v8: fix call of its own deprecated API

[sam-github]

v8.h contains calls to the deprecated IsCompressible() API causing a
deprecated warning for every include of v8.h. The warning is disabled
for clang, but GNU compiler chains. Developer builds and ci build logs
are filled with pages and pages of warnings at the moment.

@targos @ofrobots @nodejs/v8 can any of you upstream this? The procedure to do so is complex for me, technically and legally. I can do it, but if its trivial for you it would be great if this could be fixed.

Btw, I don't have clang, but I suspect that it may support GCC pragmas, in which case the easier fix would to be to just change #pragma clang to #pragma GCC instead of a new if block for GCC.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[nodejs-github-bot]

@sam-github build started: https://ci.nodejs.org/blue/organizations/jenkins/node-test-pull-request-lite-pipeline/detail/node-test-pull-request-lite-pipeline/2016/pipeline

[mscdex]

Shouldn't we be bumping the V8 node patch level since we're changing things in V8 code?

[BridgeAR]

@sam-github this is already fixed in newer V8 versions.

[sam-github]

@BridgeAR Great, do you know where to find the commit? We should be able to cherry-pick it back to master, right?

[sam-github]

Found it. Thanks for git node v8 backport @joyeecheung

PTAL @ofrobots @hashseed @targos

I don't know if we care about the difference between deprecated, and deprecated soon, but we could rewrite that small amount of the change if we do.

[sam-github]

If you wonder why it matters... It took me more than a minute just to scroll down in Chrome to the end of this travis build log because its so huge with v8 compiler warnings:

https://travis-ci.com/nodejs/node/jobs/166808240

[addaleax]

If addons use this – which I would not expect – this is a breaking change, because it makes every external string appear “cacheable”, right? I’m not sure what exactly V8 does based on this flag, though.

Btw, I don't have clang, but I suspect that it may support GCC pragmas, in which case the easier fix would to be to just change #pragma clang to #pragma GCC instead of a new if block for GCC.

That might indeed be easier…

[targos]

@addaleax this commit is only relevant for master so it's fine.

[sam-github]

ci: https://ci.nodejs.org/job/node-test-pull-request/19841/

[sam-github]

Landed in 59fa7f1