[Development] ANGLE upgrade plans for 5.6/5.7

[Knoll Lars]

Hi Andrew,

This sounds like a solid plan. For 5.6, we probably don’t have any other
choice than staying with what we have now.

For 5.7, the desktop this sounds ok IMO. I actually don’t think we need to
(or should) support VS2012 there at all.

I’d only like to get a confirmation from the WEC maintainers, that they
are ok with this plan as well.

Cheers,
Lars

On 21/09/15 11:50, "Andrew Knight" <andrew.knight at intopalo.com> wrote:

>Hello,
>
>tl;dr: I propose that the copy of ANGLE currently in the 5.6 branch of
>qtbase be maintained without being upgraded for the next minor release
>of Qt (5.6). For Qt 5.7 and beyond, we should upgrade ANGLE from
>upstream while dropping support for VS2010 and VS2012.
>
>Around each minor Qt release someone (usually me) updates the
>third-party ANGLE sources in qtbase. The last time this happened was for
>Qt 5.5, imported from Chromium branch 2356, dated 01 April 2015.
>
>Since then (and including a good chunk of code up to that commit), the
>Chromium project has adopted C++11 and C99 usage in its codebase (due to
>switching to VS2013 as the minimum Microsoft compiler). That means a
>great deal of code no longer builds with older VS versions, and we
>already patched ANGLE for VS2010/VS2012 in Qt 5.5 to deal with some of
>these issues. Due to the invasiveness and backward thinking of such
>patches, they will not be accepted upstream.
>
>Since then, the amount of such required changes to upstream ANGLE has
>exploded; the upkeep required here is truly non-trivial. Therefore, I
>now propose that we *do not* upgrade ANGLE for 5.6. Post-5.6, we will no
>longer apply patches to support older compilers. The version in Qt 5.6
>will be maintained as any other third-party library in Qt (receiving
>patches as needed), while Qt 5.7 will only support VS2013 and newer (as
>well as recent versions of MinGW, but that is tangential to this
>discussion).
>
>As Qt 5.7 will already drop support for VS2010, I believe the only
>supported compiler this affects is VS2012. This compiler is supported
>for Windows Embedded purposes, a platform which does not use ANGLE
>anyway (see opengl.prf for details; a WinCE SDK normally provides its
>own GL stack). For keeping VS2012 Desktop binaries building, we will
>need to forcefully disable ANGLE for that compiler. I think this is a
>fair trade-off, and one which has already has a precedent set by Qt
>WebEngine.
>
>Now is the time to speak up (I'm looking at you, Windows and WinCE
>maintainers) if there is something wrong with the above proposal. Of
>course, inaction will probably lead to the same result: ANGLE will not
>be upgraded for 5.6, and we can revisit the issue nearer to the 5.7
>release when it's time to upgrade again.
>
>That said, any ANGLE-specific bugs can be assigned to me and I will do
>my best to fix them or back-port the relevant changes from upstream as
>needed.
>
>Cheers,
>Andrew
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