Re: [PATCH RFC 3/9] lib/lz4: add the build environment for the vendored sources

[sashiko-bot@kernel.org]

> lz4_deps.h makes the unmodified upstream sources compile in the kernel:
> it supplies the ISO C spellings they expect, gives every upstream entry
> point internal linkage so an object carries only the codec it forwards,
> keeps every workspace off the stack, and renames the entry points the
> kernel re-exports with a trailing wrkmem argument.
> 
> freestanding/ forwards the four ISO C headers upstream includes
> (stddef.h, stdint.h, limits.h, string.h) to their <linux/> equivalents.
> 
> The vendored functions an object does not forward are unreferenced, so
> LZ4LIB_VISIBILITY carries __maybe_unused rather than disabling
> -Wunused-function for a directory. This also covers the pre-boot
> decompressors, which compile lz4_decompress.c textually and never see
> lib/lz4's ccflags.
> 
> For the same reason this header includes <linux/build_bug.h>: the entry
> points static_assert upstream's structure sizes, and only some
> architectures' pre-boot environments have static_assert in scope.
> 
> lz4_kernel_api.h undoes the renaming for the entry point files and
> declares what lib/lz4 exports. It starts out carrying its own copy of
> those prototypes, because it cannot include <linux/lz4.h> while that
> header still defines the three stream types upstream's headers also
> define. A later patch folds it away once they are incomplete.
> 
> Nothing includes either header yet.
> 
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260925-lz4-vendor-upstream-v1-0-1c7ffbe21c4b@samsung.com?part=3