Fails to build with GCC 10 / Clang 11 (-fno-common)

[jbeich]

Description

GCC 10 and Clang 11 enable -fno-common by default.

https://gcc.gnu.org/gcc-10/porting_to.html#common

GCC 10 error

/usr/bin/ld.bfd: openborscript.o:(.bss+0x78): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: openborscript.o:(.bss+0x80): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: sdl/control.o:(.bss+0x60): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: sdl/control.o:(.bss+0x68): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: sdl/menu.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: sdl/menu.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/gamelib/translation.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/gamelib/translation.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/gamelib/models.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/gamelib/models.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/utils.o:(.bss+0x830): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/utils.o:(.bss+0x838): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/animation.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/animation.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/axis.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/axis.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/binding.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/binding.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/drawmethod.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/drawmethod.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_attack.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_attack.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_body.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_body.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_entity.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/collision_entity.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/constants.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/constants.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/entity.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/entity.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/index.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/index.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/layer.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/layer.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/level.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/level.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/math.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/math.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/recursive_damage.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/recursive_damage.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
/usr/bin/ld.bfd: source/openborscript/string.o:(.bss+0x0): multiple definition of `model_cache'; openbor.o:(.bss+0x39b8): first defined here
/usr/bin/ld.bfd: source/openborscript/string.o:(.bss+0x8): multiple definition of `anim_list'; openbor.o:(.bss+0x39c0): first defined here
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:672: OpenBOR.elf] Error 1

Clang 11 error

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at openborscript.c
>>>            openborscript.o:(.bss+0xD80)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at openborscript.c
>>>            openborscript.o:(.bss+0x4B0)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at control.c
>>>            sdl/control.o:(.bss+0x68)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at control.c
>>>            sdl/control.o:(.bss+0x70)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at menu.c
>>>            sdl/menu.o:(.bss+0x30)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at menu.c
>>>            sdl/menu.o:(.bss+0x38)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at translation.c
>>>            source/gamelib/translation.o:(.bss+0x18)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at translation.c
>>>            source/gamelib/translation.o:(.bss+0x20)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at models.c
>>>            source/gamelib/models.o:(.bss+0x408)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at models.c
>>>            source/gamelib/models.o:(.bss+0x410)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at utils.c
>>>            source/utils.o:(.bss+0x850)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at utils.c
>>>            source/utils.o:(.bss+0x858)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at animation.c
>>>            source/openborscript/animation.o:(.bss+0x0)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at animation.c
>>>            source/openborscript/animation.o:(.bss+0x8)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at axis.c
>>>            source/openborscript/axis.o:(.bss+0x0)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at axis.c
>>>            source/openborscript/axis.o:(.bss+0x8)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at binding.c
>>>            source/openborscript/binding.o:(.bss+0x0)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at binding.c
>>>            source/openborscript/binding.o:(.bss+0x8)

ld.lld: error: duplicate symbol: anim_list
>>> defined at openbor.c
>>>            openbor.o:(anim_list)
>>> defined at drawmethod.c
>>>            source/openborscript/drawmethod.o:(.bss+0x0)

ld.lld: error: duplicate symbol: model_cache
>>> defined at openbor.c
>>>            openbor.o:(model_cache)
>>> defined at drawmethod.c
>>>            source/openborscript/drawmethod.o:(.bss+0x8)

ld.lld: error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
cc: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]: *** [Makefile:672: OpenBOR.elf] Error 1

Reproduce

1. Install GCC 10 or Clang 11
2. Set CC/CXX/CPP via environ(7)
3. Run build.sh or make BUILD_LINUX=1

Expected behavior

Builds fine

Version

• FreeBSD 13.0-CURRENT amd64 (Clang 11 is /usr/bin/cc aka the system compiler)
• OpenBOR v3.0 Build 7087 (e761464, downstream package)

[DCurrent]

Thanks, I'll look into this. Really couldn't care less about Clang, but definitely should compile on latest GCC.

Edit: Similar ticket open on GCC9, but the proposed solution (turning off an error flag) is not acceptable. The error log you provided will hopefully give some better insight. @Plombo might also have some observations as his low level knowledge far exceeds mine.

[jbeich]

Really couldn't care less about Clang

Looking at build.sh both darwin and android maybe affected in future:

• macOS: Clang is default since Xcode 4.2, GCC is dropped since Xcode 5.0 (gcc is symlink to Clang)
• Android: Clang is default since NDK r13b (October 2016), GCC is dropped since NDK r17c (June 2018)

[DCurrent]

Closing ticket to consolidate conversation with latest GCC compiling.