Auto merge of rust-lang#121089 - oli-obk:create_def_feed, r=<try>

Remove `feed_local_def_id`

best reviewed commit by commit

Basically I returned `TyCtxtFeed` from `create_def` and then preserved that in the local caches

based on rust-lang#121084

r? `@petrochenkov`

compiler/rustc_ast_lowering/src/lib.rs

@@ -427,7 +427,7 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
     tcx.ensure_with_value().early_lint_checks(());
     tcx.ensure_with_value().debugger_visualizers(LOCAL_CRATE);
     tcx.ensure_with_value().get_lang_items(());
-    let (mut resolver, krate) = tcx.resolver_for_lowering(()).steal();
+    let (mut resolver, krate) = tcx.resolver_for_lowering(()).0.steal();
 
     let ast_index = index_crate(&resolver.node_id_to_def_id, &krate);
     let mut owners = IndexVec::from_fn_n(

compiler/rustc_driver_impl/src/pretty.rs

@@ -229,7 +229,7 @@ impl<'tcx> PrintExtra<'tcx> {
     {
         match self {
             PrintExtra::AfterParsing { krate, .. } => f(krate),
-            PrintExtra::NeedsAstMap { tcx } => f(&tcx.resolver_for_lowering(()).borrow().1),
+            PrintExtra::NeedsAstMap { tcx } => f(&tcx.resolver_for_lowering(()).0.borrow().1),
         }
     }
 
@@ -279,7 +279,7 @@ pub fn print<'tcx>(sess: &Session, ppm: PpMode, ex: PrintExtra<'tcx>) {
         }
         AstTreeExpanded => {
             debug!("pretty-printing expanded AST");
-            format!("{:#?}", ex.tcx().resolver_for_lowering(()).borrow().1)
+            format!("{:#?}", ex.tcx().resolver_for_lowering(()).0.borrow().1)
         }
         Hir(s) => {
             debug!("pretty printing HIR {:?}", s);

compiler/rustc_interface/src/passes.rs

@@ -3,6 +3,7 @@ use crate::interface::{Compiler, Result};
 use crate::proc_macro_decls;
 use crate::util;
 
+use ast::expand::StrippedCfgItem;
 use rustc_ast::{self as ast, visit};
 use rustc_borrowck as mir_borrowck;
 use rustc_codegen_ssa::traits::CodegenBackend;
@@ -18,6 +19,7 @@ use rustc_lint::{unerased_lint_store, BufferedEarlyLint, EarlyCheckNode, LintSto
 use rustc_metadata::creader::CStore;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
+use rustc_middle::query::LocalCrate;
 use rustc_middle::ty::{self, GlobalCtxt, RegisteredTools, TyCtxt};
 use rustc_middle::util::Providers;
 use rustc_mir_build as mir_build;
@@ -280,7 +282,7 @@ fn configure_and_expand(
 
 fn early_lint_checks(tcx: TyCtxt<'_>, (): ()) {
     let sess = tcx.sess;
-    let (resolver, krate) = &*tcx.resolver_for_lowering(()).borrow();
+    let (resolver, krate) = &*tcx.resolver_for_lowering(()).0.borrow();
     let mut lint_buffer = resolver.lint_buffer.steal();
 
     if sess.opts.unstable_opts.input_stats {
@@ -534,7 +536,7 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P
 fn resolver_for_lowering<'tcx>(
     tcx: TyCtxt<'tcx>,
     (): (),
-) -> &'tcx Steal<(ty::ResolverAstLowering, Lrc<ast::Crate>)> {
+) -> (&'tcx Steal<(ty::ResolverAstLowering, Lrc<ast::Crate>)>, &'tcx ty::ResolverGlobalCtxt) {
     let arenas = Resolver::arenas();
     let _ = tcx.registered_tools(()); // Uses `crate_for_resolver`.
     let (krate, pre_configured_attrs) = tcx.crate_for_resolver(()).steal();
@@ -549,9 +551,16 @@ fn resolver_for_lowering<'tcx>(
         ast_lowering: untracked_resolver_for_lowering,
     } = resolver.into_outputs();
 
-    let feed = tcx.feed_unit_query();
-    feed.resolutions(tcx.arena.alloc(untracked_resolutions));
-    tcx.arena.alloc(Steal::new((untracked_resolver_for_lowering, Lrc::new(krate))))
+    let resolutions = tcx.arena.alloc(untracked_resolutions);
+    (tcx.arena.alloc(Steal::new((untracked_resolver_for_lowering, Lrc::new(krate)))), resolutions)
+}
+
+fn stripped_cfg_items(tcx: TyCtxt<'_>, _: LocalCrate) -> &[StrippedCfgItem] {
+    tcx.arena.alloc_from_iter(tcx.resolutions(()).stripped_cfg_items.steal())
+}
+
+fn resolutions(tcx: TyCtxt<'_>, _: ()) -> &ty::ResolverGlobalCtxt {
+    tcx.resolver_for_lowering(()).1
 }
 
 pub(crate) fn write_dep_info(tcx: TyCtxt<'_>) {
@@ -608,6 +617,8 @@ pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
     providers.analysis = analysis;
     providers.hir_crate = rustc_ast_lowering::lower_to_hir;
     providers.resolver_for_lowering = resolver_for_lowering;
+    providers.stripped_cfg_items = stripped_cfg_items;
+    providers.resolutions = resolutions;
     providers.early_lint_checks = early_lint_checks;
     proc_macro_decls::provide(providers);
     rustc_const_eval::provide(providers);

compiler/rustc_interface/src/queries.rs

@@ -8,8 +8,7 @@ use rustc_codegen_ssa::CodegenResults;
 use rustc_data_structures::steal::Steal;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::{AppendOnlyIndexVec, FreezeLock, OnceLock, WorkerLocal};
-use rustc_hir::def::DefKind;
-use rustc_hir::def_id::{StableCrateId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{StableCrateId, LOCAL_CRATE};
 use rustc_hir::definitions::Definitions;
 use rustc_incremental::setup_dep_graph;
 use rustc_metadata::creader::CStore;
@@ -144,10 +143,8 @@ impl<'tcx> Queries<'tcx> {
                 stable_crate_id,
             )) as _);
             let definitions = FreezeLock::new(Definitions::new(stable_crate_id));
-            let source_span = AppendOnlyIndexVec::new();
-            let _id = source_span.push(krate.spans.inner_span);
-            debug_assert_eq!(_id, CRATE_DEF_ID);
-            let untracked = Untracked { cstore, source_span, definitions };
+            let untracked =
+                Untracked { cstore, source_span: AppendOnlyIndexVec::new(), definitions };
 
             let qcx = passes::create_global_ctxt(
                 self.compiler,
@@ -172,9 +169,6 @@ impl<'tcx> Queries<'tcx> {
                 )));
                 feed.crate_for_resolver(tcx.arena.alloc(Steal::new((krate, pre_configured_attrs))));
                 feed.output_filenames(Arc::new(outputs));
-
-                let feed = tcx.feed_local_def_id(CRATE_DEF_ID);
-                feed.def_kind(DefKind::Mod);
             });
             Ok(qcx)
         })

compiler/rustc_middle/src/query/mod.rs

@@ -125,12 +125,11 @@ rustc_queries! {
     }
 
     query resolutions(_: ()) -> &'tcx ty::ResolverGlobalCtxt {
-        feedable
         no_hash
         desc { "getting the resolver outputs" }
     }
 
-    query resolver_for_lowering(_: ()) -> &'tcx Steal<(ty::ResolverAstLowering, Lrc<ast::Crate>)> {
+    query resolver_for_lowering(_: ()) -> (&'tcx Steal<(ty::ResolverAstLowering, Lrc<ast::Crate>)>, &'tcx ty::ResolverGlobalCtxt) {
         eval_always
         no_hash
         desc { "getting the resolver for lowering" }
@@ -2211,7 +2210,6 @@ rustc_queries! {
     /// Should not be called for the local crate before the resolver outputs are created, as it
     /// is only fed there.
     query stripped_cfg_items(cnum: CrateNum) -> &'tcx [StrippedCfgItem] {
-        feedable
         desc { "getting cfg-ed out item names" }
         separate_provide_extern
     }

compiler/rustc_middle/src/ty/context.rs

@@ -62,7 +62,7 @@ use rustc_session::config::CrateType;
 use rustc_session::cstore::{CrateStoreDyn, Untracked};
 use rustc_session::lint::Lint;
 use rustc_session::{Limit, MetadataKind, Session};
-use rustc_span::def_id::{DefPathHash, StableCrateId};
+use rustc_span::def_id::{DefPathHash, StableCrateId, CRATE_DEF_ID};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::abi::{FieldIdx, Layout, LayoutS, TargetDataLayout, VariantIdx};
@@ -76,6 +76,7 @@ use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::iter;
+use std::marker::PhantomData;
 use std::mem;
 use std::ops::{Bound, Deref};
 
@@ -522,14 +523,55 @@ pub struct TyCtxtFeed<'tcx, KEY: Copy> {
     key: KEY,
 }
 
+/// Never return a `Feed` from a query. Only queries that create a `DefId` are
+/// allowed to feed queries for that `DefId`.
+impl<KEY: Copy, CTX> !HashStable<CTX> for TyCtxtFeed<'_, KEY> {}
+
+/// The same as `TyCtxtFeed`, but does not contain a `TyCtxt`.
+/// Use this to pass around when you have a `TyCtxt` elsewhere.
+/// Just an optimization to save space and not store hundreds of
+/// `TyCtxtFeed` in the resolver.
+#[derive(Copy, Clone)]
+pub struct Feed<'tcx, KEY: Copy> {
+    _tcx: PhantomData<TyCtxt<'tcx>>,
+    // Do not allow direct access, as downstream code must not mutate this field.
+    key: KEY,
+}
+
+/// Never return a `Feed` from a query. Only queries that create a `DefId` are
+/// allowed to feed queries for that `DefId`.
+impl<KEY: Copy, CTX> !HashStable<CTX> for Feed<'_, KEY> {}
+
+impl<T: fmt::Debug + Copy> fmt::Debug for Feed<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.key.fmt(f)
+    }
+}
+
+/// Some workarounds to use cases that cannot use `create_def`.
+/// Do not add new ways to create `TyCtxtFeed` without consulting
+/// with T-compiler and making an analysis about why your addition
+/// does not cause incremental compilation issues.
 impl<'tcx> TyCtxt<'tcx> {
+    /// Can only be fed before queries are run, and is thus exempt from any
+    /// incremental issues. Do not use except for the initial query feeding.
     pub fn feed_unit_query(self) -> TyCtxtFeed<'tcx, ()> {
+        self.dep_graph.assert_ignored();
         TyCtxtFeed { tcx: self, key: () }
     }
+
+    /// Can only be fed before queries are run, and is thus exempt from any
+    /// incremental issues. Do not use except for the initial query feeding.
     pub fn feed_local_crate(self) -> TyCtxtFeed<'tcx, CrateNum> {
+        self.dep_graph.assert_ignored();
         TyCtxtFeed { tcx: self, key: LOCAL_CRATE }
     }
-    pub fn feed_local_def_id(self, key: LocalDefId) -> TyCtxtFeed<'tcx, LocalDefId> {
+
+    /// Only used in the resolver to register the `CRATE_DEF_ID` `DefId` and feed
+    /// some queries for it. It will panic if used twice.
+    pub fn create_local_crate_def_id(self, span: Span) -> TyCtxtFeed<'tcx, LocalDefId> {
+        let key = self.untracked().source_span.push(span);
+        assert_eq!(key, CRATE_DEF_ID);
         TyCtxtFeed { tcx: self, key }
     }
 
@@ -547,6 +589,23 @@ impl<'tcx, KEY: Copy> TyCtxtFeed<'tcx, KEY> {
     pub fn key(&self) -> KEY {
         self.key
     }
+
+    #[inline(always)]
+    pub fn downgrade(self) -> Feed<'tcx, KEY> {
+        Feed { _tcx: PhantomData, key: self.key }
+    }
+}
+
+impl<'tcx, KEY: Copy> Feed<'tcx, KEY> {
+    #[inline(always)]
+    pub fn key(&self) -> KEY {
+        self.key
+    }
+
+    #[inline(always)]
+    pub fn upgrade(self, tcx: TyCtxt<'tcx>) -> TyCtxtFeed<'tcx, KEY> {
+        TyCtxtFeed { tcx, key: self.key }
+    }
 }
 
 impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
@@ -1091,7 +1150,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // needs to be re-evaluated.
         self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE);
 
-        let feed = self.feed_local_def_id(def_id);
+        let feed = TyCtxtFeed { tcx: self, key: def_id };
         feed.def_kind(def_kind);
         // Unique types created for closures participate in type privacy checking.
         // They have visibilities inherited from the module they are defined in.

compiler/rustc_middle/src/ty/mod.rs

@@ -28,6 +28,7 @@ use crate::ty::fast_reject::SimplifiedType;
 use crate::ty::util::Discr;
 pub use adt::*;
 pub use assoc::*;
+use ast::expand::StrippedCfgItem;
 pub use generic_args::*;
 pub use generics::*;
 use rustc_ast as ast;
@@ -84,7 +85,8 @@ pub use self::consts::{
     Const, ConstData, ConstInt, ConstKind, Expr, ScalarInt, UnevaluatedConst, ValTree,
 };
 pub use self::context::{
-    tls, CtxtInterners, DeducedParamAttrs, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt, TyCtxtFeed,
+    tls, CtxtInterners, DeducedParamAttrs, Feed, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt,
+    TyCtxtFeed,
 };
 pub use self::instance::{Instance, InstanceDef, ShortInstance, UnusedGenericParams};
 pub use self::list::List;
@@ -187,6 +189,7 @@ pub struct ResolverGlobalCtxt {
     pub doc_link_resolutions: FxHashMap<LocalDefId, DocLinkResMap>,
     pub doc_link_traits_in_scope: FxHashMap<LocalDefId, Vec<DefId>>,
     pub all_macro_rules: FxHashMap<Symbol, Res<ast::NodeId>>,
+    pub stripped_cfg_items: Steal<Vec<StrippedCfgItem>>,
 }
 
 /// Resolutions that should only be used for lowering.

compiler/rustc_passes/src/debugger_visualizer.rs

@@ -87,7 +87,7 @@ impl<'ast> rustc_ast::visit::Visitor<'ast> for DebuggerVisualizerCollector<'_> {
 
 /// Traverses and collects the debugger visualizers for a specific crate.
 fn debugger_visualizers(tcx: TyCtxt<'_>, _: LocalCrate) -> Vec<DebuggerVisualizerFile> {
-    let resolver_and_krate = tcx.resolver_for_lowering(()).borrow();
+    let resolver_and_krate = tcx.resolver_for_lowering(()).0.borrow();
     let krate = &*resolver_and_krate.1;
 
     let mut visitor = DebuggerVisualizerCollector { sess: tcx.sess, visualizers: Vec::new() };

compiler/rustc_passes/src/lang_items.rs

@@ -243,7 +243,7 @@ impl<'ast, 'tcx> LanguageItemCollector<'ast, 'tcx> {
 
 /// Traverses and collects all the lang items in all crates.
 fn get_lang_items(tcx: TyCtxt<'_>, (): ()) -> LanguageItems {
-    let resolver = tcx.resolver_for_lowering(()).borrow();
+    let resolver = tcx.resolver_for_lowering(()).0.borrow();
     let (resolver, krate) = &*resolver;
 
     // Initialize the collector.