Use default locale fallback data

Author: robertbastian

Cargo.lock

@@ -1702,6 +1702,7 @@ dependencies = [
  "displaydoc",
  "icu_collections",
  "icu_locale_core",
+ "icu_locale_data",
  "icu_provider",
  "potential_utf",
  "tinystr",
@@ -1721,6 +1722,12 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "icu_locale_data"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fdef0c124749d06a743c69e938350816554eb63ac979166590e2b4ee4252765"
+
 [[package]]
 name = "icu_normalizer"
 version = "2.0.0"
@@ -1781,18 +1788,6 @@ dependencies = [
  "zerovec",
 ]
 
-[[package]]
-name = "icu_provider_adapters"
-version = "2.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85c260e90e962088d46a1605687f78d3293cc3a34ba66b08ff7361084bc7895e"
-dependencies = [
- "icu_locale",
- "icu_provider",
- "tinystr",
- "zerovec",
-]
-
 [[package]]
 name = "id-arena"
 version = "2.2.1"
@@ -3697,7 +3692,6 @@ dependencies = [
  "fluent-syntax",
  "icu_list",
  "icu_locale",
- "icu_provider_adapters",
  "intl-memoizer",
  "rustc_ast",
  "rustc_ast_pretty",

compiler/rustc_baked_icu_data/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 icu_list = { version = "2.0", default-features = false }
-icu_locale = { version = "2.0", default-features = false }
+icu_locale = { version = "2.0", default-features = false, features = ["compiled_data"] }
 icu_provider = { version = "2.0", features = ["baked", "sync"] }
 zerovec = "0.11.0"
 # tidy-alphabetical-end

compiler/rustc_baked_icu_data/src/data/list_and_v1.rs.data

@@ -11,6 +11,7 @@
 ///
 /// This macro requires the following crates:
 /// * `icu_list`
+/// * `icu_locale/compiled_data`
 /// * `icu_provider`
 /// * `icu_provider/baked`
 /// * `zerovec`
@@ -31,8 +32,23 @@ macro_rules! __impl_list_and_v1 {
         #[clippy::msrv = "1.82"]
         impl icu_provider::DataProvider<icu_list::provider::ListAndV1> for $provider {
             fn load(&self, req: icu_provider::DataRequest) -> Result<icu_provider::DataResponse<icu_list::provider::ListAndV1>, icu_provider::DataError> {
-                let metadata = icu_provider::DataResponseMetadata::default();
-                let Some(payload) = icu_provider::baked::DataStore::get(&Self::DATA_LIST_AND_V1, req.id, req.metadata.attributes_prefix_match) else { return Err(icu_provider::DataErrorKind::IdentifierNotFound.with_req(<icu_list::provider::ListAndV1 as icu_provider::DataMarker>::INFO, req)) };
+                let mut metadata = icu_provider::DataResponseMetadata::default();
+                let payload = if let Some(payload) = icu_provider::baked::DataStore::get(&Self::DATA_LIST_AND_V1, req.id, req.metadata.attributes_prefix_match) {
+                    payload
+                } else {
+                    const FALLBACKER: icu_locale::fallback::LocaleFallbackerWithConfig<'static> = icu_locale::fallback::LocaleFallbacker::new().for_config(<icu_list::provider::ListAndV1 as icu_provider::DataMarker>::INFO.fallback_config);
+                    let mut fallback_iterator = FALLBACKER.fallback_for(req.id.locale.clone());
+                    loop {
+                        if let Some(payload) = icu_provider::baked::DataStore::get(&Self::DATA_LIST_AND_V1, icu_provider::DataIdentifierBorrowed::for_marker_attributes_and_locale(req.id.marker_attributes, fallback_iterator.get()), req.metadata.attributes_prefix_match) {
+                            metadata.locale = Some(fallback_iterator.take());
+                            break payload;
+                        }
+                        if fallback_iterator.get().is_unknown() {
+                            return Err(icu_provider::DataErrorKind::IdentifierNotFound.with_req(<icu_list::provider::ListAndV1 as icu_provider::DataMarker>::INFO, req));
+                        }
+                        fallback_iterator.step();
+                    }
+                };
                 Ok(icu_provider::DataResponse { payload, metadata })
             }
         }