Re: [Tarantool-patches] [PATCH luajit 3/6] OSX/ARM64: Disable external unwinding for now.

[sergos via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Hi!

Thanks for the patch!

I would rephrase the original message, so that it’ll be clear that changes
are arm64-related only. 


Otherwise LGTM.

Sergos

> On 26 Sep 2022, at 18:55, Maksim Kokryashkin <max.kokryashkin@gmail.com> wrote:
> 
> From: Mike Pall <mike>
> 
> This reduces functionality, e.g. no handling of on-trace errors.
> Someone with very deep knowledge about macOS and MACH-O/DWARF stack
> unwinding internals is needed to fix this. See issue LuaJIT/LuaJIT#698.
> 
> (cherry picked from commit 27ee3bcd79b12a0c71f00427ee1a2e486c684486)
> 
> ARM64 interpreter doesn't have unwind info for Mach-O assembler
> format, which makes unwinding impossible.
> 
> For more info, see https://github.com/LuaJIT/LuaJIT/issues/698
> 
> Maxim Kokryashkin:
> * added the description for the problem
> 
> Needed for tarantool/tarantool#6096
> Needed for tarantool/tarantool#7230
> ---
> cmake/SetTargetFlags.cmake | 4 +++-
> src/Makefile.original      | 5 ++++-
> 2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/cmake/SetTargetFlags.cmake b/cmake/SetTargetFlags.cmake
> index a5a3407f..d99e1f9a 100644
> --- a/cmake/SetTargetFlags.cmake
> +++ b/cmake/SetTargetFlags.cmake
> @@ -16,7 +16,9 @@ LuaJITTestArch(TESTARCH "${TARGET_C_FLAGS}")
> LuaJITArch(LUAJIT_ARCH "${TESTARCH}")
> 
> if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
> -  AppendFlags(TARGET_C_FLAGS -DLUAJIT_UNWIND_EXTERNAL)
> +  if(NOT LUAJIT_ARCH STREQUAL "arm64")
> +    AppendFlags(TARGET_C_FLAGS -DLUAJIT_UNWIND_EXTERNAL)
> +  endif()
> else()
>   string(FIND ${TARGET_C_FLAGS} "LJ_NO_UNWIND 1" UNWIND_POS)
>   if(UNWIND_POS EQUAL -1)
> diff --git a/src/Makefile.original b/src/Makefile.original
> index d1373b40..5826a56a 100644
> --- a/src/Makefile.original
> +++ b/src/Makefile.original
> @@ -325,7 +325,10 @@ ifeq (Darwin,$(TARGET_SYS))
>     export MACOSX_DEPLOYMENT_TARGET=10.4
>   endif
>   TARGET_STRIP+= -x
> -  TARGET_XCFLAGS+= -DLUAJIT_UNWIND_EXTERNAL
> +  # Ext. unwinding is broken on OSX/ARM64 until someone finds a fix. See #698.
> +  ifneq (arm64,$(TARGET_LJARCH))
> +    TARGET_XCFLAGS+= -DLUAJIT_UNWIND_EXTERNAL
> +  endif
>   TARGET_XSHLDFLAGS= -dynamiclib -single_module -undefined dynamic_lookup -fPIC
>   TARGET_DYNXLDOPTS=
>   TARGET_XSHLDFLAGS+= -install_name $(TARGET_DYLIBPATH) -compatibility_version $(MAJVER).$(MINVER) -current_version $(MAJVER).$(MINVER).$(RELVER)
> -- 
> 2.32.1 (Apple Git-133)
>