From ea1ff8c07c3937cab6e8d02c2a9f0fbb508046a5 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Fri, 25 Oct 2019 09:20:18 -0400
Subject: [PATCH] Utilize Resolver lint buffer during HIR lowering

---
 src/librustc/hir/lowering.rs   | 11 +++++++----
 src/librustc/session/mod.rs    | 10 ++++++----
 src/librustc_interface/util.rs |  4 ++--
 src/librustc_resolve/lib.rs    |  4 ++++
 4 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs
index 12ab44515c38..6b6032516ca7 100644
--- a/src/librustc/hir/lowering.rs
+++ b/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,
@@ -3346,7 +3349,7 @@ 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()
@@ -3354,7 +3357,7 @@ impl<'a> LoweringContext<'a> {
             .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,
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 81f0853201c0..9ab5b9f13b15 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -366,7 +366,7 @@ impl Session {
         self.diagnostic().span_note_without_error(sp, msg)
     }
 
-    pub fn buffer_lint<S: Into<MultiSpan>>(
+    pub fn buffer_lint_late<S: Into<MultiSpan>>(
         &self,
         lint: &'static lint::Lint,
         id: ast::NodeId,
@@ -375,13 +375,13 @@ impl Session {
     ) {
         match *self.buffered_lints.borrow_mut() {
             Some(ref mut buffer) => {
-                buffer.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
+                buffer.buffer_lint(lint, id, sp, msg);
             }
             None => bug!("can't buffer lints after HIR lowering"),
         }
     }
 
-    pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>(
+    pub fn buffer_lint_with_diagnostic_late<S: Into<MultiSpan>>(
         &self,
         lint: &'static lint::Lint,
         id: ast::NodeId,
@@ -390,7 +390,9 @@ impl Session {
         diagnostic: BuiltinLintDiagnostics,
     ) {
         match *self.buffered_lints.borrow_mut() {
-            Some(ref mut buffer) => buffer.add_lint(lint, id, sp.into(), msg, diagnostic),
+            Some(ref mut buffer) => buffer.buffer_lint_with_diagnostic(
+                lint, id, sp.into(), msg, diagnostic,
+            ),
             None => bug!("can't buffer lints after HIR lowering"),
         }
     }
diff --git a/src/librustc_interface/util.rs b/src/librustc_interface/util.rs
index 8f11dc937272..196746593252 100644
--- a/src/librustc_interface/util.rs
+++ b/src/librustc_interface/util.rs
@@ -559,7 +559,7 @@ pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<c
                                 None
                             );
                             if let Some(candidate) = lev_candidate {
-                                session.buffer_lint_with_diagnostic(
+                                session.buffer_lint_with_diagnostic_late(
                                     lint::builtin::UNKNOWN_CRATE_TYPES,
                                     ast::CRATE_NODE_ID,
                                     span,
@@ -572,7 +572,7 @@ pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<c
                                         )
                                 );
                             } else {
-                                session.buffer_lint(
+                                session.buffer_lint_late(
                                     lint::builtin::UNKNOWN_CRATE_TYPES,
                                     ast::CRATE_NODE_ID,
                                     span,
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index f012606a5ca3..baeabbf3c1d1 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -1083,6 +1083,10 @@ impl<'a> hir::lowering::Resolver for Resolver<'a> {
         let expn_id = self.definitions.expansion_that_defined(def_id.index);
         self.has_derives(expn_id, derives)
     }
+
+    fn lint_buffer(&mut self) -> &mut lint::LintBuffer {
+        &mut self.lint_buffer
+    }
 }
 
 impl<'a> Resolver<'a> {