Move inline_fluent to a proc macro

Author: JonathanBrouwer

compiler/rustc_macros/src/diagnostics/inline_fluent.rs

@@ -0,0 +1,10 @@
+use syn::{LitStr, parse_macro_input};
+
+use crate::diagnostics::message::Message;
+
+pub(crate) fn inline_fluent(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let inline = parse_macro_input!(input as LitStr);
+    let message =
+        Message { attr_span: inline.span(), message_span: inline.span(), value: inline.value() };
+    message.diag_message(None).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`.