Add trailing newline check for rustc --print in run-make-support

[rejyr]

From this comment.

Checks that rustc --print stdout ends with a newline.
Adds CompletedProcess check closures to Command.
Unfortunately, this means that #[derive(Debug)] macro for Command no longer works.

Part of #121876.

r? @jieyouxu

[rustbot]

The run-make-support library was changed

cc @jieyouxu

This PR modifies tests/run-make/. If this PR is trying to port a Makefile
run-make test to use rmake.rs, please update the
run-make port tracking issue
so we can track our progress. You can either modify the tracking issue
directly, or you can comment on the tracking issue and link this PR.

cc @jieyouxu

[jieyouxu]

I don't really like the Vec<(String, Box<dyn Fn(&CompletedProcess)>)> related extra complexity here. Why is the

assert!(out.stdout_utf8().ends_with('\n'));

check not sufficient?

[rejyr]

I don't really like the Vec<(String, Box<dyn Fn(&CompletedProcess)>)> related extra complexity here. Why is the

assert!(out.stdout_utf8().ends_with('\n'));

check not sufficient?

This checks that every rustc invocation with --print is checked with a newline, instead of manually for every invocation.

The Vec<(String, Box<dyn Fn(&CompletedProcess)>)> is not great, it could be implemented with

#[derive(Debug)] // this works now
pub struct Command {
    cmd: StdCommand,
    stdin: Option<Box<[u8]>>,
    assert_stdout_ends_with_newline: bool,
    drop_bomb: DropBomb,
}

and

// Command::command_output
if self.assert_stdout_ends_with_newline {
    completed_process.assert_stdout_ends_with_newline();
}

[jieyouxu]

@rustbot review

[jieyouxu]

#[derive(Debug)] // this works now
pub struct Command {
    cmd: StdCommand,
    stdin: Option<Box<[u8]>>,
    assert_stdout_ends_with_newline: bool,
    drop_bomb: DropBomb,
}

and

// Command::command_output
if self.assert_stdout_ends_with_newline {
    completed_process.assert_stdout_ends_with_newline();
}

Let's use a simple bool for now, if there are more check-hooks that we wish to register upon construction, then we can always refactor into the hook form when it comes to it.

@rustbot author

[bors]

☔ The latest upstream changes (presumably #128075) made this pull request unmergeable. Please resolve the merge conflicts.

[JohnCSimon]

@rejyr
ping from triage - can you post your status on this PR? This PR has not received an update in a few months.

FYI: when a PR is ready for review, send a message containing
@rustbot ready to switch to S-waiting-on-review so the PR is in the reviewer's backlog.

Or if you're not going to continue, please close it. Thank you!

[rejyr]

I think checking rustc --print would be better accomplished with a dedicated test for all options instead of a hook.