Auto merge of #119972 - nnethercote:add-ErrCode, r=oli-obk

Add `ErrCode`

Error codes are integers, but `String` is used everywhere to represent them. Gross!

This commit introduces `ErrCode`, an integral newtype for error codes, replacing `String`. The commit also introduces constants like `E0123` for all the used error codes.

r? `@estebank`

2 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_parse/src/parser/attr.rs b/compiler/rustc_parse/src/parser/attr.rs
index a92609c2c2f..98e062dd784 100644
--- a/compiler/rustc_parse/src/parser/attr.rs
+++ b/compiler/rustc_parse/src/parser/attr.rs
@@ -8,7 +8,7 @@ use super::{AttrWrapper, Capturing, FnParseMode, ForceCollect, Parser, PathStyle
 use rustc_ast as ast;
 use rustc_ast::attr;
 use rustc_ast::token::{self, Delimiter, Nonterminal};
-use rustc_errors::{error_code, Diagnostic, PResult};
+use rustc_errors::{codes::*, Diagnostic, PResult};
 use rustc_span::{sym, BytePos, Span};
 use thin_vec::ThinVec;
 use tracing::debug;
@@ -61,7 +61,7 @@ impl<'a> Parser<'a> {
                     let mut err = self
                         .dcx()
                         .struct_span_err(span, fluent::parse_inner_doc_comment_not_permitted);
-                    err.code(error_code!(E0753));
+                    err.code(E0753);
                     if let Some(replacement_span) = self.annotate_following_item_if_applicable(
                         &mut err,
                         span,
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 3bd8ae02586..9a77643f951 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -10,7 +10,7 @@ use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree};
 use rustc_ast::util::case::Case;
 use rustc_ast::{self as ast};
 use rustc_ast_pretty::pprust;
-use rustc_errors::{struct_span_code_err, Applicability, PResult, StashKey};
+use rustc_errors::{codes::*, struct_span_code_err, Applicability, PResult, StashKey};
 use rustc_span::edit_distance::edit_distance;
 use rustc_span::edition::Edition;
 use rustc_span::source_map;