ddidderr
91c80fc8e7
The dictionary-builder sources (lib/dictBuilder) are about to start moving
to Rust, beginning with divsufsort. The Rust crate previously only modeled
the compression/decompression module split plus the forced-HUF decoder
modes, so no build could express "this C configuration includes (or
excludes) dictBuilder" to Cargo. Without that, a Rust archive could carry
dictBuilder modules into a build whose C side disabled them, or worse,
omit a migrated implementation from a build whose C shims require it.
Add a `dict-builder` cargo feature and thread it through every build that
consumes the Rust static archive, mirroring exactly how each build system
already gates the dictBuilder C sources:
- rust/Cargo.toml: new `dict-builder` feature, included in the default
set because the C library builds dictBuilder by default
(ZSTD_LIB_DICTBUILDER ?= 1). The feature is empty until the first
dictBuilder module lands.
- lib/Makefile: RUST_CARGO_FEATURES gains dict-builder when
ZSTD_LIB_DICTBUILDER is enabled, following the existing
ZSTD_LIB_COMPRESSION/ZSTD_LIB_DECOMPRESSION pattern. The archive
directory naming grows a matching `b<0|1>` dimension
(c1-d1-b1-default etc.) so differently configured archives never
collide; the repeated config prefix is factored into
RUST_MODULE_CONFIG.
- programs/Makefile: the full-featured archives now request
compression,decompression,dict-builder (equal to the default set, so
the target directory stays shared with tests). The partial-library
variants gain the `b0` name dimension, and zstd-dictBuilder gets its
own lib-c1-d0-b1 archive because it compiles the dictBuilder C sources
without decompression; it previously shared the compression-only
archive, which will lack the migrated dictBuilder symbols.
- tests/Makefile: no flag change needed since tests use the crate default
feature set; a comment now records that dict-builder arrives that way.
- build/cmake/lib/CMakeLists.txt: ZSTD_BUILD_DICTBUILDER now adds the
dict-builder feature and a `b<0|1>` component in the Rust build-config
directory name, in lockstep with the DictBuilderSources gating.
- build/meson/lib/meson.build: meson compiles the dictBuilder sources
unconditionally, so the feature list and config name gain dict-builder
unconditionally (c1-d1-b1-<huf-mode>).
The `dict-builder` feature deliberately does not imply `compression`.
lib/Makefile forces ZSTD_LIB_DICTBUILDER=0 when compression is disabled,
but CMake does not couple the two options, so encoding the C-side
constraint in Cargo would make the Rust archive diverge from the C source
list in that (already unsupported) CMake configuration.
Test plan:
- cd rust && cargo build --release
- cargo build --release --no-default-features \
--features compression,decompression
- cargo build --release --no-default-features \
--features compression,dict-builder
- Full validation (fuzzer, smoke tests, dictionary byte-identity) runs
with the follow-up commit that ports divsufsort onto this scaffolding.
Meson build system for zstandard
Meson is a build system designed to optimize programmer productivity. It aims to do this by providing simple, out-of-the-box support for modern software development tools and practices, such as unit tests, coverage reports, Valgrind, CCache and the like.
This Meson build system is provided with no guarantee and maintained by Dima Krasner <dima@dimakrasner.com>.
It outputs one libzstd, either shared or static, depending on
default_library option.
The migrated compatibility modules are built with Cargo as part of every
Meson library build. Static builds flatten the Cargo object members into
libzstd.a, so external C consumers link one archive. Shared builds use a
whole-archive link for the Cargo archive, retaining Rust-only public ABI
exports.
How to build
cd to this meson directory (build/meson)
meson setup -Dbin_programs=true -Dbin_contrib=true builddir
cd builddir
ninja # to build
ninja install # to install
You might want to install it in staging directory:
DESTDIR=./staging ninja install
To configure build options, use:
meson configure
See man meson(1).
For a cross build, set the Cargo target explicitly, for example:
meson setup -Dzstd_rust_target=aarch64-unknown-linux-gnu builddir
On 32-bit Linux, the i686-unknown-linux-gnu target is selected
automatically. Set -Dzstd_rust_archiver=... when the C cross toolchain needs
a non-default archiver. The huf_force_decompress_x1 and
huf_force_decompress_x2 options select matching C and Rust decoder modes.