Introduce rustc_interface::interface::Config::parse_sess_created callback

compiler/rustc_driver/src/lib.rs

@@ -215,6 +215,7 @@ fn run_compiler(
             diagnostic_output,
             stderr: None,
             lint_caps: Default::default(),
+            parse_sess_created: None,
             register_lints: None,
             override_queries: None,
             make_codegen_backend: make_codegen_backend.take().unwrap(),
@@ -298,6 +299,7 @@ fn run_compiler(
         diagnostic_output,
         stderr: None,
         lint_caps: Default::default(),
+        parse_sess_created: None,
         register_lints: None,
         override_queries: None,
         make_codegen_backend: make_codegen_backend.unwrap(),

compiler/rustc_interface/src/interface.rs

@@ -142,6 +142,9 @@ pub struct Config {
 
     pub lint_caps: FxHashMap<lint::LintId, lint::Level>,
 
+    /// This is a callback from the driver that is called when [`ParseSess`] is created.
+    pub parse_sess_created: Option<Box<dyn FnOnce(&mut ParseSess) + Send>>,
+
     /// This is a callback from the driver that is called when we're registering lints;
     /// it is called during plugin registration when we have the LintStore in a non-shared state.
     ///
@@ -166,7 +169,7 @@ pub struct Config {
 
 pub fn create_compiler_and_run<R>(config: Config, f: impl FnOnce(&Compiler) -> R) -> R {
     let registry = &config.registry;
-    let (sess, codegen_backend) = util::create_session(
+    let (mut sess, codegen_backend) = util::create_session(
         config.opts,
         config.crate_cfg,
         config.diagnostic_output,
@@ -177,6 +180,14 @@ pub fn create_compiler_and_run<R>(config: Config, f: impl FnOnce(&Compiler) -> R
         registry.clone(),
     );
 
+    if let Some(parse_sess_created) = config.parse_sess_created {
+        parse_sess_created(
+            &mut Lrc::get_mut(&mut sess)
+                .expect("create_session() should never share the returned session")
+                .parse_sess,
+        );
+    }
+
     let compiler = Compiler {
         sess,
         codegen_backend,

src/librustdoc/core.rs

@@ -311,6 +311,7 @@ crate fn create_config(
         diagnostic_output: DiagnosticOutput::Default,
         stderr: None,
         lint_caps,
+        parse_sess_created: None,
         register_lints: Some(box crate::lint::register_lints),
         override_queries: Some(|_sess, providers, _external_providers| {
             // Most lints will require typechecking, so just don't run them.

src/librustdoc/doctest.rs

@@ -95,6 +95,7 @@ crate fn run(options: Options) -> Result<(), ErrorReported> {
         diagnostic_output: DiagnosticOutput::Default,
         stderr: None,
         lint_caps,
+        parse_sess_created: None,
         register_lints: Some(box crate::lint::register_lints),
         override_queries: None,
         make_codegen_backend: None,

src/test/run-make-fulldeps/issue-19371/foo.rs

@@ -57,6 +57,7 @@ fn compile(code: String, output: PathBuf, sysroot: PathBuf) {
         diagnostic_output: DiagnosticOutput::Default,
         stderr: None,
         lint_caps: Default::default(),
+        parse_sess_created: None,
         register_lints: None,
         override_queries: None,
         make_codegen_backend: None,

src/tools/clippy/src/driver.rs

@@ -15,7 +15,7 @@ extern crate rustc_session;
 extern crate rustc_span;
 
 use rustc_interface::interface;
-use rustc_session::Session;
+use rustc_session::parse::ParseSess;
 use rustc_span::symbol::Symbol;
 use rustc_tools_util::VersionInfo;
 
@@ -63,8 +63,8 @@ fn test_arg_value() {
     assert_eq!(arg_value(args, "--foo", |_| true), None);
 }
 
-fn track_clippy_args(sess: &Session, args_env_var: &Option<String>) {
-    sess.parse_sess.env_depinfo.borrow_mut().insert((
+fn track_clippy_args(parse_sess: &mut ParseSess, args_env_var: &Option<String>) {
+    parse_sess.env_depinfo.get_mut().insert((
         Symbol::intern("CLIPPY_ARGS"),
         args_env_var.as_deref().map(Symbol::intern),
     ));
@@ -81,14 +81,9 @@ struct RustcCallbacks {
 
 impl rustc_driver::Callbacks for RustcCallbacks {
     fn config(&mut self, config: &mut interface::Config) {
-        let previous = config.register_lints.take();
         let clippy_args_var = self.clippy_args_var.take();
-        config.register_lints = Some(Box::new(move |sess, lint_store| {
-            if let Some(ref previous) = previous {
-                (previous)(sess, lint_store);
-            }
-
-            track_clippy_args(sess, &clippy_args_var);
+        config.parse_sess_created = Some(Box::new(move |parse_sess| {
+            track_clippy_args(parse_sess, &clippy_args_var);
         }));
     }
 }
@@ -101,15 +96,16 @@ impl rustc_driver::Callbacks for ClippyCallbacks {
     fn config(&mut self, config: &mut interface::Config) {
         let previous = config.register_lints.take();
         let clippy_args_var = self.clippy_args_var.take();
+        config.parse_sess_created = Some(Box::new(move |parse_sess| {
+            track_clippy_args(parse_sess, &clippy_args_var);
+        }));
         config.register_lints = Some(Box::new(move |sess, mut lint_store| {
             // technically we're ~guaranteed that this is none but might as well call anything that
             // is there already. Certainly it can't hurt.
             if let Some(previous) = &previous {
                 (previous)(sess, lint_store);
             }
 
-            track_clippy_args(sess, &clippy_args_var);
-
             let conf = clippy_lints::read_conf(&[], &sess);
             clippy_lints::register_plugins(&mut lint_store, &sess, &conf);
             clippy_lints::register_pre_expansion_lints(&mut lint_store);