1 files changed, 99 insertions, 0 deletions
diff --git a/compiler/rustc_passes/src/debugger_visualizer.rs b/compiler/rustc_passes/src/debugger_visualizer.rs
new file mode 100644
index 000000000..e08683fe2
--- /dev/null
+++ b/compiler/rustc_passes/src/debugger_visualizer.rs
@@ -0,0 +1,99 @@
+//! Detecting usage of the `#[debugger_visualizer]` attribute.
+
+use hir::CRATE_HIR_ID;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_expand::base::resolve_path;
+use rustc_hir as hir;
+use rustc_hir::def_id::CrateNum;
+use rustc_hir::HirId;
+use rustc_middle::ty::query::Providers;
+use rustc_middle::ty::TyCtxt;
+use rustc_span::def_id::LOCAL_CRATE;
+use rustc_span::{sym, DebuggerVisualizerFile, DebuggerVisualizerType};
+
+use std::sync::Arc;
+
+fn check_for_debugger_visualizer<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    hir_id: HirId,
+    debugger_visualizers: &mut FxHashSet<DebuggerVisualizerFile>,
+) {
+    let attrs = tcx.hir().attrs(hir_id);
+    for attr in attrs {
+        if attr.has_name(sym::debugger_visualizer) {
+            let Some(list) = attr.meta_item_list() else {
+                continue
+            };
+
+            let meta_item = match list.len() {
+                1 => match list[0].meta_item() {
+                    Some(meta_item) => meta_item,
+                    _ => continue,
+                },
+                _ => continue,
+            };
+
+            let visualizer_type = match meta_item.name_or_empty() {
+                sym::natvis_file => DebuggerVisualizerType::Natvis,
+                sym::gdb_script_file => DebuggerVisualizerType::GdbPrettyPrinter,
+                _ => continue,
+            };
+
+            let file = match meta_item.value_str() {
+                Some(value) => {
+                    match resolve_path(&tcx.sess.parse_sess, value.as_str(), attr.span) {
+                        Ok(file) => file,
+                        _ => continue,
+                    }
+                }
+                None => continue,
+            };
+
+            match std::fs::read(&file) {
+                Ok(contents) => {
+                    debugger_visualizers
+                        .insert(DebuggerVisualizerFile::new(Arc::from(contents), visualizer_type));
+                }
+                Err(err) => {
+                    tcx.sess
+                        .struct_span_err(
+                            meta_item.span,
+                            &format!("couldn't read {}: {}", file.display(), err),
+                        )
+                        .emit();
+                }
+            }
+        }
+    }
+}
+
+/// Traverses and collects the debugger visualizers for a specific crate.
+fn debugger_visualizers<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> Vec<DebuggerVisualizerFile> {
+    assert_eq!(cnum, LOCAL_CRATE);
+
+    // Initialize the collector.
+    let mut debugger_visualizers = FxHashSet::default();
+
+    // Collect debugger visualizers in this crate.
+    tcx.hir().for_each_module(|id| {
+        check_for_debugger_visualizer(
+            tcx,
+            tcx.hir().local_def_id_to_hir_id(id),
+            &mut debugger_visualizers,
+        )
+    });
+
+    // Collect debugger visualizers on the crate attributes.
+    check_for_debugger_visualizer(tcx, CRATE_HIR_ID, &mut debugger_visualizers);
+
+    // Extract out the found debugger_visualizer items.
+    let mut visualizers = debugger_visualizers.into_iter().collect::<Vec<_>>();
+
+    // Sort the visualizers so we always get a deterministic query result.
+    visualizers.sort();
+    visualizers
+}
+
+pub fn provide(providers: &mut Providers) {
+    providers.debugger_visualizers = debugger_visualizers;
+}