unstable feature usage metrics

[yaahc]

example output

test-lib on  master [?] is 📦 v0.1.0 via 🦀 v1.80.1
❯ cat src/lib.rs
───────┬───────────────────────────────────────────────────────
│ File: src/lib.rs
───────┼───────────────────────────────────────────────────────
1 │ #![feature(unix_set_mark)]
2 │ pub fn add(left: u64, right: u64) -> u64 {
3 │ left + right
4 │ }
5 │
6 │ #[cfg(test)]
7 │ mod tests {
8 │ use super::*;
9 │
10 │ #[test]
11 │ fn it_works() {
12 │ let result = add(2, 2);
13 │ assert_eq!(result, 4);
14 │ }
15 │ }
───────┴───────────────────────────────────────────────────────
test-lib on  master [?] is 📦 v0.1.0 via 🦀 v1.80.1
❯ cargo +stage1 rustc -- -Zmetrics-dir=$PWD/metrics
Compiling test-lib v0.1.0 (/home/yaahc/tmp/test-lib)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
test-lib on  master [?] is 📦 v0.1.0 via 🦀 v1.80.1
❯ cat metrics/unstable_feature_usage.json
───────┬─────────────────────────────────────────────────────────────────────
│ File: metrics/unstable_feature_usage.json
───────┼─────────────────────────────────────────────────────────────────────
1 │ {"lib_features":[{"symbol":"unix_set_mark"}],"lang_features":[]}

related to #129485

[rustbot]

r? @cjgillot

rustbot has assigned @cjgillot.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[yaahc]

r? @estebank

[yaahc]

@estebank also here's a draft PR for the subsequent PR that adds support for dumping feature status info: yaahc#3

I have this open on my fork because it's using this PR as the base branch, it's probably worth looking at now but I don't plan to open the PR until this one lands

[rustbot]

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

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

[estebank]

r=me

[estebank]

Because we use dyn Error/IOError we don't display the file path that we couldn't open. That's not ideal but ok for now. Let's revisit in the future.

[yaahc]

@bors r=estebank

[estebank]

@bors r+

[yaahc]

@bors r=estebank

[bors]

📌 Commit 0a14f71 has been approved by estebank

It is now in the queue for this repository.