Auto merge of rust-lang#105220 - oli-obk:feeding, r=cjgillot

feed resolver_for_lowering instead of storing it in a field

r? `@cjgillot`

opening this as

* a discussion for `no_hash` + `feedable` queries. I think we'll want those, but I don't quite understand why they are rejected beyond a double check of the stable hashes for situations where the query is fed but also read from incremental caches.
* and a discussion on removing all untracked fields from TyCtxt and setting it up so that they are fed queries instead

Author: bors

compiler/rustc_interface/src/passes.rs

@@ -12,6 +12,7 @@ use rustc_ast::{self as ast, visit};
 use rustc_borrowck as mir_borrowck;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::parallel;
+use rustc_data_structures::steal::Steal;
 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
 use rustc_errors::{ErrorGuaranteed, PResult};
 use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand};
@@ -801,14 +802,21 @@ pub fn create_global_ctxt<'tcx>(
         TcxQueries::new(local_providers, extern_providers, query_result_on_disk_cache)
     });
 
+    let ty::ResolverOutputs {
+        definitions,
+        global_ctxt: untracked_resolutions,
+        ast_lowering: untracked_resolver_for_lowering,
+    } = resolver_outputs;
+
     let gcx = sess.time("setup_global_ctxt", || {
         global_ctxt.get_or_init(move || {
             TyCtxt::create_global_ctxt(
                 sess,
                 lint_store,
                 arena,
                 hir_arena,
-                resolver_outputs,
+                definitions,
+                untracked_resolutions,
                 krate,
                 dep_graph,
                 queries.on_disk_cache.as_ref().map(OnDiskCache::as_dyn),
@@ -820,7 +828,12 @@ pub fn create_global_ctxt<'tcx>(
         })
     });
 
-    QueryContext { gcx }
+    let mut qcx = QueryContext { gcx };
+    qcx.enter(|tcx| {
+        tcx.feed_unit_query()
+            .resolver_for_lowering(tcx.arena.alloc(Steal::new(untracked_resolver_for_lowering)))
+    });
+    qcx
 }
 
 /// Runs the resolution, type-checking, region checking and other
@@ -965,12 +978,10 @@ fn analysis(tcx: TyCtxt<'_>, (): ()) -> Result<()> {
 pub fn start_codegen<'tcx>(
     codegen_backend: &dyn CodegenBackend,
     tcx: TyCtxt<'tcx>,
-    outputs: &OutputFilenames,
 ) -> Box<dyn Any> {
     info!("Pre-codegen\n{:?}", tcx.debug_stats());
 
-    let (metadata, need_metadata_module) =
-        rustc_metadata::fs::encode_and_write_metadata(tcx, outputs);
+    let (metadata, need_metadata_module) = rustc_metadata::fs::encode_and_write_metadata(tcx);
 
     let codegen = tcx.sess.time("codegen_crate", move || {
         codegen_backend.codegen_crate(tcx, metadata, need_metadata_module)
@@ -986,7 +997,7 @@ pub fn start_codegen<'tcx>(
     info!("Post-codegen\n{:?}", tcx.debug_stats());
 
     if tcx.sess.opts.output_types.contains_key(&OutputType::Mir) {
-        if let Err(error) = rustc_mir_transform::dump_mir::emit_mir(tcx, outputs) {
+        if let Err(error) = rustc_mir_transform::dump_mir::emit_mir(tcx) {
             tcx.sess.emit_err(CantEmitMIR { error });
             tcx.sess.abort_if_errors();
         }

compiler/rustc_interface/src/queries.rs

@@ -20,6 +20,7 @@ use rustc_span::symbol::sym;
 use std::any::Any;
 use std::cell::{Ref, RefCell, RefMut};
 use std::rc::Rc;
+use std::sync::Arc;
 
 /// Represent the result of a query.
 ///
@@ -214,7 +215,7 @@ impl<'tcx> Queries<'tcx> {
     pub fn global_ctxt(&'tcx self) -> Result<&Query<QueryContext<'tcx>>> {
         self.global_ctxt.compute(|| {
             let crate_name = self.crate_name()?.peek().clone();
-            let outputs = self.prepare_outputs()?.peek().clone();
+            let outputs = self.prepare_outputs()?.take();
             let dep_graph = self.dep_graph()?.peek().clone();
             let (krate, resolver, lint_store) = self.expansion()?.take();
             Ok(passes::create_global_ctxt(
@@ -235,7 +236,6 @@ impl<'tcx> Queries<'tcx> {
 
     pub fn ongoing_codegen(&'tcx self) -> Result<&Query<Box<dyn Any>>> {
         self.ongoing_codegen.compute(|| {
-            let outputs = self.prepare_outputs()?;
             self.global_ctxt()?.peek_mut().enter(|tcx| {
                 tcx.analysis(()).ok();
 
@@ -249,7 +249,7 @@ impl<'tcx> Queries<'tcx> {
                 // Hook for UI tests.
                 Self::check_for_rustc_errors_attr(tcx);
 
-                Ok(passes::start_codegen(&***self.codegen_backend(), tcx, &*outputs.peek()))
+                Ok(passes::start_codegen(&***self.codegen_backend(), tcx))
             })
         })
     }
@@ -293,8 +293,10 @@ impl<'tcx> Queries<'tcx> {
         let codegen_backend = self.codegen_backend().clone();
 
         let dep_graph = self.dep_graph()?.peek().clone();
-        let prepare_outputs = self.prepare_outputs()?.take();
-        let crate_hash = self.global_ctxt()?.peek_mut().enter(|tcx| tcx.crate_hash(LOCAL_CRATE));
+        let (crate_hash, prepare_outputs) = self
+            .global_ctxt()?
+            .peek_mut()
+            .enter(|tcx| (tcx.crate_hash(LOCAL_CRATE), tcx.output_filenames(()).clone()));
         let ongoing_codegen = self.ongoing_codegen()?.take();
 
         Ok(Linker {
@@ -316,7 +318,7 @@ pub struct Linker {
 
     // compilation outputs
     dep_graph: DepGraph,
-    prepare_outputs: OutputFilenames,
+    prepare_outputs: Arc<OutputFilenames>,
     crate_hash: Svh,
     ongoing_codegen: Box<dyn Any>,
 }

compiler/rustc_macros/src/query.rs

@@ -364,10 +364,6 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream {
                 modifiers.eval_always.is_none(),
                 "Query {name} cannot be both `feedable` and `eval_always`."
             );
-            assert!(
-                modifiers.no_hash.is_none(),
-                "Query {name} cannot be both `feedable` and `no_hash`."
-            );
             feedable_queries.extend(quote! {
                 #(#doc_comments)*
                 [#attribute_stream] fn #name(#arg) #result,

compiler/rustc_metadata/src/fs.rs

@@ -6,7 +6,7 @@ use crate::{encode_metadata, EncodedMetadata};
 use rustc_data_structures::temp_dir::MaybeTempDir;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::config::{CrateType, OutputFilenames, OutputType};
+use rustc_session::config::{CrateType, OutputType};
 use rustc_session::output::filename_for_metadata;
 use rustc_session::Session;
 use tempfile::Builder as TempFileBuilder;
@@ -38,10 +38,7 @@ pub fn emit_wrapper_file(
     out_filename
 }
 
-pub fn encode_and_write_metadata(
-    tcx: TyCtxt<'_>,
-    outputs: &OutputFilenames,
-) -> (EncodedMetadata, bool) {
+pub fn encode_and_write_metadata(tcx: TyCtxt<'_>) -> (EncodedMetadata, bool) {
     #[derive(PartialEq, Eq, PartialOrd, Ord)]
     enum MetadataKind {
         None,
@@ -64,7 +61,8 @@ pub fn encode_and_write_metadata(
         .unwrap_or(MetadataKind::None);
 
     let crate_name = tcx.crate_name(LOCAL_CRATE);
-    let out_filename = filename_for_metadata(tcx.sess, crate_name.as_str(), outputs);
+    let out_filename =
+        filename_for_metadata(tcx.sess, crate_name.as_str(), tcx.output_filenames(()));
     // To avoid races with another rustc process scanning the output directory,
     // we need to write the file somewhere else and atomically move it to its
     // final destination, with an `fs::rename` call. In order for the rename to

compiler/rustc_middle/src/arena.rs

@@ -28,6 +28,7 @@ macro_rules! arena_types {
             [decode] typeck_results: rustc_middle::ty::TypeckResults<'tcx>,
             [decode] borrowck_result:
                 rustc_middle::mir::BorrowCheckResult<'tcx>,
+            [] resolver: rustc_data_structures::steal::Steal<rustc_middle::ty::ResolverAstLowering>,
             [decode] unsafety_check_result: rustc_middle::mir::UnsafetyCheckResult,
             [decode] code_region: rustc_middle::mir::coverage::CodeRegion,
             [] const_allocs: rustc_middle::mir::interpret::Allocation,

compiler/rustc_middle/src/query/mod.rs

@@ -33,7 +33,7 @@ rustc_queries! {
     }
 
     query resolver_for_lowering(_: ()) -> &'tcx Steal<ty::ResolverAstLowering> {
-        eval_always
+        feedable
         no_hash
         desc { "getting the resolver for lowering" }
     }

compiler/rustc_middle/src/ty/context.rs

@@ -81,7 +81,7 @@ use std::mem;
 use std::ops::{Bound, Deref};
 use std::sync::Arc;
 
-use super::{ImplPolarity, ResolverOutputs, RvalueScopes};
+use super::{ImplPolarity, RvalueScopes};
 
 pub trait OnDiskCache<'tcx>: rustc_data_structures::sync::Sync {
     /// Creates a new `OnDiskCache` instance from the serialized data in `data`.
@@ -1034,16 +1034,29 @@ pub struct FreeRegionInfo {
 
 /// This struct should only be created by `create_def`.
 #[derive(Copy, Clone)]
-pub struct TyCtxtFeed<'tcx> {
+pub struct TyCtxtFeed<'tcx, KEY: Copy> {
     pub tcx: TyCtxt<'tcx>,
     // Do not allow direct access, as downstream code must not mutate this field.
-    def_id: LocalDefId,
+    key: KEY,
 }
 
-impl<'tcx> TyCtxtFeed<'tcx> {
+impl<'tcx> TyCtxt<'tcx> {
+    pub fn feed_unit_query(self) -> TyCtxtFeed<'tcx, ()> {
+        TyCtxtFeed { tcx: self, key: () }
+    }
+}
+
+impl<'tcx, KEY: Copy> TyCtxtFeed<'tcx, KEY> {
+    #[inline(always)]
+    pub fn key(&self) -> KEY {
+        self.key
+    }
+}
+
+impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
     #[inline(always)]
     pub fn def_id(&self) -> LocalDefId {
-        self.def_id
+        self.key
     }
 }
 
@@ -1099,7 +1112,6 @@ pub struct GlobalCtxt<'tcx> {
 
     /// Output of the resolver.
     pub(crate) untracked_resolutions: ty::ResolverGlobalCtxt,
-    untracked_resolver_for_lowering: Steal<ty::ResolverAstLowering>,
     /// The entire crate as AST. This field serves as the input for the hir_crate query,
     /// which lowers it from AST to HIR. It must not be read or used by anything else.
     pub untracked_crate: Steal<Lrc<ast::Crate>>,
@@ -1262,7 +1274,8 @@ impl<'tcx> TyCtxt<'tcx> {
         lint_store: Lrc<dyn Any + sync::Send + sync::Sync>,
         arena: &'tcx WorkerLocal<Arena<'tcx>>,
         hir_arena: &'tcx WorkerLocal<hir::Arena<'tcx>>,
-        resolver_outputs: ResolverOutputs,
+        definitions: Definitions,
+        untracked_resolutions: ty::ResolverGlobalCtxt,
         krate: Lrc<ast::Crate>,
         dep_graph: DepGraph,
         on_disk_cache: Option<&'tcx dyn OnDiskCache<'tcx>>,
@@ -1271,11 +1284,6 @@ impl<'tcx> TyCtxt<'tcx> {
         crate_name: &str,
         output_filenames: OutputFilenames,
     ) -> GlobalCtxt<'tcx> {
-        let ResolverOutputs {
-            definitions,
-            global_ctxt: untracked_resolutions,
-            ast_lowering: untracked_resolver_for_lowering,
-        } = resolver_outputs;
         let data_layout = s.target.parse_data_layout().unwrap_or_else(|err| {
             s.emit_fatal(err);
         });
@@ -1304,7 +1312,6 @@ impl<'tcx> TyCtxt<'tcx> {
             lifetimes: common_lifetimes,
             consts: common_consts,
             untracked_resolutions,
-            untracked_resolver_for_lowering: Steal::new(untracked_resolver_for_lowering),
             untracked_crate: Steal::new(krate),
             on_disk_cache,
             queries,
@@ -1515,7 +1522,7 @@ impl<'tcx> TyCtxtAt<'tcx> {
         self,
         parent: LocalDefId,
         data: hir::definitions::DefPathData,
-    ) -> TyCtxtFeed<'tcx> {
+    ) -> TyCtxtFeed<'tcx, LocalDefId> {
         // This function modifies `self.definitions` using a side-effect.
         // We need to ensure that these side effects are re-run by the incr. comp. engine.
         // Depending on the forever-red node will tell the graph that the calling query
@@ -1536,9 +1543,9 @@ impl<'tcx> TyCtxtAt<'tcx> {
         // This is fine because:
         // - those queries are `eval_always` so we won't miss their result changing;
         // - this write will have happened before these queries are called.
-        let def_id = self.definitions.write().create_def(parent, data);
+        let key = self.definitions.write().create_def(parent, data);
 
-        let feed = TyCtxtFeed { tcx: self.tcx, def_id };
+        let feed = TyCtxtFeed { tcx: self.tcx, key };
         feed.def_span(self.span);
         feed
     }
@@ -3107,7 +3114,6 @@ fn ptr_eq<T, U>(t: *const T, u: *const U) -> bool {
 
 pub fn provide(providers: &mut ty::query::Providers) {
     providers.resolutions = |tcx, ()| &tcx.untracked_resolutions;
-    providers.resolver_for_lowering = |tcx, ()| &tcx.untracked_resolver_for_lowering;
     providers.module_reexports =
         |tcx, id| tcx.resolutions(()).reexport_map.get(&id).map(|v| &v[..]);
     providers.crate_name = |tcx, id| {

compiler/rustc_middle/src/ty/mod.rs

@@ -82,8 +82,8 @@ pub use self::consts::{
 pub use self::context::{
     tls, CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations,
     CtxtInterners, DeducedParamAttrs, FreeRegionInfo, GeneratorDiagnosticData,
-    GeneratorInteriorTypeCause, GlobalCtxt, Lift, OnDiskCache, TyCtxt, TypeckResults, UserType,
-    UserTypeAnnotationIndex,
+    GeneratorInteriorTypeCause, GlobalCtxt, Lift, OnDiskCache, TyCtxt, TyCtxtFeed, TypeckResults,
+    UserType, UserTypeAnnotationIndex,
 };
 pub use self::instance::{Instance, InstanceDef, ShortInstance};
 pub use self::list::List;

compiler/rustc_middle/src/ty/query.rs

@@ -328,13 +328,25 @@ macro_rules! define_callbacks {
     };
 }
 
+macro_rules! hash_result {
+    ([]) => {{
+        Some(dep_graph::hash_result)
+    }};
+    ([(no_hash) $($rest:tt)*]) => {{
+        None
+    }};
+    ([$other:tt $($modifiers:tt)*]) => {
+        hash_result!([$($modifiers)*])
+    };
+}
+
 macro_rules! define_feedable {
     ($($(#[$attr:meta])* [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,)*) => {
-        impl<'tcx> TyCtxtFeed<'tcx> {
-            $($(#[$attr])*
+        $(impl<'tcx, K: IntoQueryParam<$($K)*> + Copy> TyCtxtFeed<'tcx, K> {
+            $(#[$attr])*
             #[inline(always)]
             pub fn $name(self, value: $V) -> query_stored::$name<'tcx> {
-                let key = self.def_id().into_query_param();
+                let key = self.key().into_query_param();
                 opt_remap_env_constness!([$($modifiers)*][key]);
 
                 let tcx = self.tcx;
@@ -358,11 +370,11 @@ macro_rules! define_feedable {
                     tcx,
                     key,
                     &value,
-                    dep_graph::hash_result,
+                    hash_result!([$($modifiers)*]),
                 );
                 cache.complete(key, value, dep_node_index)
-            })*
-        }
+            }
+        })*
     }
 }
 

compiler/rustc_mir_transform/src/dump_mir.rs

@@ -7,7 +7,7 @@ use crate::MirPass;
 use rustc_middle::mir::write_mir_pretty;
 use rustc_middle::mir::Body;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::config::{OutputFilenames, OutputType};
+use rustc_session::config::OutputType;
 
 pub struct Marker(pub &'static str);
 
@@ -19,8 +19,8 @@ impl<'tcx> MirPass<'tcx> for Marker {
     fn run_pass(&self, _tcx: TyCtxt<'tcx>, _body: &mut Body<'tcx>) {}
 }
 
-pub fn emit_mir(tcx: TyCtxt<'_>, outputs: &OutputFilenames) -> io::Result<()> {
-    let path = outputs.path(OutputType::Mir);
+pub fn emit_mir(tcx: TyCtxt<'_>) -> io::Result<()> {
+    let path = tcx.output_filenames(()).path(OutputType::Mir);
     let mut f = io::BufWriter::new(File::create(&path)?);
     write_mir_pretty(tcx, None, &mut f)?;
     Ok(())