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, 18 insertions, 8 deletions

diff --git a/compiler/rustc_errors/src/diagnostic_impls.rs b/compiler/rustc_errors/src/diagnostic_impls.rs
index 5ada85d04b0..d4ddd0c53bf 100644
--- a/compiler/rustc_errors/src/diagnostic_impls.rs
+++ b/compiler/rustc_errors/src/diagnostic_impls.rs
@@ -1,6 +1,5 @@
-use crate::{
-    fluent, DiagnosticArgValue, DiagnosticBuilder, Handler, IntoDiagnostic, IntoDiagnosticArg,
-};
+use crate::fluent_generated as fluent;
+use crate::{DiagnosticArgValue, DiagnosticBuilder, Handler, IntoDiagnostic, IntoDiagnosticArg};
 use rustc_ast as ast;
 use rustc_ast_pretty::pprust;
 use rustc_hir as hir;
diff --git a/compiler/rustc_errors/src/json/tests.rs b/compiler/rustc_errors/src/json/tests.rs
index f161532d3b7..671dc449eaa 100644
--- a/compiler/rustc_errors/src/json/tests.rs
+++ b/compiler/rustc_errors/src/json/tests.rs
@@ -46,7 +46,7 @@ fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
         let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
         sm.new_source_file(Path::new("test.rs").to_owned().into(), code.to_owned());
         let fallback_bundle =
-            crate::fallback_fluent_bundle(rustc_error_messages::DEFAULT_LOCALE_RESOURCES, false);
+            crate::fallback_fluent_bundle(vec![crate::DEFAULT_LOCALE_RESOURCE], false);
 
         let output = Arc::new(Mutex::new(Vec::new()));
         let je = JsonEmitter::new(
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 8c39feca88a..edec8cce92f 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -36,11 +36,11 @@ use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{self, Lock, Lrc};
 use rustc_data_structures::AtomicRef;
 pub use rustc_error_messages::{
-    fallback_fluent_bundle, fluent, fluent_bundle, DelayDm, DiagnosticMessage, FluentBundle,
+    fallback_fluent_bundle, fluent_bundle, DelayDm, DiagnosticMessage, FluentBundle,
     LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagnosticMessage,
-    DEFAULT_LOCALE_RESOURCES,
 };
 pub use rustc_lint_defs::{pluralize, Applicability};
+use rustc_macros::fluent_messages;
 use rustc_span::source_map::SourceMap;
 use rustc_span::HashStableContext;
 use rustc_span::{Loc, Span};
@@ -76,6 +76,8 @@ pub use snippet::Style;
 pub type PErr<'a> = DiagnosticBuilder<'a, ErrorGuaranteed>;
 pub type PResult<'a, T> = Result<T, PErr<'a>>;
 
+fluent_messages! { "../locales/en-US.ftl" }
+
 // `PResult` is used a lot. Make sure it doesn't unintentionally get bigger.
 // (See also the comment on `DiagnosticBuilderInner`'s `diagnostic` field.)
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
diff --git a/compiler/rustc_errors/src/translation.rs b/compiler/rustc_errors/src/translation.rs
index addfc9726ca..1ac9b8e03c7 100644
--- a/compiler/rustc_errors/src/translation.rs
+++ b/compiler/rustc_errors/src/translation.rs
@@ -4,6 +4,7 @@ use crate::{DiagnosticArg, DiagnosticMessage, FluentBundle};
 use rustc_data_structures::sync::Lrc;
 use rustc_error_messages::FluentArgs;
 use std::borrow::Cow;
+use std::env;
 use std::error::Report;
 
 /// Convert diagnostic arguments (a rustc internal type that exists to implement
@@ -94,8 +95,16 @@ pub trait Translate {
                 // The primary bundle was present and translation succeeded
                 Some(Ok(t)) => t,
 
-                // Always yeet out for errors on debug
-                Some(Err(primary)) if cfg!(debug_assertions) => do yeet primary,
+                // Always yeet out for errors on debug (unless
+                // `RUSTC_TRANSLATION_NO_DEBUG_ASSERT` is set in the environment - this allows
+                // local runs of the test suites, of builds with debug assertions, to test the
+                // behaviour in a normal build).
+                Some(Err(primary))
+                    if cfg!(debug_assertions)
+                        && env::var("RUSTC_TRANSLATION_NO_DEBUG_ASSERT").is_err() =>
+                {
+                    do yeet primary
+                }
 
                 // If `translate_with_bundle` returns `Err` with the primary bundle, this is likely
                 // just that the primary bundle doesn't contain the message being translated or