Bug 179750 – REGRESSION(r224887): GCC 5 build broken

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Michael Catanzaro]

r224887 avoids relying on implementation-defined behavior (multichar constants). We don't want to roll out that commit.

But it also breaks the build with GCC 5. We'd like to continue supporting GCC 5 in trunk for another half a year, as per https://trac.webkit.org/wiki/WebKitGTK/DependenciesPolicy.

This is actually pretty difficult and messy, but I think I have a solution that works for GCC 5 without sacrificing Jer's nice constexpr constructor when using newer compilers.

[Michael Catanzaro]

Created attachment 327037 [details]
Patch

[Ms2ger (he/him; ⌚ UTC+1/+2)]

Alternatively, would it be possible to add a no-argument constructor that initializes to zero? FourCC { 0 } would still be broken, but the alternative would be less ugly.

[Carlos Alberto Lopez Perez]

Comment on attachment 327037 [details]
Patch

Jer .. any opinion on this? I will r+ it tomorrow if there isn't concern about this patch.
Its a build fix, so it has a bit of urgency.

[Michael Catanzaro]

(In reply to Ms2ger from comment #2)
> Alternatively, would it be possible to add a no-argument constructor that
> initializes to zero? FourCC { 0 } would still be broken, but the alternative
> would be less ugly.

Seems like a good idea. Let's see what Jer thinks before I spend more time on this, though, because this was harder than it looks and I don't care to admit how much time I spent on it. :P

[Jer Noble]

Comment on attachment 327037 [details]
Patch

This looks fine.

[Michael Catanzaro]

(In reply to Ms2ger from comment #2)
> Alternatively, would it be possible to add a no-argument constructor that
> initializes to zero? FourCC { 0 } would still be broken, but the alternative
> would be less ugly.

Although it's ugly, I decided to stick with the current approach to avoid needing to define the no-argument constructor in the non-GCC 5 case. This way, when we delete the fallback code, we won't have the extra constructor left over.

[WebKit Commit Bot]

Comment on attachment 327037 [details]
Patch

Clearing flags on attachment: 327037

Committed r224937: <https://trac.webkit.org/changeset/224937>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/35600883>