Link libc++ statically to reduce runtime dependency of wamrc

[no1wudi]

No description provided.

[yamt]

which instance of these libraries are used by shared libraries loaded by --native-lib?
is it ok to have multiple copies of these libraries in a process?

[no1wudi]

I'm not sure which copy will be used in the native lib, but it seems OK since I have used a cxx based custom compiler plugin with prebuilt wasi-sdk, it works fine without special action, please refer to: https://clang.llvm.org/docs/ClangPlugins.html

I guess it use the dynamic libc++ from system instead of the static version in the clang/wamrc

[xujuntwt95329]

Can we make this configurable?
I think static link such libraries is not a very common requirement.

[no1wudi]

@xujuntwt95329 @yamt I'm trying to make wamrc compatible with different linux distributions like https://github.com/WebAssembly/wasi-sdk/releases.

I thinks it's useful since we also provide prebuilt binary for wamrc.

[wenyongh]

@xujuntwt95329 @yamt I'm trying to make wamrc compatible with different linux distributions like https://github.com/WebAssembly/wasi-sdk/releases.

I thinks it's useful since we also provide prebuilt binary for wamrc.

@no1wudi it sounds good to me, but it increases the wamrc binary size. Could we link the static gcc/g++ lib only for the CI prebuilt binaries and keep it unchanged for normal compilation? Not sure whether it is easy to achieve that?

[lum1n0us]

I guess libc++ is a basement for every platform. If there are compatible issues with a dynamic libc++ library, it highly likely suggests there is a real compatible issue with the platform(via libc++). Using a static library may let wamrc run, but also covers some real problems, I am afraid.

[no1wudi]

Please refer to widely used wasi-sdk and llvm does if you have any concerns:
https://github.com/llvm/llvm-project/blob/de3e4a9dfe89dfc0a4d6d5e0891c542f6c82ca57/llvm/cmake/modules/HandleLLVMStdlib.cmake#L35

https://github.com/WebAssembly/wasi-sdk/blob/99abb024209dc7a9a8d8f3eb6d03908a18bb0594/Makefile#L84

Static link stdc++ should be except increase the binary size, the real problem is glibc, it's can not be linked statically.

The wasi-sdk build the toolchain on older version system (glibc, Ubuntu-18), so if glibc version in your system higher than it then you can run it.

[yamt]

Please refer to widely used wasi-sdk and llvm does if you have any concerns: https://github.com/llvm/llvm-project/blob/de3e4a9dfe89dfc0a4d6d5e0891c542f6c82ca57/llvm/cmake/modules/HandleLLVMStdlib.cmake#L35

https://github.com/WebAssembly/wasi-sdk/blob/99abb024209dc7a9a8d8f3eb6d03908a18bb0594/Makefile#L84

Static link stdc++ should be except increase the binary size, the real problem is glibc, it's can not be linked statically.

The wasi-sdk build the toolchain on older version system (glibc, Ubuntu-18), so if glibc version in your system higher than it then you can run it.

i can understand about libstdc++.
but do you have any specific concerns about libgcc?

also, can you answer this question? #3331 (comment)

[no1wudi]

Please refer to widely used wasi-sdk and llvm does if you have any concerns: https://github.com/llvm/llvm-project/blob/de3e4a9dfe89dfc0a4d6d5e0891c542f6c82ca57/llvm/cmake/modules/HandleLLVMStdlib.cmake#L35
https://github.com/WebAssembly/wasi-sdk/blob/99abb024209dc7a9a8d8f3eb6d03908a18bb0594/Makefile#L84
Static link stdc++ should be except increase the binary size, the real problem is glibc, it's can not be linked statically.
The wasi-sdk build the toolchain on older version system (glibc, Ubuntu-18), so if glibc version in your system higher than it then you can run it.

i can understand about libstdc++. but do you have any specific concerns about libgcc?

also, can you answer this question? #3331 (comment)

Maybe libgcc is not a problem for this case, but I'm not sure will it lead to compatibility issue in early test so it static linked here, we can remove it after more test.