[llvm] r315854 - Reverting r315590; it did not include changes for llvm-tblgen, which is causing link errors for several people.

[Justin Bogner via llvm-commits]

Don Hinton <hintonda at gmail.com> writes:
> Hi Justin:
>
> The problem was with generators like XCode and MSVC that create multiple
> configurations, e.g., Release, Debug, etc., and need to rely on passing
> -DNDEBUG in order to work.  That makes it tough to use a variable like
> LLVM_ENABLE_DUMP that gets set at configure time..

One other option may be to pass the -DLLVM_ENABLE_DUMP flag to the build
as well as adding it to llvm-config.h. Would that work?

> We could probably do a partial change that doesn't remove the NDEBUG tests,
> but it still wouldn't work well with XCode and MSVC generators -- would
> still compile and link, but just not as useful on a per configuration
> basis.
>
> Please let me know if that would be helpful, and I'll create a new diff for
> you to review.

At the very least we need to make the change to move the
LLVM_ENABLE_DUMP definition into Config/llvm-config.h. Headers aren't allowed
to include Config/config.h (since it isn't installed), which means that
currently we have some uses that aren't actually correct.

An example of this is MC/MCSchedule.h, where we check LLVM_ENABLE_DUMP,
but we don't include anything that defines it.

I think we should break this into two pieces: 1. Move LLVM_ENABLE_DUMP
to llvm-config.h, and 2. Try to make this work with multi-config
generators.

> thanks...
> don
>
>
>
> On Mon, Dec 4, 2017 at 4:55 PM, Justin Bogner <mail at justinbogner.com> wrote:
>
>> Aaron Ballman <aaron at aaronballman.com> writes:
>> > On Mon, Dec 4, 2017 at 5:24 PM, Justin Bogner <mail at justinbogner.com>
>> wrote:
>> >> Aaron Ballman via llvm-commits <llvm-commits at lists.llvm.org> writes:
>> >>> Author: aaronballman
>> >>> Date: Sun Oct 15 07:32:27 2017
>> >>> New Revision: 315854
>> >>>
>> >>> URL: http://llvm.org/viewvc/llvm-project?rev=315854&view=rev
>> >>> Log:
>> >>> Reverting r315590; it did not include changes for llvm-tblgen, which
>> >>> is causing link errors for several people.
>> >>
>> >> What's happening with this? Is someone investigating these errors? I'd
>> >> really like the part of this change that moves LLVM_ENABLE_DUMP into
>> >> llvm-config.h to get in, as it's currently kind of awkward to use in the
>> >> half finished state.
>> >>
>> >>> Error LNK2019 unresolved external symbol "public: void __cdecl
>> >>> `anonymous namespace'::MatchableInfo::dump(void)const "
>> >>> (?dump at MatchableInfo@?A0xf4f1c304@@QEBAXXZ) referenced in function
>> >>> "public: void __cdecl `anonymous
>> >>> namespace'::AsmMatcherEmitter::run(class llvm::raw_ostream &)"
>> >>> (?run at AsmMatcherEmitter@?A0xf4f1c304@@QEAAXAEAVraw_ostream at llvm@@@Z)
>> >>> llvm-tblgen D:\llvm\2017\utils\TableGen\AsmMatcherEmitter.obj 1
>> >
>> > I've not been investigating -- I was only trying to get the bot back
>> > to green. Perhaps Don has worked on this, however.
>>
>> Okay, I couldn't find any email trail of followup (not even to mention
>> the commit was reverted!), so I wasn't sure if I'd just missed the
>> conversation here.
>>