From 3eebf9bb8085461d1d46c2fd204e75e7284aee16 Mon Sep 17 00:00:00 2001
From: Eric Huss <eric@huss.org>
Date: Mon, 25 Jan 2021 12:28:29 -0800
Subject: [PATCH] tidy: Remove cargo check.

The cargo check was checking that every dependency had an `extern crate`.
The compiler has not used `extern crate` in a long time (edition 2018).
The test was broken (the call to `!super::filter_dirs(path)` was backwards).
This just removes it since it is no longer valid.
---
 src/tools/tidy/src/cargo.rs | 90 -------------------------------------
 src/tools/tidy/src/lib.rs   |  1 -
 src/tools/tidy/src/main.rs  |  4 --
 3 files changed, 95 deletions(-)
 delete mode 100644 src/tools/tidy/src/cargo.rs

diff --git a/src/tools/tidy/src/cargo.rs b/src/tools/tidy/src/cargo.rs
deleted file mode 100644
index e06616a59f38..000000000000
--- a/src/tools/tidy/src/cargo.rs
+++ /dev/null
@@ -1,90 +0,0 @@
-//! Tidy check to ensure that `[dependencies]` and `extern crate` are in sync.
-//!
-//! This tidy check ensures that all crates listed in the `[dependencies]`
-//! section of a `Cargo.toml` are present in the corresponding `lib.rs` as
-//! `extern crate` declarations. This should help us keep the DAG correctly
-//! structured through various refactorings to prune out unnecessary edges.
-
-use std::fs;
-use std::path::Path;
-
-pub fn check(path: &Path, bad: &mut bool) {
-    if !super::filter_dirs(path) {
-        return;
-    }
-    for entry in t!(path.read_dir(), path).map(|e| t!(e)) {
-        // Look for `Cargo.toml` with a sibling `src/lib.rs` or `lib.rs`.
-        if entry.file_name().to_str() == Some("Cargo.toml") {
-            if path.join("src/lib.rs").is_file() {
-                verify(&entry.path(), &path.join("src/lib.rs"), bad)
-            }
-            if path.join("lib.rs").is_file() {
-                verify(&entry.path(), &path.join("lib.rs"), bad)
-            }
-        } else if t!(entry.file_type()).is_dir() {
-            check(&entry.path(), bad);
-        }
-    }
-}
-
-/// Verifies that the dependencies in Cargo.toml at `tomlfile` are synced with
-/// the `extern crate` annotations in the lib.rs at `libfile`.
-fn verify(tomlfile: &Path, libfile: &Path, bad: &mut bool) {
-    let toml = t!(fs::read_to_string(&tomlfile));
-    let librs = t!(fs::read_to_string(&libfile));
-
-    if toml.contains("name = \"bootstrap\"") {
-        return;
-    }
-
-    // "Poor man's TOML parser" -- just assume we use one syntax for now.
-    //
-    // We just look for:
-    //
-    // ````
-    // [dependencies]
-    // name = ...
-    // name2 = ...
-    // name3 = ...
-    // ```
-    //
-    // If we encounter a line starting with `[` then we assume it's the end of
-    // the dependency section and bail out.
-    let deps = match toml.find("[dependencies]") {
-        Some(i) => &toml[i + 1..],
-        None => return,
-    };
-    for line in deps.lines() {
-        if line.starts_with('[') {
-            break;
-        }
-
-        let krate = match line.split_once('=') {
-            None => continue,
-            Some((krate, _)) => krate.trim(),
-        };
-
-        // Don't worry about depending on core/std while not writing `extern crate
-        // core/std` -- that's intentional.
-        if krate == "core" || krate == "std" {
-            continue;
-        }
-
-        // This is intentional -- this dependency just makes the crate available
-        // for others later on.
-        let allowed = krate.starts_with("panic");
-        if toml.contains("name = \"std\"") && allowed {
-            continue;
-        }
-
-        if !librs.contains(&format!("extern crate {}", krate)) {
-            tidy_error!(
-                bad,
-                "{} doesn't have `extern crate {}`, but Cargo.toml \
-                              depends on it",
-                libfile.display(),
-                krate
-            );
-        }
-    }
-}
diff --git a/src/tools/tidy/src/lib.rs b/src/tools/tidy/src/lib.rs
index d282d240d823..27972c499244 100644
--- a/src/tools/tidy/src/lib.rs
+++ b/src/tools/tidy/src/lib.rs
@@ -40,7 +40,6 @@ macro_rules! tidy_error {
 }
 
 pub mod bins;
-pub mod cargo;
 pub mod debug_artifacts;
 pub mod deps;
 pub mod edition;
diff --git a/src/tools/tidy/src/main.rs b/src/tools/tidy/src/main.rs
index 080e16316242..2ac96e404acb 100644
--- a/src/tools/tidy/src/main.rs
+++ b/src/tools/tidy/src/main.rs
@@ -49,10 +49,6 @@ fn main() {
     style::check(&compiler_path, &mut bad);
     style::check(&library_path, &mut bad);
 
-    cargo::check(&src_path, &mut bad);
-    cargo::check(&compiler_path, &mut bad);
-    cargo::check(&library_path, &mut bad);
-
     edition::check(&src_path, &mut bad);
     edition::check(&compiler_path, &mut bad);
     edition::check(&library_path, &mut bad);