Remove export_name query

Part of rust-lang#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,
-    [] ExportName(DefId),
     [] ContainsExternIndicator(DefId),
     [] IsTranslatedItem(DefId),
     [] CodegenUnit(InternedString),

src/librustc/hir/mod.rs

@@ -2216,6 +2216,7 @@ pub fn provide(providers: &mut Providers) {
 pub struct TransFnAttrs {
     pub flags: TransFnAttrFlags,
     pub inline: InlineAttr,
+    pub export_name: Option<Symbol>,
 }
 
 bitflags! {
@@ -2234,6 +2235,7 @@ impl TransFnAttrs {
         TransFnAttrs {
             flags: TransFnAttrFlags::empty(),
             inline: InlineAttr::None,
+            export_name: None,
         }
     }
 

src/librustc/ich/impls_hir.rs

@@ -1147,10 +1147,12 @@ impl<'hir> HashStable<StableHashingContext<'hir>> for hir::TransFnAttrs
         let hir::TransFnAttrs {
             flags,
             inline,
+            export_name,
         } = *self;
 
         flags.hash_stable(hcx, hasher);
         inline.hash_stable(hcx, hasher);
+        export_name.hash_stable(hcx, hasher);
     }
 }
 

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 export_name: ExportName(DefId) -> Option<Symbol>,
     [] fn contains_extern_indicator: ContainsExternIndicator(DefId) -> bool,
     [] fn symbol_export_level: GetSymbolExportLevel(DefId) -> SymbolExportLevel,
     [] fn is_translated_item: IsTranslatedItem(DefId) -> bool,

src/librustc/ty/maps/plumbing.rs

@@ -926,7 +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::ExportName => { force!(export_name, def_id!()); }
         DepKind::ContainsExternIndicator => {
             force!(contains_extern_indicator, def_id!());
         }

src/librustc_trans_utils/diagnostics.rs

@@ -37,7 +37,6 @@ extern crate rustc;
 extern crate rustc_back;
 extern crate rustc_mir;
 extern crate rustc_incremental;
-#[macro_use]
 extern crate syntax;
 extern crate syntax_pos;
 extern crate rustc_data_structures;
@@ -46,7 +45,6 @@ pub extern crate rustc as __rustc;
 
 use rustc::ty::TyCtxt;
 
-pub mod diagnostics;
 pub mod link;
 pub mod trans_crate;
 pub mod symbol_names;

src/librustc_trans_utils/lib.rs

@@ -120,27 +120,9 @@ pub fn provide(providers: &mut Providers) {
         def_symbol_name,
         symbol_name,
 
-        export_name: |tcx, id| {
-            tcx.get_attrs(id).iter().fold(None, |ia, attr| {
-                if attr.check_name("export_name") {
-                    if let s @ Some(_) = attr.value_str() {
-                        s
-                    } else {
-                        struct_span_err!(tcx.sess, attr.span, E0558,
-                                         "export_name attribute has invalid format")
-                            .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
-                            .emit();
-                        None
-                    }
-                } else {
-                    ia
-                }
-            })
-        },
-
         contains_extern_indicator: |tcx, id| {
             attr::contains_name(&tcx.get_attrs(id), "no_mangle") ||
-                tcx.export_name(id).is_some()
+                tcx.trans_fn_attrs(id).export_name.is_some()
         },
 
         ..*providers
@@ -287,7 +269,7 @@ fn compute_symbol_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, instance: Instance
         return tcx.item_name(def_id).to_string();
     }
 
-    if let Some(name) = tcx.export_name(def_id) {
+    if let Some(name) = tcx.trans_fn_attrs(def_id).export_name {
         // Use provided name
         return name.to_string();
     }

src/librustc_trans_utils/symbol_names.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.export_name(def_id);
                         let _ = tcx.contains_extern_indicator(def_id);
                         let _ = inst.def.is_inline(tcx);
                         let _ = tcx.trans_fn_attrs(def_id);

src/librustc_trans_utils/trans_crate.rs

@@ -1777,6 +1777,15 @@ fn trans_fn_attrs<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: DefId) -> TransFnAt
                     _ => ia,
                 }
             });
+        } else if attr.check_name("export_name") {
+            if let s @ Some(_) = attr.value_str() {
+                trans_fn_attrs.export_name = s;
+            } else {
+                struct_span_err!(tcx.sess, attr.span, E0558,
+                                    "export_name attribute has invalid format")
+                    .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
+                    .emit();
+            }
         }
     }
 

src/librustc_typeck/collect.rs

@@ -3774,6 +3774,29 @@ For more information about the inline attribute, https:
 read://doc.rust-lang.org/reference.html#inline-attributes
 "##,
 
+E0558: r##"
+The `export_name` attribute was malformed.
+
+Erroneous code example:
+
+```ignore (error-emitted-at-codegen-which-cannot-be-handled-by-compile_fail)
+#[export_name] // error: export_name attribute has invalid format
+pub fn something() {}
+
+fn main() {}
+```
+
+The `export_name` attribute expects a string in order to determine the name of
+the exported symbol. Example:
+
+```
+#[export_name = "some_function"] // ok!
+pub fn something() {}
+
+fn main() {}
+```
+"##,
+
 E0559: r##"
 An unknown field was specified into an enum's structure variant.