Remove the contains_extern_indicator query

Part of #47320

Author: wesleywiser

src/librustc/dep_graph/dep_node.rs

@@ -627,7 +627,6 @@ define_dep_nodes!( <'tcx>
     [input] AllCrateNums,
     [] ExportedSymbols(CrateNum),
     [eval_always] CollectAndPartitionTranslationItems,
-    [] ContainsExternIndicator(DefId),
     [] IsTranslatedItem(DefId),
     [] CodegenUnit(InternedString),
     [] CompileCodegenUnit(InternedString),

src/librustc/hir/mod.rs

@@ -2227,6 +2227,7 @@ bitflags! {
         const UNWIND                    = 0b0000_0100;
         const RUSTC_ALLOCATOR_NOUNWIND  = 0b0000_1000;
         const NAKED                     = 0b0001_0000;
+        const NO_MANGLE                 = 0b0010_0000;
     }
 }
 
@@ -2246,5 +2247,10 @@ impl TransFnAttrs {
             InlineAttr::None | InlineAttr::Never => false,
         }
     }
+
+    /// True if `#[no_mangle]` or `#[export_name(...)]` is present.
+    pub fn contains_extern_indicator(&self) -> bool {
+        self.flags.contains(TransFnAttrFlags::NO_MANGLE) || self.export_name.is_some()
+    }
 }
 

src/librustc/middle/reachable.rs

@@ -233,7 +233,7 @@ impl<'a, 'tcx> ReachableContext<'a, 'tcx> {
                     false
                 };
                 let def_id = self.tcx.hir.local_def_id(item.id);
-                let is_extern = self.tcx.contains_extern_indicator(def_id);
+                let is_extern = self.tcx.trans_fn_attrs(def_id).contains_extern_indicator();
                 if reachable || is_extern {
                     self.reachable_symbols.insert(search_item);
                 }

src/librustc/ty/maps/config.rs

@@ -687,7 +687,6 @@ impl_disk_cacheable_query!(borrowck, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(mir_borrowck, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(mir_const_qualif, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(check_match, |def_id| def_id.is_local());
-impl_disk_cacheable_query!(contains_extern_indicator, |_| true);
 impl_disk_cacheable_query!(def_symbol_name, |_| true);
 impl_disk_cacheable_query!(type_of, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(predicates_of, |def_id| def_id.is_local());

src/librustc/ty/maps/mod.rs

@@ -363,7 +363,6 @@ define_maps! { <'tcx>
     [] fn collect_and_partition_translation_items:
         collect_and_partition_translation_items_node(CrateNum)
         -> (Arc<DefIdSet>, Arc<Vec<Arc<CodegenUnit<'tcx>>>>),
-    [] fn contains_extern_indicator: ContainsExternIndicator(DefId) -> bool,
     [] fn symbol_export_level: GetSymbolExportLevel(DefId) -> SymbolExportLevel,
     [] fn is_translated_item: IsTranslatedItem(DefId) -> bool,
     [] fn codegen_unit: CodegenUnit(InternedString) -> Arc<CodegenUnit<'tcx>>,

src/librustc/ty/maps/on_disk_cache.rs

@@ -217,7 +217,6 @@ impl<'sess> OnDiskCache<'sess> {
                 encode_query_results::<mir_const_qualif, _>(tcx, enc, qri)?;
                 encode_query_results::<def_symbol_name, _>(tcx, enc, qri)?;
                 encode_query_results::<const_is_rvalue_promotable_to_static, _>(tcx, enc, qri)?;
-                encode_query_results::<contains_extern_indicator, _>(tcx, enc, qri)?;
                 encode_query_results::<symbol_name, _>(tcx, enc, qri)?;
                 encode_query_results::<check_match, _>(tcx, enc, qri)?;
             }

src/librustc/ty/maps/plumbing.rs

@@ -926,9 +926,6 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>,
         DepKind::CollectAndPartitionTranslationItems => {
             force!(collect_and_partition_translation_items, LOCAL_CRATE);
         }
-        DepKind::ContainsExternIndicator => {
-            force!(contains_extern_indicator, def_id!());
-        }
         DepKind::IsTranslatedItem => { force!(is_translated_item, def_id!()); }
         DepKind::OutputFilenames => { force!(output_filenames, LOCAL_CRATE); }
 
@@ -997,7 +994,6 @@ impl_load_from_cache!(
     MirConstQualif => mir_const_qualif,
     SymbolName => def_symbol_name,
     ConstIsRvaluePromotableToStatic => const_is_rvalue_promotable_to_static,
-    ContainsExternIndicator => contains_extern_indicator,
     CheckMatch => check_match,
     TypeOfItem => type_of,
     GenericsOfItem => generics_of,

src/librustc_trans/back/symbol_export.rs

@@ -256,7 +256,8 @@ fn symbol_export_level_provider(tcx: TyCtxt, sym_def_id: DefId) -> SymbolExportL
     // special symbols in the standard library for various plumbing between
     // core/std/allocators/etc. For example symbols used to hook up allocation
     // are not considered for export
-    let is_extern = tcx.contains_extern_indicator(sym_def_id);
+    let trans_fn_attrs = tcx.trans_fn_attrs(sym_def_id);
+    let is_extern = trans_fn_attrs.contains_extern_indicator();
     let std_internal = attr::contains_name(&tcx.get_attrs(sym_def_id),
                                            "rustc_std_internal_symbol");
     if is_extern && !std_internal {

src/librustc_trans_utils/symbol_names.rs

@@ -120,11 +120,6 @@ pub fn provide(providers: &mut Providers) {
         def_symbol_name,
         symbol_name,
 
-        contains_extern_indicator: |tcx, id| {
-            attr::contains_name(&tcx.get_attrs(id), "no_mangle") ||
-                tcx.trans_fn_attrs(id).export_name.is_some()
-        },
-
         ..*providers
     };
 }

src/librustc_trans_utils/trans_crate.rs

@@ -233,7 +233,6 @@ impl TransCrate for MetadataOnlyTransCrate {
                 MonoItem::Fn(inst) => {
                     let def_id = inst.def_id();
                     if def_id.is_local()  {
-                        let _ = tcx.contains_extern_indicator(def_id);
                         let _ = inst.def.is_inline(tcx);
                         let _ = tcx.trans_fn_attrs(def_id);
                     }

src/librustc_typeck/collect.rs

@@ -1743,6 +1743,8 @@ fn trans_fn_attrs<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: DefId) -> TransFnAt
             trans_fn_attrs.flags |= TransFnAttrFlags::RUSTC_ALLOCATOR_NOUNWIND;
         } else if attr.check_name("naked") {
             trans_fn_attrs.flags |= TransFnAttrFlags::NAKED;
+        } else if attr.check_name("no_mangle") {
+            trans_fn_attrs.flags |= TransFnAttrFlags::NO_MANGLE;
         } else if attr.check_name("inline") {
             trans_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| {
                 if attr.path != "inline" {