Intl: Build "English-only" binaries for the distribution.

[srl295]

A new issue to continue the discussion in #6371 and #4689 - especially to implement #6371 (comment)

• provide a way to build against any ICU, not just Chromium's
• default build has very little data (just English) for a small file size
• default disk location at build time for additional data --with-default-icu-path=...
• runtime option --icu-data-dir=path.. or NODE_ICU_DATA env var can override the default
• ICU won't be in github, but can be enabled by default in builds.

/cc @tjfontaine @trevnorris

[srl295]

opened a couple of tickets in v8 that may be needed here.

[trevnorris]

Does static bool InitializeICU(const char* icu_data_file = NULL); not do enough? The API doesn't say it can't be run multiple times for each icu_data_file.

[srl295]

@trevnorris that one has some odd behavior (maybe fixable) , ignored under some build configs, and also reads the entire file into memory (fread) before applying it. My version just configures ICU to do the right thing.

Could maybe improve the API upstream (v8) and just have one function.

I actually think that InitializeICU's model may be what we will need to go with eventually, though. u_setDataDirectory() doesn't have the effect I expected it to have - in particular, it cannot override inbuilt data.

[srl295]

@tjfontaine as #7719 is nearing completion and is marked for v0.12 .. what else will need to happen so that we can get "icu .. enabled by default in builds, but not necessarily included in github"? Who builds the binaries for http://nodejs.org and is there anything that should be done to make things easier for building those?

[trevnorris]

Three things I'd like fixed before --with-intl is part of the default build:

1. ./configure shouldn't show the path to every source file that's being included for build.
2. The warning: overriding commands for target messages should be fixed (if this is a problem with gyp then either upstream the fix and update gyp, or float a patch).
3. Determine how the icu dep is included. The icu4c-53_1-src.tgz decompresses to 108 MB, but we only need ~40MB of that to do the build. So either we strip it down and include only the necessary or we download it at compile time. I don't know what we want to do, but the decision will have to be made.

[srl295]

@trevnorris

• #1 - will do.
• #2 Who is the best contact or contacts to figure this out? EDIT done in build: i18n: fix issue with icu toolset dependencies #8681
• #3 There are pros and cons here. For example, the build doesn't need ICU's unit tests, but I hesitate to separate them because they give insight into build correctness. I would like to keep investigating reducing the on disk footprint as well.

[trevnorris]

@bnoordhuis You have any ideas about the possible bug in gyp wrt the warning: overriding commands for target message?

[bnoordhuis]

I looked into it and I know what causes it now but I'm not sure how to fix it. You get that warning when using multiple toolsets for a target of type 'executable' (because both binaries end up in the PRODUCT_DIR directory) or when multiple actions have the same filename as their output (for pretty much the same reason.)

Neither is something that @srl295's patch seems to do outright but perhaps it's the result of transitive dependencies. It may be a bug in our .gyp and .gypi files after all.