V8 gyp scaffolding responsibility handoff

[refack]

Refs: nodejs/CTC#76 (comment)
Refs: nodejs/CTC#2 (comment)

As per The Plan

... the legacy GYP config will be removed from V8’s repository, but stays in node/deps/v8. Keeping it in sync with GN build config becomes Node.js’ responsibility ...

AFAICT V8 has already stopped CI testing the .gyp scaffolding, and are planning to remove the .gyp files by the end of the year.

1. Should we designate an "owner" for those files?
2. Should we keep upstreaming fixes meanwhile (deps: update V8 to 6.2.414.44 node#16848 (comment))?

/CC @nodejs/v8 @nodejs/gyp @nodejs/build @targos @hashseed

[fhinkel]

Our bot is still running the regular Node make with gyp just like official Node.

[hashseed]

Precisely. We still test Node with gyp. We have plans to change this, and will notify once we have something usable.

[refack]

Our bot is still running the regular Node make with gyp just like official Node.

Obviously any CI coverage provided by V8 is greatly appreciated!
AFAICT there seems to be coverage missing - ARM was broken for a while, and Windows wasn't covered (maybe just building with MSBuild vs. ninja? While we use MSBuild and both VS2015 and VS2017).

IMHO the deprecation of the gyp scaffolding, and the pending removal is starting to be felt by node, and I'm just saying we should be ready. This way we won't need to scramble last minute to smooth over build problems when we want to backport fixes (nodejs/node#16848 (comment)).

Another point is that ATM reviewing these patches is cumbersome, since they can only land together with V8 backports or version bumps, see nodejs/node#16848 (comment)

[refack]

To reiterate, we already have knowledge and time investment in maintaining GYP (the tool), so taking ownership of the tool and the .gyp files is not too far fetched.

[seishun]

@hashseed It's 2018, any news?

[hashseed]

In the meantime I created a wrapper script as planned to create a libv8_monolith.a static library that can be used to link node instead of libv8_base.a. I haven't created a PR on the Node.js side yet to make things work smoothly.

To build node without using V8's gyp configs, perform following steps:

1. check out branch vee-eight-lkgr from https://github.com/v8/node
2. apply following patch

diff --git a/common.gypi b/common.gypi
index ba44178169..2e16bacb2b 100644
--- a/common.gypi
+++ b/common.gypi
@@ -48,7 +48,7 @@
         'V8_BASE': '<(PRODUCT_DIR)/obj/deps/v8/src/libv8_base.a',
        }, {
          'OBJ_DIR%': '<(PRODUCT_DIR)/obj.target',
-         'V8_BASE%': '<(PRODUCT_DIR)/obj.target/deps/v8/src/libv8_base.a',
+         'V8_BASE%': '<(PRODUCT_DIR)/obj.target/v8_monolith/geni/gn/obj/libv8_monolith.a',
       }],
       ['OS == "win"', {
         'os_posix': 0,
diff --git a/node.gypi b/node.gypi
index 718ef0c9e7..e88bc0520b 100644
--- a/node.gypi
+++ b/node.gypi
@@ -17,7 +17,7 @@
     }],
     [ 'node_use_bundled_v8=="true"', {
       'dependencies': [
-        'deps/v8/src/v8.gyp:v8',
+        'deps/v8/src/v8.gyp:v8_monolith',
         'deps/v8/src/v8.gyp:v8_libplatform'
       ],
     }],

3. chdir into the node checkout
4. run deps/v8/tools/node/fetch_deps.py deps/v8 force to fetch the necessary dependencies.
5. run ./configure && make -j 4 node. This uses deps/v8/tools/node/build_gn.py to build out/Release/obj.target/deps/v8/src/libv8_monolith.a to link into the final executable.

I only tested this with a static build for x64 linux. Once that's usable and streamlined I'll work on a few more build configurations.

[seishun]

Is there any difference between v8 and v8_monolith other than the way it's built?

[hashseed]

Not really. Except that v8 is a collection of files and v8_monolith just one.

[seishun]

run deps/v8/tools/node/fetch_deps.py deps/v8 to fetch the necessary dependencies.

The file deps/v8/tools/node/fetch_deps.py does not exist.

[hashseed]

Did you check out from github.com/v8/node? I landed it in the last few weeks so it's not yet in node master.

[seishun]

Yes, there's no node directory here: https://github.com/v8/node/tree/vee-eight-lkgr/deps/v8/tools