Record clang USR strings in C++ item reports

We can use this to unambiguously refer to C++ declarations across translation units.

PiperOrigin-RevId: 869916605

Author: mvanbem-goog

cc_bindings_from_rs/generate_bindings/lib.rs

@@ -1323,7 +1323,7 @@ fn item_name_for_error_report(db: &BindingsGenerator<'_>, def_id: DefId) -> erro
     )
     .into();
     let id = ((def_id.index.as_u32() as u64) << 32) | def_id.krate.as_u32() as u64;
-    error_report::ItemName { name, id }
+    error_report::ItemName { name, id, unique_name: None }
 }
 
 /// Implementation of `BindingsGenerator::generate_item`.

common/error_report.rs

@@ -228,6 +228,9 @@ pub struct ItemName {
     pub name: Rc<str>,
     /// Unique ID per target. (E.g. the address of the AST node.)
     pub id: u64,
+    // A unique name for log aggregation purposes. For C++ items, this is a clang Unified Symbol
+    // Resolution (USR) string.
+    pub unique_name: Option<Rc<str>>,
 }
 
 pub struct ItemScope<'a> {
@@ -328,7 +331,7 @@ impl ErrorReport {
 }
 
 thread_local! {
-    static DEFAULT_ITEM: ItemName = ItemName {name: Rc::from(""), id: 0};
+    static DEFAULT_ITEM: ItemName = ItemName {name: Rc::from(""), id: 0, unique_name: None };
 }
 
 impl ErrorReporting for ErrorReport {
@@ -367,7 +370,11 @@ impl ErrorReporting for ErrorReport {
         let mut map = self.map.borrow_mut();
         match map.entry(item.id) {
             Entry::Vacant(e) => {
-                e.insert(ErrorReportEntry { name: item.name.clone(), ..Default::default() });
+                e.insert(ErrorReportEntry {
+                    name: item.name.clone(),
+                    unique_name: item.unique_name.clone(),
+                    ..Default::default()
+                });
             }
             Entry::Occupied(e) => {
                 assert_eq!(
@@ -420,6 +427,11 @@ pub struct ErrorReportEntry {
     /// (Note: can't use flagset, because it fails in recent rustc.)
     #[serde(default, skip_serializing_if = "is_default")]
     pub category: u32,
+
+    // A unique name for log aggregation purposes. For C++ items, this is a clang Unified Symbol
+    // Resolution (USR) string.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub unique_name: Option<Rc<str>>,
 }
 
 fn is_default<T: Default + PartialEq>(value: &T) -> bool {
@@ -711,11 +723,15 @@ mod tests {
     fn error_report_item_name() {
         let report = ErrorReport::new();
         {
-            let _scope = ItemScope::new(&report, ItemName { name: "foo".into(), id: 1 });
+            let _scope =
+                ItemScope::new(&report, ItemName { name: "foo".into(), id: 1, unique_name: None });
             report.report(&anyhow!("error in {}", "item 1"));
         }
         {
-            let _scope = ItemScope::new(&report, ItemName { name: "bar".into(), id: 2 });
+            let _scope = ItemScope::new(
+                &report,
+                ItemName { name: "bar".into(), id: 2, unique_name: Some("abc123".into()) },
+            );
             report.report(&anyhow!("error in {}", "item 2"));
         }
 
@@ -739,6 +755,7 @@ mod tests {
                             "full_error": "error in item 2",
                         },
                     ],
+                    "unique_name": "abc123",
                 },
             ]),
         );

rs_bindings_from_cc/generate_bindings/generate_comment_test.rs

@@ -154,7 +154,11 @@ fn test_generate_unsupported_item_with_environment_production() -> Result<()> {
     let db = factory.make_db(Environment::Production);
     let _scope = error_report::ItemScope::new(
         db.errors(),
-        error_report::ItemName { name: "test_item".into(), id: TEST_ITEM_ID.as_u64() },
+        error_report::ItemName {
+            name: "test_item".into(),
+            id: TEST_ITEM_ID.as_u64(),
+            unique_name: None,
+        },
     );
     let actual = generate_unsupported(
         &db,
@@ -182,7 +186,11 @@ fn test_generate_unsupported_item_with_missing_source_loc() -> Result<()> {
     let db = factory.make_db(Environment::Production);
     let _scope = error_report::ItemScope::new(
         db.errors(),
-        error_report::ItemName { name: "test_item".into(), id: TEST_ITEM_ID.as_u64() },
+        error_report::ItemName {
+            name: "test_item".into(),
+            id: TEST_ITEM_ID.as_u64(),
+            unique_name: None,
+        },
     );
     let actual = generate_unsupported(
         &db,
@@ -207,7 +215,11 @@ fn test_generate_unsupported_item_with_environment_golden_test() -> Result<()> {
     let db = factory.make_db(Environment::GoldenTest);
     let _scope = error_report::ItemScope::new(
         db.errors(),
-        error_report::ItemName { name: "test_item".into(), id: TEST_ITEM_ID.as_u64() },
+        error_report::ItemName {
+            name: "test_item".into(),
+            id: TEST_ITEM_ID.as_u64(),
+            unique_name: None,
+        },
     );
     let actual = generate_unsupported(
         &db,

rs_bindings_from_cc/ir.rs

@@ -2071,7 +2071,7 @@ impl Item {
 
     fn error_item_name(&self, ir: &IR) -> error_report::ItemName {
         let name = self.debug_name(ir);
-        error_report::ItemName { name, id: self.id().as_u64() }
+        error_report::ItemName { name, id: self.id().as_u64(), unique_name: self.unique_name() }
     }
 
     pub fn error_scope<'a>(