features-status-dump: add new build-metrics tool

Co-authored-by: Jane Losare-Lusby <jlusby42@gmail.com>

Cargo.lock

@@ -186,6 +186,9 @@ name = "anyhow"
 version = "1.0.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34ac096ce696dc2fcabef30516bb13c0a68a11d30131d3df6f04711467681b04"
+dependencies = [
+ "backtrace",
+]
 
 [[package]]
 name = "ar_archive_writer"
@@ -1195,6 +1198,17 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "features-status-dump"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "clap",
+ "serde",
+ "serde_json",
+ "tidy",
+]
+
 [[package]]
 name = "field-offset"
 version = "0.3.6"
@@ -5373,6 +5387,7 @@ dependencies = [
  "regex",
  "rustc-hash 2.1.0",
  "semver",
+ "serde",
  "similar",
  "termcolor",
  "walkdir",

Cargo.toml

@@ -47,6 +47,7 @@ members = [
   "src/tools/coverage-dump",
   "src/tools/rustc-perf-wrapper",
   "src/tools/wasm-component-ld",
+  "src/tools/features-status-dump",
 ]
 
 exclude = [

src/tools/features-status-dump/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "features-status-dump"
+version = "0.1.0"
+license = "MIT OR Apache-2.0"
+edition = "2021"
+
+[dependencies]
+anyhow = { version = "1", features = ["backtrace"] }
+clap = { version = "4", features = ["derive"] }
+serde = { version = "1.0.125", features = [ "derive" ] }
+serde_json = "1.0.59"
+tidy = { path = "../tidy", features = ["build-metrics"] }

src/tools/features-status-dump/src/main.rs

@@ -0,0 +1,53 @@
+use std::collections::HashMap;
+use std::fs::File;
+use std::io::BufWriter;
+use std::path::PathBuf;
+
+use anyhow::{Context, Result};
+use clap::Parser;
+use tidy::features::{Feature, collect_lang_features, collect_lib_features};
+
+#[derive(Debug, Parser)]
+struct Cli {
+    /// Path to `library/` directory.
+    #[arg(long)]
+    library_path: PathBuf,
+    /// Path to `compiler/` directory.
+    #[arg(long)]
+    compiler_path: PathBuf,
+    /// Path to `output/` directory.
+    #[arg(long)]
+    output_path: PathBuf,
+}
+
+#[derive(Debug, serde::Serialize)]
+struct FeaturesStatus {
+    lang_features_status: HashMap<String, Feature>,
+    lib_features_status: HashMap<String, Feature>,
+}
+
+fn main() -> Result<()> {
+    let Cli { compiler_path, library_path, output_path } = Cli::parse();
+
+    let lang_features_status = collect_lang_features(&compiler_path, &mut false);
+    let lib_features_status = collect_lib_features(&library_path)
+        .into_iter()
+        .filter(|&(ref name, _)| !lang_features_status.contains_key(name))
+        .collect();
+    let features_status = FeaturesStatus { lang_features_status, lib_features_status };
+
+    let output_dir = output_path.parent().with_context(|| {
+        format!("failed to get parent dir of output path `{}`", output_path.display())
+    })?;
+    std::fs::create_dir_all(output_dir).with_context(|| {
+        format!("failed to create output directory at `{}`", output_dir.display())
+    })?;
+
+    let output_file = File::create(&output_path).with_context(|| {
+        format!("failed to create file at given output path `{}`", output_path.display())
+    })?;
+    let writer = BufWriter::new(output_file);
+    serde_json::to_writer_pretty(writer, &features_status)
+        .context("failed to write json output")?;
+    Ok(())
+}