Strip tokens from trait and impl items before printing AST JSON

Fixes #78510

compiler/rustc_interface/src/passes.rs

@@ -70,6 +70,17 @@ impl mut_visit::MutVisitor for TokenStripper {
         i.tokens = None;
         mut_visit::noop_flat_map_foreign_item(i, self)
     }
+    fn flat_map_trait_item(
+        &mut self,
+        mut i: P<ast::AssocItem>,
+    ) -> SmallVec<[P<ast::AssocItem>; 1]> {
+        i.tokens = None;
+        mut_visit::noop_flat_map_assoc_item(i, self)
+    }
+    fn flat_map_impl_item(&mut self, mut i: P<ast::AssocItem>) -> SmallVec<[P<ast::AssocItem>; 1]> {
+        i.tokens = None;
+        mut_visit::noop_flat_map_assoc_item(i, self)
+    }
     fn visit_block(&mut self, b: &mut P<ast::Block>) {
         b.tokens = None;
         mut_visit::noop_visit_block(b, self);

src/test/ui/ast-json/issue-78510-assoc-ice.rs

@@ -0,0 +1,18 @@
+// compile-flags: -Zast-json
+//
+// Regression test for issue #78510
+// Tests that we don't ICE when we have tokens for an associated item
+
+struct S;
+
+impl S {
+    #[derive(Debug)] //~ ERROR `derive` may only be applied to structs, enums and unions
+    fn f() {}
+}
+
+trait Bar {
+    #[derive(Debug)] //~ ERROR `derive` may only be applied to structs, enums and unions
+    fn foo() {}
+}
+
+fn main() {}

src/test/ui/ast-json/issue-78510-assoc-ice.stderr

@@ -0,0 +1,15 @@
+error[E0774]: `derive` may only be applied to structs, enums and unions
+  --> $DIR/issue-78510-assoc-ice.rs:9:5
+   |
+LL |     #[derive(Debug)]
+   |     ^^^^^^^^^^^^^^^^
+
+error[E0774]: `derive` may only be applied to structs, enums and unions
+  --> $DIR/issue-78510-assoc-ice.rs:14:5
+   |
+LL |     #[derive(Debug)]
+   |     ^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0774`.

src/test/ui/ast-json/issue-78510-assoc-ice.stdout

@@ -0,0 +1 @@
+{"module":{"inner":{"lo":139,"hi":397},"unsafety":"No","items":[{"attrs":[{"kind":{"variant":"Normal","fields":[{"path":{"span":{"lo":0,"hi":0},"segments":[{"ident":{"name":"prelude_import","span":{"lo":0,"hi":0}},"id":3,"args":null}],"tokens":null},"args":"Empty","tokens":null}]},"id":null,"style":"Outer","span":{"lo":0,"hi":0},"tokens":null}],"id":4,"span":{"lo":0,"hi":0},"vis":{"kind":"Inherited","span":{"lo":0,"hi":0},"tokens":null},"ident":{"name":"","span":{"lo":0,"hi":0}},"kind":{"variant":"Use","fields":[{"prefix":{"span":{"lo":0,"hi":0},"segments":[{"ident":{"name":"{{root}}","span":{"lo":0,"hi":0}},"id":5,"args":null},{"ident":{"name":"std","span":{"lo":0,"hi":0}},"id":6,"args":null},{"ident":{"name":"prelude","span":{"lo":0,"hi":0}},"id":7,"args":null},{"ident":{"name":"v1","span":{"lo":0,"hi":0}},"id":8,"args":null}],"tokens":null},"kind":"Glob","span":{"lo":0,"hi":0}}]},"tokens":null},{"attrs":[{"kind":{"variant":"Normal","fields":[{"path":{"span":{"lo":0,"hi":0},"segments":[{"ident":{"name":"macro_use","span":{"lo":0,"hi":0}},"id":9,"args":null}],"tokens":null},"args":"Empty","tokens":null}]},"id":null,"style":"Outer","span":{"lo":0,"hi":0},"tokens":null}],"id":10,"span":{"lo":0,"hi":0},"vis":{"kind":"Inherited","span":{"lo":0,"hi":0},"tokens":null},"ident":{"name":"std","span":{"lo":0,"hi":0}},"kind":{"variant":"ExternCrate","fields":[null]},"tokens":null},{"attrs":[],"id":11,"span":{"lo":139,"hi":148},"vis":{"kind":"Inherited","span":{"lo":139,"hi":139},"tokens":null},"ident":{"name":"S","span":{"lo":146,"hi":147}},"kind":{"variant":"Struct","fields":[{"variant":"Unit","fields":[12]},{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":147,"hi":147}},"span":{"lo":147,"hi":147}}]},"tokens":null},{"attrs":[],"id":13,"span":{"lo":150,"hi":263},"vis":{"kind":"Inherited","span":{"lo":150,"hi":150},"tokens":null},"ident":{"name":"","span":{"lo":0,"hi":0}},"kind":{"variant":"Impl","fields":["No","Positive","Final","No",{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":156,"hi":156}},"span":{"lo":154,"hi":154}},null,{"id":14,"kind":{"variant":"Path","fields":[null,{"span":{"lo":155,"hi":156},"segments":[{"ident":{"name":"S","span":{"lo":155,"hi":156}},"id":15,"args":null}],"tokens":null}]},"span":{"lo":155,"hi":156},"tokens":null},[{"attrs":[],"id":19,"span":{"lo":252,"hi":261},"vis":{"kind":"Inherited","span":{"lo":252,"hi":252},"tokens":null},"ident":{"name":"f","span":{"lo":255,"hi":256}},"kind":{"variant":"Fn","fields":["Final",{"header":{"unsafety":"No","asyncness":"No","constness":"No","ext":"None"},"decl":{"inputs":[],"output":{"variant":"Default","fields":[{"lo":259,"hi":259}]}},"span":{"lo":252,"hi":258}},{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":258,"hi":258}},"span":{"lo":256,"hi":256}},{"stmts":[],"id":20,"rules":"Default","span":{"lo":259,"hi":261},"tokens":null}]},"tokens":null}]]},"tokens":null},{"attrs":[],"id":16,"span":{"lo":265,"hi":383},"vis":{"kind":"Inherited","span":{"lo":265,"hi":265},"tokens":null},"ident":{"name":"Bar","span":{"lo":271,"hi":274}},"kind":{"variant":"Trait","fields":["No","No",{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":274,"hi":274}},"span":{"lo":274,"hi":274}},[],[{"attrs":[],"id":21,"span":{"lo":370,"hi":381},"vis":{"kind":"Inherited","span":{"lo":370,"hi":370},"tokens":null},"ident":{"name":"foo","span":{"lo":373,"hi":376}},"kind":{"variant":"Fn","fields":["Final",{"header":{"unsafety":"No","asyncness":"No","constness":"No","ext":"None"},"decl":{"inputs":[],"output":{"variant":"Default","fields":[{"lo":379,"hi":379}]}},"span":{"lo":370,"hi":378}},{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":378,"hi":378}},"span":{"lo":376,"hi":376}},{"stmts":[],"id":22,"rules":"Default","span":{"lo":379,"hi":381},"tokens":null}]},"tokens":null}]]},"tokens":null},{"attrs":[],"id":17,"span":{"lo":385,"hi":397},"vis":{"kind":"Inherited","span":{"lo":385,"hi":385},"tokens":null},"ident":{"name":"main","span":{"lo":388,"hi":392}},"kind":{"variant":"Fn","fields":["Final",{"header":{"unsafety":"No","asyncness":"No","constness":"No","ext":"None"},"decl":{"inputs":[],"output":{"variant":"Default","fields":[{"lo":395,"hi":395}]}},"span":{"lo":385,"hi":394}},{"params":[],"where_clause":{"has_where_token":false,"predicates":[],"span":{"lo":394,"hi":394}},"span":{"lo":392,"hi":392}},{"stmts":[],"id":18,"rules":"Default","span":{"lo":395,"hi":397},"tokens":null}]},"tokens":null}],"inline":true},"attrs":[],"span":{"lo":139,"hi":397},"proc_macros":[]}