[libcxx-commits] [PATCH] D70815: Enable `-funwind-tables` flag when building libunwind

[Jon Roelofs via libcxx-commits]

LGTM

On Thu, Nov 28, 2019 at 6:47 AM Sergej Jaskiewicz via Phabricator <
reviews at reviews.llvm.org> wrote:

> broadwaylamb added inline comments.
>
>
> ================
> Comment at: libunwind/CMakeLists.txt:311
> +
> +if (LIBUNWIND_USES_ARM_EHABI AND NOT
> LIBUNWIND_SUPPORTS_FUNWIND_TABLES_FLAG)
> +  message(FATAL_ERROR "The -funwind-tables flag must be supported "
> ----------------
> peter.smith wrote:
> > Assuming we can't set CMAKE_TRY_COMPILE_TARGET_TYPE is to do something
> like:
> > ```
> > if (LIBUNWIND_USES_ARM_EHABI)
> >   // unconditionally add -funwind-tables
> > ```
> > Anyone trying to compile libunwind without a compiler that supports
> -funwind-tables gets an error message at build rather than configure time,
> but is there anyone that wouldn't use a form of Clang or GCC?
> My opinion is that we want to fail as early as possible. Also, we can show
> a dedicated error message if we're failing at configure time, rather than
> leaving the user on their own with the obscure 'unsupported flag' message
> (why do I need this flag, the user may ask then).
>
> I too would like to avoid the `CMAKE_TRY_COMPILE_TARGET_TYPE` dance, but
> I'd like to hear more opinions on this from the people that understand
> things better than me.
>
>
> Repository:
>   rG LLVM Github Monorepo
>
> CHANGES SINCE LAST ACTION
>   https://reviews.llvm.org/D70815/new/
>
> https://reviews.llvm.org/D70815
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/libcxx-commits/attachments/20191128/b57cad67/attachment-0001.html>