From 66a98d2658997ad8ede2939e68222bd4df626718 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-no-reply-9879165716479413131@oli-obk.de>
Date: Wed, 28 Mar 2018 11:50:17 +0200
Subject: [PATCH] Use cargo check instead of cargo rustc

---
 src/driver.rs |  5 ++++-
 src/main.rs   | 18 +++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/driver.rs b/src/driver.rs
index 78bccb74ab9c..73746798601d 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -186,10 +186,13 @@ pub fn main() {
     let clippy_enabled = env::var("CLIPPY_TESTS")
         .ok()
         .map_or(false, |val| val == "true")
-        || orig_args.iter().any(|s| s == "--emit=metadata");
+        || orig_args.iter().any(|s| s == "--emit=dep-info,metadata");
 
     if clippy_enabled {
         args.extend_from_slice(&["--cfg".to_owned(), r#"feature="cargo-clippy""#.to_owned()]);
+        if let Ok(extra_args) = env::var("CLIPPY_ARGS") {
+            args.extend(extra_args.split("__CLIPPY_HACKERY__").filter(|s| !s.is_empty()).map(str::to_owned));
+        }
     }
 
     let mut ccc = ClippyCompilerCalls::new(clippy_enabled);
diff --git a/src/main.rs b/src/main.rs
index 98201af7e277..598d129dec2b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -175,23 +175,22 @@ pub fn main() {
     }
 }
 
-fn process<I>(old_args: I) -> Result<(), i32>
+fn process<I>(mut old_args: I) -> Result<(), i32>
 where
     I: Iterator<Item = String>,
 {
-    let mut args = vec!["rustc".to_owned()];
+    let mut args = vec!["check".to_owned()];
 
     let mut found_dashes = false;
-    for arg in old_args {
+    for arg in old_args.by_ref() {
         found_dashes |= arg == "--";
+        if found_dashes {
+            break;
+        }
         args.push(arg);
     }
-    if !found_dashes {
-        args.push("--".to_owned());
-    }
-    args.push("--emit=metadata".to_owned());
-    args.push("--cfg".to_owned());
-    args.push(r#"feature="cargo-clippy""#.to_owned());
+
+    let clippy_args: String = old_args.map(|arg| format!("{}__CLIPPY_HACKERY__", arg)).collect();
 
     let mut path = std::env::current_exe()
         .expect("current executable path invalid")
@@ -202,6 +201,7 @@ where
     let exit_status = std::process::Command::new("cargo")
         .args(&args)
         .env("RUSTC_WRAPPER", path)
+        .env("CLIPPY_ARGS", clippy_args)
         .spawn()
         .expect("could not run cargo")
         .wait()