From 4c9c1cd199d18719351034a4c358f5a6878880b0 Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijnh@gmail.com>
Date: Wed, 11 Jan 2012 21:40:13 +0100
Subject: [PATCH] Fix dependency bug iface-did-of-impl resolving

By simply not resolving that def id until the typeck pass.

Closes #1494
---
 src/comp/metadata/common.rs  |  1 -
 src/comp/metadata/decoder.rs | 13 +------------
 src/comp/metadata/encoder.rs |  7 -------
 src/comp/middle/resolve.rs   |  9 +--------
 src/comp/middle/typeck.rs    | 10 +++++++++-
 src/libstd/test.rs           |  2 +-
 6 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/src/comp/metadata/common.rs b/src/comp/metadata/common.rs
index e1c05bf2c9f54..b16120d1bec1e 100644
--- a/src/comp/metadata/common.rs
+++ b/src/comp/metadata/common.rs
@@ -68,7 +68,6 @@ const tag_mod_impl: uint = 0x30u;
 
 const tag_item_method: uint = 0x31u;
 const tag_impl_iface: uint = 0x32u;
-const tag_impl_iface_did: uint = 0x33u;
 
 // discriminator value for variants
 const tag_disr_val: uint = 0x34u;
diff --git a/src/comp/metadata/decoder.rs b/src/comp/metadata/decoder.rs
index b1da9f840a893..c076b044f52b1 100644
--- a/src/comp/metadata/decoder.rs
+++ b/src/comp/metadata/decoder.rs
@@ -126,16 +126,6 @@ fn item_impl_iface(item: ebml::doc, tcx: ty::ctxt, cdata: cmd)
     result
 }
 
-fn item_impl_iface_did(item: ebml::doc, cdata: cmd)
-    -> option::t<ast::def_id> {
-    let result = none;
-    ebml::tagged_docs(item, tag_impl_iface_did) {|doc|
-        let did = translate_def_id(cdata, parse_def_id(ebml::doc_data(doc)));
-        result = some(did);
-    }
-    result
-}
-
 fn item_ty_param_bounds(item: ebml::doc, tcx: ty::ctxt, cdata: cmd)
     -> @[ty::param_bounds] {
     let bounds = [];
@@ -297,8 +287,7 @@ fn get_impls_for_mod(cdata: cmd, m_id: ast::node_id,
         let item = lookup_item(did.node, data), nm = item_name(item);
         if alt name { some(n) { n == nm } none. { true } } {
             let base_tps = item_ty_param_count(doc);
-            let i_did = item_impl_iface_did(item, cdata);
-            result += [@{did: did, iface_did: i_did, ident: nm,
+            result += [@{did: did, ident: nm,
                          methods: item_impl_methods(cdata, item, base_tps)}];
         }
     }
diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index e7d5c47643f46..634947941d64a 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -405,13 +405,6 @@ fn encode_info_for_item(ecx: @encode_ctxt, ebml_w: ebml::writer, item: @item,
             ebml::start_tag(ebml_w, tag_impl_iface);
             write_type(ecx, ebml_w, i_ty);
             ebml::end_tag(ebml_w);
-            ebml::start_tag(ebml_w, tag_impl_iface_did);
-            alt ty::struct(tcx, i_ty) {
-              ty::ty_iface(did, _) {
-                ebml_w.writer.write(str::bytes(def_to_str(did)));
-              }
-            }
-            ebml::end_tag(ebml_w);
           }
           _ {}
         }
diff --git a/src/comp/middle/resolve.rs b/src/comp/middle/resolve.rs
index 1232926499519..8925ca6b31295 100644
--- a/src/comp/middle/resolve.rs
+++ b/src/comp/middle/resolve.rs
@@ -1825,8 +1825,7 @@ fn check_exports(e: @env) {
 // Impl resolution
 
 type method_info = {did: def_id, n_tps: uint, ident: ast::ident};
-type _impl = {did: def_id, iface_did: option::t<def_id>,
-              ident: ast::ident, methods: [@method_info]};
+type _impl = {did: def_id, ident: ast::ident, methods: [@method_info]};
 type iscopes = list<@[@_impl]>;
 
 fn resolve_impls(e: @env, c: @ast::crate) {
@@ -1893,12 +1892,6 @@ fn find_impls_in_item(e: env, i: @ast::item, &impls: [@_impl],
              _ { true }
            } {
             impls += [@{did: local_def(i.id),
-                        iface_did: alt ifce {
-                            some(@{node: ast::ty_path(_, id), _}) {
-                                some(def_id_of_def(e.def_map.get(id)))
-                            }
-                            _ { none }
-                        },
                         ident: i.ident,
                         methods: vec::map(mthds, {|m|
                             @{did: local_def(m.id),
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index 1d701f9b9ab6f..0b0e2bdfe703c 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -2947,7 +2947,15 @@ mod dict {
             std::list::iter(isc) {|impls|
                 if option::is_some(found) { ret; }
                 for im in *impls {
-                    if im.iface_did == some(iface_id) {
+                    let match = alt ty::impl_iface(tcx, im.did) {
+                      some(ity) {
+                        alt ty::struct(tcx, ity) {
+                          ty::ty_iface(id, _) { id == iface_id }
+                        }
+                      }
+                      _ { false }
+                    };
+                    if match {
                         let {n_tps, ty: self_ty} = impl_self_ty(tcx, im.did);
                         let {vars, ty: self_ty} = if n_tps > 0u {
                             bind_params(fcx, self_ty, n_tps)
diff --git a/src/libstd/test.rs b/src/libstd/test.rs
index af2910536b24f..7b9157f2afe11 100644
--- a/src/libstd/test.rs
+++ b/src/libstd/test.rs
@@ -31,7 +31,7 @@ native mod rustrt {
 }
 
 // FIXME Kludge to work around issue #1494 . Simply import io::writer_util
-// when that is fixed.
+// after the next snapshot.
 impl writer_util for io::writer {
     fn write_str(s: str) { self.write(str::bytes(s)); }
     fn write_line(s: str) { self.write(str::bytes(s + "\n")); }