build zstd program against zstd shared lib

[pizzard]

zstds cmake seems to not allow to build the zstd program against the shared libary. In deploying it to our embedded platform this leads to a almost doubled artifact size, which is a problem.

Is there a simple way to allow to build the zstd program against the zstd so library? this would reduce package size significantly.

[felixhandte]

See #1680 for previous discussion.

If you want to do this yourself, you certainly can: you can build libzstd.so in the normal way and then build the (minimal) binary just like you would any other executable with a dynamic dependency:

make lib
cc \
  -O3 \
  -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement -Wstrict-prototypes -Wundef -Wpointer-arith -Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings -Wredundant-decls -Wmissing-prototypes -Wc++-compat \
  -DXXH_NAMESPACE=ZSTD_ -DZSTD_NOBENCH -DZSTD_NODICT \
  programs/fileio.c programs/timefn.c programs/util.c programs/zstdcli.c \
  -Llib -lzstd -Ilib -Ilib/common -Ilib/compress -Ilib/decompress -Ilib/dictBuilder \
  -o zstd
# run it:
LD_LIBRARY_PATH=lib ./zstd --help

Does that help? Or are you specifically asking for us to include a build mode that does this?

[pizzard]

Using your feedback, my colleague created the following PR to do this.
Activation of a build switch would be a lot easier to maintain as the code above and it did work for my cross-compiled arm platform.