[FFmpeg-devel] CONFIG_W64_DEMUXER and dead-code elimination

Hendrik Leppkes h.leppkes at gmail.com
Sat Apr 23 13:41:13 CEST 2016

On Sat, Apr 23, 2016 at 1:21 PM, wm4 <nfxjfg at googlemail.com> wrote:
> On Sat, 23 Apr 2016 01:16:31 +0200
> Hendrik Leppkes <h.leppkes at gmail.com> wrote:
>> On Sat, Apr 23, 2016 at 1:02 AM, Bruce Dawson
>> <brucedawson-at-google.com at ffmpeg.org> wrote:
>> > I've noticed that when CONFIG_W64_DEMUXER is defined to zero that ffmpeg
>> > compiles in a reference to ff_w64_guid_data but doesn't not link w64.o
>> > (which defines that symbol).
>> >
>> > This normally works because most optimizers discard the reference
>> > to ff_w64_guid_data early enough to not cause a linker failure. However
>> > this assumption means that /Od (debug, unoptimized) and /GL (Link Time Code
>> > Generation - super optimized) builds with VC++ don't work.
>> >
>> We require dead code elimination to be available in all build modes,
>> therefor such build settings that do not have it are not supported.
>> This is not the only place that uses this, and its a design decision
>> to rely on it, therefor we won't be accepting patches to change that
>> at this time, sorry.
> Why not? Someone just volunteered to cleanup this non-sense, so why not
> let them?

Because its a concious design decision which should not be changed on
a whim, but mutually agreed by all developers.
You do know perfectly well that one person offering to clean something
up usually is not where such a topic ends, so at the very least the
decision should be baked by the active developers and followed through

- Hendrik

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