ddidderr
bdd35c838d
The legacy decoders (lib/legacy/zstd_v01.c .. zstd_v07.c) are next in the Rust migration. Each of those files is a frozen snapshot of the FSE/Huff0 entropy coders and frame logic of one historical release, so their ports must not reuse the modern Rust entropy modules and must not share code with each other: outputs and error codes have to stay byte-identical to the frozen C forever. This commit installs the build-system scaffolding so seven per-version ports can land independently, each adding only its own module file plus a one-line registration in rust/src/legacy/mod.rs. Cargo grows features legacy-v01 .. legacy-v07. They are never default features: the C build defaults differ per build system, so each build system passes the list explicitly, derived from its own legacy configuration: - lib/Makefile and programs/Makefile map ZSTD_LEGACY_SUPPORT=N to the features for versions N..7 (0 disables legacy), mirroring the ZSTD_LEGACY_FILES selection in lib/libzstd.mk. - tests/Makefile always enables all seven features because its ZSTDLEGACY_FILES wildcard compiles every lib/legacy/*.c regardless of the dispatch level. - build/meson maps legacy_level exactly like the makefiles; build/cmake enables all seven whenever ZSTD_LEGACY_SUPPORT is ON because it always compiles all seven C files (ZSTD_LEGACY_LEVEL only selects the C dispatch). Every build system also encodes the legacy selection in the Rust target directory name (e.g. c1-d1-default-legacy5), for the same reason the HUF mode is encoded there: a cached archive built for one configuration must never be linked into a build expecting another. In tests/Makefile the legacy level additionally flows into the existing HUF C-mode stamp, so the flat C test objects (which bake -DZSTD_LEGACY_SUPPORT into the dispatch) are rebuilt whenever the level changes. In programs/Makefile the compress-only, decompress-only, and CLI archives keep level-independent directories (RUST_HUF_MODE) because they are only linked into ZSTD_LEGACY_SUPPORT=0 program variants and carry no legacy features. A feature whose version has not been ported yet gates nothing: the module registration in rust/src/legacy/mod.rs is added by each port, so enabling e.g. legacy-v05 today simply leaves that decoder in C. This is what makes mixed C/Rust legacy levels link cleanly while the seven ports land in any order. Test plan: - cd rust && cargo fmt --check && cargo clippy --all-targets -- -D warnings && cargo test --all-targets - cargo clippy with --no-default-features --features decompression,legacy-v01 and with all seven legacy features - make -C tests fuzzer && ./tests/fuzzer -i1 --no-big-tests - make -C tests test-rust-lib-smoke; make -C tests test-legacy - make -C lib libzstd.a with ZSTD_LEGACY_SUPPORT=0, 1 and default (5) - cmake configure and meson setup (including -Dlegacy_level=1) emit the expected --features lists and legacy-suffixed target directories
31 lines
765 B
TOML
31 lines
765 B
TOML
[package]
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name = "zstd-rs"
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version = "0.1.0"
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edition = "2021"
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[lib]
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crate-type = ["staticlib"]
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[features]
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default = ["compression", "decompression", "dict-builder"]
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compression = []
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decompression = []
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dict-builder = []
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huf-force-decompress-x1 = []
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huf-force-decompress-x2 = []
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# Legacy-format decoders (zstd v0.1 .. v0.7). Never default features: the
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# build systems map ZSTD_LEGACY_SUPPORT=N to the features for versions >= N,
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# exactly mirroring which lib/legacy/zstd_v0N.c files the C build compiles.
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# A feature whose version is not yet ported to Rust gates nothing; the
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# original C file still provides that decoder.
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legacy-v01 = []
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legacy-v02 = []
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legacy-v03 = []
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legacy-v04 = []
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legacy-v05 = []
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legacy-v06 = []
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legacy-v07 = []
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[dependencies]
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libc = "0.2"
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