[PATCH v1] libstdc++-v3: Update VTV vars for libtool link commands [PR99172]

[Jakub Jelinek]

On Thu, Mar 11, 2021 at 04:31:51PM +0000, Jonathan Wakely via Gcc-patches wrote:
> On 11/03/21 16:27 +0000, Jonathan Wakely wrote:
> > That seems cleaner to me, rather than adding another variable with
> > minor differences from the existing AM_CXXFLAGS.
> 
> My specific concern is that AM_CXXFLAGS and AM_CXXFLAGS_LT will get
> out of sync, i.e. we'll add something to the former and forget to add
> it to the latter.
> 
> If we keep using AM_CXXFLAGS but cancel out the -fvtable-verify=std
> option, then there aren't two separate variables that can diverge.
> 
> But I think it's too late in the gcc-11 process for that kind of
> refactoring.

I think $(filter-out -fvtable-verify=std,$(AM_CXXFLAGS)) should be fairly
simple thing if that is all that needs to be done.

	Jakub