1 //! Walks the crate looking for items/impl-items/trait-items that have
2 //! either a `rustc_symbol_name` or `rustc_def_path` attribute and
3 //! generates an error giving, respectively, the symbol name or
4 //! def-path. This is used for unit testing the code that generates
5 //! paths etc in all kinds of annoying scenarios.
7 use crate::errors::{Kind, TestOutput};
8 use rustc_hir::def_id::LocalDefId;
9 use rustc_middle::ty::print::with_no_trimmed_paths;
10 use rustc_middle::ty::{subst::InternalSubsts, Instance, TyCtxt};
11 use rustc_span::symbol::{sym, Symbol};
13 const SYMBOL_NAME: Symbol = sym::rustc_symbol_name;
14 const DEF_PATH: Symbol = sym::rustc_def_path;
16 pub fn report_symbol_names(tcx: TyCtxt<'_>) {
17 // if the `rustc_attrs` feature is not enabled, then the
18 // attributes we are interested in cannot be present anyway, so
20 if !tcx.features().rustc_attrs {
24 tcx.dep_graph.with_ignore(|| {
25 let mut symbol_names = SymbolNamesTest { tcx };
26 let crate_items = tcx.hir_crate_items(());
28 for id in crate_items.items() {
29 symbol_names.process_attrs(id.def_id);
32 for id in crate_items.trait_items() {
33 symbol_names.process_attrs(id.def_id);
36 for id in crate_items.impl_items() {
37 symbol_names.process_attrs(id.def_id);
40 for id in crate_items.foreign_items() {
41 symbol_names.process_attrs(id.def_id);
46 struct SymbolNamesTest<'tcx> {
50 impl SymbolNamesTest<'_> {
51 fn process_attrs(&mut self, def_id: LocalDefId) {
53 // The formatting of `tag({})` is chosen so that tests can elect
54 // to test the entirety of the string, if they choose, or else just
56 for attr in tcx.get_attrs(def_id.to_def_id(), SYMBOL_NAME) {
57 let def_id = def_id.to_def_id();
58 let instance = Instance::new(
60 tcx.erase_regions(InternalSubsts::identity_for_item(tcx, def_id)),
62 let mangled = tcx.symbol_name(instance);
63 tcx.sess.emit_err(TestOutput {
65 kind: Kind::SymbolName,
66 content: format!("{mangled}"),
68 if let Ok(demangling) = rustc_demangle::try_demangle(mangled.name) {
69 tcx.sess.emit_err(TestOutput {
71 kind: Kind::Demangling,
72 content: format!("{demangling}"),
74 tcx.sess.emit_err(TestOutput {
76 kind: Kind::DemanglingAlt,
77 content: format!("{:#}", demangling),
82 for attr in tcx.get_attrs(def_id.to_def_id(), DEF_PATH) {
83 tcx.sess.emit_err(TestOutput {
86 content: with_no_trimmed_paths!(tcx.def_path_str(def_id.to_def_id())),