Auto merge of #126623 - oli-obk:do_not_count_errors, r=davidtwco

Replace all `&DiagCtxt` with a `DiagCtxtHandle<'_>` wrapper type

r? `@davidtwco`

This paves the way for tracking more state (e.g. error tainting) in the diagnostic context handle

Basically I will add a field to the `DiagCtxtHandle` that refers back to the `InferCtxt`'s (and others) `Option<ErrorHandled>`, allowing us to immediately taint these contexts when emitting an error and not needing manual tainting anymore (which is easy to forget and we don't do in general anyway)

14 files changed, 39 insertions, 43 deletions

diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index 6c1fcbe06fc..7566a4d5066 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -3,7 +3,7 @@ use std::borrow::Cow;
 use rustc_ast::token::Token;
 use rustc_ast::{Path, Visibility};
 use rustc_errors::{
-    codes::*, Applicability, Diag, DiagCtxt, Diagnostic, EmissionGuarantee, Level,
+    codes::*, Applicability, Diag, DiagCtxtHandle, Diagnostic, EmissionGuarantee, Level,
     SubdiagMessageOp, Subdiagnostic,
 };
 use rustc_macros::{Diagnostic, Subdiagnostic};
@@ -1052,7 +1052,7 @@ pub(crate) struct ExpectedIdentifier {
 
 impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedIdentifier {
     #[track_caller]
-    fn into_diag(self, dcx: &'a DiagCtxt, level: Level) -> Diag<'a, G> {
+    fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> {
         let token_descr = TokenDescription::from_token(&self.token);
 
         let mut diag = Diag::new(
@@ -1112,7 +1112,7 @@ pub(crate) struct ExpectedSemi {
 
 impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for ExpectedSemi {
     #[track_caller]
-    fn into_diag(self, dcx: &'a DiagCtxt, level: Level) -> Diag<'a, G> {
+    fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> {
         let token_descr = TokenDescription::from_token(&self.token);
 
         let mut diag = Diag::new(
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 43f4963b27a..511805cf8d6 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -7,7 +7,7 @@ use rustc_ast::ast::{self, AttrStyle};
 use rustc_ast::token::{self, CommentKind, Delimiter, IdentIsRaw, Token, TokenKind};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::util::unicode::contains_text_flow_control_chars;
-use rustc_errors::{codes::*, Applicability, Diag, DiagCtxt, StashKey};
+use rustc_errors::{codes::*, Applicability, Diag, DiagCtxtHandle, StashKey};
 use rustc_lexer::unescape::{self, EscapeError, Mode};
 use rustc_lexer::{Base, DocStyle, RawStrError};
 use rustc_lexer::{Cursor, LiteralKind};
@@ -113,8 +113,8 @@ struct StringReader<'psess, 'src> {
 }
 
 impl<'psess, 'src> StringReader<'psess, 'src> {
-    fn dcx(&self) -> &'psess DiagCtxt {
-        &self.psess.dcx
+    fn dcx(&self) -> DiagCtxtHandle<'psess> {
+        self.psess.dcx()
     }
 
     fn mk_sp(&self, lo: BytePos, hi: BytePos) -> Span {
@@ -248,8 +248,8 @@ impl<'psess, 'src> StringReader<'psess, 'src> {
                     let suffix = if suffix_start < self.pos {
                         let string = self.str_from(suffix_start);
                         if string == "_" {
-                            self.psess
-                                .dcx
+                            self
+                                .dcx()
                                 .emit_err(errors::UnderscoreLiteralSuffix { span: self.mk_sp(suffix_start, self.pos) });
                             None
                         } else {
@@ -597,8 +597,7 @@ impl<'psess, 'src> StringReader<'psess, 'src> {
     }
 
     fn report_non_started_raw_string(&self, start: BytePos, bad_char: char) -> ! {
-        self.psess
-            .dcx
+        self.dcx()
             .struct_span_fatal(
                 self.mk_sp(start, self.pos),
                 format!(
diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs
index f7645446081..8e543454691 100644
--- a/compiler/rustc_parse/src/lexer/tokentrees.rs
+++ b/compiler/rustc_parse/src/lexer/tokentrees.rs
@@ -71,7 +71,7 @@ impl<'psess, 'src> TokenTreesReader<'psess, 'src> {
 
     fn eof_err(&mut self) -> PErr<'psess> {
         let msg = "this file contains an unclosed delimiter";
-        let mut err = self.string_reader.psess.dcx.struct_span_err(self.token.span, msg);
+        let mut err = self.string_reader.dcx().struct_span_err(self.token.span, msg);
         for &(_, sp) in &self.diag_info.open_braces {
             err.span_label(sp, "unclosed delimiter");
             self.diag_info.unmatched_delims.push(UnmatchedDelim {
@@ -290,7 +290,7 @@ impl<'psess, 'src> TokenTreesReader<'psess, 'src> {
         // An unexpected closing delimiter (i.e., there is no matching opening delimiter).
         let token_str = token_to_string(&self.token);
         let msg = format!("unexpected closing delimiter: `{token_str}`");
-        let mut err = self.string_reader.psess.dcx.struct_span_err(self.token.span, msg);
+        let mut err = self.string_reader.dcx().struct_span_err(self.token.span, msg);
 
         report_suspicious_mismatch_block(
             &mut err,
diff --git a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
index cad25c66827..b7a790fcf83 100644
--- a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
+++ b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
@@ -3,7 +3,7 @@
 use std::iter::once;
 use std::ops::Range;
 
-use rustc_errors::{Applicability, DiagCtxt, ErrorGuaranteed};
+use rustc_errors::{Applicability, DiagCtxtHandle, ErrorGuaranteed};
 use rustc_lexer::unescape::{EscapeError, Mode};
 use rustc_span::{BytePos, Span};
 use tracing::debug;
@@ -11,7 +11,7 @@ use tracing::debug;
 use crate::errors::{MoreThanOneCharNote, MoreThanOneCharSugg, NoBraceUnicodeSub, UnescapeError};
 
 pub(crate) fn emit_unescape_error(
-    dcx: &DiagCtxt,
+    dcx: DiagCtxtHandle<'_>,
     // interior part of the literal, between quotes
     lit: &str,
     // full span of the literal, including quotes and any prefix
diff --git a/compiler/rustc_parse/src/lexer/unicode_chars.rs b/compiler/rustc_parse/src/lexer/unicode_chars.rs
index 8eb299108d1..0a82ede3b75 100644
--- a/compiler/rustc_parse/src/lexer/unicode_chars.rs
+++ b/compiler/rustc_parse/src/lexer/unicode_chars.rs
@@ -351,7 +351,7 @@ pub(super) fn check_for_substitution(
 
     let Some((_, ascii_name, token)) = ASCII_ARRAY.iter().find(|&&(s, _, _)| s == ascii_str) else {
         let msg = format!("substitution character not found for '{ch}'");
-        reader.psess.dcx.span_bug(span, msg);
+        reader.dcx().span_bug(span, msg);
     };
 
     // special help suggestion for "directed" double quotes
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index 25cab7252a3..5522127be83 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -73,7 +73,7 @@ pub fn new_parser_from_file<'a>(
 ) -> Result<Parser<'a>, Vec<Diag<'a>>> {
     let source_file = psess.source_map().load_file(path).unwrap_or_else(|e| {
         let msg = format!("couldn't read {}: {}", path.display(), e);
-        let mut err = psess.dcx.struct_fatal(msg);
+        let mut err = psess.dcx().struct_fatal(msg);
         if let Some(sp) = sp {
             err.span(sp);
         }
@@ -115,7 +115,7 @@ fn source_file_to_stream<'psess>(
     override_span: Option<Span>,
 ) -> Result<TokenStream, Vec<Diag<'psess>>> {
     let src = source_file.src.as_ref().unwrap_or_else(|| {
-        psess.dcx.bug(format!(
+        psess.dcx().bug(format!(
             "cannot lex `source_file` without source: {}",
             psess.source_map().filename_for_diagnostics(&source_file.name)
         ));
@@ -179,7 +179,7 @@ pub fn parse_cfg_attr(
             }
         }
         _ => {
-            psess.dcx.emit_err(errors::MalformedCfgAttr {
+            psess.dcx().emit_err(errors::MalformedCfgAttr {
                 span: attr.span,
                 sugg: CFG_ATTR_GRAMMAR_HELP,
             });
diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs
index 62c8f9f5dac..f5c931034fd 100644
--- a/compiler/rustc_parse/src/parser/attr_wrapper.rs
+++ b/compiler/rustc_parse/src/parser/attr_wrapper.rs
@@ -41,7 +41,7 @@ impl AttrWrapper {
     }
 
     pub(crate) fn take_for_recovery(self, psess: &ParseSess) -> AttrVec {
-        psess.dcx.span_delayed_bug(
+        psess.dcx().span_delayed_bug(
             self.attrs.get(0).map(|attr| attr.span).unwrap_or(DUMMY_SP),
             "AttrVec is taken for recovery but no error is produced",
         );
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 0c326c8eca2..c1aac84bcae 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -34,7 +34,7 @@ use rustc_ast::{
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{
-    pluralize, Applicability, Diag, DiagCtxt, ErrorGuaranteed, FatalError, PErr, PResult,
+    pluralize, Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, FatalError, PErr, PResult,
     Subdiagnostic,
 };
 use rustc_session::errors::ExprParenthesesNeeded;
@@ -240,8 +240,8 @@ impl<'a> DerefMut for SnapshotParser<'a> {
 }
 
 impl<'a> Parser<'a> {
-    pub fn dcx(&self) -> &'a DiagCtxt {
-        &self.psess.dcx
+    pub fn dcx(&self) -> DiagCtxtHandle<'a> {
+        self.psess.dcx()
     }
 
     /// Replace `self` with `snapshot.parser`.
@@ -666,7 +666,7 @@ impl<'a> Parser<'a> {
         {
             err.note("you may be trying to write a c-string literal");
             err.note("c-string literals require Rust 2021 or later");
-            err.subdiagnostic(self.dcx(), HelpUseLatestEdition::new());
+            err.subdiagnostic(HelpUseLatestEdition::new());
         }
 
         // `pub` may be used for an item or `pub(crate)`
@@ -2357,7 +2357,7 @@ impl<'a> Parser<'a> {
         let mut err = self.dcx().struct_span_err(span, msg);
         let sp = self.psess.source_map().start_point(self.token.span);
         if let Some(sp) = self.psess.ambiguous_block_expr_parse.borrow().get(&sp) {
-            err.subdiagnostic(self.dcx(), ExprParenthesesNeeded::surrounding(*sp));
+            err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
         }
         err.span_label(span, "expected expression");
 
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 8916c5de63d..5decfc142da 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1461,7 +1461,7 @@ impl<'a> Parser<'a> {
                     // If the input is something like `if a { 1 } else { 2 } | if a { 3 } else { 4 }`
                     // then suggest parens around the lhs.
                     if let Some(sp) = this.psess.ambiguous_block_expr_parse.borrow().get(&lo) {
-                        err.subdiagnostic(this.dcx(), ExprParenthesesNeeded::surrounding(*sp));
+                        err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
                     }
                     err
                 })
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 3d2eee247b8..42f8c6e38b9 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -1966,7 +1966,7 @@ impl<'a> Parser<'a> {
         if self.token.kind == token::Not {
             if let Err(mut err) = self.unexpected() {
                 // Encounter the macro invocation
-                err.subdiagnostic(self.dcx(), MacroExpandsToAdtField { adt_ty });
+                err.subdiagnostic(MacroExpandsToAdtField { adt_ty });
                 return Err(err);
             }
         }
@@ -2382,13 +2382,10 @@ impl<'a> Parser<'a> {
                             .into_iter()
                             .any(|s| self.prev_token.is_ident_named(s));
 
-                        err.subdiagnostic(
-                            self.dcx(),
-                            errors::FnTraitMissingParen {
-                                span: self.prev_token.span,
-                                machine_applicable,
-                            },
-                        );
+                        err.subdiagnostic(errors::FnTraitMissingParen {
+                            span: self.prev_token.span,
+                            machine_applicable,
+                        });
                     }
                     return Err(err);
                 }
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 604959b1cda..6dee913c141 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -1596,7 +1596,7 @@ pub(crate) fn make_unclosed_delims_error(
     if let Some(sp) = unmatched.unclosed_span {
         spans.push(sp);
     };
-    let err = psess.dcx.create_err(MismatchedClosingDelimiter {
+    let err = psess.dcx().create_err(MismatchedClosingDelimiter {
         spans,
         delimiter: pprust::token_kind_to_string(&token::CloseDelim(found_delim)).to_string(),
         unmatched: unmatched.found_span,
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index 8af415f7c9d..f7f06ab7cbd 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -851,7 +851,7 @@ impl<'a> Parser<'a> {
 
         let sp = self.psess.source_map().start_point(self.token.span);
         if let Some(sp) = self.psess.ambiguous_block_expr_parse.borrow().get(&sp) {
-            err.subdiagnostic(self.dcx(), ExprParenthesesNeeded::surrounding(*sp));
+            err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
         }
 
         Err(err)
diff --git a/compiler/rustc_parse/src/parser/tests.rs b/compiler/rustc_parse/src/parser/tests.rs
index 79a6cf1b541..3a4690670af 100644
--- a/compiler/rustc_parse/src/parser/tests.rs
+++ b/compiler/rustc_parse/src/parser/tests.rs
@@ -61,7 +61,7 @@ where
 {
     let mut p = string_to_parser(&psess, s);
     let x = f(&mut p).unwrap();
-    p.psess.dcx.abort_if_errors();
+    p.dcx().abort_if_errors();
     x
 }
 
@@ -193,7 +193,7 @@ impl<T: Write> Write for Shared<T> {
 #[allow(rustc::untranslatable_diagnostic)] // no translation needed for tests
 fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &str) {
     create_default_session_globals_then(|| {
-        let (handler, source_map, output) = create_test_handler();
+        let (dcx, source_map, output) = create_test_handler();
         source_map.new_source_file(Path::new("test.rs").to_owned().into(), file_text.to_owned());
 
         let primary_span = make_span(&file_text, &span_labels[0].start, &span_labels[0].end);
@@ -205,7 +205,7 @@ fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &
             println!("text: {:?}", source_map.span_to_snippet(span));
         }
 
-        handler.span_err(msp, "foo");
+        dcx.handle().span_err(msp, "foo");
 
         assert!(
             expected_output.chars().next() == Some('\n'),
diff --git a/compiler/rustc_parse/src/validate_attr.rs b/compiler/rustc_parse/src/validate_attr.rs
index 19d6f512572..4ca52146039 100644
--- a/compiler/rustc_parse/src/validate_attr.rs
+++ b/compiler/rustc_parse/src/validate_attr.rs
@@ -65,7 +65,7 @@ pub fn parse_meta<'a>(psess: &'a ParseSess, attr: &Attribute) -> PResult<'a, Met
                     let res = match res {
                         Ok(lit) => {
                             if token_lit.suffix.is_some() {
-                                let mut err = psess.dcx.struct_span_err(
+                                let mut err = psess.dcx().struct_span_err(
                                     expr.span,
                                     "suffixed literals are not allowed in attributes",
                                 );
@@ -98,7 +98,7 @@ pub fn parse_meta<'a>(psess: &'a ParseSess, attr: &Attribute) -> PResult<'a, Met
                     //   the error because an earlier error will have already
                     //   been reported.
                     let msg = "attribute value must be a literal";
-                    let mut err = psess.dcx.struct_span_err(expr.span, msg);
+                    let mut err = psess.dcx().struct_span_err(expr.span, msg);
                     if let ast::ExprKind::Err(_) = expr.kind {
                         err.downgrade_to_delayed_bug();
                     }
@@ -114,7 +114,7 @@ fn check_meta_bad_delim(psess: &ParseSess, span: DelimSpan, delim: Delimiter) {
     if let Delimiter::Parenthesis = delim {
         return;
     }
-    psess.dcx.emit_err(errors::MetaBadDelim {
+    psess.dcx().emit_err(errors::MetaBadDelim {
         span: span.entire(),
         sugg: errors::MetaBadDelimSugg { open: span.open, close: span.close },
     });
@@ -124,7 +124,7 @@ pub(super) fn check_cfg_attr_bad_delim(psess: &ParseSess, span: DelimSpan, delim
     if let Delimiter::Parenthesis = delim {
         return;
     }
-    psess.dcx.emit_err(errors::CfgAttrBadDelim {
+    psess.dcx().emit_err(errors::CfgAttrBadDelim {
         span: span.entire(),
         sugg: errors::MetaBadDelimSugg { open: span.open, close: span.close },
     });
@@ -191,7 +191,7 @@ fn emit_malformed_attribute(
     } else {
         suggestions.sort();
         psess
-            .dcx
+            .dcx()
             .struct_span_err(span, error_msg)
             .with_span_suggestions(
                 span,