Merge remote-tracking branch 'origin/master' into mpk/add-long-error-message-for-E0311

3 files changed, 138 insertions, 29 deletions

diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 356f9dfdb3b..f75e2596f36 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -13,6 +13,7 @@ use rustc_span::{edition::Edition, Span, DUMMY_SP};
 use std::borrow::Cow;
 use std::fmt;
 use std::hash::{Hash, Hasher};
+use std::path::{Path, PathBuf};
 
 /// Error type for `Diagnostic`'s `suggestions` field, indicating that
 /// `.disable_suggestions()` was called on the `Diagnostic`.
@@ -83,6 +84,7 @@ into_diagnostic_arg_using_display!(
     u64,
     i128,
     u128,
+    std::io::Error,
     std::num::NonZeroU32,
     hir::Target,
     Edition,
@@ -124,6 +126,18 @@ impl IntoDiagnosticArg for String {
     }
 }
 
+impl<'a> IntoDiagnosticArg for &'a Path {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Owned(self.display().to_string()))
+    }
+}
+
+impl IntoDiagnosticArg for PathBuf {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Owned(self.display().to_string()))
+    }
+}
+
 impl IntoDiagnosticArg for usize {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
         DiagnosticArgValue::Number(self)
@@ -672,19 +686,12 @@ impl Diagnostic {
         suggestion: Vec<(Span, String)>,
         applicability: Applicability,
     ) -> &mut Self {
-        assert!(!suggestion.is_empty());
-        self.push_suggestion(CodeSuggestion {
-            substitutions: vec![Substitution {
-                parts: suggestion
-                    .into_iter()
-                    .map(|(span, snippet)| SubstitutionPart { snippet, span })
-                    .collect(),
-            }],
-            msg: self.subdiagnostic_message_to_diagnostic_message(msg),
-            style: SuggestionStyle::CompletelyHidden,
+        self.multipart_suggestion_with_style(
+            msg,
+            suggestion,
             applicability,
-        });
-        self
+            SuggestionStyle::CompletelyHidden,
+        )
     }
 
     /// Prints out a message with a suggested edit of the code.
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index 9e68ee282e6..61d767a1cc6 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -84,6 +84,13 @@ pub trait EmissionGuarantee: Sized {
     /// of `Self` without actually performing the emission.
     #[track_caller]
     fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self;
+
+    /// Creates a new `DiagnosticBuilder` that will return this type of guarantee.
+    #[track_caller]
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self>;
 }
 
 /// Private module for sealing the `IsError` helper trait.
@@ -166,6 +173,15 @@ impl EmissionGuarantee for ErrorGuaranteed {
             }
         }
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new_guaranteeing_error::<_, { Level::Error { lint: false } }>(
+            handler, msg,
+        )
+    }
 }
 
 impl<'a> DiagnosticBuilder<'a, ()> {
@@ -208,6 +224,13 @@ impl EmissionGuarantee for () {
             DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
         }
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new(handler, Level::Warning(None), msg)
+    }
 }
 
 impl<'a> DiagnosticBuilder<'a, !> {
@@ -247,6 +270,13 @@ impl EmissionGuarantee for ! {
         // Then fatally error, returning `!`
         crate::FatalError.raise()
     }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new_fatal(handler, msg)
+    }
 }
 
 /// In general, the `DiagnosticBuilder` uses deref to allow access to
@@ -566,7 +596,7 @@ impl Drop for DiagnosticBuilderInner<'_> {
                         ),
                     ));
                     handler.emit_diagnostic(&mut self.diagnostic);
-                    panic!();
+                    panic!("error was constructed but not emitted");
                 }
             }
             // `.emit()` was previously called, or maybe we're during `.cancel()`.
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 6555b93ac0b..68abdd0bad1 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(drain_filter)]
 #![feature(if_let_guard)]
 #![feature(adt_const_params)]
+#![feature(let_chains)]
 #![feature(let_else)]
 #![feature(never_type)]
 #![feature(result_option_inspect)]
@@ -459,6 +460,7 @@ struct HandlerInner {
 pub enum StashKey {
     ItemNoType,
     UnderscoreForArrayLengths,
+    EarlySyntaxWarning,
 }
 
 fn default_track_diagnostic(_: &Diagnostic) {}
@@ -626,19 +628,13 @@ impl Handler {
     /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
     pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
         let mut inner = self.inner.borrow_mut();
-        // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
-        // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
-        // See the PR for a discussion.
-        inner.stashed_diagnostics.insert((span, key), diag);
+        inner.stash((span, key), diag);
     }
 
     /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
     pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_, ()>> {
-        self.inner
-            .borrow_mut()
-            .stashed_diagnostics
-            .remove(&(span, key))
-            .map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
+        let mut inner = self.inner.borrow_mut();
+        inner.steal((span, key)).map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
     }
 
     /// Emit all stashed diagnostics.
@@ -646,6 +642,15 @@ impl Handler {
         self.inner.borrow_mut().emit_stashed_diagnostics()
     }
 
+    /// Construct a builder with the `msg` at the level appropriate for the specific `EmissionGuarantee`.
+    #[rustc_lint_diagnostics]
+    pub fn struct_diagnostic<G: EmissionGuarantee>(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, G> {
+        G::make_diagnostic_builder(self, msg)
+    }
+
     /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
     ///
     /// Attempting to `.emit()` the builder will only emit if either:
@@ -1106,13 +1111,31 @@ impl HandlerInner {
 
     /// Emit all stashed diagnostics.
     fn emit_stashed_diagnostics(&mut self) -> Option<ErrorGuaranteed> {
+        let has_errors = self.has_errors();
         let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>();
         let mut reported = None;
         for mut diag in diags {
+            // Decrement the count tracking the stash; emitting will increment it.
             if diag.is_error() {
-                reported = Some(ErrorGuaranteed(()));
+                if matches!(diag.level, Level::Error { lint: true }) {
+                    self.lint_err_count -= 1;
+                } else {
+                    self.err_count -= 1;
+                }
+            } else {
+                if diag.is_force_warn() {
+                    self.warn_count -= 1;
+                } else {
+                    // Unless they're forced, don't flush stashed warnings when
+                    // there are errors, to avoid causing warning overload. The
+                    // stash would've been stolen already if it were important.
+                    if has_errors {
+                        continue;
+                    }
+                }
             }
-            self.emit_diagnostic(&mut diag);
+            let reported_this = self.emit_diagnostic(&mut diag);
+            reported = reported.or(reported_this);
         }
         reported
     }
@@ -1226,9 +1249,13 @@ impl HandlerInner {
     }
 
     fn treat_err_as_bug(&self) -> bool {
-        self.flags
-            .treat_err_as_bug
-            .map_or(false, |c| self.err_count() + self.lint_err_count >= c.get())
+        self.flags.treat_err_as_bug.map_or(false, |c| {
+            self.err_count()
+                + self.lint_err_count
+                + self.delayed_span_bugs.len()
+                + self.delayed_good_path_bugs.len()
+                >= c.get()
+        })
     }
 
     fn print_error_count(&mut self, registry: &Registry) {
@@ -1302,9 +1329,47 @@ impl HandlerInner {
         }
     }
 
+    fn stash(&mut self, key: (Span, StashKey), diagnostic: Diagnostic) {
+        // Track the diagnostic for counts, but don't panic-if-treat-err-as-bug
+        // yet; that happens when we actually emit the diagnostic.
+        if diagnostic.is_error() {
+            if matches!(diagnostic.level, Level::Error { lint: true }) {
+                self.lint_err_count += 1;
+            } else {
+                self.err_count += 1;
+            }
+        } else {
+            // Warnings are only automatically flushed if they're forced.
+            if diagnostic.is_force_warn() {
+                self.warn_count += 1;
+            }
+        }
+
+        // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
+        // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
+        // See the PR for a discussion.
+        self.stashed_diagnostics.insert(key, diagnostic);
+    }
+
+    fn steal(&mut self, key: (Span, StashKey)) -> Option<Diagnostic> {
+        let diagnostic = self.stashed_diagnostics.remove(&key)?;
+        if diagnostic.is_error() {
+            if matches!(diagnostic.level, Level::Error { lint: true }) {
+                self.lint_err_count -= 1;
+            } else {
+                self.err_count -= 1;
+            }
+        } else {
+            if diagnostic.is_force_warn() {
+                self.warn_count -= 1;
+            }
+        }
+        Some(diagnostic)
+    }
+
     #[inline]
     fn err_count(&self) -> usize {
-        self.err_count + self.stashed_diagnostics.len()
+        self.err_count
     }
 
     fn has_errors(&self) -> bool {
@@ -1346,7 +1411,14 @@ impl HandlerInner {
         // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
         // incrementing `err_count` by one, so we need to +1 the comparing.
         // FIXME: Would be nice to increment err_count in a more coherent way.
-        if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c.get()) {
+        if self.flags.treat_err_as_bug.map_or(false, |c| {
+            self.err_count()
+                + self.lint_err_count
+                + self.delayed_span_bugs.len()
+                + self.delayed_good_path_bugs.len()
+                + 1
+                >= c.get()
+        }) {
             // FIXME: don't abort here if report_delayed_bugs is off
             self.span_bug(sp, msg);
         }