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

5 files changed, 69 insertions, 1 deletions

diff --git a/compiler/rustc_interface/locales/en-US.ftl b/compiler/rustc_interface/locales/en-US.ftl
new file mode 100644
index 00000000000..a7bc0e7af1f
--- /dev/null
+++ b/compiler/rustc_interface/locales/en-US.ftl
@@ -0,0 +1,56 @@
+interface_ferris_identifier =
+    Ferris cannot be used as an identifier
+    .suggestion = try using their name instead
+
+interface_emoji_identifier =
+    identifiers cannot contain emoji: `{$ident}`
+
+interface_mixed_bin_crate =
+    cannot mix `bin` crate type with others
+
+interface_mixed_proc_macro_crate =
+    cannot mix `proc-macro` crate type with others
+
+interface_proc_macro_doc_without_arg =
+    Trying to document proc macro crate without passing '--crate-type proc-macro to rustdoc
+    .warn = The generated documentation may be incorrect
+
+interface_error_writing_dependencies =
+    error writing dependencies to `{$path}`: {$error}
+
+interface_input_file_would_be_overwritten =
+    the input file "{$path}" would be overwritten by the generated executable
+
+interface_generated_file_conflicts_with_directory =
+    the generated executable for the input file "{$input_path}" conflicts with the existing directory "{$dir_path}"
+
+interface_temps_dir_error =
+    failed to find or create the directory specified by `--temps-dir`
+
+interface_out_dir_error =
+    failed to find or create the directory specified by `--out-dir`
+
+interface_cant_emit_mir =
+    could not emit MIR: {$error}
+
+interface_rustc_error_fatal =
+    fatal error triggered by #[rustc_error]
+
+interface_rustc_error_unexpected_annotation =
+    unexpected annotation used with `#[rustc_error(...)]!
+
+interface_failed_writing_file =
+    failed to write file {$path}: {$error}"
+
+interface_proc_macro_crate_panic_abort =
+    building proc macro crate with `panic=abort` may crash the compiler should the proc-macro panic
+
+interface_unsupported_crate_type_for_target =
+    dropping unsupported crate type `{$crate_type}` for target `{$target_triple}`
+
+interface_multiple_output_types_adaption =
+    due to multiple output types requested, the explicitly specified output file name will be adapted for each output type
+
+interface_ignoring_extra_filename = ignoring -C extra-filename flag due to -o flag
+
+interface_ignoring_out_dir = ignoring --out-dir flag due to -o flag
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,