Introduce VecPerParamSpace and use it to represent sets of types and

parameters

This involves numerous substeps:

1. Treat Self same as any other parameter.
2. No longer compute offsets for method parameters.
3. Store all generic types (both trait/impl and method) with a method,
   eliminating odd discrepancies.
4. Stop doing unspeakable things to static methods and instead just use
   the natural types, now that we can easily add the type parameters from
   trait into the method's polytype.
5. No doubt some more. It was hard to separate these into distinct commits.

Fixes rust-lang#13564

Author: nikomatsakis

src/librustc/metadata/common.rs

@@ -189,9 +189,7 @@ pub static tag_impls_impl: uint = 0x81;
 pub static tag_items_data_item_inherent_impl: uint = 0x82;
 pub static tag_items_data_item_extension_impl: uint = 0x83;
 
-pub static tag_region_param_def: uint = 0x84;
-pub static tag_region_param_def_ident: uint = 0x85;
-pub static tag_region_param_def_def_id: uint = 0x86;
+// GAP 0x84, 0x85, 0x86
 
 pub static tag_native_libraries: uint = 0x87;
 pub static tag_native_libraries_lib: uint = 0x88;
@@ -214,3 +212,9 @@ pub struct LinkMeta {
     pub crateid: CrateId,
     pub crate_hash: Svh,
 }
+
+pub static tag_region_param_def: uint = 0x90;
+pub static tag_region_param_def_ident: uint = 0x91;
+pub static tag_region_param_def_def_id: uint = 0x92;
+pub static tag_region_param_def_space: uint = 0x93;
+pub static tag_region_param_def_index: uint = 0x94;

src/librustc/metadata/csearch.rs

@@ -223,8 +223,8 @@ pub fn get_field_type(tcx: &ty::ctxt, class_id: ast::DefId,
         });
     let ty = decoder::item_type(def, the_field, tcx, &*cdata);
     ty::ty_param_bounds_and_ty {
-        generics: ty::Generics {type_param_defs: Rc::new(Vec::new()),
-                                region_param_defs: Rc::new(Vec::new())},
+        generics: ty::Generics {types: VecPerParamSpace::empty(),
+                                regions: VecPerParamSpace::empty()},
         ty: ty
     }
 }
@@ -240,7 +240,8 @@ pub fn get_impl_trait(tcx: &ty::ctxt,
 
 // Given a def_id for an impl, return information about its vtables
 pub fn get_impl_vtables(tcx: &ty::ctxt,
-                        def: ast::DefId) -> typeck::impl_res {
+                        def: ast::DefId)
+                        -> typeck::vtable_res {
     let cstore = &tcx.sess.cstore;
     let cdata = cstore.get_crate_data(def.krate);
     decoder::get_impl_vtables(&*cdata, def.node, tcx)

src/librustc/metadata/decoder.rs

@@ -23,6 +23,7 @@ use metadata::tydecode::{parse_ty_data, parse_def_id,
                          parse_bare_fn_ty_data, parse_trait_ref_data};
 use middle::lang_items;
 use middle::def;
+use middle::subst;
 use middle::ty::{ImplContainer, TraitContainer};
 use middle::ty;
 use middle::typeck;
@@ -257,34 +258,44 @@ fn item_ty_param_defs(item: ebml::Doc,
                       tcx: &ty::ctxt,
                       cdata: Cmd,
                       tag: uint)
-                      -> Rc<Vec<ty::TypeParameterDef> > {
-    let mut bounds = Vec::new();
+                      -> subst::VecPerParamSpace<ty::TypeParameterDef> {
+    let mut bounds = subst::VecPerParamSpace::empty();
     reader::tagged_docs(item, tag, |p| {
         let bd = parse_type_param_def_data(
             p.data, p.start, cdata.cnum, tcx,
             |_, did| translate_def_id(cdata, did));
-        bounds.push(bd);
+        bounds.push(bd.space, bd);
         true
     });
-    Rc::new(bounds)
+    bounds
 }
 
 fn item_region_param_defs(item_doc: ebml::Doc, cdata: Cmd)
-                          -> Rc<Vec<ty::RegionParameterDef> > {
-    let mut v = Vec::new();
+                          -> subst::VecPerParamSpace<ty::RegionParameterDef>
+{
+    let mut v = subst::VecPerParamSpace::empty();
     reader::tagged_docs(item_doc, tag_region_param_def, |rp_doc| {
-            let ident_str_doc = reader::get_doc(rp_doc,
-                                                tag_region_param_def_ident);
-            let ident = item_name(&*token::get_ident_interner(), ident_str_doc);
-            let def_id_doc = reader::get_doc(rp_doc,
-                                             tag_region_param_def_def_id);
-            let def_id = reader::with_doc_data(def_id_doc, parse_def_id);
-            let def_id = translate_def_id(cdata, def_id);
-            v.push(ty::RegionParameterDef { name: ident.name,
-                                            def_id: def_id });
-            true
-        });
-    Rc::new(v)
+        let ident_str_doc = reader::get_doc(rp_doc,
+                                            tag_region_param_def_ident);
+        let ident = item_name(&*token::get_ident_interner(), ident_str_doc);
+        let def_id_doc = reader::get_doc(rp_doc,
+                                         tag_region_param_def_def_id);
+        let def_id = reader::with_doc_data(def_id_doc, parse_def_id);
+        let def_id = translate_def_id(cdata, def_id);
+
+        let doc = reader::get_doc(rp_doc, tag_region_param_def_space);
+        let space = subst::ParamSpace::from_uint(reader::doc_as_u64(doc) as uint);
+
+        let doc = reader::get_doc(rp_doc, tag_region_param_def_index);
+        let index = reader::doc_as_u64(doc) as uint;
+
+        v.push(space, ty::RegionParameterDef { name: ident.name,
+                                               def_id: def_id,
+                                               space: space,
+                                               index: index });
+        true
+    });
+    v
 }
 
 fn enum_variant_ids(item: ebml::Doc, cdata: Cmd) -> Vec<ast::DefId> {
@@ -403,8 +414,8 @@ pub fn get_trait_def(cdata: Cmd,
     }
 
     ty::TraitDef {
-        generics: ty::Generics {type_param_defs: tp_defs,
-                                region_param_defs: rp_defs},
+        generics: ty::Generics {types: tp_defs,
+                                regions: rp_defs},
         bounds: bounds,
         trait_ref: Rc::new(item_trait_ref(item_doc, tcx, cdata))
     }
@@ -422,8 +433,8 @@ pub fn get_type(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt)
     let rp_defs = item_region_param_defs(item, cdata);
 
     ty::ty_param_bounds_and_ty {
-        generics: ty::Generics {type_param_defs: tp_defs,
-                                region_param_defs: rp_defs},
+        generics: ty::Generics {types: tp_defs,
+                                regions: rp_defs},
         ty: t
     }
 }
@@ -440,16 +451,13 @@ pub fn get_impl_trait(cdata: Cmd,
 
 pub fn get_impl_vtables(cdata: Cmd,
                         id: ast::NodeId,
-                        tcx: &ty::ctxt) -> typeck::impl_res
+                        tcx: &ty::ctxt)
+                        -> typeck::vtable_res
 {
     let item_doc = lookup_item(id, cdata.data());
     let vtables_doc = reader::get_doc(item_doc, tag_item_impl_vtables);
     let mut decoder = reader::Decoder::new(vtables_doc);
-
-    typeck::impl_res {
-        trait_vtables: decoder.read_vtable_res(tcx, cdata),
-        self_vtables: decoder.read_vtable_param_res(tcx, cdata)
-    }
+    decoder.read_vtable_res(tcx, cdata)
 }
 
 
@@ -802,8 +810,8 @@ pub fn get_method(intr: Rc<IdentInterner>, cdata: Cmd, id: ast::NodeId,
     ty::Method::new(
         name,
         ty::Generics {
-            type_param_defs: type_param_defs,
-            region_param_defs: rp_defs,
+            types: type_param_defs,
+            regions: rp_defs,
         },
         fty,
         explicit_self,

src/librustc/metadata/encoder.rs

@@ -19,6 +19,7 @@ use metadata::common::*;
 use metadata::cstore;
 use metadata::decoder;
 use metadata::tyencode;
+use middle::subst::VecPerParamSpace;
 use middle::ty::{node_id_to_type, lookup_item_type};
 use middle::astencode;
 use middle::ty;
@@ -125,10 +126,9 @@ fn encode_trait_ref(ebml_w: &mut Encoder,
 
 fn encode_impl_vtables(ebml_w: &mut Encoder,
                        ecx: &EncodeContext,
-                       vtables: &typeck::impl_res) {
+                       vtables: &typeck::vtable_res) {
     ebml_w.start_tag(tag_item_impl_vtables);
-    astencode::encode_vtable_res(ecx, ebml_w, &vtables.trait_vtables);
-    astencode::encode_vtable_param_res(ecx, ebml_w, &vtables.self_vtables);
+    astencode::encode_vtable_res(ecx, ebml_w, vtables);
     ebml_w.end_tag();
 }
 
@@ -145,7 +145,7 @@ pub fn def_to_str(did: DefId) -> String {
 
 fn encode_ty_type_param_defs(ebml_w: &mut Encoder,
                              ecx: &EncodeContext,
-                             params: &[ty::TypeParameterDef],
+                             params: &VecPerParamSpace<ty::TypeParameterDef>,
                              tag: uint) {
     let ty_str_ctxt = &tyencode::ctxt {
         diag: ecx.diag,
@@ -161,7 +161,7 @@ fn encode_ty_type_param_defs(ebml_w: &mut Encoder,
 }
 
 fn encode_region_param_defs(ebml_w: &mut Encoder,
-                            params: &[ty::RegionParameterDef]) {
+                            params: &VecPerParamSpace<ty::RegionParameterDef>) {
     for param in params.iter() {
         ebml_w.start_tag(tag_region_param_def);
 
@@ -172,6 +172,12 @@ fn encode_region_param_defs(ebml_w: &mut Encoder,
         ebml_w.wr_tagged_str(tag_region_param_def_def_id,
                              def_to_str(param.def_id).as_slice());
 
+        ebml_w.wr_tagged_u64(tag_region_param_def_space,
+                             param.space.to_uint() as u64);
+
+        ebml_w.wr_tagged_u64(tag_region_param_def_index,
+                             param.index as u64);
+
         ebml_w.end_tag();
     }
 }
@@ -188,9 +194,9 @@ fn encode_item_variances(ebml_w: &mut Encoder,
 fn encode_bounds_and_type(ebml_w: &mut Encoder,
                           ecx: &EncodeContext,
                           tpt: &ty::ty_param_bounds_and_ty) {
-    encode_ty_type_param_defs(ebml_w, ecx, tpt.generics.type_param_defs(),
+    encode_ty_type_param_defs(ebml_w, ecx, &tpt.generics.types,
                               tag_items_data_item_ty_param_bounds);
-    encode_region_param_defs(ebml_w, tpt.generics.region_param_defs());
+    encode_region_param_defs(ebml_w, &tpt.generics.regions);
     encode_type(ecx, ebml_w, tpt.ty);
 }
 
@@ -722,8 +728,7 @@ fn encode_method_ty_fields(ecx: &EncodeContext,
                            method_ty: &ty::Method) {
     encode_def_id(ebml_w, method_ty.def_id);
     encode_name(ebml_w, method_ty.ident.name);
-    encode_ty_type_param_defs(ebml_w, ecx,
-                              method_ty.generics.type_param_defs(),
+    encode_ty_type_param_defs(ebml_w, ecx, &method_ty.generics.types,
                               tag_item_method_tps);
     encode_method_fty(ecx, ebml_w, &method_ty.fty);
     encode_visibility(ebml_w, method_ty.vis);
@@ -767,10 +772,8 @@ fn encode_info_for_method(ecx: &EncodeContext,
     }
 
     for &ast_method in ast_method_opt.iter() {
-        let num_params = tpt.generics.type_param_defs().len();
-        if num_params > 0u ||
-                is_default_impl ||
-                should_inline(ast_method.attrs.as_slice()) {
+        let any_types = !tpt.generics.types.is_empty();
+        if any_types || is_default_impl || should_inline(ast_method.attrs.as_slice()) {
             encode_inlined_item(ecx, ebml_w,
                                 IIMethodRef(local_def(parent_id), false, ast_method));
         } else {
@@ -1121,9 +1124,9 @@ fn encode_info_for_item(ecx: &EncodeContext,
         encode_item_variances(ebml_w, ecx, item.id);
         let trait_def = ty::lookup_trait_def(tcx, def_id);
         encode_ty_type_param_defs(ebml_w, ecx,
-                                  trait_def.generics.type_param_defs(),
+                                  &trait_def.generics.types,
                                   tag_items_data_item_ty_param_bounds);
-        encode_region_param_defs(ebml_w, trait_def.generics.region_param_defs());
+        encode_region_param_defs(ebml_w, &trait_def.generics.regions);
         encode_trait_ref(ebml_w, ecx, &*trait_def.trait_ref, tag_item_trait_ref);
         encode_name(ebml_w, item.ident.name);
         encode_attributes(ebml_w, item.attrs.as_slice());