include_bytes! now registers the file included

[tbelaire]

This is a little bit tricky, since with include_str!, we know that we
are including utf-8 content, so it's safe to store the source as a
String in a FileMap. We don't know that for include_bytes!, but I don't
think we actually need to track the contents anyways, so I'm passing "".

new_filemap does check for the zero length content, and it should be
reasonable, howeven I'm not sure if it would be better to pass None
instead of Some(Rc::new("")) as the src component of a FileMap.

Fixes bug #24348

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @sfackler (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. The way Github handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see CONTRIBUTING.md for more information.

[tbelaire]

Thanks @nicholasbishop, your test case was really helpful.

[alexcrichton]

Thanks! Could you add a test for this as well?

[tbelaire]

I have no idea how to test this, I'm sorry. Help?

[tbelaire]

I mean, I did test using cargo and seeing if it rebuild the target when the input changed, but I don't know how to integrate that with rust's tests.

[nagisa]

howeven I'm not sure if it would be better to pass None instead of Some(Rc::new("")) as the src component of a FileMap.

No, because then the file won’t be included into the list of dependencies.

[alexcrichton]

You'll probably want to add a run-make test which generates a dep-info file with a source that has include_bytes!, and then you can check to make sure the emitted .d file indeed has the file name as expected.

[tbelaire]

Alright, I think I understand how the tests work. How this look?

[alexcrichton]

@bors: r+ e4b3fac

Thanks!

[bors]

⌛ Testing commit e4b3fac with merge 8f209d5...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-32-nopt-t, auto-win-32-opt, auto-win-64-nopt-t, auto-win-64-opt

[krh]

Hi, sorry to crash the discussion 6 years later, but is there a way now that this kind of dependency can be logged from custom, user-written macros? I'd like to write a macro that parses an xml spec and generates code on-the-fly, but I'd want to be able to log this kind of dependency so that when the spec is edited, the rust file that includes it is recompiled.

[jonas-schievink]

Please ask questions on https://users.rust-lang.org/, not on the issue tracker