Remove LintBuffer from Session

src/librustc/hir/lowering.rs

@@ -43,6 +43,7 @@ use crate::hir::def_id::{DefId, DefIndex, CRATE_DEF_INDEX};
 use crate::hir::def::{Namespace, Res, DefKind, PartialRes, PerNS};
 use crate::hir::{GenericArg, ConstArg};
 use crate::hir::ptr::P;
+use crate::lint;
 use crate::lint::builtin::{self, PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
                     ELIDED_LIFETIMES_IN_PATHS};
 use crate::middle::cstore::CrateStore;
@@ -184,6 +185,8 @@ pub trait Resolver {
     ) -> (ast::Path, Res<NodeId>);
 
     fn has_derives(&self, node_id: NodeId, derives: SpecialDerives) -> bool;
+
+    fn lint_buffer(&mut self) -> &mut lint::LintBuffer;
 }
 
 type NtToTokenstream = fn(&Nonterminal, &ParseSess, Span) -> TokenStream;
@@ -1857,7 +1860,7 @@ impl<'a> LoweringContext<'a> {
                 GenericArgs::Parenthesized(ref data) => match parenthesized_generic_args {
                     ParenthesizedGenericArgs::Ok => self.lower_parenthesized_parameter_data(data),
                     ParenthesizedGenericArgs::Warn => {
-                        self.sess.buffer_lint(
+                        self.resolver.lint_buffer().buffer_lint(
                             PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
                             CRATE_NODE_ID,
                             data.span,
@@ -1953,7 +1956,7 @@ impl<'a> LoweringContext<'a> {
                     }
                     AnonymousLifetimeMode::PassThrough |
                     AnonymousLifetimeMode::ReportError => {
-                        self.sess.buffer_lint_with_diagnostic(
+                        self.resolver.lint_buffer().buffer_lint_with_diagnostic(
                             ELIDED_LIFETIMES_IN_PATHS,
                             CRATE_NODE_ID,
                             path_span,
@@ -3346,15 +3349,15 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
-    fn maybe_lint_bare_trait(&self, span: Span, id: NodeId, is_global: bool) {
+    fn maybe_lint_bare_trait(&mut self, span: Span, id: NodeId, is_global: bool) {
         // FIXME(davidtwco): This is a hack to detect macros which produce spans of the
         // call site which do not have a macro backtrace. See #61963.
         let is_macro_callsite = self.sess.source_map()
             .span_to_snippet(span)
             .map(|snippet| snippet.starts_with("#["))
             .unwrap_or(true);
         if !is_macro_callsite {
-            self.sess.buffer_lint_with_diagnostic(
+            self.resolver.lint_buffer().buffer_lint_with_diagnostic(
                 builtin::BARE_TRAIT_OBJECTS,
                 id,
                 span,

src/librustc/lint/context.rs

@@ -34,7 +34,6 @@ use crate::util::common::time;
 
 use errors::DiagnosticBuilder;
 use std::slice;
-use std::default::Default as StdDefault;
 use rustc_data_structures::sync::{self, ParallelIterator, join, par_iter};
 use rustc_serialize::{Decoder, Decodable, Encoder, Encodable};
 use syntax::ast;
@@ -584,12 +583,13 @@ impl<'a> EarlyContext<'a> {
         lint_store: &'a LintStore,
         krate: &'a ast::Crate,
         buffered: LintBuffer,
+        warn_about_weird_lints: bool,
     ) -> EarlyContext<'a> {
         EarlyContext {
             sess,
             krate,
             lint_store,
-            builder: LintLevelSets::builder(sess, lint_store),
+            builder: LintLevelSets::builder(sess, warn_about_weird_lints, lint_store),
             buffered,
         }
     }
@@ -1490,9 +1490,10 @@ fn early_lint_crate<T: EarlyLintPass>(
     krate: &ast::Crate,
     pass: T,
     buffered: LintBuffer,
+    warn_about_weird_lints: bool,
 ) -> LintBuffer {
     let mut cx = EarlyContextAndPass {
-        context: EarlyContext::new(sess, lint_store, krate, buffered),
+        context: EarlyContext::new(sess, lint_store, krate, buffered, warn_about_weird_lints),
         pass,
     };
 
@@ -1514,22 +1515,19 @@ pub fn check_ast_crate<T: EarlyLintPass>(
     lint_store: &LintStore,
     krate: &ast::Crate,
     pre_expansion: bool,
+    lint_buffer: Option<LintBuffer>,
     builtin_lints: T,
 ) {
-    let (mut passes, mut buffered): (Vec<_>, _) = if pre_expansion {
-        (
-            lint_store.pre_expansion_passes.iter().map(|p| (p)()).collect(),
-            LintBuffer::default(),
-        )
+    let mut passes: Vec<_> = if pre_expansion {
+        lint_store.pre_expansion_passes.iter().map(|p| (p)()).collect()
     } else {
-        (
-            lint_store.early_passes.iter().map(|p| (p)()).collect(),
-            sess.buffered_lints.borrow_mut().take().unwrap(),
-        )
+        lint_store.early_passes.iter().map(|p| (p)()).collect()
     };
+    let mut buffered = lint_buffer.unwrap_or_default();
 
     if !sess.opts.debugging_opts.no_interleave_lints {
-        buffered = early_lint_crate(sess, lint_store, krate, builtin_lints, buffered);
+        buffered = early_lint_crate(sess, lint_store, krate, builtin_lints, buffered,
+            pre_expansion);
 
         if !passes.is_empty() {
             buffered = early_lint_crate(
@@ -1538,6 +1536,7 @@ pub fn check_ast_crate<T: EarlyLintPass>(
                 krate,
                 EarlyLintPassObjects { lints: &mut passes[..] },
                 buffered,
+                pre_expansion,
             );
         }
     } else {
@@ -1549,6 +1548,7 @@ pub fn check_ast_crate<T: EarlyLintPass>(
                     krate,
                     EarlyLintPassObjects { lints: slice::from_mut(pass) },
                     buffered,
+                    pre_expansion,
                 )
             });
         }

src/librustc/lint/levels.rs

@@ -44,8 +44,12 @@ impl LintLevelSets {
         return me
     }
 
-    pub fn builder<'a>(sess: &'a Session, store: &LintStore) -> LintLevelsBuilder<'a> {
-        LintLevelsBuilder::new(sess, LintLevelSets::new(sess, store))
+    pub fn builder<'a>(
+        sess: &'a Session,
+        warn_about_weird_lints: bool,
+        store: &LintStore,
+    ) -> LintLevelsBuilder<'a> {
+        LintLevelsBuilder::new(sess, warn_about_weird_lints, LintLevelSets::new(sess, store))
     }
 
     fn process_command_line(&mut self, sess: &Session, store: &LintStore) {
@@ -160,14 +164,18 @@ pub struct BuilderPush {
 }
 
 impl<'a> LintLevelsBuilder<'a> {
-    pub fn new(sess: &'a Session, sets: LintLevelSets) -> LintLevelsBuilder<'a> {
+    pub fn new(
+        sess: &'a Session,
+        warn_about_weird_lints: bool,
+        sets: LintLevelSets,
+    ) -> LintLevelsBuilder<'a> {
         assert_eq!(sets.list.len(), 1);
         LintLevelsBuilder {
             sess,
             sets,
             cur: 0,
             id_to_set: Default::default(),
-            warn_about_weird_lints: sess.buffered_lints.borrow().is_some(),
+            warn_about_weird_lints,
         }
     }
 

src/librustc/lint/mod.rs

@@ -643,13 +643,29 @@ impl LintBuffer {
         }
     }
 
-    pub fn take(&mut self, id: ast::NodeId) -> Vec<BufferedEarlyLint> {
+    fn take(&mut self, id: ast::NodeId) -> Vec<BufferedEarlyLint> {
         self.map.remove(&id).unwrap_or_default()
     }
 
-    pub fn get_any(&self) -> Option<&[BufferedEarlyLint]> {
-        let key = self.map.keys().next().map(|k| *k);
-        key.map(|k| &self.map[&k][..])
+    pub fn buffer_lint<S: Into<MultiSpan>>(
+        &mut self,
+        lint: &'static Lint,
+        id: ast::NodeId,
+        sp: S,
+        msg: &str,
+    ) {
+        self.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
+    }
+
+    pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
+        &mut self,
+        lint: &'static Lint,
+        id: ast::NodeId,
+        sp: S,
+        msg: &str,
+        diagnostic: BuiltinLintDiagnostics,
+    ) {
+        self.add_lint(lint, id, sp.into(), msg, diagnostic)
     }
 }
 
@@ -779,7 +795,7 @@ fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap {
     assert_eq!(cnum, LOCAL_CRATE);
     let store = &tcx.lint_store;
     let mut builder = LintLevelMapBuilder {
-        levels: LintLevelSets::builder(tcx.sess, &store),
+        levels: LintLevelSets::builder(tcx.sess, false, &store),
         tcx: tcx,
         store: store,
     };

src/librustc/middle/stability.rs

@@ -586,7 +586,7 @@ pub fn rustc_deprecation_message(depr: &RustcDeprecation, path: &str) -> (String
 }
 
 pub fn early_report_deprecation(
-    sess: &Session,
+    lint_buffer: &'a mut lint::LintBuffer,
     message: &str,
     suggestion: Option<Symbol>,
     lint: &'static Lint,
@@ -597,7 +597,7 @@ pub fn early_report_deprecation(
     }
 
     let diag = BuiltinLintDiagnostics::DeprecatedMacro(suggestion, span);
-    sess.buffer_lint_with_diagnostic(lint, CRATE_NODE_ID, span, message, diag);
+    lint_buffer.buffer_lint_with_diagnostic(lint, CRATE_NODE_ID, span, message, diag);
 }
 
 fn late_report_deprecation(

src/librustc/session/config.rs

@@ -1469,7 +1469,7 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
          (such as entering an empty infinite loop) by inserting llvm.sideeffect"),
 }
 
-pub fn default_lib_output() -> CrateType {
+pub const fn default_lib_output() -> CrateType {
     CrateType::Rlib
 }
 

src/librustc/session/mod.rs

@@ -6,7 +6,6 @@ use crate::hir::def_id::CrateNum;
 use rustc_data_structures::fingerprint::Fingerprint;
 
 use crate::lint;
-use crate::lint::builtin::BuiltinLintDiagnostics;
 use crate::session::config::{OutputType, PrintRequest, Sanitizer, SwitchWithOptPath};
 use crate::session::search_paths::{PathKind, SearchPath};
 use crate::util::nodemap::{FxHashMap, FxHashSet};
@@ -77,13 +76,6 @@ pub struct Session {
     /// if the value stored here has been affected by path remapping.
     pub working_dir: (PathBuf, bool),
 
-    /// This is intended to be used from a single thread.
-    ///
-    /// FIXME: there was a previous comment about this not being thread safe,
-    /// but it's not clear how or why that's the case. The LintBuffer itself is certainly thread
-    /// safe at least from a "Rust safety" standpoint.
-    pub buffered_lints: Lock<Option<lint::LintBuffer>>,
-
     /// Set of `(DiagnosticId, Option<Span>, message)` tuples tracking
     /// (sub)diagnostics that have been set once, but should not be set again,
     /// in order to avoid redundantly verbose output (Issue #24690, #44953).
@@ -366,35 +358,6 @@ impl Session {
         self.diagnostic().span_note_without_error(sp, msg)
     }
 
-    pub fn buffer_lint<S: Into<MultiSpan>>(
-        &self,
-        lint: &'static lint::Lint,
-        id: ast::NodeId,
-        sp: S,
-        msg: &str,
-    ) {
-        match *self.buffered_lints.borrow_mut() {
-            Some(ref mut buffer) => {
-                buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
-            }
-            None => bug!("can't buffer lints after HIR lowering"),
-        }
-    }
-
-    pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
-        &self,
-        lint: &'static lint::Lint,
-        id: ast::NodeId,
-        sp: S,
-        msg: &str,
-        diagnostic: BuiltinLintDiagnostics,
-    ) {
-        match *self.buffered_lints.borrow_mut() {
-            Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
-            None => bug!("can't buffer lints after HIR lowering"),
-        }
-    }
-
     pub fn reserve_node_ids(&self, count: usize) -> ast::NodeId {
         let id = self.next_node_id.get();
 
@@ -1218,7 +1181,6 @@ fn build_session_(
         sysroot,
         local_crate_source_file,
         working_dir,
-        buffered_lints: Lock::new(Some(Default::default())),
         one_time_diagnostics: Default::default(),
         plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
         plugin_attributes: Lock::new(Vec::new()),

src/librustc_interface/passes.rs

@@ -267,6 +267,7 @@ fn configure_and_expand_inner<'a>(
             lint_store,
             &krate,
             true,
+            None,
             rustc_lint::BuiltinCombinedPreExpansionLintPass::new());
     });
 
@@ -293,6 +294,8 @@ fn configure_and_expand_inner<'a>(
         krate
     });
 
+    util::check_attr_crate_type(&krate.attrs, &mut resolver.lint_buffer());
+
     syntax_ext::plugin_macro_defs::inject(
         &mut krate, &mut resolver, plugin_info.syntax_exts, sess.edition()
     );
@@ -366,7 +369,7 @@ fn configure_and_expand_inner<'a>(
         for span in missing_fragment_specifiers {
             let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
             let msg = "missing fragment specifier";
-            sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
+            resolver.lint_buffer().buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
         }
         if cfg!(windows) {
             env::set_var("PATH", &old_path);
@@ -395,7 +398,7 @@ fn configure_and_expand_inner<'a>(
     }
 
     let has_proc_macro_decls = time(sess, "AST validation", || {
-        ast_validation::check_crate(sess, &krate)
+        ast_validation::check_crate(sess, &krate, &mut resolver.lint_buffer())
     });
 
 
@@ -464,7 +467,7 @@ fn configure_and_expand_inner<'a>(
         info!("{} parse sess buffered_lints", buffered_lints.len());
         for BufferedEarlyLint{id, span, msg, lint_id} in buffered_lints.drain(..) {
             let lint = lint::Lint::from_parser_lint_id(lint_id);
-            sess.buffer_lint(lint, id, span, &msg);
+            resolver.lint_buffer().buffer_lint(lint, id, span, &msg);
         }
     });
 
@@ -496,6 +499,7 @@ pub fn lower_to_hir(
             lint_store,
             &krate,
             false,
+            Some(std::mem::take(resolver.lint_buffer())),
             rustc_lint::BuiltinCombinedEarlyLintPass::new(),
         )
     });