Auto merge of #145773 - jhpratt:rollup-kocqnzv, r=jhpratt

Rollup of 28 pull requests

Successful merges:

 - rust-lang/rust#132087 (Fix overly restrictive lifetime in `core::panic::Location::file` return type)
 - rust-lang/rust#137396 (Recover `param: Ty = EXPR`)
 - rust-lang/rust#137457 (Fix host code appearing in Wasm binaries)
 - rust-lang/rust#142185 (Convert moves of references to copies in ReferencePropagation)
 - rust-lang/rust#144648 (Implementation: `#[feature(nonpoison_rwlock)]`)
 - rust-lang/rust#144897 (print raw lifetime idents with r#)
 - rust-lang/rust#145218 ([Debuginfo] improve enum value formatting in LLDB for better readability)
 - rust-lang/rust#145380 (Add codegen-llvm regression tests)
 - rust-lang/rust#145573 (Add an experimental unsafe(force_target_feature) attribute.)
 - rust-lang/rust#145597 (resolve: Remove `ScopeSet::Late`)
 - rust-lang/rust#145633 (Fix some typos in LocalKey documentation)
 - rust-lang/rust#145641 (On E0277, point at type that doesn't implement bound)
 - rust-lang/rust#145669 (rustdoc-search: GUI tests check for `//` in URL)
 - rust-lang/rust#145695 (Introduce ProjectionElem::try_map.)
 - rust-lang/rust#145710 (Fix the ABI parameter inconsistency issue in debug.rs for LoongArch64)
 - rust-lang/rust#145726 (Experiment: Reborrow trait)
 - rust-lang/rust#145731 (Make raw pointers work in type-based search)
 - rust-lang/rust#145736 (triagebot: Update style team reviewers)
 - rust-lang/rust#145738 (Uplift rustc_mir_transform::coverage::counters::union_find to rustc_data_structures.)
 - rust-lang/rust#145742 (rustdoc js: Even more typechecking improvments )
 - rust-lang/rust#145743 (doc: fix some typos in comment)
 - rust-lang/rust#145745 (tests: Ignore basic-stepping.rs on LoongArch)
 - rust-lang/rust#145747 (Refactor lint buffering to avoid requiring a giant enum)
 - rust-lang/rust#145751 (fix(lexer): Allow '-' in the frontmatter infostring continue set)
 - rust-lang/rust#145761 (Add aarch64_be-unknown-hermit target)
 - rust-lang/rust#145762 (convert strings to symbols in attr diagnostics)
 - rust-lang/rust#145763 (Ship LLVM tools for the correct target when cross-compiling)
 - rust-lang/rust#145765 (Revert suggestions for missing methods in tuples)

r? `@ghost`
`@rustbot` modify labels: rollup

3 files changed, 99 insertions, 2 deletions

diff --git a/compiler/rustc_errors/src/decorate_diag.rs b/compiler/rustc_errors/src/decorate_diag.rs
new file mode 100644
index 00000000000..5aef26ccf97
--- /dev/null
+++ b/compiler/rustc_errors/src/decorate_diag.rs
@@ -0,0 +1,85 @@
+/// This module provides types and traits for buffering lints until later in compilation.
+use rustc_ast::node_id::NodeId;
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_error_messages::MultiSpan;
+use rustc_lint_defs::{BuiltinLintDiag, Lint, LintId};
+
+use crate::{DynSend, LintDiagnostic, LintDiagnosticBox};
+
+/// We can't implement `LintDiagnostic` for `BuiltinLintDiag`, because decorating some of its
+/// variants requires types we don't have yet. So, handle that case separately.
+pub enum DecorateDiagCompat {
+    Dynamic(Box<dyn for<'a> LintDiagnosticBox<'a, ()> + DynSend + 'static>),
+    Builtin(BuiltinLintDiag),
+}
+
+impl std::fmt::Debug for DecorateDiagCompat {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("DecorateDiagCompat").finish()
+    }
+}
+
+impl !LintDiagnostic<'_, ()> for BuiltinLintDiag {}
+
+impl<D: for<'a> LintDiagnostic<'a, ()> + DynSend + 'static> From<D> for DecorateDiagCompat {
+    #[inline]
+    fn from(d: D) -> Self {
+        Self::Dynamic(Box::new(d))
+    }
+}
+
+impl From<BuiltinLintDiag> for DecorateDiagCompat {
+    #[inline]
+    fn from(b: BuiltinLintDiag) -> Self {
+        Self::Builtin(b)
+    }
+}
+
+/// Lints that are buffered up early on in the `Session` before the
+/// `LintLevels` is calculated.
+#[derive(Debug)]
+pub struct BufferedEarlyLint {
+    /// The span of code that we are linting on.
+    pub span: Option<MultiSpan>,
+
+    /// The `NodeId` of the AST node that generated the lint.
+    pub node_id: NodeId,
+
+    /// A lint Id that can be passed to
+    /// `rustc_lint::early::EarlyContextAndPass::check_id`.
+    pub lint_id: LintId,
+
+    /// Customization of the `Diag<'_>` for the lint.
+    pub diagnostic: DecorateDiagCompat,
+}
+
+#[derive(Default, Debug)]
+pub struct LintBuffer {
+    pub map: FxIndexMap<NodeId, Vec<BufferedEarlyLint>>,
+}
+
+impl LintBuffer {
+    pub fn add_early_lint(&mut self, early_lint: BufferedEarlyLint) {
+        self.map.entry(early_lint.node_id).or_default().push(early_lint);
+    }
+
+    pub fn take(&mut self, id: NodeId) -> Vec<BufferedEarlyLint> {
+        // FIXME(#120456) - is `swap_remove` correct?
+        self.map.swap_remove(&id).unwrap_or_default()
+    }
+
+    pub fn buffer_lint(
+        &mut self,
+        lint: &'static Lint,
+        node_id: NodeId,
+        span: impl Into<MultiSpan>,
+        decorate: impl Into<DecorateDiagCompat>,
+    ) {
+        self.add_early_lint(BufferedEarlyLint {
+            lint_id: LintId::of(lint),
+            node_id,
+            span: Some(span.into()),
+            diagnostic: decorate.into(),
+        });
+    }
+}
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 183dceddd2c..43ce886975c 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -138,10 +138,20 @@ where
 /// `#[derive(LintDiagnostic)]` -- see [rustc_macros::LintDiagnostic].
 #[rustc_diagnostic_item = "LintDiagnostic"]
 pub trait LintDiagnostic<'a, G: EmissionGuarantee> {
-    /// Decorate and emit a lint.
+    /// Decorate a lint with the information from this type.
     fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, G>);
 }
 
+pub trait LintDiagnosticBox<'a, G: EmissionGuarantee> {
+    fn decorate_lint_box<'b>(self: Box<Self>, diag: &'b mut Diag<'a, G>);
+}
+
+impl<'a, G: EmissionGuarantee, D: LintDiagnostic<'a, G>> LintDiagnosticBox<'a, G> for D {
+    fn decorate_lint_box<'b>(self: Box<Self>, diag: &'b mut Diag<'a, G>) {
+        self.decorate_lint(diag);
+    }
+}
+
 #[derive(Clone, Debug, Encodable, Decodable)]
 pub(crate) struct DiagLocation {
     file: Cow<'static, str>,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index a775b70dbee..38c5716348f 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -40,9 +40,10 @@ use std::{fmt, panic};
 
 use Level::*;
 pub use codes::*;
+pub use decorate_diag::{BufferedEarlyLint, DecorateDiagCompat, LintBuffer};
 pub use diagnostic::{
     BugAbort, Diag, DiagArgMap, DiagInner, DiagStyledString, Diagnostic, EmissionGuarantee,
-    FatalAbort, LintDiagnostic, StringPart, Subdiag, Subdiagnostic,
+    FatalAbort, LintDiagnostic, LintDiagnosticBox, StringPart, Subdiag, Subdiagnostic,
 };
 pub use diagnostic_impls::{
     DiagSymbolList, ElidedLifetimeInPathSubdiag, ExpectedLifetimeParameter,
@@ -80,6 +81,7 @@ use crate::timings::TimingRecord;
 
 pub mod annotate_snippet_emitter_writer;
 pub mod codes;
+mod decorate_diag;
 mod diagnostic;
 mod diagnostic_impls;
 pub mod emitter;