rustc_errors: let `DiagnosticBuilder::emit` return a "guarantee of emission".

2 files changed, 18 insertions, 14 deletions

diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 4cdd83c0acd..3212fc39fb9 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -3,7 +3,9 @@ use rustc_ast::ast::{self, AttrStyle};
 use rustc_ast::token::{self, CommentKind, Token, TokenKind};
 use rustc_ast::tokenstream::{Spacing, TokenStream};
 use rustc_ast::util::unicode::contains_text_flow_control_chars;
-use rustc_errors::{error_code, Applicability, DiagnosticBuilder, FatalError, PResult};
+use rustc_errors::{
+    error_code, Applicability, DiagnosticBuilder, ErrorReported, FatalError, PResult,
+};
 use rustc_lexer::unescape::{self, Mode};
 use rustc_lexer::{Base, DocStyle, RawStrError};
 use rustc_session::lint::builtin::{
@@ -127,7 +129,7 @@ impl<'a> StringReader<'a> {
         to_pos: BytePos,
         m: &str,
         c: char,
-    ) -> DiagnosticBuilder<'a> {
+    ) -> DiagnosticBuilder<'a, ErrorReported> {
         self.sess
             .span_diagnostic
             .struct_span_fatal(self.mk_sp(from_pos, to_pos), &format!("{}: {}", m, escaped_char(c)))
diff --git a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
index a41956c58f0..c7d166319ea 100644
--- a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
+++ b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
@@ -144,7 +144,7 @@ pub(crate) fn emit_unescape_error(
                     c.escape_default().to_string(),
                     Applicability::MachineApplicable,
                 )
-                .emit()
+                .emit();
         }
         EscapeError::BareCarriageReturn => {
             let msg = if mode.in_double_quotes() {
@@ -292,16 +292,18 @@ pub(crate) fn emit_unescape_error(
                 .span_label(span, "must have at most 6 hex digits")
                 .emit();
         }
-        EscapeError::UnclosedUnicodeEscape => handler
-            .struct_span_err(span, "unterminated unicode escape")
-            .span_label(span, "missing a closing `}`")
-            .span_suggestion_verbose(
-                span.shrink_to_hi(),
-                "terminate the unicode escape",
-                "}".to_string(),
-                Applicability::MaybeIncorrect,
-            )
-            .emit(),
+        EscapeError::UnclosedUnicodeEscape => {
+            handler
+                .struct_span_err(span, "unterminated unicode escape")
+                .span_label(span, "missing a closing `}`")
+                .span_suggestion_verbose(
+                    span.shrink_to_hi(),
+                    "terminate the unicode escape",
+                    "}".to_string(),
+                    Applicability::MaybeIncorrect,
+                )
+                .emit();
+        }
         EscapeError::NoBraceInUnicodeEscape => {
             let msg = "incorrect unicode escape sequence";
             let mut diag = handler.struct_span_err(span, msg);
@@ -347,7 +349,7 @@ pub(crate) fn emit_unescape_error(
         }
         EscapeError::ZeroChars => {
             let msg = "empty character literal";
-            handler.struct_span_err(span, msg).span_label(span, msg).emit()
+            handler.struct_span_err(span, msg).span_label(span, msg).emit();
         }
         EscapeError::LoneSlash => {
             let msg = "invalid trailing slash in literal";