diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc/ty/context.rs | 2 | ||||
| -rw-r--r-- | src/librustc_metadata/rmeta/encoder.rs | 164 | ||||
| -rw-r--r-- | src/librustc_metadata/rmeta/mod.rs | 3 |
3 files changed, 136 insertions, 33 deletions
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs index 0e3776f32e0..9b67d423510 100644 --- a/src/librustc/ty/context.rs +++ b/src/librustc/ty/context.rs @@ -1323,7 +1323,7 @@ impl<'tcx> TyCtxt<'tcx> { } pub fn encode_metadata(self) -> EncodedMetadata { - let _prof_timer = self.prof.generic_activity("generate_crate_metadata"); + let _prof_timer = self.prof.verbose_generic_activity("generate_crate_metadata"); self.cstore.encode_metadata(self) } diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs index 6280fd62de9..5963047fc76 100644 --- a/src/librustc_metadata/rmeta/encoder.rs +++ b/src/librustc_metadata/rmeta/encoder.rs @@ -18,12 +18,13 @@ use rustc_ast::attr; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::stable_hasher::StableHasher; -use rustc_data_structures::sync::Lrc; +use rustc_data_structures::sync::{join, Lrc}; use rustc_hir as hir; use rustc_hir::def::CtorKind; +use rustc_hir::def_id::DefIdSet; use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE}; use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; -use rustc_hir::itemlikevisit::ItemLikeVisitor; +use rustc_hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor}; use rustc_hir::{AnonConst, GenericParamKind}; use rustc_index::vec::Idx; use rustc_serialize::{opaque, Encodable, Encoder, SpecializedEncoder}; @@ -467,12 +468,6 @@ impl<'tcx> EncodeContext<'tcx> { let impls = self.encode_impls(); let impl_bytes = self.position() - i; - // Encode exported symbols info. - i = self.position(); - let exported_symbols = self.tcx.exported_symbols(LOCAL_CRATE); - let exported_symbols = self.encode_exported_symbols(&exported_symbols); - let exported_symbols_bytes = self.position() - i; - let tcx = self.tcx; // Encode the items. @@ -513,6 +508,13 @@ impl<'tcx> EncodeContext<'tcx> { let proc_macro_data = self.encode_proc_macros(); let proc_macro_data_bytes = self.position() - i; + // Encode exported symbols info. This is prefetched in `encode_metadata` so we encode + // this last to give the prefetching as much time as possible to complete. + i = self.position(); + let exported_symbols = self.tcx.exported_symbols(LOCAL_CRATE); + let exported_symbols = self.encode_exported_symbols(&exported_symbols); + let exported_symbols_bytes = self.position() - i; + let attrs = tcx.hir().krate_attrs(); let has_default_lib_allocator = attr::contains_name(&attrs, sym::default_lib_allocator); @@ -888,6 +890,8 @@ impl EncodeContext<'tcx> { self.encode_generics(def_id); self.encode_explicit_predicates(def_id); self.encode_inferred_outlives(def_id); + + // This should be kept in sync with `PrefetchVisitor.visit_trait_item`. self.encode_optimized_mir(def_id); self.encode_promoted_mir(def_id); } @@ -959,6 +963,9 @@ impl EncodeContext<'tcx> { self.encode_generics(def_id); self.encode_explicit_predicates(def_id); self.encode_inferred_outlives(def_id); + + // The following part should be kept in sync with `PrefetchVisitor.visit_impl_item`. + let mir = match ast_item.kind { hir::ImplItemKind::Const(..) => true, hir::ImplItemKind::Fn(ref sig, _) => { @@ -1250,6 +1257,8 @@ impl EncodeContext<'tcx> { _ => {} } + // The following part should be kept in sync with `PrefetchVisitor.visit_item`. + let mir = match item.kind { hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => true, hir::ItemKind::Fn(ref sig, ..) => { @@ -1697,6 +1706,70 @@ impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> { } } +/// Used to prefetch queries which will be needed later by metadata encoding. +/// Only a subset of the queries are actually prefetched to keep this code smaller. +struct PrefetchVisitor<'tcx> { + tcx: TyCtxt<'tcx>, + mir_keys: &'tcx DefIdSet, +} + +impl<'tcx> PrefetchVisitor<'tcx> { + fn prefetch_mir(&self, def_id: DefId) { + if self.mir_keys.contains(&def_id) { + self.tcx.optimized_mir(def_id); + self.tcx.promoted_mir(def_id); + } + } +} + +impl<'tcx, 'v> ParItemLikeVisitor<'v> for PrefetchVisitor<'tcx> { + fn visit_item(&self, item: &hir::Item<'_>) { + // This should be kept in sync with `encode_info_for_item`. + let tcx = self.tcx; + match item.kind { + hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => { + self.prefetch_mir(tcx.hir().local_def_id(item.hir_id)) + } + hir::ItemKind::Fn(ref sig, ..) => { + let def_id = tcx.hir().local_def_id(item.hir_id); + let generics = tcx.generics_of(def_id); + let needs_inline = generics.requires_monomorphization(tcx) + || tcx.codegen_fn_attrs(def_id).requests_inline(); + if needs_inline || sig.header.constness == hir::Constness::Const { + self.prefetch_mir(def_id) + } + } + _ => (), + } + } + + fn visit_trait_item(&self, trait_item: &'v hir::TraitItem<'v>) { + // This should be kept in sync with `encode_info_for_trait_item`. + self.prefetch_mir(self.tcx.hir().local_def_id(trait_item.hir_id)); + } + + fn visit_impl_item(&self, impl_item: &'v hir::ImplItem<'v>) { + // This should be kept in sync with `encode_info_for_impl_item`. + let tcx = self.tcx; + match impl_item.kind { + hir::ImplItemKind::Const(..) => { + self.prefetch_mir(tcx.hir().local_def_id(impl_item.hir_id)) + } + hir::ImplItemKind::Fn(ref sig, _) => { + let def_id = tcx.hir().local_def_id(impl_item.hir_id); + let generics = tcx.generics_of(def_id); + let needs_inline = generics.requires_monomorphization(tcx) + || tcx.codegen_fn_attrs(def_id).requests_inline(); + let is_const_fn = sig.header.constness == hir::Constness::Const; + if needs_inline || is_const_fn { + self.prefetch_mir(def_id) + } + } + hir::ImplItemKind::OpaqueTy(..) | hir::ImplItemKind::TyAlias(..) => (), + } + } +} + // NOTE(eddyb) The following comment was preserved for posterity, even // though it's no longer relevant as EBML (which uses nested & tagged // "documents") was replaced with a scheme that can't go out of bounds. @@ -1721,35 +1794,64 @@ impl<'tcx, 'v> ItemLikeVisitor<'v> for ImplVisitor<'tcx> { // generated regardless of trailing bytes that end up in it. pub(super) fn encode_metadata(tcx: TyCtxt<'_>) -> EncodedMetadata { + // Since encoding metadata is not in a query, and nothing is cached, + // there's no need to do dep-graph tracking for any of it. + tcx.dep_graph.assert_ignored(); + + join( + || encode_metadata_impl(tcx), + || { + if tcx.sess.threads() == 1 { + return; + } + // Prefetch some queries used by metadata encoding. + // This is not necessary for correctness, but is only done for performance reasons. + // It can be removed if it turns out to cause trouble or be detrimental to performance. + join( + || { + if !tcx.sess.opts.output_types.should_codegen() { + // We won't emit MIR, so don't prefetch it. + return; + } + tcx.hir().krate().par_visit_all_item_likes(&PrefetchVisitor { + tcx, + mir_keys: tcx.mir_keys(LOCAL_CRATE), + }); + }, + || tcx.exported_symbols(LOCAL_CRATE), + ); + }, + ) + .0 +} + +fn encode_metadata_impl(tcx: TyCtxt<'_>) -> EncodedMetadata { let mut encoder = opaque::Encoder::new(vec![]); encoder.emit_raw_bytes(METADATA_HEADER); // Will be filled with the root position after encoding everything. encoder.emit_raw_bytes(&[0, 0, 0, 0]); - // Since encoding metadata is not in a query, and nothing is cached, - // there's no need to do dep-graph tracking for any of it. - let (root, mut result) = tcx.dep_graph.with_ignore(move || { - let mut ecx = EncodeContext { - opaque: encoder, - tcx, - per_def: Default::default(), - lazy_state: LazyState::NoNode, - type_shorthands: Default::default(), - predicate_shorthands: Default::default(), - source_file_cache: tcx.sess.source_map().files()[0].clone(), - interpret_allocs: Default::default(), - interpret_allocs_inverse: Default::default(), - }; - - // Encode the rustc version string in a predictable location. - rustc_version().encode(&mut ecx).unwrap(); - - // Encode all the entries and extra information in the crate, - // culminating in the `CrateRoot` which points to all of it. - let root = ecx.encode_crate_root(); - (root, ecx.opaque.into_inner()) - }); + let mut ecx = EncodeContext { + opaque: encoder, + tcx, + per_def: Default::default(), + lazy_state: LazyState::NoNode, + type_shorthands: Default::default(), + predicate_shorthands: Default::default(), + source_file_cache: tcx.sess.source_map().files()[0].clone(), + interpret_allocs: Default::default(), + interpret_allocs_inverse: Default::default(), + }; + + // Encode the rustc version string in a predictable location. + rustc_version().encode(&mut ecx).unwrap(); + + // Encode all the entries and extra information in the crate, + // culminating in the `CrateRoot` which points to all of it. + let root = ecx.encode_crate_root(); + + let mut result = ecx.opaque.into_inner(); // Encode the root position. let header = METADATA_HEADER.len(); diff --git a/src/librustc_metadata/rmeta/mod.rs b/src/librustc_metadata/rmeta/mod.rs index 05d834e5dee..448c1610c13 100644 --- a/src/librustc_metadata/rmeta/mod.rs +++ b/src/librustc_metadata/rmeta/mod.rs @@ -196,7 +196,6 @@ crate struct CrateRoot<'tcx> { source_map: Lazy<[rustc_span::SourceFile]>, def_path_table: Lazy<map::definitions::DefPathTable>, impls: Lazy<[TraitImpls]>, - exported_symbols: Lazy!([(ExportedSymbol<'tcx>, SymbolExportLevel)]), interpret_alloc_index: Lazy<[u32]>, per_def: LazyPerDefTables<'tcx>, @@ -204,6 +203,8 @@ crate struct CrateRoot<'tcx> { /// The DefIndex's of any proc macros declared by this crate. proc_macro_data: Option<Lazy<[DefIndex]>>, + exported_symbols: Lazy!([(ExportedSymbol<'tcx>, SymbolExportLevel)]), + compiler_builtins: bool, needs_allocator: bool, needs_panic_runtime: bool, |