Why do we pass "-std=gnu++0x" to the compiler?

[targos]

Ref: https://chromium-review.googlesource.com/c/v8/v8/+/728026#message-a337cd5c8611b2408a8972deb3d20528b5845be1

It seems that we should pass -std=gnu++11 at least. Unless we support compilers that don't have this option?

[targos]

-std=gnu++14 would be even better and Clang supports it since version 3.4: https://clang.llvm.org/cxx_status.html

[targos]

Ref: nodejs/node@e43c109891d

I'm going to try and change this option to see if CI can pass.

[targos]

CI: https://ci.nodejs.org/job/node-test-commit/13446/

I already see that LinuxONE does not support it.

[targos]

/cc @nodejs/build and @nodejs/v8

[gibfahn]

cc/ @joransiu @jBarz

[targos]

So, by looking at this build, I see that we are still compiling with GCC 4.8. but we officially stopped to support it for Node 8.

New CI with -std=gnu++11: https://ci.nodejs.org/job/node-test-commit/13447/

Edit: GCC 4.8 does not support C++14. I don't know if 4.9 does.

[targos]

/cc @bnoordhuis

[refack]

RE migration to a newer version: we're trying to balance the new requirements (GCC 4.9 for example is a "soft" requirement) and still keeping the old configuration for LTS node versions.
Refs: #809
Refs: #797

1. Some old platforms (CentOS5 & 6) don't have well supported binaries of newer GCC.
2. changing the global GCC changes the global stdlib++ which requires the users to upgrade, so we're trying figure out way to either have it side-by-side, or have multiple build-bots
3. getting prebuilt toolschains for 32bit environments is also a challenge. Dropping 32-bit builds #885

[targos]

From https://chromium-review.googlesource.com/c/v8/v8/+/728026#message-697b6bb5ae15281bdd7c9b457aa75b75ef8a14ea:

C++14 is generally allowed in chromium (https://chromium-cpp.appspot.com/), hence also in V8. The only restriction is that it has to compile in GCC 4.8 (and all the other compilers we use on the bots). GCC 4.8 only supports C++11, so all code used by this compiler has to compile with c++11.

If CI is green, I'll start a new run with -std=gnu++11 with the canary branch. If it is still green, I'll submit a PR to core.

[targos]

Canary build: https://ci.nodejs.org/view/MyJobs/job/node-test-commit-node-v8/193/

Edit: that obviously does not work :(

[targos]

It's looking good on osx with -std=gnu++14.

Here is a proposition that should work:

• Build with -std=gnu++11 in GCC
• Build with -std=gnu++14 in LLVM (including osx and freebsd)

@refack do you think it's possible to modify common.gypi do achieve that?

[refack]

@refack do you think it's possible to modify common.gypi do achieve that?

Yep, I'll make a PR

[refack]

refack/node@master...higher-c++-ver-by-default

https://ci.nodejs.org/job/node-test-commit/13465/

For now I see that freebsd10 is not happy - error: invalid value 'c++14' in '-std=c++14'

[bnoordhuis]

changing the global GCC changes the global stdlib++

Right, that might be a problem. Technically it already matters if you compile with 4.8.2 or 4.8.3 (libstdc++ 6.0.18 vs. 6.0.19; 4.9 is 6.0.20) but yeah.

[fhinkel]

I know this is closed already, but I would very much like it if we could go up to GCC 4.9. We can't use a bunch of C++14 feature in V8, because then Node wouldn't compile anymore with 4.8.

[targos]

@fhinkel do you mind opening a new issue? IMO It's important that we arrive to a conclusion before the release of Node 10.