better support for classes with polymorphic methods

Author: nikomatsakis

src/rustc/metadata/encoder.rs

@@ -664,7 +664,7 @@ fn encode_info_for_item(ecx: @encode_ctxt, ebml_w: ebml::writer, item: @item,
                 ebml_w.start_tag(tag_item_iface_method);
                 encode_family(ebml_w, purity_fn_family(m.decl.purity));
                 encode_name(ebml_w, m.ident);
-                encode_type_param_bounds(ebml_w, ecx, tps + m.tps);
+                encode_type_param_bounds(ebml_w, ecx, m.tps);
                 encode_type(ecx, ebml_w, node_id_to_type(tcx, m.id));
                 encode_def_id(ebml_w, local_def(m.id));
                 ebml_w.end_tag();

src/rustc/middle/kind.rs

@@ -254,29 +254,16 @@ fn check_expr(e: @expr, cx: ctx, v: visit::vt<ctx>) {
               expr_field(base, _, _) {
                 alt cx.method_map.get(e.id) {
                   typeck::method_static(did) {
-                   /*
-                        If this is a class method, we want to use the
-                        class bounds plus the method bounds -- otherwise the
-                        indices come out wrong. So we check base's type...
-                   */
-                   let mut bounds = ty::lookup_item_type(cx.tcx, did).bounds;
-                   alt ty::get(ty::node_id_to_type(cx.tcx, base.id)).struct {
-                        ty::ty_class(parent_id, ts) {
-                            /* ...and if it has a class type, prepend the
-                               class bounds onto the method bounds */
-                            /* n.b. this code is very likely sketchy --
-                             currently, class-impl-very-parameterized-iface
-                             fails here and is thus xfailed */
-                            bounds =
-                             @(*ty::lookup_item_type(cx.tcx, parent_id).bounds
-                               + *bounds);
-                        }
-                        _ { }
-                      }
-                      bounds
+                    // n.b.: When we encode class/impl methods, the bounds
+                    // that we encode include both the class/impl bounds
+                    // and then the method bounds themselves...
+                    ty::lookup_item_type(cx.tcx, did).bounds
                   }
                   typeck::method_param(ifce_id, n_mth, _, _) |
                   typeck::method_iface(ifce_id, n_mth) {
+                    // ...iface methods bounds, in contrast, include only the
+                    // method bounds, so we must preprend the tps from the
+                    // iface itself.  This ought to be harmonized.
                     let ifce_bounds =
                         ty::lookup_item_type(cx.tcx, ifce_id).bounds;
                     let mth = ty::iface_methods(cx.tcx, ifce_id)[n_mth];

src/rustc/middle/typeck/check/method.rs

@@ -18,6 +18,9 @@ enum lookup = {
 impl methods for lookup {
     // Entrypoint:
     fn method() -> option<method_origin> {
+        #debug["method lookup(m_name=%s, self_ty=%s)",
+               self.m_name, self.fcx.infcx.ty_to_str(self.self_ty)];
+
         // First, see whether this is an interface-bounded parameter
         let pass1 = alt ty::get(self.self_ty).struct {
           ty::ty_param(n, did) {
@@ -288,6 +291,11 @@ impl methods for lookup {
 
         let tcx = self.fcx.ccx.tcx;
 
+        #debug["write_mty_from_fty(n_tps_m=%u, fty=%s, origin=%?)",
+               n_tps_m,
+               self.fcx.infcx.ty_to_str(fty),
+               origin];
+
         // Here I will use the "c_" prefix to refer to the method's
         // owner.  You can read it as class, but it may also be an iface.
 

src/rustc/middle/typeck/collect.rs

@@ -228,17 +228,15 @@ fn check_methods_against_iface(ccx: @crate_ctxt,
                                rp: ast::region_param,
                                selfty: ty::t,
                                a_ifacety: @ast::iface_ref,
-                               ms: [@ast::method]) {
+                               ms: [converted_method]) {
 
     let tcx = ccx.tcx;
-    let i_bounds = ty_param_bounds(ccx, tps);
-    let my_methods = convert_methods(ccx, ms, rp, i_bounds, selfty);
     let (did, tpt) = instantiate_iface_ref(ccx, a_ifacety, rp);
     if did.crate == ast::local_crate {
         ensure_iface_methods(ccx, did.node);
     }
     for vec::each(*ty::iface_methods(tcx, did)) {|if_m|
-        alt vec::find(my_methods, {|m| if_m.ident == m.mty.ident}) {
+        alt vec::find(ms, {|m| if_m.ident == m.mty.ident}) {
           some({mty: m, id, span}) {
             if m.purity != if_m.purity {
                 ccx.tcx.sess.span_err(
@@ -274,12 +272,13 @@ fn convert_class_item(ccx: @crate_ctxt,
     ccx.tcx.tcache.insert(local_def(v.id), {bounds: bounds, rp: rp, ty: tt});
 }
 
+type converted_method = {mty: ty::method, id: ast::node_id, span: span};
+
 fn convert_methods(ccx: @crate_ctxt,
                    ms: [@ast::method],
                    rp: ast::region_param,
-                   i_bounds: @[ty::param_bounds],
-                   self_ty: ty::t)
-    -> [{mty: ty::method, id: ast::node_id, span: span}] {
+                   rcvr_bounds: @[ty::param_bounds],
+                   self_ty: ty::t) -> [converted_method] {
 
     let tcx = ccx.tcx;
     vec::map(ms) { |m|
@@ -289,9 +288,10 @@ fn convert_methods(ccx: @crate_ctxt,
         let fty = ty::mk_fn(tcx, mty.fty);
         tcx.tcache.insert(
             local_def(m.id),
-            // n.b. This code is kind of sketchy (concat'ing i_bounds
-            // with bounds), but removing *i_bounds breaks other stuff
-            {bounds: @(*i_bounds + *bounds), rp: rp, ty: fty});
+
+            // n.b.: the type of a method is parameterized by both
+            // the tps on the receiver and those on the method itself
+            {bounds: @(*rcvr_bounds + *bounds), rp: rp, ty: fty});
         write_ty_to_tcx(tcx, m.id, fty);
         {mty: mty, id: m.id, span: m.span}
     }
@@ -316,19 +316,10 @@ fn convert(ccx: @crate_ctxt, it: @ast::item) {
                           {bounds: i_bounds,
                            rp: rp,
                            ty: selfty});
-        alt ifce {
-          some(t) {
-            check_methods_against_iface(
-                ccx, tps, rp,
-                selfty, t, ms);
-          }
-          _ {
-            // Still have to do this to write method types
-            // into the table
-            convert_methods(
-                ccx, ms, rp,
-                i_bounds, selfty);
-          }
+
+        let cms = convert_methods(ccx, ms, rp, i_bounds, selfty);
+        for ifce.each { |t|
+            check_methods_against_iface(ccx, tps, rp, selfty, t, cms);
         }
       }
       ast::item_res(decl, tps, _, dtor_id, ctor_id, rp) {
@@ -412,23 +403,11 @@ fn convert(ccx: @crate_ctxt, it: @ast::item) {
         for fields.each {|f|
            convert_class_item(ccx, rp, tpt.bounds, f);
         }
-        // The selfty is just the class type
-        let {bounds:_, substs} = mk_substs(ccx, tps, rp);
+        let {bounds, substs} = mk_substs(ccx, tps, rp);
         let selfty = ty::mk_class(tcx, local_def(it.id), substs);
-        // Need to convert all methods so we can check internal
-        // references to private methods
-
-        // NDM to TJC---I think we ought to be using bounds here, not @[].
-        // But doing so causes errors later on.
-        convert_methods(ccx, methods, rp, @[], selfty);
-
-        /*
-        Finally, check that the class really implements the ifaces
-        that it claims to implement.
-        */
+        let cms = convert_methods(ccx, methods, rp, bounds, selfty);
         for ifaces.each { |ifce|
-            check_methods_against_iface(ccx, tps, rp, selfty,
-                                        ifce, methods);
+            check_methods_against_iface(ccx, tps, rp, selfty, ifce, cms);
 
             // FIXME #2434---this is somewhat bogus, but it seems that
             // the id of iface_ref is also the id of the impl, and so

src/test/run-pass/borrowck-preserve-box-in-pat.rs

@@ -1,4 +1,3 @@
-// xfail-test  (still buggy)
 // xfail-fast  (compile-flags unsupported on windows)
 // compile-flags:--borrowck=err
 // exec-env:RUST_POISON_ON_FREE=1

src/test/run-pass/class-impl-very-parameterized-iface.rs

@@ -1,5 +1,3 @@
-// xfail-test
-// xfail-fast
 use std;
 import std::map::*;
 
@@ -59,7 +57,7 @@ class cat<T: copy> implements map<int, T> {
      }
      else { none }
   }
-  
+
   fn remove(&&k:int) -> option<T> {
     alt self.find(k) {
       some(x) {
@@ -76,7 +74,7 @@ class cat<T: copy> implements map<int, T> {
         n -= 1;
     }
   }
-  
+
   fn each_key(&&f: fn(&&int) -> bool) {
     for self.each {|k, _v| if !f(k) { break; } cont;};
   }
@@ -88,11 +86,11 @@ class cat<T: copy> implements map<int, T> {
 
 fn main() {
   let nyan : cat<str> = cat(0, 2, "nyan");
-  uint::range(1u, 5u) {|_i| nyan.speak(); }
+  for uint::range(1u, 5u) {|_i| nyan.speak(); }
   assert(nyan.find(1) == some("nyan"));
   assert(nyan.find(10) == none);
   let spotty : cat<cat_type> = cat(2, 57, tuxedo);
-  uint::range(0u, 6u) {|_i| spotty.speak(); }
+  for uint::range(0u, 6u) {|_i| spotty.speak(); }
   assert(spotty.size() == 8u);
   assert(spotty.contains_key(2));
   assert(spotty.get(3) == tuxedo);

src/test/run-pass/class-poly-methods-cross-crate.rs

@@ -1,5 +1,3 @@
-// xfail-test
-
 // xfail-fast
 // aux-build:cci_class_6.rs
 use cci_class_6;

src/test/run-pass/class-typarams.rs

@@ -1,5 +1,3 @@
-// xfail-test
-// needs metadata encoding on Windows
 class cat<U> {
   priv {
     let mut meows : uint;