Auto merge of #103345 - Nilstrieb:diag-flat, r=compiler-errors

Flatten diagnostic slug modules

This makes it easier to grep for the slugs in the code.

See https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Localization.20infra.20interferes.20with.20grepping.20for.20error for more discussion about it.

This was mostly done with a few regexes and a bunch of manual work. This also exposes a pretty annoying inconsistency for the extra labels. Some of the extra labels are defined as additional properties in the fluent message (which makes them not prefixed with the crate name) and some of them are new fluent messages themselves (which makes them prefixed with the crate name). I don't know whether we want to clean this up at some point but it's useful to know.

r? `@davidtwco`

3 files changed, 40 insertions, 43 deletions

diff --git a/compiler/rustc_macros/src/diagnostics/diagnostic.rs b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
index 8cf307df5a5..ef1985b960e 100644
--- a/compiler/rustc_macros/src/diagnostics/diagnostic.rs
+++ b/compiler/rustc_macros/src/diagnostics/diagnostic.rs
@@ -40,7 +40,7 @@ impl<'a> DiagnosticDerive<'a> {
                     span_err(builder.span, "diagnostic slug not specified")
                         .help(&format!(
                             "specify the slug as the first argument to the `#[diag(...)]` \
-                            attribute, such as `#[diag(hir_analysis::example_error)]`",
+                            attribute, such as `#[diag(hir_analysis_example_error)]`",
                         ))
                         .emit();
                     return DiagnosticDeriveError::ErrorHandled.to_compile_error();
@@ -121,7 +121,7 @@ impl<'a> LintDiagnosticDerive<'a> {
                     span_err(builder.span, "diagnostic slug not specified")
                         .help(&format!(
                             "specify the slug as the first argument to the attribute, such as \
-                            `#[diag(compiletest::example)]`",
+                            `#[diag(compiletest_example)]`",
                         ))
                         .emit();
                     return DiagnosticDeriveError::ErrorHandled.to_compile_error();
diff --git a/compiler/rustc_macros/src/diagnostics/fluent.rs b/compiler/rustc_macros/src/diagnostics/fluent.rs
index f7d8b494ee2..3e447c94ef1 100644
--- a/compiler/rustc_macros/src/diagnostics/fluent.rs
+++ b/compiler/rustc_macros/src/diagnostics/fluent.rs
@@ -25,18 +25,18 @@ use syn::{
 use unic_langid::langid;
 
 struct Resource {
-    ident: Ident,
+    krate: Ident,
     #[allow(dead_code)]
     fat_arrow_token: token::FatArrow,
-    resource: LitStr,
+    resource_path: LitStr,
 }
 
 impl Parse for Resource {
     fn parse(input: ParseStream<'_>) -> Result<Self> {
         Ok(Resource {
-            ident: input.parse()?,
+            krate: input.parse()?,
             fat_arrow_token: input.parse()?,
-            resource: input.parse()?,
+            resource_path: input.parse()?,
         })
     }
 }
@@ -94,19 +94,20 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
     // diagnostics.
     let mut previous_defns = HashMap::new();
 
+    // Set of Fluent attribute names already output, to avoid duplicate type errors - any given
+    // constant created for a given attribute is the same.
+    let mut previous_attrs = HashSet::new();
+
     let mut includes = TokenStream::new();
     let mut generated = TokenStream::new();
-    for res in resources.0 {
-        let ident_span = res.ident.span().unwrap();
-        let path_span = res.resource.span().unwrap();
 
-        // Set of Fluent attribute names already output, to avoid duplicate type errors - any given
-        // constant created for a given attribute is the same.
-        let mut previous_attrs = HashSet::new();
+    for res in resources.0 {
+        let krate_span = res.krate.span().unwrap();
+        let path_span = res.resource_path.span().unwrap();
 
-        let relative_ftl_path = res.resource.value();
+        let relative_ftl_path = res.resource_path.value();
         let absolute_ftl_path =
-            invocation_relative_path_to_absolute(ident_span, &relative_ftl_path);
+            invocation_relative_path_to_absolute(krate_span, &relative_ftl_path);
         // As this macro also outputs an `include_str!` for this file, the macro will always be
         // re-executed when the file changes.
         let mut resource_file = match File::open(absolute_ftl_path) {
@@ -185,7 +186,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
 
         let mut constants = TokenStream::new();
         for entry in resource.entries() {
-            let span = res.ident.span();
+            let span = res.krate.span();
             if let Entry::Message(Message { id: Identifier { name }, attributes, .. }) = entry {
                 let _ = previous_defns.entry(name.to_string()).or_insert(path_span);
 
@@ -199,29 +200,30 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
                     .emit();
                 }
 
-                // `typeck_foo_bar` => `foo_bar` (in `typeck.ftl`)
-                // `const_eval_baz` => `baz` (in `const_eval.ftl`)
+                // Require that the message name starts with the crate name
+                // `hir_typeck_foo_bar` (in `hir_typeck.ftl`)
+                // `const_eval_baz` (in `const_eval.ftl`)
                 // `const-eval-hyphen-having` => `hyphen_having` (in `const_eval.ftl`)
                 // The last case we error about above, but we want to fall back gracefully
                 // so that only the error is being emitted and not also one about the macro
                 // failing.
-                let crate_prefix = format!("{}_", res.ident);
+                let crate_prefix = format!("{}_", res.krate);
 
                 let snake_name = name.replace('-', "_");
-                let snake_name = match snake_name.strip_prefix(&crate_prefix) {
-                    Some(rest) => Ident::new(rest, span),
-                    None => {
-                        Diagnostic::spanned(
-                            path_span,
-                            Level::Error,
-                            format!("name `{name}` does not start with the crate name"),
-                        )
-                        .help(format!("prepend `{crate_prefix}` to the slug name: `{crate_prefix}{snake_name}`"))
-                        .emit();
-                        Ident::new(&snake_name, span)
-                    }
+                if !snake_name.starts_with(&crate_prefix) {
+                    Diagnostic::spanned(
+                        path_span,
+                        Level::Error,
+                        format!("name `{name}` does not start with the crate name"),
+                    )
+                    .help(format!(
+                        "prepend `{crate_prefix}` to the slug name: `{crate_prefix}{snake_name}`"
+                    ))
+                    .emit();
                 };
 
+                let snake_name = Ident::new(&snake_name, span);
+
                 constants.extend(quote! {
                     pub const #snake_name: crate::DiagnosticMessage =
                         crate::DiagnosticMessage::FluentIdentifier(
@@ -275,12 +277,7 @@ pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::Tok
 
         includes.extend(quote! { include_str!(#relative_ftl_path), });
 
-        let ident = res.ident;
-        generated.extend(quote! {
-            pub mod #ident {
-                #constants
-            }
-        });
+        generated.extend(constants);
     }
 
     quote! {
diff --git a/compiler/rustc_macros/src/diagnostics/mod.rs b/compiler/rustc_macros/src/diagnostics/mod.rs
index f98cc66e9e9..860340b4390 100644
--- a/compiler/rustc_macros/src/diagnostics/mod.rs
+++ b/compiler/rustc_macros/src/diagnostics/mod.rs
@@ -23,14 +23,14 @@ use synstructure::Structure;
 /// # extern crate rust_middle;
 /// # use rustc_middle::ty::Ty;
 /// #[derive(Diagnostic)]
-/// #[diag(borrowck::move_out_of_borrow, code = "E0505")]
+/// #[diag(borrowck_move_out_of_borrow, code = "E0505")]
 /// pub struct MoveOutOfBorrowError<'tcx> {
 ///     pub name: Ident,
 ///     pub ty: Ty<'tcx>,
 ///     #[primary_span]
 ///     #[label]
 ///     pub span: Span,
-///     #[label(borrowck::first_borrow_label)]
+///     #[label(first_borrow_label)]
 ///     pub first_borrow_span: Span,
 ///     #[suggestion(code = "{name}.clone()")]
 ///     pub clone_sugg: Option<(Span, Applicability)>
@@ -67,14 +67,14 @@ pub fn session_diagnostic_derive(s: Structure<'_>) -> TokenStream {
 ///
 /// ```ignore (rust)
 /// #[derive(LintDiagnostic)]
-/// #[diag(lint::atomic_ordering_invalid_fail_success)]
+/// #[diag(lint_atomic_ordering_invalid_fail_success)]
 /// pub struct AtomicOrderingInvalidLint {
 ///     method: Symbol,
 ///     success_ordering: Symbol,
 ///     fail_ordering: Symbol,
-///     #[label(lint::fail_label)]
+///     #[label(fail_label)]
 ///     fail_order_arg_span: Span,
-///     #[label(lint::success_label)]
+///     #[label(success_label)]
 ///     #[suggestion(
 ///         code = "std::sync::atomic::Ordering::{success_suggestion}",
 ///         applicability = "maybe-incorrect"
@@ -115,12 +115,12 @@ pub fn lint_diagnostic_derive(s: Structure<'_>) -> TokenStream {
 /// ```ignore (rust)
 /// #[derive(Subdiagnostic)]
 /// pub enum ExpectedIdentifierLabel<'tcx> {
-///     #[label(parser::expected_identifier)]
+///     #[label(expected_identifier)]
 ///     WithoutFound {
 ///         #[primary_span]
 ///         span: Span,
 ///     }
-///     #[label(parser::expected_identifier_found)]
+///     #[label(expected_identifier_found)]
 ///     WithFound {
 ///         #[primary_span]
 ///         span: Span,