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
This was added in r273204.
Thanks! It's a typo: - roundUpToMultipleOf<sizeof(std::max_align_t)> + roundUpToMultipleOf<alignof(std::max_align_t)>
I can fix it on coming Monday the latest, if nobody gets around fixing it before.
Created attachment 421699 [details] Patch Here is the patch, thanks!
Comment on attachment 421699 [details] Patch Thanks, looks good.
Committed r273643: <https://commits.webkit.org/r273643>