Bug 222480 – [GTK] Fails to build in i386: static assertion failed: divisor must be a power of two

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Alberto Garcia]

I can reproduce this with WebKitGTK 2.31.90:

In file included from DerivedSources/ForwardingHeaders/wtf/FastMalloc.h:26,
                 from ../Source/WebKit/config.h:42,
                 from DerivedSources/WebKit/WebPageProxyMessageReceiver.cpp:25:
DerivedSources/ForwardingHeaders/wtf/StdLibExtras.h: In instantiation of ‘constexpr size_t WTF::roundUpToMultipleOf(size_t) [with unsigned int divisor = 48; size_t = unsigned int]’:
../Source/WebKit/Platform/IPC/StreamConnectionBuffer.h:117:96:   required from here
DerivedSources/ForwardingHeaders/wtf/StdLibExtras.h:187:27: error: static assertion failed: divisor must be a power of two!
  187 |     static_assert(divisor && !(divisor & (divisor - 1)), "divisor must be a power of two!");
      |                   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As you can see 'divisor' is 48, I suspect that the problem is in sizeof(Header) due to the differences in size_t between 32-bit and 64-bit platforms:

https://trac.webkit.org/browser/webkit/trunk/Source/WebKit/Platform/IPC/StreamConnectionBuffer.h?rev=273204#L117

[Alberto Garcia]

This was added in r273204.

[Kimmo Kinnunen]

Thanks! It's a typo:
- roundUpToMultipleOf<sizeof(std::max_align_t)>
+ roundUpToMultipleOf<alignof(std::max_align_t)>

[Kimmo Kinnunen]

I can fix it on coming Monday the latest, if nobody gets around fixing it before.

[Alberto Garcia]

Created attachment 421699 [details]
Patch

Here is the patch, thanks!

[Kimmo Kinnunen]

Comment on attachment 421699 [details]
Patch

Thanks, looks good.

[Alberto Garcia]

Committed r273643: <https://commits.webkit.org/r273643>