Don't include common.gypi from node source tree

[bnoordhuis]

node-gyp includes $nodedir/common.gypi when creating build files for an add-on.

Per nodejs/CTC#62 (comment), that probably isn't future-proof and it's a bad idea in general: it makes add-ons pick up compiler and linker settings that aren't intended for them and may be actively harmful. People have filed bug reports about it.

Plan of action:

1. Merge common.gypi into addon.gypi.
2. Strip everything that isn't needed by add-ons.
3. Test the bejebus out of it with citgm.

[murgatroid99]

I would support this change. I got burned by the fact that common.gypi explicitly disables -Werror

[richardlau]

Node.js 10's common.gypi requires C++14:
https://github.com/nodejs/node/blob/cf41627411886000429bde058a6594fb7f6d6d47/common.gypi#L324

which may expose anyone using older compilers to compile addons.

[bnoordhuis]

Yep, but that flows on down from V8. We'd still carry that change with a separate common.gypi.

[rvagg]

still planning on making this happen @bnoordhuis? I fear this is just going to linger as a perpetually open issue unless you make it happen, I suspect there's too many dragons for most mortals to want to attempt this

[bnoordhuis]

@rvagg It's one of those projects that I do want to get around to someday but I don't know when. If you want to close it, that's fine by me.

Good job on the cleanup action, by the way. :-)

[rvagg]

I think I got throttled along the way with my cleanup, I stopped being able to close issues, a red error box from GitHub as if I was blocked. Seems to be working again now.

I don't mind this being left open if it's genuinely a TODO, your call. I'm just aiming to get rid of the clutter so this starts being manageable again.