Migrate resolver over to internal lint buffer

Author: Mark-Simulacrum

src/librustc/lint/mod.rs

@@ -646,6 +646,27 @@ impl LintBuffer {
     fn take(&mut self, id: ast::NodeId) -> Vec<BufferedEarlyLint> {
         self.map.remove(&id).unwrap_or_default()
     }
+
+    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)
+    }
 }
 
 pub fn struct_lint_level<'a>(sess: &'a Session,

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_interface/passes.rs

@@ -270,12 +270,14 @@ fn configure_and_expand_inner<'a>(
             rustc_lint::BuiltinCombinedPreExpansionLintPass::new());
     });
 
+    let lint_buffer = lint::LintBuffer::default();
     let mut resolver = Resolver::new(
         sess,
         &krate,
         crate_name,
         metadata_loader,
         &resolver_arenas,
+        lint_buffer,
     );
     syntax_ext::register_builtin_macros(&mut resolver, sess.edition());
 
@@ -366,7 +368,7 @@ 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 +397,7 @@ 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 +466,7 @@ 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);
         }
     });
 

src/librustc_passes/ast_validation.rs

@@ -73,6 +73,8 @@ struct AstValidator<'a> {
     /// these booleans.
     warning_period_57979_didnt_record_next_impl_trait: bool,
     warning_period_57979_impl_trait_in_proj: bool,
+
+    lint_buffer: &'a mut lint::LintBuffer,
 }
 
 impl<'a> AstValidator<'a> {
@@ -229,7 +231,7 @@ impl<'a> AstValidator<'a> {
         err.emit();
     }
 
-    fn check_decl_no_pat<ReportFn: Fn(Span, bool)>(&self, decl: &FnDecl, report_err: ReportFn) {
+    fn check_decl_no_pat<F: FnMut(Span, bool)>(decl: &FnDecl, mut report_err: F) {
         for arg in &decl.inputs {
             match arg.pat.kind {
                 PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), _, None) |
@@ -460,7 +462,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         match ty.kind {
             TyKind::BareFn(ref bfty) => {
                 self.check_fn_decl(&bfty.decl);
-                self.check_decl_no_pat(&bfty.decl, |span, _| {
+                Self::check_decl_no_pat(&bfty.decl, |span, _| {
                     struct_span_err!(self.session, span, E0561,
                                      "patterns aren't allowed in function pointer types").emit();
                 });
@@ -483,7 +485,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
             TyKind::ImplTrait(_, ref bounds) => {
                 if self.is_impl_trait_banned {
                     if self.warning_period_57979_impl_trait_in_proj {
-                        self.session.buffer_lint(
+                        self.lint_buffer.buffer_lint(
                             NESTED_IMPL_TRAIT, ty.id, ty.span,
                             "`impl Trait` is not allowed in path parameters");
                     } else {
@@ -494,7 +496,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
 
                 if let Some(outer_impl_trait) = self.outer_impl_trait {
                     if outer_impl_trait.should_warn_instead_of_error() {
-                        self.session.buffer_lint_with_diagnostic(
+                        self.lint_buffer.buffer_lint_with_diagnostic(
                             NESTED_IMPL_TRAIT, ty.id, ty.span,
                             "nested `impl Trait` is not allowed",
                             BuiltinLintDiagnostics::NestedImplTrait {
@@ -634,9 +636,9 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                         self.check_trait_fn_not_async(trait_item.span, sig.header.asyncness.node);
                         self.check_trait_fn_not_const(sig.header.constness);
                         if block.is_none() {
-                            self.check_decl_no_pat(&sig.decl, |span, mut_ident| {
+                            Self::check_decl_no_pat(&sig.decl, |span, mut_ident| {
                                 if mut_ident {
-                                    self.session.buffer_lint(
+                                    self.lint_buffer.buffer_lint(
                                         lint::builtin::PATTERNS_IN_FNS_WITHOUT_BODY,
                                         trait_item.id, span,
                                         "patterns aren't allowed in methods without bodies");
@@ -655,7 +657,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 if attr::contains_name(&item.attrs, sym::warn_directory_ownership) {
                     let lint = lint::builtin::LEGACY_DIRECTORY_OWNERSHIP;
                     let msg = "cannot declare a new module at this location";
-                    self.session.buffer_lint(lint, item.id, item.span, msg);
+                    self.lint_buffer.buffer_lint(lint, item.id, item.span, msg);
                 }
             }
             ItemKind::Union(ref vdata, _) => {
@@ -686,7 +688,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         match fi.kind {
             ForeignItemKind::Fn(ref decl, _) => {
                 self.check_fn_decl(decl);
-                self.check_decl_no_pat(decl, |span, _| {
+                Self::check_decl_no_pat(decl, |span, _| {
                     struct_span_err!(self.session, span, E0130,
                                      "patterns aren't allowed in foreign function declarations")
                         .span_label(span, "pattern not allowed in foreign function").emit();
@@ -840,7 +842,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
     }
 }
 
-pub fn check_crate(session: &Session, krate: &Crate) -> bool {
+pub fn check_crate(session: &Session, krate: &Crate, lints: &mut lint::LintBuffer) -> bool {
     let mut validator = AstValidator {
         session,
         has_proc_macro_decls: false,
@@ -849,6 +851,7 @@ pub fn check_crate(session: &Session, krate: &Crate) -> bool {
         is_assoc_ty_bound_banned: false,
         warning_period_57979_didnt_record_next_impl_trait: false,
         warning_period_57979_impl_trait_in_proj: false,
+        lint_buffer: lints,
     };
     visit::walk_crate(&mut validator, krate);
 

src/librustc_resolve/check_unused.rs

@@ -232,7 +232,7 @@ impl Resolver<'_> {
                     directive.span.is_dummy() => {
                     if let ImportDirectiveSubclass::MacroUse = directive.subclass {
                         if !directive.span.is_dummy() {
-                            self.session.buffer_lint(
+                            self.lint_buffer.buffer_lint(
                                 lint::builtin::MACRO_USE_EXTERN_CRATE,
                                 directive.id,
                                 directive.span,
@@ -250,7 +250,7 @@ impl Resolver<'_> {
                 ImportDirectiveSubclass::MacroUse => {
                     let lint = lint::builtin::UNUSED_IMPORTS;
                     let msg = "unused `#[macro_use]` import";
-                    self.session.buffer_lint(lint, directive.id, directive.span, msg);
+                    self.lint_buffer.buffer_lint(lint, directive.id, directive.span, msg);
                 }
                 _ => {}
             }
@@ -312,7 +312,7 @@ impl Resolver<'_> {
                 "remove the unused import"
             };
 
-            visitor.r.session.buffer_lint_with_diagnostic(
+            visitor.r.lint_buffer.buffer_lint_with_diagnostic(
                 lint::builtin::UNUSED_IMPORTS,
                 unused.use_tree_id,
                 ms,

src/librustc_resolve/late.rs

@@ -1548,7 +1548,7 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> {
                             if is_expected(ctor_res) &&
                                self.r.is_accessible_from(ctor_vis, self.parent_scope.module) {
                                 let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
-                                self.r.session.buffer_lint(lint, id, span,
+                                self.r.lint_buffer.buffer_lint(lint, id, span,
                                     "private struct constructors are not usable through \
                                      re-exports in outer modules",
                                 );
@@ -1774,7 +1774,7 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> {
             };
             if result.base_res() == unqualified_result {
                 let lint = lint::builtin::UNUSED_QUALIFICATIONS;
-                self.r.session.buffer_lint(lint, id, span, "unnecessary qualification")
+                self.r.lint_buffer.buffer_lint(lint, id, span, "unnecessary qualification")
             }
         }
 
@@ -2111,7 +2111,7 @@ impl<'a> Resolver<'a> {
         let mut late_resolution_visitor = LateResolutionVisitor::new(self);
         visit::walk_crate(&mut late_resolution_visitor, krate);
         for (id, span) in late_resolution_visitor.diagnostic_metadata.unused_labels.iter() {
-            self.session.buffer_lint(lint::builtin::UNUSED_LABELS, *id, *span, "unused label");
+            self.lint_buffer.buffer_lint(lint::builtin::UNUSED_LABELS, *id, *span, "unused label");
         }
     }
 }

src/librustc_resolve/lib.rs

@@ -962,6 +962,8 @@ pub struct Resolver<'a> {
     /// Stores enum visibilities to properly build a reduced graph
     /// when visiting the correspondent variants.
     variant_vis: DefIdMap<ty::Visibility>,
+
+    pub lint_buffer: lint::LintBuffer,
 }
 
 /// Nothing really interesting here; it just provides memory for the rest of the crate.
@@ -1088,7 +1090,8 @@ impl<'a> Resolver<'a> {
                krate: &Crate,
                crate_name: &str,
                metadata_loader: &'a MetadataLoaderDyn,
-               arenas: &'a ResolverArenas<'a>)
+               arenas: &'a ResolverArenas<'a>,
+               lint_buffer: lint::LintBuffer)
                -> Resolver<'a> {
         let root_def_id = DefId::local(CRATE_DEF_INDEX);
         let root_module_kind = ModuleKind::Def(
@@ -1227,7 +1230,8 @@ impl<'a> Resolver<'a> {
                 features.declared_lib_features.iter().map(|(feat, ..)| *feat)
                     .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
                     .collect(),
-            variant_vis: Default::default()
+            variant_vis: Default::default(),
+            lint_buffer,
         }
     }
 
@@ -1653,7 +1657,7 @@ impl<'a> Resolver<'a> {
             match result {
                 Ok(binding) => {
                     if let Some(node_id) = poisoned {
-                        self.session.buffer_lint_with_diagnostic(
+                        self.lint_buffer.buffer_lint_with_diagnostic(
                             lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
                             node_id, ident.span,
                             &format!("cannot find {} `{}` in this scope", ns.descr(), ident),
@@ -2118,7 +2122,7 @@ impl<'a> Resolver<'a> {
     }
 
     fn lint_if_path_starts_with_module(
-        &self,
+        &mut self,
         crate_lint: CrateLint,
         path: &[Segment],
         path_span: Span,
@@ -2169,7 +2173,7 @@ impl<'a> Resolver<'a> {
 
         let diag = lint::builtin::BuiltinLintDiagnostics
             ::AbsPathWithModule(diag_span);
-        self.session.buffer_lint_with_diagnostic(
+        self.lint_buffer.buffer_lint_with_diagnostic(
             lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
             diag_id, diag_span,
             "absolute paths must start with `self`, `super`, \
@@ -2419,7 +2423,7 @@ impl<'a> Resolver<'a> {
         for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
             let msg = "macro-expanded `macro_export` macros from the current crate \
                        cannot be referred to by absolute paths";
-            self.session.buffer_lint_with_diagnostic(
+            self.lint_buffer.buffer_lint_with_diagnostic(
                 lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
                 CRATE_NODE_ID, span_use, msg,
                 lint::builtin::BuiltinLintDiagnostics::

src/librustc_resolve/macros.rs

@@ -247,9 +247,9 @@ impl<'a> base::Resolver for Resolver<'a> {
         Ok(InvocationRes::Single(ext))
     }
 
-    fn check_unused_macros(&self) {
+    fn check_unused_macros(&mut self) {
         for (&node_id, &span) in self.unused_macros.iter() {
-            self.session.buffer_lint(
+            self.lint_buffer.buffer_lint(
                 lint::builtin::UNUSED_MACROS, node_id, span, "unused macro definition"
             );
         }
@@ -789,15 +789,17 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn check_stability_and_deprecation(&self, ext: &SyntaxExtension, path: &ast::Path) {
+    fn check_stability_and_deprecation(&mut self, ext: &SyntaxExtension, path: &ast::Path) {
         let span = path.span;
         if let Some(stability) = &ext.stability {
             if let StabilityLevel::Unstable { reason, issue, is_soft } = stability.level {
                 let feature = stability.feature;
                 if !self.active_features.contains(&feature) && !span.allows_unstable(feature) {
                     let node_id = ast::CRATE_NODE_ID;
-                    let soft_handler =
-                        |lint, span, msg: &_| self.session.buffer_lint(lint, node_id, span, msg);
+                    let lint_buffer = &mut self.lint_buffer;
+                    let soft_handler = |lint, span, msg: &_| {
+                        lint_buffer.buffer_lint(lint, node_id, span, msg)
+                    };
                     stability::report_unstable(
                         self.session, feature, reason, issue, is_soft, span, soft_handler
                     );
@@ -807,14 +809,14 @@ impl<'a> Resolver<'a> {
                 let path = pprust::path_to_string(path);
                 let (message, lint) = stability::rustc_deprecation_message(depr, &path);
                 stability::early_report_deprecation(
-                    self.session, &message, depr.suggestion, lint, span
+                    &mut self.lint_buffer, &message, depr.suggestion, lint, span
                 );
             }
         }
         if let Some(depr) = &ext.deprecation {
             let path = pprust::path_to_string(&path);
             let (message, lint) = stability::deprecation_message(depr, &path);
-            stability::early_report_deprecation(self.session, &message, None, lint, span);
+            stability::early_report_deprecation(&mut self.lint_buffer, &message, None, lint, span);
         }
     }
 

src/librustc_resolve/resolve_imports.rs

@@ -496,7 +496,7 @@ impl<'a> Resolver<'a> {
                         if let (&NameBindingKind::Res(_, true), &NameBindingKind::Res(_, true)) =
                                (&old_binding.kind, &binding.kind) {
 
-                            this.session.buffer_lint_with_diagnostic(
+                            this.lint_buffer.buffer_lint_with_diagnostic(
                                 DUPLICATE_MACRO_EXPORTS,
                                 CRATE_NODE_ID,
                                 binding.span,
@@ -979,7 +979,9 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                    !max_vis.get().is_at_least(directive.vis.get(), &*self) {
                     let msg =
                     "glob import doesn't reexport anything because no candidate is public enough";
-                    self.r.session.buffer_lint(UNUSED_IMPORTS, directive.id, directive.span, msg);
+                    self.r.lint_buffer.buffer_lint(
+                        UNUSED_IMPORTS, directive.id, directive.span, msg,
+                    );
                 }
                 return None;
             }
@@ -1148,7 +1150,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                                    re-exported (error E0365), consider declaring with \
                                    `pub`",
                                    ident);
-                self.r.session.buffer_lint(PUB_USE_OF_PRIVATE_EXTERN_CRATE,
+                self.r.lint_buffer.buffer_lint(PUB_USE_OF_PRIVATE_EXTERN_CRATE,
                                          directive.id,
                                          directive.span,
                                          &msg);
@@ -1273,7 +1275,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
             let mut redundant_spans: Vec<_> = redundant_span.present_items().collect();
             redundant_spans.sort();
             redundant_spans.dedup();
-            self.r.session.buffer_lint_with_diagnostic(
+            self.r.lint_buffer.buffer_lint_with_diagnostic(
                 UNUSED_IMPORTS,
                 directive.id,
                 directive.span,