Move inline_fluent to a proc macro

Author: JonathanBrouwer

compiler/rustc_errors/src/lib.rs

@@ -63,6 +63,7 @@ pub use rustc_error_messages::{
 use rustc_hashes::Hash128;
 use rustc_lint_defs::LintExpectationId;
 pub use rustc_lint_defs::{Applicability, listify, pluralize};
+pub use rustc_macros::inline_fluent;
 use rustc_macros::{Decodable, Encodable};
 pub use rustc_span::ErrorGuaranteed;
 pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker, catch_fatal_errors};

compiler/rustc_errors/src/translation.rs

@@ -90,14 +90,3 @@ impl Translator {
         }
     }
 }
-
-/// This macro creates a translatable `DiagMessage` from a literal string.
-/// It should be used in places where a translatable message is needed, but struct diagnostics are undesired.
-///
-/// This is a macro because in the future we may want to globally register these messages.
-#[macro_export]
-macro_rules! inline_fluent {
-    ($inline: literal) => {
-        rustc_errors::DiagMessage::Inline(std::borrow::Cow::Borrowed($inline))
-    };
-}

compiler/rustc_macros/src/diagnostics/inline_fluent.rs

@@ -0,0 +1,10 @@
+use quote::quote;
+use syn::{LitStr, parse_macro_input};
+
+pub(crate) fn inline_fluent(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let inline = parse_macro_input!(input as LitStr);
+    quote! {
+        rustc_errors::DiagMessage::Inline(std::borrow::Cow::Borrowed(#inline))
+    }
+    .into()
+}

compiler/rustc_macros/src/diagnostics/mod.rs

@@ -1,11 +1,13 @@
 mod diagnostic;
 mod diagnostic_builder;
 mod error;
+mod inline_fluent;
 mod message;
 mod subdiagnostic;
 mod utils;
 
 use diagnostic::{DiagnosticDerive, LintDiagnosticDerive};
+pub(super) use inline_fluent::inline_fluent;
 use proc_macro2::TokenStream;
 use subdiagnostic::SubdiagnosticDerive;
 use synstructure::Structure;

compiler/rustc_macros/src/lib.rs

@@ -241,6 +241,15 @@ decl_derive!(
         applicability)] => diagnostics::subdiagnostic_derive
 );
 
+/// This macro creates a translatable `DiagMessage` from a fluent format string.
+/// It should be used in places where a translatable message is needed, but struct diagnostics are undesired.
+///
+/// This macro statically checks that the message is valid Fluent, but not that variables in the Fluent message actually exist.
+#[proc_macro]
+pub fn inline_fluent(input: TokenStream) -> TokenStream {
+    diagnostics::inline_fluent(input)
+}
+
 decl_derive! {
     [PrintAttribute] =>
     /// Derives `PrintAttribute` for `AttributeKind`.