[llvm] r303590 - Support for taking the max of module flags when linking, use for PIE/PIC

[Davide Italiano via llvm-commits]

On Mon, May 22, 2017 at 5:08 PM, Teresa Johnson via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: tejohnson
> Date: Mon May 22 19:08:00 2017
> New Revision: 303590
>
> URL: http://llvm.org/viewvc/llvm-project?rev=303590&view=rev
> Log:
> Support for taking the max of module flags when linking, use for PIE/PIC
>
> Summary:
> Add Max ModFlagBehavior, which can be used to take the max of two
> module flag values when merging modules. Use it for the PIE and PIC
> levels.
>
> This avoids an error when we try to import from a module built -fpic
> into a module built -fPIC, for example. For both PIE and PIC levels,
> this will be legal, since the code generation gets more conservative
> as the level is increased. Therefore we can take the max instead of
> somehow trying to block importing between modules compiled with
> different levels.
>

Related, and FYI.

Thanks!

--
Davide