=dev-lang/rust-1.85 >=dev-lang/rust-bin-1.85 )
	>=dev-build/cmake-3.20
	${PYTHON_DEPS}
	virtual/pkgconfig
"

# runtime: AMD ROCm/HIP stack. cdylibs we install link these via ext/*
# sys-crates (verified 2026-05-28 via ldd against the v6-preview.75 install):
#   zluda         -> hip_runtime-sys -> libamdhip64 (+ statically-bundled lz4)
#   zluda_ml      -> rocm_smi-sys    -> librocm_smi64
#   zluda_blas    -> rocblas-sys     -> librocblas    (+ libamdhip64)
#   zluda_blaslt  -> hipblaslt-sys   -> libhipblaslt  (+ libamdhip64)
#   zluda_sparse  -> rocsparse-sys   -> librocsparse
#   zluda_fft     -> stub, no extra dep
# LLVM is bundled in-tree via ext/llvm-project since upstream fc204af
# ("Build and distribute LLVM", #555); libamd_comgr is no longer linked.
RDEPEND="
	dev-util/hip
	dev-util/rocm-smi
	sci-libs/rocBLAS
	sci-libs/hipBLASLt
	sci-libs/rocSPARSE
"
DEPEND="${RDEPEND}"

src_compile() {
	# Default xtask invocation per upstream docs/src/building.md: `cargo build
	# --release` on the workspace default-members (zluda, zluda_ml, zluda_inject,
	# zluda_redirect, compiler), creating the libnvcuda.so -> libcuda.so{,.1}
	# symlinks from zluda/Cargo.toml's [package.metadata.zluda].linux_symlinks.
	cargo xtask --release || die "cargo xtask --release failed"

	# Math-library replacements (cuFFT / cuBLAS / cuBLASLt / cuSPARSE) live
	# in the workspace but aren't default-members, so xtask skips them. Build
	# them here so /opt/zluda can satisfy the corresponding libcufft.so.12 /
	# libcublas.so.12 / etc. lookups when a CUDA app is run with
	# LD_LIBRARY_PATH=/opt/zluda. Note: there is no zluda_curand crate, so
	# applications that use cuRAND (e.g. mumax3 with thermal noise) still
	# fall through to the NVIDIA stub or fail.
	local extra_pkgs=( zluda_fft zluda_blas zluda_blaslt zluda_sparse )
	local p
	for p in "${extra_pkgs[@]}"; do
		cargo build --release --package "${p}" || die "cargo build ${p} failed"
	done
}

src_install() {
	# Install to /opt/zluda (flat layout, matching upstream's prebuilt zip);
	# users opt in via LD_LIBRARY_PATH per upstream docs/src/quick_start.md.
	# Dropping libcuda.so into the default search path would shadow
	# nvidia-drivers' libcuda for any user with both installed.
	local zdir="/opt/zluda"

	insinto "${zdir}"
	# cdylibs built by xtask on Linux. Names follow each crate's [lib].name:
	#   zluda    -> libnvcuda.so
	#   zluda_ml -> libnvml.so
	#   zluda_ld -> libzluda_ld.so
	# (zluda_inject / zluda_redirect are windows_only, compiler is debug_only.)
	doins target/release/libnvcuda.so
	doins target/release/libnvml.so
	doins target/release/libzluda_ld.so

	# Symlinks declared in each crate's [package.metadata.zluda].linux_symlinks.
	dosym libnvcuda.so "${zdir}/libcuda.so"
	dosym libnvcuda.so "${zdir}/libcuda.so.1"
	dosym libnvml.so "${zdir}/libnvidia-ml.so"
	dosym libnvml.so "${zdir}/libnvidia-ml.so.1"
	# LD_AUDIT entry point (extension-less filename per quick_start.md).
	dosym libzluda_ld.so "${zdir}/zluda_ld"

	# Math-library cdylibs + their versioned-soname symlinks (see each
	# crate's [package.metadata.zluda].linux_symlinks).
	doins target/release/libcufft.so
	dosym libcufft.so "${zdir}/libcufft.so.10"
	dosym libcufft.so "${zdir}/libcufft.so.11"
	dosym libcufft.so "${zdir}/libcufft.so.12"

	doins target/release/libcublas.so
	dosym libcublas.so "${zdir}/libcublas.so.11"
	dosym libcublas.so "${zdir}/libcublas.so.12"
	dosym libcublas.so "${zdir}/libcublas.so.13"

	# zluda_blaslt's [lib].name = "cublaslt" (lowercase), so the real
	# cdylib is libcublaslt.so; libcublasLt.so (capital L) is one of the
	# linux_symlinks pointing at it, matching NVIDIA's filename casing.
	doins target/release/libcublaslt.so
	dosym libcublaslt.so "${zdir}/libcublasLt.so"
	dosym libcublaslt.so "${zdir}/libcublasLt.so.11"
	dosym libcublaslt.so "${zdir}/libcublasLt.so.12"
	dosym libcublaslt.so "${zdir}/libcublasLt.so.13"

	doins target/release/libcusparse.so
	dosym libcusparse.so "${zdir}/libcusparse.so.10"
	dosym libcusparse.so "${zdir}/libcusparse.so.11"
	dosym libcusparse.so "${zdir}/libcusparse.so.12"

	dodoc README.md
}

pkg_postinst() {
	elog ""
	elog "ZLUDA ${PV} (upstream tag v${PV/_pre/-preview.}) installed under /opt/zluda/."
	elog ""
	elog "Run a CUDA application against ZLUDA:"
	elog "  LD_LIBRARY_PATH=/opt/zluda:\${LD_LIBRARY_PATH} <APP>"
	elog ""
	elog "or via the LD_AUDIT entry point:"
	elog "  LD_AUDIT=/opt/zluda/zluda_ld <APP>"
	elog ""
	elog "ZLUDA targets AMD GPUs only — requires a working ROCm/HIP runtime"
	elog "(dev-util/hip) and a supported AMD GPU. v6 is upstream's first"
	elog "stable release, but the project remains under heavy development and"
	elog "may not yet work for your particular CUDA application."
	elog ""
	elog "For the rolling tip, use =dev-util/zluda-9999 instead."
}