Can't link with zlib

[Ilya Kantor]

Hello,

I'm building git with emscripten ;)

Not libgit2, but the actual git.

Everything compiled, but at the linking stage, seems it can't find zlib.

Here's the command that I use on the (almost unpatched) fork https://github.com/iliakan/git:

emmake make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 -s USE_ZLIB=1

This is the output

==========================

...

emcc: warning: /opt/local/lib/libz.a: archive is missing an index; Use emar when creating libraries to ensure an index is created [-Wemcc]
emcc: warning: /opt/local/lib/libz.a: adding index [-Wemcc]
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflateInit_
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflate
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateInit_
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflate
emcc: error: '/opt/local/libexec/llvm-devel/bin/wasm-ld -o git-daemon.wasm -L/opt/local/lib daemon.o common-main.o libgit.a xdiff/lib.a reftable/libreftable.a libgit.a /opt/local/lib/libz.a -L/opt/local/libexec/emscripten/cache/sysroot/lib/wasm32-emscripten -lGL -lal -lhtml5 -lstubs -lnoexit -lc -ldlmalloc -lcompiler_rt -lc++-noexcept -lc++abi-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --allow-undefined-file=/var/folders/8c/z0mt42s97yz4ts2sxkbt_zv40000gn/T/tmpnnm6g2pg.undefined --export-if-defined=main --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=__main_argc_argv --export=stackSave --export=stackRestore --export=stackAlloc --export=__wasm_call_ctors --export=__errno_location --export=__get_temp_ret --export=__set_temp_ret --export=_emscripten_timeout --export=ntohs --export=htons --export=malloc --export=emscripten_builtin_memalign --export-table -z stack-size=65536 --initial-memory=16777216 --no-entry --max-memory=16777216 --global-base=1024' failed (returned 1)
make: *** [git-daemon] Error 1
emmake: error: 'make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 -s USE_ZLIB=1' failed (returned 2)

=====================

I googled around, tried some solutions, but nothing helped so far.

My host machine is MacOs Ventura.

As you can see, just adding "-s USE_ZLIB=1" doesn't work.

Please advise, how to solve this? 

[Brion Vibber]

> emcc: warning: /opt/local/lib/libz.a: archive is missing an index; Use emar when creating libraries to ensure an index is created [-Wemcc]
> emcc: warning: /opt/local/lib/libz.a: adding index [-Wemcc]

> ...

> -L/opt/local/lib

> ...

> /opt/local/lib/libz.a

It looks like you're trying to link a native macOS library? You need to build everything to wasm.

-- brion

--
You received this message because you are subscribed to the Google Groups "emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to emscripten-disc...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/emscripten-discuss/7ed7c0bf-2dc2-4f1f-91c3-0e4d70f219fbn%40googlegroups.com.

[Александр Гурьянов]

If you use -s USE_ZLIB=1, then no need to link libz.a manually

ср, 8 февр. 2023 г. в 20:06, Brion Vibber <br...@pobox.com>:

To view this discussion on the web visit https://groups.google.com/d/msgid/emscripten-discuss/CAFnWYTntKH3Yh5UPCJVQ1aBKFzxwn7RR_xe41b-JjfmV7MtZPA%40mail.gmail.com.

[Ilya Kantor]

You're right, it tries to pick up the native macOS library.

So I removed this from Makefile: EXTLIBS += -lz

The output now changed, but the symbols are still missing:

============

➜  git git:(master) ✗ emmake make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 -s USE_ZLIB=1
make: make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 -s USE_ZLIB=1
GIT_VERSION = 2.39.0.49.gf66d6d1.dirty
    * new build flags
    * new link flags
    * new prefix flags

wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(csum-file.o): undefined symbol: crc32
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflateInit_
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: inflate
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateInit_
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflateEnd
wasm-ld: error: libgit.a(zlib.o): undefined symbol: deflate

emcc: error: '/opt/local/libexec/llvm-devel/bin/wasm-ld -o git-daemon.wasm -L/opt/local/lib daemon.o common-main.o libgit.a xdiff/lib.a reftable/libreftable.a libgit.a -L/opt/local/libexec/emscripten/cache/sysroot/lib/wasm32-emscripten -lGL -lal -lhtml5 -lstubs -lnoexit -lc -ldlmalloc -lcompiler_rt -lc++-noexcept -lc++abi-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --allow-undefined-file=/var/folders/8c/z0mt42s97yz4ts2sxkbt_zv40000gn/T/tmpq3drggh0.undefined --export-if-defined=main --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=__main_argc_argv --export=stackSave --export=stackRestore --export=stackAlloc --export=__wasm_call_ctors --export=__errno_location --export=__get_temp_ret --export=__set_temp_ret --export=_emscripten_timeout --export=ntohs --export=htons --export=malloc --export=emscripten_builtin_memalign --export-table -z stack-size=65536 --initial-memory=16777216 --no-entry --max-memory=16777216 --global-base=1024' failed (returned 1)

make: *** [git-daemon] Error 1
emmake: error: 'make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 -s USE_ZLIB=1' failed (returned 2)
===================

=

[Ilya Kantor]

It seems, this line allows the linked to go on:

emmake make all CXX=em++ CC=emcc NO_REGEX=NeedsStartEnd NO_NSEC=1 NO_APPLE_COMMON_CRYPTO=1 AR=emar CSPRNG_METHOD=getentropy NO_PTHREADS=1 NO_UNIX_SOCKETS=1 NO_PERL=1 NO_GETTEXT=1 NO_PYTHON=1 NO_IPV6=1 RANLIB=emranlib NO_INITGROUPS=1 NO_ICONV=1 CFLAGS="-s USE_ZLIB=1"

In other words, I should use CFLAGS for USE_ZLIB, not pass it directly.

To view this discussion on the web visit https://groups.google.com/d/msgid/emscripten-discuss/7c29075d-c73c-4f9e-934e-bcd651b2993en%40googlegroups.com.