Add `rustc_fluent_macro` to decouple fluent from `rustc_macros`

Fluent, with all the icu4x it brings in, takes quite some time to
compile. `fluent_messages!` is only needed in further downstream rustc
crates, but is blocking more upstream crates like `rustc_index`. By
splitting it out, we allow `rustc_macros` to be compiled earlier, which
speeds up `x check compiler` by about 5 seconds (and even more after the
needless dependency on `serde_json` is removed from
`rustc_data_structures`).

1 files changed, 0 insertions, 54 deletions

diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index 737500cc257..904f8eb5731 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -54,60 +54,6 @@ pub fn newtype_index(input: TokenStream) -> TokenStream {
     newtype::newtype(input)
 }
 
-/// Implements the `fluent_messages` macro, which performs compile-time validation of the
-/// compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same
-/// messages) and generates constants that make using those messages in diagnostics more ergonomic.
-///
-/// For example, given the following invocation of the macro..
-///
-/// ```ignore (rust)
-/// fluent_messages! { "./typeck.ftl" }
-/// ```
-/// ..where `typeck.ftl` has the following contents..
-///
-/// ```fluent
-/// typeck_field_multiply_specified_in_initializer =
-///     field `{$ident}` specified more than once
-///     .label = used more than once
-///     .label_previous_use = first use of `{$ident}`
-/// ```
-/// ...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so, and
-/// will generate the following code:
-///
-/// ```ignore (rust)
-/// pub static DEFAULT_LOCALE_RESOURCE: &'static [&'static str] = include_str!("./typeck.ftl");
-///
-/// mod fluent_generated {
-///     mod typeck {
-///         pub const field_multiply_specified_in_initializer: DiagnosticMessage =
-///             DiagnosticMessage::fluent("typeck_field_multiply_specified_in_initializer");
-///         pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
-///             DiagnosticMessage::fluent_attr(
-///                 "typeck_field_multiply_specified_in_initializer",
-///                 "previous_use_label"
-///             );
-///     }
-/// }
-/// ```
-/// When emitting a diagnostic, the generated constants can be used as follows:
-///
-/// ```ignore (rust)
-/// let mut err = sess.struct_span_err(
-///     span,
-///     fluent::typeck::field_multiply_specified_in_initializer
-/// );
-/// err.span_default_label(span);
-/// err.span_label(
-///     previous_use_span,
-///     fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
-/// );
-/// err.emit();
-/// ```
-#[proc_macro]
-pub fn fluent_messages(input: TokenStream) -> TokenStream {
-    diagnostics::fluent_messages(input)
-}
-
 decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
 decl_derive!(
     [HashStable_Generic, attributes(stable_hasher)] =>