compiler/rustc_passes/src/debugger_visualizer.rs

   1 //! Detecting usage of the `#[debugger_visualizer]` attribute.
   2
   3 use hir::CRATE_HIR_ID;
   4 use rustc_data_structures::fx::FxHashSet;
   5 use rustc_expand::base::resolve_path;
   6 use rustc_hir as hir;
   7 use rustc_hir::def_id::CrateNum;
   8 use rustc_hir::HirId;
   9 use rustc_middle::ty::query::Providers;
  10 use rustc_middle::ty::TyCtxt;
  11 use rustc_span::def_id::LOCAL_CRATE;
  12 use rustc_span::{sym, DebuggerVisualizerFile, DebuggerVisualizerType};
  13
  14 use std::sync::Arc;
  15
  16 use crate::errors::DebugVisualizerUnreadable;
  17
  18 fn check_for_debugger_visualizer<'tcx>(
  19     tcx: TyCtxt<'tcx>,
  20     hir_id: HirId,
  21     debugger_visualizers: &mut FxHashSet<DebuggerVisualizerFile>,
  22 ) {
  23     let attrs = tcx.hir().attrs(hir_id);
  24     for attr in attrs {
  25         if attr.has_name(sym::debugger_visualizer) {
  26             let Some(list) = attr.meta_item_list() else {
  27                 continue
  28             };
  29
  30             let meta_item = match list.len() {
  31                 1 => match list[0].meta_item() {
  32                     Some(meta_item) => meta_item,
  33                     _ => continue,
  34                 },
  35                 _ => continue,
  36             };
  37
  38             let visualizer_type = match meta_item.name_or_empty() {
  39                 sym::natvis_file => DebuggerVisualizerType::Natvis,
  40                 sym::gdb_script_file => DebuggerVisualizerType::GdbPrettyPrinter,
  41                 _ => continue,
  42             };
  43
  44             let file = match meta_item.value_str() {
  45                 Some(value) => {
  46                     match resolve_path(&tcx.sess.parse_sess, value.as_str(), attr.span) {
  47                         Ok(file) => file,
  48                         _ => continue,
  49                     }
  50                 }
  51                 None => continue,
  52             };
  53
  54             match std::fs::read(&file) {
  55                 Ok(contents) => {
  56                     debugger_visualizers
  57                         .insert(DebuggerVisualizerFile::new(Arc::from(contents), visualizer_type));
  58                 }
  59                 Err(error) => {
  60                     tcx.sess.emit_err(DebugVisualizerUnreadable {
  61                         span: meta_item.span,
  62                         file: &file,
  63                         error,
  64                     });
  65                 }
  66             }
  67         }
  68     }
  69 }
  70
  71 /// Traverses and collects the debugger visualizers for a specific crate.
  72 fn debugger_visualizers<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> Vec<DebuggerVisualizerFile> {
  73     assert_eq!(cnum, LOCAL_CRATE);
  74
  75     // Initialize the collector.
  76     let mut debugger_visualizers = FxHashSet::default();
  77
  78     // Collect debugger visualizers in this crate.
  79     tcx.hir().for_each_module(|id| {
  80         check_for_debugger_visualizer(
  81             tcx,
  82             tcx.hir().local_def_id_to_hir_id(id),
  83             &mut debugger_visualizers,
  84         )
  85     });
  86
  87     // Collect debugger visualizers on the crate attributes.
  88     check_for_debugger_visualizer(tcx, CRATE_HIR_ID, &mut debugger_visualizers);
  89
  90     // Extract out the found debugger_visualizer items.
  91     let mut visualizers = debugger_visualizers.into_iter().collect::<Vec<_>>();
  92
  93     // Sort the visualizers so we always get a deterministic query result.
  94     visualizers.sort();
  95     visualizers
  96 }
  97
  98 pub fn provide(providers: &mut Providers) {
  99     providers.debugger_visualizers = debugger_visualizers;
 100 }