Auto merge of #103042 - davidtwco:translation-distributed-ftl, r=oli-obk

errors: generate typed identifiers in each crate

Instead of loading the Fluent resources for every crate in `rustc_error_messages`, each crate generates typed identifiers for its own diagnostics and creates a static which are pulled together in the `rustc_driver` crate and provided to the diagnostic emitter.

There are advantages and disadvantages to this change..

#### Advantages
- Changing a diagnostic now only recompiles the crate for that diagnostic and those crates that depend on it, rather than `rustc_error_messages` and all crates thereafter.
- This approach can be used to support first-party crates that want to supply translatable diagnostics (e.g. `rust-lang/thorin` in https://github.com/rust-lang/rust/pull/102612#discussion_r985372582, cc `@JhonnyBillM)`
- We can extend this a little so that tools built using rustc internals (like clippy or rustdoc) can add their own diagnostic resources (much more easily than those resources needing to be available to `rustc_error_messages`)

#### Disadvantages
- Crates can only refer to the diagnostic messages defined in the current crate (or those from dependencies), rather than all diagnostic messages.
- `rustc_driver` (or some other crate we create for this purpose) has to directly depend on *everything* that has error messages.
  - It already transitively depended on all these crates.

#### Pending work
- [x] I don't know how to make `rustc_codegen_gcc`'s translated diagnostics work with this approach - because `rustc_driver` can't depend on that crate and so can't get its resources to provide to the diagnostic emission. I don't really know how the alternative codegen backends are actually wired up to the compiler at all.
- [x] Update `triagebot.toml` to track the moved FTL files.

r? `@compiler-errors`
cc #100717

4 files changed, 13 insertions, 1 deletions

diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index d504aea77d0..5e38ca034ac 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -222,6 +222,7 @@ pub struct Config {
     pub output_dir: Option<PathBuf>,
     pub output_file: Option<PathBuf>,
     pub file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
+    pub locale_resources: &'static [&'static str],
 
     pub lint_caps: FxHashMap<lint::LintId, lint::Level>,
 
@@ -267,6 +268,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
                 config.opts,
                 config.crate_cfg,
                 config.crate_check_cfg,
+                config.locale_resources,
                 config.file_loader,
                 CompilerIO {
                     input: config.input,
diff --git a/compiler/rustc_interface/src/lib.rs b/compiler/rustc_interface/src/lib.rs
index 82bc4770b6b..1abbe8d4fab 100644
--- a/compiler/rustc_interface/src/lib.rs
+++ b/compiler/rustc_interface/src/lib.rs
@@ -12,6 +12,9 @@
 #[macro_use]
 extern crate tracing;
 
+use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
+use rustc_macros::fluent_messages;
+
 mod callbacks;
 mod errors;
 pub mod interface;
@@ -27,3 +30,5 @@ pub use queries::Queries;
 
 #[cfg(test)]
 mod tests;
+
+fluent_messages! { "../locales/en-US.ftl" }
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index bfb1e822a26..71a72036994 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -50,7 +50,7 @@ fn mk_session(matches: getopts::Matches) -> (Session, CfgSpecs) {
         output_file: None,
         temps_dir,
     };
-    let sess = build_session(sessopts, io, None, registry, Default::default(), None, None);
+    let sess = build_session(sessopts, io, None, registry, vec![], Default::default(), None, None);
     (sess, cfg)
 }
 
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index 475d3601b52..e5d2fb2ea28 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -59,6 +59,7 @@ pub fn create_session(
     sopts: config::Options,
     cfg: FxHashSet<(String, Option<String>)>,
     check_cfg: CheckCfg,
+    locale_resources: &'static [&'static str],
     file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
     io: CompilerIO,
     lint_caps: FxHashMap<lint::LintId, lint::Level>,
@@ -89,11 +90,15 @@ pub fn create_session(
         }
     };
 
+    let mut locale_resources = Vec::from(locale_resources);
+    locale_resources.push(codegen_backend.locale_resource());
+
     let mut sess = session::build_session(
         sopts,
         io,
         bundle,
         descriptions,
+        locale_resources,
         lint_caps,
         file_loader,
         target_override,