compiler/rustc_symbol_mangling/src/test.rs

   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.
   6
   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};
  12
  13 const SYMBOL_NAME: Symbol = sym::rustc_symbol_name;
  14 const DEF_PATH: Symbol = sym::rustc_def_path;
  15
  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
  19     // skip the walk.
  20     if !tcx.features().rustc_attrs {
  21         return;
  22     }
  23
  24     tcx.dep_graph.with_ignore(|| {
  25         let mut symbol_names = SymbolNamesTest { tcx };
  26         let crate_items = tcx.hir_crate_items(());
  27
  28         for id in crate_items.items() {
  29             symbol_names.process_attrs(id.owner_id.def_id);
  30         }
  31
  32         for id in crate_items.trait_items() {
  33             symbol_names.process_attrs(id.owner_id.def_id);
  34         }
  35
  36         for id in crate_items.impl_items() {
  37             symbol_names.process_attrs(id.owner_id.def_id);
  38         }
  39
  40         for id in crate_items.foreign_items() {
  41             symbol_names.process_attrs(id.owner_id.def_id);
  42         }
  43     })
  44 }
  45
  46 struct SymbolNamesTest<'tcx> {
  47     tcx: TyCtxt<'tcx>,
  48 }
  49
  50 impl SymbolNamesTest<'_> {
  51     fn process_attrs(&mut self, def_id: LocalDefId) {
  52         let tcx = self.tcx;
  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
  55         // some subset.
  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(
  59                 def_id,
  60                 tcx.erase_regions(InternalSubsts::identity_for_item(tcx, def_id)),
  61             );
  62             let mangled = tcx.symbol_name(instance);
  63             tcx.sess.emit_err(TestOutput {
  64                 span: attr.span,
  65                 kind: Kind::SymbolName,
  66                 content: format!("{mangled}"),
  67             });
  68             if let Ok(demangling) = rustc_demangle::try_demangle(mangled.name) {
  69                 tcx.sess.emit_err(TestOutput {
  70                     span: attr.span,
  71                     kind: Kind::Demangling,
  72                     content: format!("{demangling}"),
  73                 });
  74                 tcx.sess.emit_err(TestOutput {
  75                     span: attr.span,
  76                     kind: Kind::DemanglingAlt,
  77                     content: format!("{:#}", demangling),
  78                 });
  79             }
  80         }
  81
  82         for attr in tcx.get_attrs(def_id.to_def_id(), DEF_PATH) {
  83             tcx.sess.emit_err(TestOutput {
  84                 span: attr.span,
  85                 kind: Kind::DefPath,
  86                 content: with_no_trimmed_paths!(tcx.def_path_str(def_id.to_def_id())),
  87             });
  88         }
  89     }
  90 }