Allow for representing exported monomorphizations in crate metadata.

src/librustc/middle/exported_symbols.rs

@@ -9,8 +9,13 @@
 // except according to those terms.
 
 use hir::def_id::{DefId, LOCAL_CRATE};
+use ich::StableHashingContext;
+use rustc_data_structures::stable_hasher::{StableHasher, HashStable,
+                                           StableHasherResult};
 use std::cmp;
+use std::mem;
 use ty;
+use ty::subst::Substs;
 
 /// The SymbolExportLevel of a symbols specifies from which kinds of crates
 /// the symbol will be exported. `C` symbols will be exported from any
@@ -40,56 +45,89 @@ impl SymbolExportLevel {
 }
 
 #[derive(Eq, PartialEq, Debug, Copy, Clone, RustcEncodable, RustcDecodable)]
-pub enum ExportedSymbol {
+pub enum ExportedSymbol<'tcx> {
     NonGeneric(DefId),
+    Generic(DefId, &'tcx Substs<'tcx>),
     NoDefId(ty::SymbolName),
 }
 
-impl ExportedSymbol {
-    pub fn symbol_name(&self, tcx: ty::TyCtxt) -> ty::SymbolName {
+impl<'tcx> ExportedSymbol<'tcx> {
+    pub fn symbol_name(&self,
+                       tcx: ty::TyCtxt<'_, 'tcx, '_>)
+                       -> ty::SymbolName {
         match *self {
             ExportedSymbol::NonGeneric(def_id) => {
                 tcx.symbol_name(ty::Instance::mono(tcx, def_id))
             }
+            ExportedSymbol::Generic(def_id, substs) => {
+                tcx.symbol_name(ty::Instance::new(def_id, substs))
+            }
             ExportedSymbol::NoDefId(symbol_name) => {
                 symbol_name
             }
         }
     }
 
-    pub fn compare_stable(&self, tcx: ty::TyCtxt, other: &ExportedSymbol) -> cmp::Ordering {
+    pub fn compare_stable(&self,
+                          tcx: ty::TyCtxt<'_, 'tcx, '_>,
+                          other: &ExportedSymbol<'tcx>)
+                          -> cmp::Ordering {
         match *self {
-            ExportedSymbol::NonGeneric(self_def_id) => {
-                match *other {
-                    ExportedSymbol::NonGeneric(other_def_id) => {
-                        tcx.def_path_hash(self_def_id).cmp(&tcx.def_path_hash(other_def_id))
-                    }
-                    ExportedSymbol::NoDefId(_) => {
-                        cmp::Ordering::Less
-                    }
+            ExportedSymbol::NonGeneric(self_def_id) => match *other {
+                ExportedSymbol::NonGeneric(other_def_id) => {
+                    tcx.def_path_hash(self_def_id).cmp(&tcx.def_path_hash(other_def_id))
+                }
+                ExportedSymbol::Generic(..) |
+                ExportedSymbol::NoDefId(_) => {
+                    cmp::Ordering::Less
+                }
+            }
+            ExportedSymbol::Generic(..) => match *other {
+                ExportedSymbol::NonGeneric(_) => {
+                    cmp::Ordering::Greater
+                }
+                ExportedSymbol::Generic(..) => {
+                    self.symbol_name(tcx).cmp(&other.symbol_name(tcx))
+                }
+                ExportedSymbol::NoDefId(_) => {
+                    cmp::Ordering::Less
                 }
             }
-            ExportedSymbol::NoDefId(self_symbol_name) => {
-                match *other {
-                    ExportedSymbol::NonGeneric(_) => {
-                        cmp::Ordering::Greater
-                    }
-                    ExportedSymbol::NoDefId(ref other_symbol_name) => {
-                        self_symbol_name.cmp(other_symbol_name)
-                    }
+            ExportedSymbol::NoDefId(self_symbol_name) => match *other {
+                ExportedSymbol::NonGeneric(_) |
+                ExportedSymbol::Generic(..) => {
+                    cmp::Ordering::Greater
+                }
+                ExportedSymbol::NoDefId(ref other_symbol_name) => {
+                    self_symbol_name.cmp(other_symbol_name)
                 }
             }
         }
     }
 }
 
-impl_stable_hash_for!(enum self::ExportedSymbol {
-    NonGeneric(def_id),
-    NoDefId(symbol_name)
-});
-
 pub fn metadata_symbol_name(tcx: ty::TyCtxt) -> String {
     format!("rust_metadata_{}_{}",
             tcx.original_crate_name(LOCAL_CRATE),
             tcx.crate_disambiguator(LOCAL_CRATE).to_fingerprint().to_hex())
 }
+
+impl<'gcx> HashStable<StableHashingContext<'gcx>> for ExportedSymbol<'gcx> {
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'gcx>,
+                                          hasher: &mut StableHasher<W>) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+        match *self {
+            ExportedSymbol::NonGeneric(def_id) => {
+                def_id.hash_stable(hcx, hasher);
+            }
+            ExportedSymbol::Generic(def_id, substs) => {
+                def_id.hash_stable(hcx, hasher);
+                substs.hash_stable(hcx, hasher);
+            }
+            ExportedSymbol::NoDefId(symbol_name) => {
+                symbol_name.hash_stable(hcx, hasher);
+            }
+        }
+    }
+}

src/librustc/ty/maps/mod.rs

@@ -381,7 +381,7 @@ define_maps! { <'tcx>
     [] fn all_crate_nums: all_crate_nums_node(CrateNum) -> Lrc<Vec<CrateNum>>,
 
     [] fn exported_symbols: ExportedSymbols(CrateNum)
-        -> Arc<Vec<(ExportedSymbol, SymbolExportLevel)>>,
+        -> Arc<Vec<(ExportedSymbol<'tcx>, SymbolExportLevel)>>,
     [] fn collect_and_partition_translation_items:
         collect_and_partition_translation_items_node(CrateNum)
         -> (Arc<DefIdSet>, Arc<Vec<Arc<CodegenUnit<'tcx>>>>),

src/librustc_metadata/cstore_impl.rs

@@ -268,7 +268,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
             return Arc::new(Vec::new())
         }
 
-        Arc::new(cdata.exported_symbols())
+        Arc::new(cdata.exported_symbols(tcx))
     }
 
     wasm_custom_sections => { Lrc::new(cdata.wasm_custom_sections()) }

src/librustc_metadata/decoder.rs

@@ -1065,11 +1065,13 @@ impl<'a, 'tcx> CrateMetadata {
         arg_names.decode(self).collect()
     }
 
-    pub fn exported_symbols(&self) -> Vec<(ExportedSymbol, SymbolExportLevel)> {
-        self.root
-            .exported_symbols
-            .decode(self)
-            .collect()
+    pub fn exported_symbols(&self,
+                            tcx: TyCtxt<'a, 'tcx, 'tcx>)
+                            -> Vec<(ExportedSymbol<'tcx>, SymbolExportLevel)> {
+        let lazy_seq: LazySeq<(ExportedSymbol<'tcx>, SymbolExportLevel)> =
+            LazySeq::with_position_and_length(self.root.exported_symbols.position,
+                                              self.root.exported_symbols.len);
+        lazy_seq.decode((self, tcx)).collect()
     }
 
     pub fn wasm_custom_sections(&self) -> Vec<DefId> {

src/librustc_metadata/encoder.rs

@@ -1444,13 +1444,12 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
     // definition (as that's not defined in this crate).
     fn encode_exported_symbols(&mut self,
                                exported_symbols: &[(ExportedSymbol, SymbolExportLevel)])
-                               -> LazySeq<(ExportedSymbol, SymbolExportLevel)> {
-
+                               -> EncodedExportedSymbols {
         // The metadata symbol name is special. It should not show up in
         // downstream crates.
         let metadata_symbol_name = SymbolName::new(&metadata_symbol_name(self.tcx));
 
-        self.lazy_seq(exported_symbols
+        let lazy_seq = self.lazy_seq(exported_symbols
             .iter()
             .filter(|&&(ref exported_symbol, _)| {
                 match *exported_symbol {
@@ -1460,7 +1459,12 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
                     _ => true,
                 }
             })
-            .cloned())
+            .cloned());
+
+        EncodedExportedSymbols {
+            len: lazy_seq.len,
+            position: lazy_seq.position,
+        }
     }
 
     fn encode_wasm_custom_sections(&mut self, statics: &[DefId]) -> LazySeq<DefIndex> {

src/librustc_metadata/schema.rs

@@ -15,7 +15,6 @@ use rustc::hir;
 use rustc::hir::def::{self, CtorKind};
 use rustc::hir::def_id::{DefIndex, DefId, CrateNum};
 use rustc::ich::StableHashingContext;
-use rustc::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
 use rustc::middle::cstore::{DepKind, LinkagePreference, NativeLibrary, ForeignModule};
 use rustc::middle::lang_items;
 use rustc::mir;
@@ -206,7 +205,7 @@ pub struct CrateRoot {
     pub codemap: LazySeq<syntax_pos::FileMap>,
     pub def_path_table: Lazy<hir::map::definitions::DefPathTable>,
     pub impls: LazySeq<TraitImpls>,
-    pub exported_symbols: LazySeq<(ExportedSymbol, SymbolExportLevel)>,
+    pub exported_symbols: EncodedExportedSymbols,
     pub wasm_custom_sections: LazySeq<DefIndex>,
 
     pub index: LazySeq<index::Index>,
@@ -531,3 +530,9 @@ impl_stable_hash_for!(struct GeneratorData<'tcx> { layout });
 // Tags used for encoding Spans:
 pub const TAG_VALID_SPAN: u8 = 0;
 pub const TAG_INVALID_SPAN: u8 = 1;
+
+#[derive(RustcEncodable, RustcDecodable)]
+pub struct EncodedExportedSymbols {
+    pub position: usize,
+    pub len: usize,
+}

src/librustc_trans/back/symbol_export.rs

@@ -94,7 +94,7 @@ fn is_reachable_non_generic_provider<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
 fn exported_symbols_provider_local<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                              cnum: CrateNum)
-                                             -> Arc<Vec<(ExportedSymbol,
+                                             -> Arc<Vec<(ExportedSymbol<'tcx>,
                                                          SymbolExportLevel)>>
 {
     assert_eq!(cnum, LOCAL_CRATE);

src/librustc_trans/lib.rs

@@ -33,6 +33,7 @@
 #![cfg_attr(stage0, feature(conservative_impl_trait))]
 #![feature(optin_builtin_traits)]
 #![feature(inclusive_range_fields)]
+#![feature(underscore_lifetimes)]
 
 use rustc::dep_graph::WorkProduct;
 use syntax_pos::symbol::Symbol;