atom-shell causing problems

[kkoopa]

brianmcd/contextify#145

I hope this is just some temporary fork and that they'll move to io.js instead of running yet another fork. It will be impossible to support three things each claiming to be Node without any reliable way of telling them apart. Why can't v8 announce which version it is?

[bnoordhuis]

Why can't v8 announce which version it is?

I can try sending a patch. I remember looking into it one time and not quite being able to figure out how their homegrown release script updated version numbers.

[kkoopa]

That would be good. However, Node forkers need to backport that patch too, because having it only in the very latest version of v8 won't do much good in the short time.

[bnoordhuis]

You can detect that the version macro is not there, that at least tells you something. But yes, it won't do a great deal of good in the short term.

[kkoopa]

What if every fork could add a define to node-version.h

#define MY_UNIQUE_DEFINITION 1

or use a standard name, but unique value,

#define NODE_FORK_IDENTIFIER 23

[bnoordhuis]

It could work but it's not ideal because we're really only interested in the V8 version. Also, it may be an unreliable indicator when linked against a shared libv8.

[waTeim]

Here's some workaround possibilities; tl;dr PREPARSER_H in in 3.25 and 3.26 but not in 3.29, lots of changes in v8 3.14 to 3.25 (V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT for instance) I have not downloaded iojs yet.

node 11.14 and 11.13 (v8 3.26.33, 3.25.30)

bizarro% grep \\#define v8*
v8-debug.h:#define V8_V8_DEBUG_H_
v8-platform.h:#define V8_V8_PLATFORM_H_
v8-preparser.h:#define PREPARSER_H
v8-preparser.h:#define V8EXPORT __declspec(dllexport)
v8-preparser.h:#define V8EXPORT __declspec(dllimport)
v8-preparser.h:#define V8EXPORT
v8-preparser.h:#define V8EXPORT __attribute__ ((visibility("default")))
v8-preparser.h:#define V8EXPORT
v8-profiler.h:#define V8_V8_PROFILER_H_
v8-testing.h:#define V8_V8_TEST_H_
v8-util.h:#define V8_UTIL_H_
v8.h:#define V8_H_
v8.h:#define TYPE_CHECK(T, S)                                       \
v8.h:#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
v8.h:#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
v8config.h:#define V8CONFIG_H_
v8stdint.h:#define V8STDINT_H_

atom-shell (v8 3.29.88.17)

bizarro% grep \\#define v8*
v8-debug.h:#define V8_V8_DEBUG_H_
v8-platform.h:#define V8_V8_PLATFORM_H_
v8-profiler.h:#define V8_V8_PROFILER_H_
v8-testing.h:#define V8_V8_TEST_H_
v8-util.h:#define V8_UTIL_H_
v8.h:#define V8_H_
v8.h:#define TYPE_CHECK(T, S)                                       \
v8.h:#define V8_ARRAY_BUFFER_INTERNAL_FIELD_COUNT 2
v8.h:#define V8_ARRAY_BUFFER_VIEW_INTERNAL_FIELD_COUNT 2
v8config.h:#define V8CONFIG_H_
v8stdint.h:#define V8STDINT_H_

node 10.35 (v8 3.14.5.9)

v8-debug.h:#define V8_V8_DEBUG_H_
v8-debug.h:#define EXPORT __declspec(dllexport)
v8-debug.h:#define EXPORT __declspec(dllimport)
v8-debug.h:#define EXPORT
v8-debug.h:#define EXPORT __attribute__ ((visibility("default")))
v8-debug.h:#define EXPORT
v8-platform.h:#define V8_V8_PLATFORM_H_
v8-preparser.h:#define PREPARSER_H
v8-preparser.h:#define V8EXPORT __declspec(dllexport)
v8-preparser.h:#define V8EXPORT __declspec(dllimport)
v8-preparser.h:#define V8EXPORT
v8-preparser.h:#define V8EXPORT __attribute__ ((visibility("default")))
v8-preparser.h:#define V8EXPORT
v8-profiler.h:#define V8_V8_PROFILER_H_
v8-profiler.h:#define V8EXPORT __declspec(dllexport)
v8-profiler.h:#define V8EXPORT __declspec(dllimport)
v8-profiler.h:#define V8EXPORT
v8-profiler.h:#define V8EXPORT __attribute__ ((visibility("default")))
v8-profiler.h:#define V8EXPORT
v8-testing.h:#define V8_V8_TEST_H_
v8-testing.h:#define V8EXPORT __declspec(dllexport)
v8-testing.h:#define V8EXPORT __declspec(dllimport)
v8-testing.h:#define V8EXPORT
v8-testing.h:#define V8EXPORT __attribute__ ((visibility("default")))
v8-testing.h:#define V8EXPORT
v8-util.h:#define V8_UTIL_H_
v8.h:#define V8_H_
v8.h:#define V8EXPORT __declspec(dllexport)
v8.h:#define V8EXPORT __declspec(dllimport)
v8.h:#define V8EXPORT
v8.h:#define V8EXPORT __attribute__ ((visibility("default")))
v8.h:#define V8EXPORT
v8.h:#define V8EXPORT
v8.h:#define TYPE_CHECK(T, S)                                       \
v8config.h:#define V8CONFIG_H_
v8stdint.h:#define V8STDINT_H_

[kkoopa]

Seems atom-shell is about to upgrade to Chromium 40 and will raise NODE_MODULE_VERSION to 100 atom/node@83f1b41 and move to io.js. Hopefully the original problem will resolve itself then.

However, being able to actually condition on the v8 version is still highly desirable.

[waTeim]

100? lol. But there are still incompatible v8 that contextify (among others) have to worry about, though now it's 3 instead of 4 (although I don't know what will happen with node-webkit) if I remember correctly, the list node minor = 10,11,13,17,100 (but 100 == 17), or are you saying that io.js will also change to 100, but no atom might want their freedom and fork io.js too.

I think I have a solution in mind though, but it will take some cooperation. Does anyone not use node-gyp these days?

[kkoopa]

io.js will stay in range 42 -- 100, atom will be 100+, nw.js will bundle io.js
I imagine atom needs forking mostly to match v8 versions with chrome, which no other project cares about.

This might all still be manageable, but the underlying problem of not being able to reliably identify the version of v8 remains.

[mathiask88]

Why do node.js and io.js not offer a V8 version macro of the embedded version? I think the V8 team won't add a macro because there were some tries before and they were rejected. But still a backporting problem :/

[kkoopa]

The problem is shared dependencies. Lesser packagers insist on removing bundled dependencies with no regard to patches and modifications.

[waTeim]

This can be solved, I feel, so long as the maintainers of node-gyp are agreeable.

[zcbenz]

Hi, I'm upgrading atom-shell to Chrome 40, and I have noticed the problem with compatibility with nan.

In v1.6, nan assumes NODE_MODULE_VERSION < 42 is Node, otherwise it would be io.js v1.0.0. However atom-shell uses neither, we are currently using atom/node@0d02515 which is io.js < v.1.0.0, because atom-shell uses the stable release of Chrome and from atom/node@7f9a6c6 io.js started to use ES6 octal literals that is not available in Chrome 40.

Once after atom-shell starts to use Chrome 41, I can safely set NODE_MODULE_VERSION to 42 to make atom-shell compatible with nan, however currently changing NODE_MODULE_VERSION to neither 42 or some value smaller won't work.

How about making nan compatible with V8 3.30.33.15 (used by Chrome 40) when NODE_MODULE_VERSION is set to 41? So nan still works with Node and io.js v1.0.0, and I can set NODE_MODULE_VERSION to 41 in atom-shell to make it compatible with nan.

And please make sure NODE_MODULE_VERSION in io.js bumps when V8 version changes, otherwise we will still have this headache in future.