Turn debugger_visualizers from feed- into regular query.

Author: michaelwoerister

compiler/rustc_ast_lowering/src/lib.rs

@@ -58,7 +58,7 @@ use rustc_errors::{
 use rustc_fluent_macro::fluent_messages;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
-use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
+use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::definitions::DefPathData;
 use rustc_hir::{ConstArg, GenericArg, ItemLocalId, ParamName, TraitCandidate};
 use rustc_index::{Idx, IndexSlice, IndexVec};
@@ -435,6 +435,7 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
     // Queries that borrow `resolver_for_lowering`.
     tcx.ensure_with_value().output_filenames(());
     tcx.ensure_with_value().early_lint_checks(());
+    tcx.ensure_with_value().debugger_visualizers(LOCAL_CRATE);
     let (mut resolver, krate) = tcx.resolver_for_lowering(()).steal();
 
     let ast_index = index_crate(&resolver.node_id_to_def_id, &krate);

compiler/rustc_interface/src/passes.rs

@@ -572,12 +572,6 @@ fn resolver_for_lowering<'tcx>(
     // Make sure we don't mutate the cstore from here on.
     tcx.untracked().cstore.leak();
 
-    {
-        let debugger_visualizers = rustc_passes::debugger_visualizer::collect(tcx.sess, &krate);
-        let feed = tcx.feed_local_crate();
-        feed.debugger_visualizers(debugger_visualizers);
-    }
-
     let ty::ResolverOutputs {
         global_ctxt: untracked_resolutions,
         ast_lowering: untracked_resolver_for_lowering,

compiler/rustc_middle/src/hir/map/mod.rs

@@ -1165,6 +1165,11 @@ pub(super) fn crate_hash(tcx: TyCtxt<'_>, _: LocalCrate) -> Svh {
 
     source_file_names.sort_unstable();
 
+    // We have to take care of debugger visualizers explicitly. The HIR (and
+    // thus `hir_body_hash`) contains the #[debugger_visualizer] attributes but
+    // these attributes only store the file path to the visualizer file, not
+    // their content. Yet that content is exported into crate metadata, so any
+    // changes to it need to be reflected in the crate hash.
     let debugger_visualizers: Vec<_> = tcx
         .debugger_visualizers(LOCAL_CRATE)
         .iter()

compiler/rustc_middle/src/query/mod.rs

@@ -1790,13 +1790,18 @@ rustc_queries! {
         desc { "looking at the source for a crate" }
         separate_provide_extern
     }
+
     /// Returns the debugger visualizers defined for this crate.
+    /// NOTE: This query has to be marked `eval_always` because it reads data
+    ///       directly from disk that is not tracked anywhere else. I.e. it
+    ///       represents a genuine input to the query system.
     query debugger_visualizers(_: CrateNum) -> &'tcx Vec<rustc_span::DebuggerVisualizerFile> {
         arena_cache
         desc { "looking up the debugger visualizers for this crate" }
         separate_provide_extern
-        feedable
+        eval_always
     }
+
     query postorder_cnums(_: ()) -> &'tcx [CrateNum] {
         eval_always
         desc { "generating a postorder list of CrateNums" }

compiler/rustc_passes/src/debugger_visualizer.rs

@@ -3,6 +3,10 @@
 use rustc_ast::Attribute;
 use rustc_data_structures::sync::Lrc;
 use rustc_expand::base::resolve_path;
+use rustc_middle::{
+    query::{LocalCrate, Providers},
+    ty::TyCtxt,
+};
 use rustc_session::Session;
 use rustc_span::{sym, DebuggerVisualizerFile, DebuggerVisualizerType};
 
@@ -12,7 +16,7 @@ impl DebuggerVisualizerCollector<'_> {
     fn check_for_debugger_visualizer(&mut self, attr: &Attribute) {
         if attr.has_name(sym::debugger_visualizer) {
             let Some(hints) = attr.meta_item_list() else {
-            self.sess.emit_err(DebugVisualizerInvalid { span: attr.span });
+                self.sess.emit_err(DebugVisualizerInvalid { span: attr.span });
                 return;
             };
 
@@ -82,12 +86,18 @@ impl<'ast> rustc_ast::visit::Visitor<'ast> for DebuggerVisualizerCollector<'_> {
 }
 
 /// Traverses and collects the debugger visualizers for a specific crate.
-pub fn collect(sess: &Session, krate: &rustc_ast::ast::Crate) -> Vec<DebuggerVisualizerFile> {
-    // Initialize the collector.
-    let mut visitor = DebuggerVisualizerCollector { sess, visualizers: Vec::new() };
+fn debugger_visualizers(tcx: TyCtxt<'_>, _: LocalCrate) -> Vec<DebuggerVisualizerFile> {
+    let resolver_and_krate = tcx.resolver_for_lowering(()).borrow();
+    let krate = &*resolver_and_krate.1;
+
+    let mut visitor = DebuggerVisualizerCollector { sess: tcx.sess, visualizers: Vec::new() };
     rustc_ast::visit::Visitor::visit_crate(&mut visitor, krate);
 
     // Sort the visualizers so we always get a deterministic query result.
     visitor.visualizers.sort_unstable();
     visitor.visualizers
 }
+
+pub fn provide(providers: &mut Providers) {
+    providers.debugger_visualizers = debugger_visualizers;
+}

compiler/rustc_passes/src/lib.rs

@@ -27,7 +27,7 @@ use rustc_middle::query::Providers;
 mod check_attr;
 mod check_const;
 pub mod dead;
-pub mod debugger_visualizer;
+mod debugger_visualizer;
 mod diagnostic_items;
 pub mod entry;
 mod errors;
@@ -50,6 +50,7 @@ pub fn provide(providers: &mut Providers) {
     check_attr::provide(providers);
     check_const::provide(providers);
     dead::provide(providers);
+    debugger_visualizer::provide(providers);
     diagnostic_items::provide(providers);
     entry::provide(providers);
     lang_items::provide(providers);