auto merge of #5141 : nikomatsakis/rust/region-syntax-expl-lifetimes,…

… r=nikomatsakis

Major changes are:
- replace ~[ty_param] with Generics structure, which includes
  both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;

cc #4846

r? @graydon

src/librustc/front/test.rs

@@ -200,14 +200,14 @@ fn is_bench_fn(i: @ast::item) -> bool {
         vec::len(attr::find_attrs_by_name(i.attrs, ~"bench")) > 0u;
 
     fn has_test_signature(i: @ast::item) -> bool {
-        match /*bad*/copy i.node {
-            ast::item_fn(decl, _, tps, _) => {
+        match i.node {
+            ast::item_fn(ref decl, _, ref generics, _) => {
                 let input_cnt = vec::len(decl.inputs);
                 let no_output = match decl.output.node {
                     ast::ty_nil => true,
                     _ => false
                 };
-                let tparm_cnt = vec::len(tps);
+                let tparm_cnt = generics.ty_params.len();
                 // NB: inadequate check, but we're running
                 // well before resolve, can't get too deep.
                 input_cnt == 1u

src/librustc/metadata/encoder.rs

@@ -49,6 +49,8 @@ use syntax::diagnostic::span_handler;
 use syntax::parse::token::special_idents;
 use syntax::print::pprust;
 use syntax::{ast_util, visit};
+use syntax::opt_vec::OptVec;
+use syntax::opt_vec;
 use syntax;
 use writer = std::ebml::writer;
 
@@ -187,10 +189,11 @@ fn encode_ty_type_param_bounds(ebml_w: writer::Encoder, ecx: @EncodeContext,
     }
 }
 
-fn encode_type_param_bounds(ebml_w: writer::Encoder, ecx: @EncodeContext,
-                            params: &[ty_param]) {
+fn encode_type_param_bounds(ebml_w: writer::Encoder,
+                            ecx: @EncodeContext,
+                            params: &OptVec<TyParam>) {
     let ty_param_bounds =
-        @params.map(|param| ecx.tcx.ty_param_bounds.get(&param.id));
+        @params.map_to_vec(|param| ecx.tcx.ty_param_bounds.get(&param.id));
     encode_ty_type_param_bounds(ebml_w, ecx, ty_param_bounds);
 }
 
@@ -265,7 +268,7 @@ fn encode_enum_variant_info(ecx: @EncodeContext, ebml_w: writer::Encoder,
                             id: node_id, variants: &[variant],
                             path: &[ast_map::path_elt],
                             index: @mut ~[entry<int>],
-                            ty_params: &[ty_param]) {
+                            generics: &ast::Generics) {
     let mut disr_val = 0;
     let mut i = 0;
     let vi = ty::enum_variants(ecx.tcx,
@@ -281,7 +284,7 @@ fn encode_enum_variant_info(ecx: @EncodeContext, ebml_w: writer::Encoder,
                     node_id_to_type(ecx.tcx, variant.node.id));
         match variant.node.kind {
             ast::tuple_variant_kind(ref args)
-                    if args.len() > 0 && ty_params.len() == 0 => {
+                    if args.len() > 0 && generics.ty_params.len() == 0 => {
                 encode_symbol(ecx, ebml_w, variant.node.id);
             }
             ast::tuple_variant_kind(_) | ast::struct_variant_kind(_) |
@@ -292,7 +295,7 @@ fn encode_enum_variant_info(ecx: @EncodeContext, ebml_w: writer::Encoder,
             encode_disr_val(ecx, ebml_w, vi[i].disr_val);
             disr_val = vi[i].disr_val;
         }
-        encode_type_param_bounds(ebml_w, ecx, ty_params);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_path(ecx, ebml_w, path,
                     ast_map::path_name(variant.node.name));
         ebml_w.end_tag();
@@ -465,14 +468,18 @@ fn encode_info_for_struct(ecx: @EncodeContext, ebml_w: writer::Encoder,
 }
 
 // This is for encoding info for ctors and dtors
-fn encode_info_for_ctor(ecx: @EncodeContext, ebml_w: writer::Encoder,
-                        id: node_id, ident: ident, path: &[ast_map::path_elt],
-                        item: Option<inlined_item>, tps: &[ty_param]) {
+fn encode_info_for_ctor(ecx: @EncodeContext,
+                        ebml_w: writer::Encoder,
+                        id: node_id,
+                        ident: ident,
+                        path: &[ast_map::path_elt],
+                        item: Option<inlined_item>,
+                        generics: &ast::Generics) {
         ebml_w.start_tag(tag_items_data_item);
         encode_name(ecx, ebml_w, ident);
         encode_def_id(ebml_w, local_def(id));
         encode_family(ebml_w, purity_fn_family(ast::impure_fn));
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         let its_ty = node_id_to_type(ecx.tcx, id);
         debug!("fn name = %s ty = %s its node id = %d",
                *ecx.tcx.sess.str_of(ident),
@@ -518,9 +525,12 @@ fn encode_info_for_method(ecx: @EncodeContext,
                           should_inline: bool,
                           parent_id: node_id,
                           m: @method,
-                          +all_tps: ~[ty_param]) {
-    debug!("encode_info_for_method: %d %s %u", m.id,
-           *ecx.tcx.sess.str_of(m.ident), all_tps.len());
+                          owner_generics: &ast::Generics,
+                          method_generics: &ast::Generics) {
+    debug!("encode_info_for_method: %d %s %u %u", m.id,
+           *ecx.tcx.sess.str_of(m.ident),
+           owner_generics.ty_params.len(),
+           method_generics.ty_params.len());
     ebml_w.start_tag(tag_items_data_item);
     encode_def_id(ebml_w, local_def(m.id));
     match m.self_ty.node {
@@ -529,8 +539,13 @@ fn encode_info_for_method(ecx: @EncodeContext,
         }
         _ => encode_family(ebml_w, purity_fn_family(m.purity))
     }
-    let len = all_tps.len();
-    encode_type_param_bounds(ebml_w, ecx, all_tps);
+
+    let mut combined_ty_params = opt_vec::Empty;
+    combined_ty_params.push_all(&owner_generics.ty_params);
+    combined_ty_params.push_all(&method_generics.ty_params);
+    let len = combined_ty_params.len();
+    encode_type_param_bounds(ebml_w, ecx, &combined_ty_params);
+
     encode_type(ecx, ebml_w, node_id_to_type(ecx.tcx, m.id));
     encode_name(ecx, ebml_w, m.ident);
     encode_path(ecx, ebml_w, impl_path, ast_map::path_name(m.ident));
@@ -604,13 +619,13 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
         ebml_w.end_tag();
       }
-      item_fn(_, purity, tps, _) => {
+      item_fn(_, purity, ref generics, _) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
         encode_family(ebml_w, purity_fn_family(purity));
-        let tps_len = tps.len();
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        let tps_len = generics.ty_params.len();
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
         encode_attributes(ebml_w, item.attrs);
@@ -634,24 +649,24 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
         ebml_w.end_tag();
       }
-      item_ty(_, tps) => {
+      item_ty(_, ref generics) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
         encode_family(ebml_w, 'y');
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
         encode_name(ecx, ebml_w, item.ident);
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
         encode_region_param(ecx, ebml_w, item);
         ebml_w.end_tag();
       }
-      item_enum(ref enum_definition, ref tps) => {
+      item_enum(ref enum_definition, ref generics) => {
         add_to_index();
         do ebml_w.wr_tag(tag_items_data_item) {
             encode_def_id(ebml_w, local_def(item.id));
             encode_family(ebml_w, 't');
-            encode_type_param_bounds(ebml_w, ecx, *tps);
+            encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
             encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
             encode_name(ecx, ebml_w, item.ident);
             for (*enum_definition).variants.each |v| {
@@ -667,9 +682,9 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
                                  (*enum_definition).variants,
                                  path,
                                  index,
-                                 *tps);
+                                 generics);
       }
-      item_struct(struct_def, tps) => {
+      item_struct(struct_def, ref generics) => {
         /* First, encode the fields
            These come first because we need to write them to make
            the index, and the index needs to be in the item for the
@@ -686,24 +701,25 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
                                    *ecx.tcx.sess.str_of(item.ident) +
                                    ~"_dtor"),
                                path,
-                               if tps.len() > 0u {
+                               if generics.ty_params.len() > 0u {
                                    Some(ii_dtor(copy *dtor,
                                                 item.ident,
-                                                copy tps,
+                                                copy *generics,
                                                 local_def(item.id))) }
                                else {
                                    None
                                },
-                               tps);
+                               generics);
         }
 
         /* Index the class*/
         add_to_index();
+
         /* Now, make an item for the class itself */
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
         encode_family(ebml_w, 'S');
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
 
         // If this is a tuple- or enum-like struct, encode the type of the
@@ -759,13 +775,13 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         encode_index(ebml_w, bkts, write_int);
         ebml_w.end_tag();
       }
-      item_impl(tps, opt_trait, ty, methods) => {
+      item_impl(ref generics, opt_trait, ty, ref methods) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
         encode_family(ebml_w, 'i');
         encode_region_param(ecx, ebml_w, item);
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
         encode_name(ecx, ebml_w, item.ident);
         encode_attributes(ebml_w, item.attrs);
@@ -797,18 +813,18 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
             encode_info_for_method(ecx, ebml_w, impl_path,
                                    should_inline(m.attrs),
                                    item.id, *m,
-                                   vec::append(/*bad*/copy tps, m.tps));
+                                   generics, &m.generics);
         }
       }
-      item_trait(ref tps, ref traits, ref ms) => {
+      item_trait(ref generics, ref traits, ref ms) => {
         let provided_methods = dvec::DVec();
 
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
         encode_family(ebml_w, 'I');
         encode_region_param(ecx, ebml_w, item);
-        encode_type_param_bounds(ebml_w, ecx, *tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
         encode_name(ecx, ebml_w, item.ident);
         encode_attributes(ebml_w, item.attrs);
@@ -820,7 +836,7 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
                 encode_def_id(ebml_w, local_def((*ty_m).id));
                 encode_name(ecx, ebml_w, mty.ident);
                 encode_type_param_bounds(ebml_w, ecx,
-                                         (*ty_m).tps);
+                                         &ty_m.generics.ty_params);
                 encode_type(ecx, ebml_w,
                             ty::mk_bare_fn(tcx, copy mty.fty));
                 encode_family(ebml_w, purity_fn_family(mty.fty.purity));
@@ -834,7 +850,8 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
                 ebml_w.start_tag(tag_item_trait_method);
                 encode_def_id(ebml_w, local_def(m.id));
                 encode_name(ecx, ebml_w, mty.ident);
-                encode_type_param_bounds(ebml_w, ecx, m.tps);
+                encode_type_param_bounds(ebml_w, ecx,
+                                         &m.generics.ty_params);
                 encode_type(ecx, ebml_w,
                             ty::mk_bare_fn(tcx, copy mty.fty));
                 encode_family(ebml_w, purity_fn_family(mty.fty.purity));
@@ -880,8 +897,14 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         // Finally, output all the provided methods as items.
         for provided_methods.each |m| {
             index.push(entry { val: m.id, pos: ebml_w.writer.tell() });
+
+            // We do not concatenate the generics of the owning impl and that
+            // of provided methods.  I am not sure why this is. -ndm
+            let owner_generics = ast_util::empty_generics();
+
             encode_info_for_method(ecx, ebml_w, /*bad*/copy path,
-                                   true, item.id, *m, /*bad*/copy m.tps);
+                                   true, item.id, *m,
+                                   &owner_generics, &m.generics);
         }
       }
       item_mac(*) => fail!(~"item macros unimplemented")
@@ -898,11 +921,11 @@ fn encode_info_for_foreign_item(ecx: @EncodeContext,
     index.push(entry { val: nitem.id, pos: ebml_w.writer.tell() });
 
     ebml_w.start_tag(tag_items_data_item);
-    match /*bad*/copy nitem.node {
-      foreign_item_fn(_, purity, tps) => {
+    match nitem.node {
+      foreign_item_fn(_, purity, ref generics) => {
         encode_def_id(ebml_w, local_def(nitem.id));
         encode_family(ebml_w, purity_fn_family(purity));
-        encode_type_param_bounds(ebml_w, ecx, tps);
+        encode_type_param_bounds(ebml_w, ecx, &generics.ty_params);
         encode_type(ecx, ebml_w, node_id_to_type(ecx.tcx, nitem.id));
         if abi == foreign_abi_rust_intrinsic {
             (ecx.encode_inlined_item)(ecx, ebml_w, path, ii_foreign(nitem));

src/librustc/middle/astencode.rs

@@ -371,10 +371,10 @@ fn renumber_ast(xcx: @ExtendedDecodeContext, ii: ast::inlined_item)
       ast::ii_foreign(i) => {
         ast::ii_foreign(fld.fold_foreign_item(i))
       }
-      ast::ii_dtor(ref dtor, nm, ref tps, parent_id) => {
+      ast::ii_dtor(ref dtor, nm, ref generics, parent_id) => {
         let dtor_body = fld.fold_block((*dtor).node.body);
-        let dtor_attrs = fld.fold_attributes(/*bad*/copy (*dtor).node.attrs);
-        let new_params = fold::fold_ty_params(/*bad*/copy *tps, fld);
+        let dtor_attrs = fld.fold_attributes(copy dtor.node.attrs);
+        let new_generics = fold::fold_generics(generics, fld);
         let dtor_id = fld.new_id((*dtor).node.id);
         let new_parent = xcx.tr_def_id(parent_id);
         let new_self = fld.new_id((*dtor).node.self_id);
@@ -386,7 +386,7 @@ fn renumber_ast(xcx: @ExtendedDecodeContext, ii: ast::inlined_item)
                                           body: dtor_body },
                 .. (/*bad*/copy *dtor)
             },
-            nm, new_params, new_parent)
+            nm, new_generics, new_parent)
       }
      }
 }

src/librustc/middle/lint.rs

@@ -753,7 +753,7 @@ fn check_item_structural_records(cx: ty::ctxt, it: @ast::item) {
 fn check_item_ctypes(cx: ty::ctxt, it: @ast::item) {
 
     fn check_foreign_fn(cx: ty::ctxt, fn_id: ast::node_id,
-                       decl: ast::fn_decl) {
+                        decl: ast::fn_decl) {
         let tys = vec::map(decl.inputs, |a| a.ty );
         for vec::each(vec::append_one(tys, decl.output)) |ty| {
             match ty.node {
@@ -786,9 +786,9 @@ fn check_item_ctypes(cx: ty::ctxt, it: @ast::item) {
       if attr::foreign_abi(it.attrs) !=
             either::Right(ast::foreign_abi_rust_intrinsic) => {
         for nmod.items.each |ni| {
-            match /*bad*/copy ni.node {
-              ast::foreign_item_fn(decl, _, _) => {
-                check_foreign_fn(cx, it.id, decl);
+            match ni.node {
+              ast::foreign_item_fn(ref decl, _, _) => {
+                check_foreign_fn(cx, it.id, *decl);
               }
               // FIXME #4622: Not implemented.
               ast::foreign_item_const(*) => {}

src/librustc/middle/region.rs

@@ -621,7 +621,8 @@ pub fn determine_rp_in_fn(fk: visit::fn_kind,
             }
         }
         (visitor.visit_ty)(decl.output, cx, visitor);
-        (visitor.visit_ty_params)(visit::tps_of_fn(fk), cx, visitor);
+        let generics = visit::generics_of_fn(fk);
+        (visitor.visit_generics)(&generics, cx, visitor);
         (visitor.visit_block)(body, cx, visitor);
     }
 }