Use RUSTC_WRAPPER so AllCrates also runs on dependencies

crates/rustc_plugin/src/cli.rs

@@ -42,8 +42,13 @@ pub fn cli_main<T: RustcPlugin>(plugin: T) -> ExitCode {
     path.set_extension("exe");
   }
 
+  let wrapper = match args.filter {
+    CrateFilter::AllCrates => "RUSTC_WRAPPER",
+    _ => "RUSTC_WORKSPACE_WRAPPER",
+  };
+
   cmd
-    .env("RUSTC_WORKSPACE_WRAPPER", path)
+    .env(wrapper, path)
     .args(["check", "--target-dir"])
     .arg(&target_dir);
 

crates/rustc_plugin/tests/test_example.rs

@@ -89,3 +89,13 @@ fn multi() -> Result<()> {
   run("workspaces/multi", |_cmd| {})?;
   Ok(())
 }
+
+#[test]
+fn dependency() -> Result<()> {
+  let output = run("workspaces/deps", |_cmd| {})?;
+  assert!(
+    output.contains(r#"There is an item "mul" of type "function""#),
+    "output:\n{output}"
+  );
+  Ok(())
+}

crates/rustc_plugin/tests/workspaces/deps/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "deps"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+dep = { path = "dep" }

crates/rustc_plugin/tests/workspaces/deps/dep/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "dep"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

crates/rustc_plugin/tests/workspaces/deps/dep/src/lib.rs

@@ -0,0 +1,3 @@
+pub fn mul(left: usize, right: usize) -> usize {
+  left * right
+}

crates/rustc_plugin/tests/workspaces/deps/src/lib.rs

@@ -0,0 +1,3 @@
+pub fn square(x: usize) -> usize {
+  dep::mul(x, x)
+}