Issue #20152 has been updated by nobu (Nobuyoshi Nakada). byroot (Jean Boussier) wrote:

It would be very useful to have some proper first class API to skip compiling the extension.

Something like:

```ruby require "mkmf"

if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ```

Where will this be used? ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106024 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier). In case you meant which gems would use this, then I think the 3 I listed as example would make a good use of it, and I'm certain there are some more that are in similar cases. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106029 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by nobu (Nobuyoshi Nakada). byroot (Jean Boussier) wrote in #note-2:

This would be called in `extconf.rb`

Does `skip_compilation` just make a Makefile does nothing? Then it won't be able to fix the issue that `make` is needed, since `make` is called outside `extconf.rb`. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106048 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by Eregon (Benoit Daloze). This is not something mkmf can do on its own, it would need changes in RubyGems, and it seems not so easy for RubyGems to know. When one uses `spec.extensions = ["ext/mygem/extconf.rb"]` in a `.gemspec` file, RubyGems will: 1. Run `ruby -rmkmf ext/mygem/extconf.rb`. 2. Run `make` in `ext/mygem`. Maybe RubyGems could recognize dummy Makefiles like the one created with `File.write("Makefile", dummy_makefile($srcdir).join(""))` which is the most common pattern? A bit hacky, but it would address the problem with very few changes. `File.write("Makefile", dummy_makefile($srcdir).join(""))` is already used in many gems: https://github.com/search?q=language%3ARuby+dummy_makefile%28%24srcdir%29.join&type=code But a shorter variant could be nice, e.g. `create_dummy_makefile` that does the same as `File.write("Makefile", dummy_makefile($srcdir).join(""))`. OTOH, IMO it's not a big ask for devs/users to install `make` when they are installing gems. If devs/users really want to cut dependencies in production they can and should install gems in a separate Docker image than the runtime one (already necessary e.g. for CRuby & TruffleRuby if ones wants to not ship a `cc` in the final image, [example](https://github.com/graalvm/container/blob/2a8e138fe0b0200a80a7addddedf186b5f...)). Also one might need `make` anyway, e.g. for gems used via FFI like sassc and prism, where make is used to build the C code (which does not include `ruby.h`). So trying to avoid needing make on JRuby seems very niche to me. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106051 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by kou (Kouhei Sutou). byroot (Jean Boussier) wrote in #note-8:

...

OTOH, IMO it's not a big ask for devs/users to install make when they are installing gems.

On UNIX systems it's not, but on Windows it start to be a bit more complicated.

Really? https://rubyinstaller.org/ provides MSYS2 integration by "Devkit". It provides `make`. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106055 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by Eregon (Benoit Daloze). jeremyevans0 (Jeremy Evans) wrote in #note-10:

I agree that this isn't a `mkmf`/`extconf.rb` issue. This is a rubygems issue. I think the easiest way to fix this would be for rubygems to check for a `skip-compilation-RUBY_ENGINE` file in the same directory as `extconf.rb`. If it exists, do not run `extconf.rb` or `make`. If it exists after calling `extconf.rb`, do not call `make`. This fixes cases where an extension is not needed for a certain engine, as well as cases where an extension is not needed in certain configurations, such as when a pure-ruby implementation is also shipped in the same gem, and a native library necessary for the native extension is not available.

I think `skip-compilation-RUBY_ENGINE` is going too far and counter-productive. For instance I have seen some C extensions in gems which realistically will only work on CRuby (e.g. depends on CRuby deep internals, on CRuby bytecode, optimization only profitable on CRuby, etc), in that case we'd want to avoid the extension on any `RUBY_ENGINE != "ruby"`, so a `skip-compilation-RUBY_ENGINE` would not help. There could be a `skip-make`/`skip-compilation` or so file which does not include `RUBY_ENGINE` in the filename and is created dynamically by the `extconf.rb`, but this will take a lot longer to get adopted, as it means each gem skipping compilation would need to use that. But it is error-prone, because e.g. then if one builds (e.g. `rake compile`) a gem locally on JRuby and then on CRuby then compilation will be unexpectedly skipped on CRuby, unless the code also takes care of removing that file (I guess mkmf create_makefile could remove it, it seems too annoying if `extconf.rb` or `Rakefile` needs to remove it manually). OTOH if we detect the `dummy_makefile` pattern, it's immediately picked up as soon as that RubyGems change is in, and JRuby could even cherry-pick it sooner if they care enough about it. That is why I think this is the best solution as it solves it with very few changes and faster. Another possibility would be if there is no Makefile created by extconf.rb, then RubyGems would not call `make` (`make` in a dir with no Makefile is an error so we cannot just use that). It's very simple and I think rather intuitive. And extconf.rb could just e.g. `return if RUBY_ENGINE == "jruby"/RUBY_ENGINE != "ruby"/...` at the top. A concern is if one builds (e.g. `rake compile`) a gem locally on CRuby and then on JRuby. But `rake clean` should already remove the Makefile and so that seems no problem. It is already expected and necessary that one needs to `rake clean` when switching Rubies before `rake compile`. kou (Kouhei Sutou) wrote in #note-9:

Really? https://rubyinstaller.org/ provides MSYS2 integration by "Devkit". It provides `make`.

It's mostly relevant for JRuby, it's basically not relevant for CRuby (where it's very common to have non-precompiled native extensions, like `erb`). ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106062 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by vo.x (Vit Ondruch). I believe that if something complex is needed, `RakeBuilder` could be used instead: https://github.com/rubygems/rubygems/blob/master/lib/rubygems/ext/rake_build... Just FTR, these are currently supported builders: https://github.com/rubygems/rubygems/blob/8ffa73df3a250623b13c5bf7ab48ed8b8e... ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106117 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by ivoanjo (Ivo Anjo). +1 this would be useful for the ddtrace gem as well, we also do the "if (a bunch of conditions) generate an empty makefile" [dance](https://github.com/DataDog/dd-trace-rb/blob/fd56a11a252f5887b31b783f96fc8505...). ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106144 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by Eregon (Benoit Daloze).

Another possibility would be if there is no Makefile created by extconf.rb, then RubyGems would not call make

One problem with that though is it would not work on older RubyGems, so if any gem uses that it would fail on existing Ruby releases, which kinda makes it useless unfortunately (at least short term). That's why I like detecting the dummy makefile approach so much, because it's harmless on existing Ruby releases, it helps immediately for newer Ruby releases/newer RubyGems and even requires no changes in gems (which takes a while and might not work for older RubyGems). ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106149 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by lloeki (Loic Nageleisen). There's [`spec.required_rubygems_version`](https://guides.rubygems.org/specification-reference/#required_rubygems_versi...) to enforce compatibility. On rubygems versions before the feature a dependency would then resolve to the last one non-compatible with compilation skipping. Agreed that Benoit's approach could be a transitional solution to maintain backwards compatibility while introducing the feature in short order. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106155 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier). Status changed from Open to Closed Closing since https://github.com/ruby/rubygems/pull/8879 solved the problem (but we might need to wait a while before we can really use it as it's not backward compatible). ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-116300 * Author: byroot (Jean Boussier) * Status: Closed ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/