Remove all borrows of lint store from Session from librustc

Access through tcx is fine -- by that point, the lint store is frozen,
but direct access through Session will go away in future commits, as
lint store is still mutable in early stages of Session, and will be
removed completely.

4 files changed, 37 insertions, 24 deletions

diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index 4146606d443..515d4d3cd72 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -480,7 +480,7 @@ pub struct EarlyContext<'a> {
     builder: LintLevelsBuilder<'a>,
 
     /// The store of registered lints and the lint levels.
-    lint_store: ReadGuard<'a, LintStore>,
+    lint_store: &'a LintStore,
 
     buffered: LintBuffer,
 }
@@ -569,14 +569,15 @@ pub trait LintContext: Sized {
 impl<'a> EarlyContext<'a> {
     fn new(
         sess: &'a Session,
+        lint_store: &'a LintStore,
         krate: &'a ast::Crate,
         buffered: LintBuffer,
     ) -> EarlyContext<'a> {
         EarlyContext {
             sess,
             krate,
-            lint_store: sess.lint_store.borrow(),
-            builder: LintLevelSets::builder(sess),
+            lint_store,
+            builder: LintLevelSets::builder(sess, lint_store),
             buffered,
         }
     }
@@ -611,7 +612,7 @@ impl<'a, T: EarlyLintPass> EarlyContextAndPass<'a, T> {
                           f: F)
         where F: FnOnce(&mut Self)
     {
-        let push = self.context.builder.push(attrs);
+        let push = self.context.builder.push(attrs, &self.context.lint_store);
         self.check_id(id);
         self.enter_attrs(attrs);
         f(self);
@@ -1473,12 +1474,13 @@ early_lint_methods!(early_lint_pass_impl, []);
 
 fn early_lint_crate<T: EarlyLintPass>(
     sess: &Session,
+    lint_store: &LintStore,
     krate: &ast::Crate,
     pass: T,
     buffered: LintBuffer,
 ) -> LintBuffer {
     let mut cx = EarlyContextAndPass {
-        context: EarlyContext::new(sess, krate, buffered),
+        context: EarlyContext::new(sess, lint_store, krate, buffered),
         pass,
     };
 
@@ -1497,28 +1499,30 @@ fn early_lint_crate<T: EarlyLintPass>(
 
 pub fn check_ast_crate<T: EarlyLintPass>(
     sess: &Session,
+    lint_store: &LintStore,
     krate: &ast::Crate,
     pre_expansion: bool,
     builtin_lints: T,
 ) {
     let (mut passes, mut buffered): (Vec<_>, _) = if pre_expansion {
         (
-            sess.lint_store.borrow().pre_expansion_passes.iter().map(|p| (p)()).collect(),
+            lint_store.pre_expansion_passes.iter().map(|p| (p)()).collect(),
             LintBuffer::default(),
         )
     } else {
         (
-            sess.lint_store.borrow().early_passes.iter().map(|p| (p)()).collect(),
+            lint_store.early_passes.iter().map(|p| (p)()).collect(),
             sess.buffered_lints.borrow_mut().take().unwrap(),
         )
     };
 
     if !sess.opts.debugging_opts.no_interleave_lints {
-        buffered = early_lint_crate(sess, krate, builtin_lints, buffered);
+        buffered = early_lint_crate(sess, lint_store, krate, builtin_lints, buffered);
 
         if !passes.is_empty() {
             buffered = early_lint_crate(
                 sess,
+                lint_store,
                 krate,
                 EarlyLintPassObjects { lints: &mut passes[..] },
                 buffered,
@@ -1529,6 +1533,7 @@ pub fn check_ast_crate<T: EarlyLintPass>(
             buffered = time(sess, &format!("running lint: {}", pass.name()), || {
                 early_lint_crate(
                     sess,
+                    lint_store,
                     krate,
                     EarlyLintPassObjects { lints: slice::from_mut(pass) },
                     buffered,
diff --git a/src/librustc/lint/levels.rs b/src/librustc/lint/levels.rs
index 60b1b192d10..36c7c5b20fd 100644
--- a/src/librustc/lint/levels.rs
+++ b/src/librustc/lint/levels.rs
@@ -3,7 +3,7 @@ use std::cmp;
 use crate::hir::HirId;
 use crate::ich::StableHashingContext;
 use crate::lint::builtin;
-use crate::lint::context::CheckLintNameResult;
+use crate::lint::context::{LintStore, CheckLintNameResult};
 use crate::lint::{self, Lint, LintId, Level, LintSource};
 use crate::session::Session;
 use crate::util::nodemap::FxHashMap;
@@ -35,21 +35,20 @@ enum LintSet {
 }
 
 impl LintLevelSets {
-    pub fn new(sess: &Session) -> LintLevelSets {
+    pub fn new(sess: &Session, lint_store: &LintStore) -> LintLevelSets {
         let mut me = LintLevelSets {
             list: Vec::new(),
             lint_cap: Level::Forbid,
         };
-        me.process_command_line(sess);
+        me.process_command_line(sess, lint_store);
         return me
     }
 
-    pub fn builder(sess: &Session) -> LintLevelsBuilder<'_> {
-        LintLevelsBuilder::new(sess, LintLevelSets::new(sess))
+    pub fn builder<'a>(sess: &'a Session, store: &LintStore) -> LintLevelsBuilder<'a> {
+        LintLevelsBuilder::new(sess, LintLevelSets::new(sess, store))
     }
 
-    fn process_command_line(&mut self, sess: &Session) {
-        let store = sess.lint_store.borrow();
+    fn process_command_line(&mut self, sess: &Session, store: &LintStore) {
         let mut specs = FxHashMap::default();
         self.lint_cap = sess.opts.lint_cap.unwrap_or(Level::Forbid);
 
@@ -186,9 +185,8 @@ impl<'a> LintLevelsBuilder<'a> {
     ///   #[allow]
     ///
     /// Don't forget to call `pop`!
-    pub fn push(&mut self, attrs: &[ast::Attribute]) -> BuilderPush {
+    pub fn push(&mut self, attrs: &[ast::Attribute], store: &LintStore) -> BuilderPush {
         let mut specs = FxHashMap::default();
-        let store = self.sess.lint_store.borrow();
         let sess = self.sess;
         let bad_attr = |span| {
             struct_span_err!(sess, span, E0452, "malformed lint attribute input")
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index e3219b71790..ea06884d2c4 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -777,13 +777,15 @@ pub fn maybe_lint_level_root(tcx: TyCtxt<'_>, id: hir::HirId) -> bool {
 
 fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap {
     assert_eq!(cnum, LOCAL_CRATE);
+    let store = tcx.sess.lint_store.borrow();
     let mut builder = LintLevelMapBuilder {
-        levels: LintLevelSets::builder(tcx.sess),
+        levels: LintLevelSets::builder(tcx.sess, &store),
         tcx: tcx,
+        store: &*store,
     };
     let krate = tcx.hir().krate();
 
-    let push = builder.levels.push(&krate.attrs);
+    let push = builder.levels.push(&krate.attrs, &store);
     builder.levels.register_id(hir::CRATE_HIR_ID);
     for macro_def in &krate.exported_macros {
        builder.levels.register_id(macro_def.hir_id);
@@ -794,19 +796,20 @@ fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap {
     tcx.arena.alloc(builder.levels.build_map())
 }
 
-struct LintLevelMapBuilder<'tcx> {
+struct LintLevelMapBuilder<'a, 'tcx> {
     levels: levels::LintLevelsBuilder<'tcx>,
     tcx: TyCtxt<'tcx>,
+    store: &'a LintStore,
 }
 
-impl LintLevelMapBuilder<'tcx> {
+impl LintLevelMapBuilder<'_, '_> {
     fn with_lint_attrs<F>(&mut self,
                           id: hir::HirId,
                           attrs: &[ast::Attribute],
                           f: F)
         where F: FnOnce(&mut Self)
     {
-        let push = self.levels.push(attrs);
+        let push = self.levels.push(attrs, self.store);
         if push.changed {
             self.levels.register_id(id);
         }
@@ -815,7 +818,7 @@ impl LintLevelMapBuilder<'tcx> {
     }
 }
 
-impl intravisit::Visitor<'tcx> for LintLevelMapBuilder<'tcx> {
+impl intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> {
     fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'tcx> {
         intravisit::NestedVisitorMap::All(&self.tcx.hir())
     }
diff --git a/src/librustc_interface/passes.rs b/src/librustc_interface/passes.rs
index fdea437d37f..2fd7b2507a7 100644
--- a/src/librustc_interface/passes.rs
+++ b/src/librustc_interface/passes.rs
@@ -329,6 +329,7 @@ fn configure_and_expand_inner<'a>(
     time(sess, "pre-AST-expansion lint checks", || {
         lint::check_ast_crate(
             sess,
+            &*sess.lint_store.borrow(),
             &krate,
             true,
             rustc_lint::BuiltinCombinedPreExpansionLintPass::new());
@@ -556,7 +557,13 @@ pub fn lower_to_hir(
     });
 
     time(sess, "early lint checks", || {
-        lint::check_ast_crate(sess, &krate, false, rustc_lint::BuiltinCombinedEarlyLintPass::new())
+        lint::check_ast_crate(
+            sess,
+            &*sess.lint_store.borrow(),
+            &krate,
+            false,
+            rustc_lint::BuiltinCombinedEarlyLintPass::new(),
+        )
     });
 
     // Discard hygiene data, which isn't required after lowering to HIR.