Update upstream source from tag 'upstream/1.52.1+dfsg1'

[rustc.git] / src / tools / clippy / clippy_dev / src / ra_setup.rs

diff --git a/src/tools/clippy/clippy_dev/src/ra_setup.rs b/src/tools/clippy/clippy_dev/src/ra_setup.rs
new file mode 100644 (file)
index 0000000..d0e2193
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/ra_setup.rs
@@ -0,0 +1,103 @@
+use std::fs;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::{Path, PathBuf};
+
+// This module takes an absolute path to a rustc repo and alters the dependencies to point towards
+// the respective rustc subcrates instead of using extern crate xyz.
+// This allows rust analyzer to analyze rustc internals and show proper information inside clippy
+// code. See https://github.com/rust-analyzer/rust-analyzer/issues/3517 and https://github.com/rust-lang/rust-clippy/issues/5514 for details
+
+/// # Panics
+///
+/// Panics if `rustc_path` does not lead to a rustc repo or the files could not be read
+pub fn run(rustc_path: Option<&str>) {
+    // we can unwrap here because the arg is required by clap
+    let rustc_path = PathBuf::from(rustc_path.unwrap())
+        .canonicalize()
+        .expect("failed to get the absolute repo path");
+    assert!(rustc_path.is_dir(), "path is not a directory");
+    let rustc_source_basedir = rustc_path.join("compiler");
+    assert!(
+        rustc_source_basedir.is_dir(),
+        "are you sure the path leads to a rustc repo?"
+    );
+
+    let clippy_root_manifest = fs::read_to_string("Cargo.toml").expect("failed to read ./Cargo.toml");
+    let clippy_root_lib_rs = fs::read_to_string("src/driver.rs").expect("failed to read ./src/driver.rs");
+    inject_deps_into_manifest(
+        &rustc_source_basedir,
+        "Cargo.toml",
+        &clippy_root_manifest,
+        &clippy_root_lib_rs,
+    )
+    .expect("Failed to inject deps into ./Cargo.toml");
+
+    let clippy_lints_manifest =
+        fs::read_to_string("clippy_lints/Cargo.toml").expect("failed to read ./clippy_lints/Cargo.toml");
+    let clippy_lints_lib_rs =
+        fs::read_to_string("clippy_lints/src/lib.rs").expect("failed to read ./clippy_lints/src/lib.rs");
+    inject_deps_into_manifest(
+        &rustc_source_basedir,
+        "clippy_lints/Cargo.toml",
+        &clippy_lints_manifest,
+        &clippy_lints_lib_rs,
+    )
+    .expect("Failed to inject deps into ./clippy_lints/Cargo.toml");
+}
+
+fn inject_deps_into_manifest(
+    rustc_source_dir: &Path,
+    manifest_path: &str,
+    cargo_toml: &str,
+    lib_rs: &str,
+) -> std::io::Result<()> {
+    // do not inject deps if we have aleady done so
+    if cargo_toml.contains("[target.'cfg(NOT_A_PLATFORM)'.dependencies]") {
+        eprintln!(
+            "cargo dev ra_setup: warning: deps already found inside {}, doing nothing.",
+            manifest_path
+        );
+        return Ok(());
+    }
+
+    let extern_crates = lib_rs
+        .lines()
+        // get the deps
+        .filter(|line| line.starts_with("extern crate"))
+        // we have something like "extern crate foo;", we only care about the "foo"
+        //              ↓          ↓
+        // extern crate rustc_middle;
+        .map(|s| &s[13..(s.len() - 1)]);
+
+    let new_deps = extern_crates.map(|dep| {
+        // format the dependencies that are going to be put inside the Cargo.toml
+        format!(
+            "{dep} = {{ path = \"{source_path}/{dep}\" }}\n",
+            dep = dep,
+            source_path = rustc_source_dir.display()
+        )
+    });
+
+    // format a new [dependencies]-block with the new deps we need to inject
+    let mut all_deps = String::from("[target.'cfg(NOT_A_PLATFORM)'.dependencies]\n");
+    new_deps.for_each(|dep_line| {
+        all_deps.push_str(&dep_line);
+    });
+    all_deps.push_str("\n[dependencies]\n");
+
+    // replace "[dependencies]" with
+    // [dependencies]
+    // dep1 = { path = ... }
+    // dep2 = { path = ... }
+    // etc
+    let new_manifest = cargo_toml.replacen("[dependencies]\n", &all_deps, 1);
+
+    // println!("{}", new_manifest);
+    let mut file = File::create(manifest_path)?;
+    file.write_all(new_manifest.as_bytes())?;
+
+    println!("Dependency paths injected: {}", manifest_path);
+
+    Ok(())
+}