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Are people still using pre-Solaris SunOS? Or is this for Solaris?

I wonder if we could set up a Github action on one or both of these platforms to test this?

In my case I used Solaris 10, so maybe Solaris would be the better name. I can modify the commit message if you like.

@googlebot I signed it!

Can we make sure that any AIX fix includes support for xlC and gcc compilers on AIX.

@gdharley Are you asking that we also support xLC and gcc, or are you worried that this might break support that is already working?

We use gcc on AIX and while protobufs compile, there are linking issues with libstdc++ which means protoc when executed has missing symbols. I have tried linking against every libstdc++ available and always different symbols are missing. Have manually edited the Makefile and can't see anything wrong.

To get around the dependencies to libstdc++ or libgcc we use LDFLAGS -static-libgcc -static-libstdc++.

Btw, we are using the cmake build instead of the autotools build. But also cmake build needs some tweaks to work. For AIX we are using a toolchain file as cmake by default generates some commands wrong (ar, ranlib).

Thanks Dietmar, I thought I had tried static linking, will try again.
I guess it is all these tweaks that need to be fixed to properly support gcc on AIX.

To get you started, here my toolchain.cmake:

set(CMAKE_C_FLAGS_INIT "-maix64 -pthread")
set(CMAKE_CXX_FLAGS_INIT "-maix64 -pthread")
set(CMAKE_SHARED_LINKER_FLAGS_INIT "-static-libgcc -static-libstdc++ -Wl,-bbigtoc")
set(CMAKE_EXE_LINKER_FLAGS_INIT "-static-libgcc -static-libstdc++ -Wl,-bbigtoc")

set(CMAKE_C_ARCHIVE_CREATE
    "<CMAKE_AR> <LINK_FLAGS> -X64 qc <TARGET> <OBJECTS>")
set(CMAKE_C_ARCHIVE_APPEND
    "<CMAKE_AR> <LINK_FLAGS> -X64 q <TARGET> <OBJECTS>")
set(CMAKE_C_ARCHIVE_FINISH "<CMAKE_RANLIB> -X64 <TARGET>")

set(CMAKE_CXX_ARCHIVE_CREATE
    "<CMAKE_AR> <LINK_FLAGS> -X64 qc <TARGET> <OBJECTS>")
set(CMAKE_CXX_ARCHIVE_APPEND
    "<CMAKE_AR> <LINK_FLAGS> -X64 q <TARGET> <OBJECTS>")
set(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -X64 <TARGET>")

Now I can build with:

cd cmake
cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
cmake --build build

This yields:

$ file build/protoc
build/protoc: 64-bit XCOFF executable or object module not stripped
$ ldd build/protoc
build/protoc needs:
         /opt/freeware/lib/libz.a(libz.so.1)
         /usr/lib/libpthreads.a(shr_xpg5_64.o)
         /usr/lib/libc.a(shr_64.o)
         /unix
         /usr/lib/libcrypt.a(shr_64.o)
$ build/protoc --version
libprotoc 3.18.1

@scddev Thanks for the fix!