auto merge of #5467 : nikomatsakis/rust/issues-3888-4036-4492-cannot-encode-region-variables, r=nikomatsakis

The basic problem was that vtables were not being resolved.  The fix uncovered another issue, which was that the syntax extensions were not creating method calls properly and were relying on outdated code in typeck, so I fixed that too.  

Resolves issues #3888, #4036, #4492.

r? @catamorphism 

6 files changed, 93 insertions, 119 deletions

diff --git a/src/libsyntax/ext/auto_encode.rs b/src/libsyntax/ext/auto_encode.rs
index 54ca5dc0d72..e81e460e832 100644
--- a/src/libsyntax/ext/auto_encode.rs
+++ b/src/libsyntax/ext/auto_encode.rs
@@ -416,6 +416,16 @@ priv impl @ext_ctxt {
         self.expr(span, ast::expr_call(expr, args, ast::NoSugar))
     }
 
+    fn expr_method_call(
+        &self,
+        span: span,
+        expr: @ast::expr,
+        ident: ast::ident,
+        +args: ~[@ast::expr]
+    ) -> @ast::expr {
+        self.expr(span, ast::expr_method_call(expr, ident, ~[], args, ast::NoSugar))
+    }
+
     fn lambda_expr(&self, expr: @ast::expr) -> @ast::expr {
         self.lambda(self.expr_blk(expr))
     }
@@ -712,30 +722,24 @@ fn mk_struct_ser_impl(
     let fields = do mk_struct_fields(fields).mapi |idx, field| {
         // ast for `|| self.$(name).encode(__s)`
         let expr_lambda = cx.lambda_expr(
-            cx.expr_call(
+            cx.expr_method_call(
                 span,
                 cx.expr_field(
                     span,
-                    cx.expr_field(
-                        span,
-                        cx.expr_var(span, ~"self"),
-                        field.ident
-                    ),
-                    cx.ident_of(~"encode")
+                    cx.expr_var(span, ~"self"),
+                    field.ident
                 ),
+                cx.ident_of(~"encode"),
                 ~[cx.expr_var(span, ~"__s")]
             )
         );
 
         // ast for `__s.emit_field($(name), $(idx), $(expr_lambda))`
         cx.stmt(
-            cx.expr_call(
+            cx.expr_method_call(
                 span,
-                cx.expr_field(
-                    span,
-                    cx.expr_var(span, ~"__s"),
-                    cx.ident_of(~"emit_field")
-                ),
+                cx.expr_var(span, ~"__s"),
+                cx.ident_of(~"emit_field"),
                 ~[
                     cx.lit_str(span, @cx.str_of(field.ident)),
                     cx.lit_uint(span, idx),
@@ -746,13 +750,10 @@ fn mk_struct_ser_impl(
     };
 
     // ast for `__s.emit_struct($(name), || $(fields))`
-    let ser_body = cx.expr_call(
+    let ser_body = cx.expr_method_call(
         span,
-        cx.expr_field(
-            span,
-            cx.expr_var(span, ~"__s"),
-            cx.ident_of(~"emit_struct")
-        ),
+        cx.expr_var(span, ~"__s"),
+        cx.ident_of(~"emit_struct"),
         ~[
             cx.lit_str(span, @cx.str_of(ident)),
             cx.lit_uint(span, vec::len(fields)),
@@ -788,13 +789,10 @@ fn mk_struct_deser_impl(
         );
 
         // ast for `__d.read_field($(name), $(idx), $(expr_lambda))`
-        let expr: @ast::expr = cx.expr_call(
+        let expr: @ast::expr = cx.expr_method_call(
             span,
-            cx.expr_field(
-                span,
-                cx.expr_var(span, ~"__d"),
-                cx.ident_of(~"read_field")
-            ),
+            cx.expr_var(span, ~"__d"),
+            cx.ident_of(~"read_field"),
             ~[
                 cx.lit_str(span, @cx.str_of(field.ident)),
                 cx.lit_uint(span, idx),
@@ -813,13 +811,10 @@ fn mk_struct_deser_impl(
     };
 
     // ast for `read_struct($(name), || $(fields))`
-    let body = cx.expr_call(
+    let body = cx.expr_method_call(
         span,
-        cx.expr_field(
-            span,
-            cx.expr_var(span, ~"__d"),
-            cx.ident_of(~"read_struct")
-        ),
+        cx.expr_var(span, ~"__d"),
+        cx.ident_of(~"read_struct"),
         ~[
             cx.lit_str(span, @cx.str_of(ident)),
             cx.lit_uint(span, vec::len(fields)),
@@ -943,13 +938,10 @@ fn ser_variant(
 
         // ast for `|| $(v).encode(__s)`
         let expr_encode = cx.lambda_expr(
-             cx.expr_call(
+             cx.expr_method_call(
                 span,
-                cx.expr_field(
-                    span,
-                    cx.expr_path(span, ~[names[a_idx]]),
-                    cx.ident_of(~"encode")
-                ),
+                 cx.expr_path(span, ~[names[a_idx]]),
+                 cx.ident_of(~"encode"),
                 ~[cx.expr_var(span, ~"__s")]
             )
         );
@@ -965,13 +957,10 @@ fn ser_variant(
     };
 
     // ast for `__s.emit_enum_variant($(name), $(idx), $(sz), $(lambda))`
-    let body = cx.expr_call(
+    let body = cx.expr_method_call(
         span,
-        cx.expr_field(
-            span,
-            cx.expr_var(span, ~"__s"),
-            cx.ident_of(~"emit_enum_variant")
-        ),
+        cx.expr_var(span, ~"__s"),
+        cx.ident_of(~"emit_enum_variant"),
         ~[
             cx.lit_str(span, @cx.str_of(v_name)),
             cx.lit_uint(span, v_idx),
@@ -1019,13 +1008,10 @@ fn mk_enum_ser_body(
     );
 
     // ast for `__s.emit_enum($(name), || $(match_expr))`
-    cx.expr_call(
+    cx.expr_method_call(
         span,
-        cx.expr_field(
-            span,
-            cx.expr_var(span, ~"__s"),
-            cx.ident_of(~"emit_enum")
-        ),
+        cx.expr_var(span, ~"__s"),
+        cx.ident_of(~"emit_enum"),
         ~[
             cx.lit_str(span, @cx.str_of(name)),
             cx.lambda_expr(match_expr),
@@ -1055,13 +1041,10 @@ fn mk_enum_deser_variant_nary(
         );
 
         // ast for `__d.read_enum_variant_arg($(a_idx), $(expr_lambda))`
-        cx.expr_call(
+        cx.expr_method_call(
             span,
-            cx.expr_field(
-                span,
-                cx.expr_var(span, ~"__d"),
-                cx.ident_of(~"read_enum_variant_arg")
-            ),
+            cx.expr_var(span, ~"__d"),
+            cx.ident_of(~"read_enum_variant_arg"),
             ~[cx.lit_uint(span, idx), expr_lambda]
         )
     };
@@ -1171,25 +1154,19 @@ fn mk_enum_deser_body(
 
     // ast for `__d.read_enum_variant($(expr_lambda))`
     let expr_lambda = ext_cx.lambda_expr(
-        ext_cx.expr_call(
+        ext_cx.expr_method_call(
             span,
-            ext_cx.expr_field(
-                span,
-                ext_cx.expr_var(span, ~"__d"),
-                ext_cx.ident_of(~"read_enum_variant")
-            ),
+            ext_cx.expr_var(span, ~"__d"),
+            ext_cx.ident_of(~"read_enum_variant"),
             ~[expr_lambda]
         )
     );
 
     // ast for `__d.read_enum($(e_name), $(expr_lambda))`
-    ext_cx.expr_call(
+    ext_cx.expr_method_call(
         span,
-        ext_cx.expr_field(
-            span,
-            ext_cx.expr_var(span, ~"__d"),
-            ext_cx.ident_of(~"read_enum")
-        ),
+        ext_cx.expr_var(span, ~"__d"),
+        ext_cx.ident_of(~"read_enum"),
         ~[
             ext_cx.lit_str(span, @ext_cx.str_of(name)),
             expr_lambda
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index c2f4cbf3db2..ad71441e046 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -111,6 +111,13 @@ pub fn mk_addr_of(cx: @ext_ctxt, sp: span, e: @ast::expr) -> @ast::expr {
 pub fn mk_mut_addr_of(cx: @ext_ctxt, sp: span, e: @ast::expr) -> @ast::expr {
     return mk_expr(cx, sp, ast::expr_addr_of(ast::m_mutbl, e));
 }
+pub fn mk_method_call(cx: @ext_ctxt,
+                      sp: span,
+                      rcvr_expr: @ast::expr,
+                      method_ident: ast::ident,
+                      +args: ~[@ast::expr]) -> @ast::expr {
+    mk_expr(cx, sp, ast::expr_method_call(rcvr_expr, method_ident, ~[], args, ast::NoSugar))
+}
 pub fn mk_call_(cx: @ext_ctxt, sp: span, fn_expr: @ast::expr,
                 +args: ~[@ast::expr]) -> @ast::expr {
     mk_expr(cx, sp, ast::expr_call(fn_expr, args, ast::NoSugar))
diff --git a/src/libsyntax/ext/deriving/clone.rs b/src/libsyntax/ext/deriving/clone.rs
index 4ab83cb5f1e..68458bd516e 100644
--- a/src/libsyntax/ext/deriving/clone.rs
+++ b/src/libsyntax/ext/deriving/clone.rs
@@ -120,8 +120,9 @@ fn call_substructure_clone_method(cx: @ext_ctxt,
                                -> @expr {
     // Call the substructure method.
     let clone_ident = cx.ident_of(~"clone");
-    let self_method = build::mk_access_(cx, span, self_field, clone_ident);
-    build::mk_call_(cx, span, self_method, ~[])
+    build::mk_method_call(cx, span,
+                          self_field, clone_ident,
+                          ~[])
 }
 
 fn expand_deriving_clone_struct_def(cx: @ext_ctxt,
diff --git a/src/libsyntax/ext/deriving/eq.rs b/src/libsyntax/ext/deriving/eq.rs
index 5e94134f70a..8cee6bd7290 100644
--- a/src/libsyntax/ext/deriving/eq.rs
+++ b/src/libsyntax/ext/deriving/eq.rs
@@ -147,11 +147,9 @@ fn call_substructure_eq_method(cx: @ext_ctxt,
                                junction: Junction,
                                chain_expr: &mut Option<@expr>) {
     // Call the substructure method.
-    let self_method = build::mk_access_(cx, span, self_field, method_ident);
-    let self_call = build::mk_call_(cx,
-                                    span,
-                                    self_method,
-                                    ~[ other_field_ref ]);
+    let self_call = build::mk_method_call(cx, span,
+                                          self_field, method_ident,
+                                          ~[ other_field_ref ]);
 
     // Connect to the outer expression if necessary.
     *chain_expr = match *chain_expr {
diff --git a/src/libsyntax/ext/deriving/iter_bytes.rs b/src/libsyntax/ext/deriving/iter_bytes.rs
index 75d7b396c7e..3c1ee7e0296 100644
--- a/src/libsyntax/ext/deriving/iter_bytes.rs
+++ b/src/libsyntax/ext/deriving/iter_bytes.rs
@@ -125,14 +125,11 @@ fn call_substructure_iter_bytes_method(cx: @ext_ctxt,
 
     // Call the substructure method.
     let iter_bytes_ident = cx.ident_of(~"iter_bytes");
-    let self_method = build::mk_access_(cx,
-                                        span,
-                                        self_field,
-                                        iter_bytes_ident);
-    let self_call = build::mk_call_(cx,
-                                    span,
-                                    self_method,
-                                    ~[ lsb0_expr, f_expr ]);
+    let self_call = build::mk_method_call(cx,
+                                          span,
+                                          self_field,
+                                          iter_bytes_ident,
+                                          ~[ lsb0_expr, f_expr ]);
 
     // Create a statement out of this expression.
     build::mk_stmt(cx, span, self_call)
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 2cf52c47959..6044c3ad3d2 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -270,11 +270,11 @@ fn id_ext(cx: @ext_ctxt, +str: ~str) -> ast::ident {
 
 // Lift an ident to the expr that evaluates to that ident.
 fn mk_ident(cx: @ext_ctxt, sp: span, ident: ast::ident) -> @ast::expr {
-    let e_meth = build::mk_access(cx, sp,
-                                  ids_ext(cx, ~[~"ext_cx"]),
-                                  id_ext(cx, ~"ident_of"));
     let e_str = build::mk_uniq_str(cx, sp, cx.str_of(ident));
-    build::mk_call_(cx, sp, e_meth, ~[e_str])
+    build::mk_method_call(cx, sp,
+                          build::mk_path(cx, sp, ids_ext(cx, ~[~"ext_cx"])),
+                          id_ext(cx, ~"ident_of"),
+                          ~[e_str])
 }
 
 fn mk_bytepos(cx: @ext_ctxt, sp: span, bpos: BytePos) -> @ast::expr {
@@ -462,11 +462,10 @@ fn mk_tt(cx: @ext_ctxt, sp: span, tt: &ast::token_tree)
                                ids_ext(cx, ~[~"tt_tok"]),
                                ~[e_sp, mk_token(cx, sp, *tok)]);
             let e_push =
-                build::mk_call_(cx, sp,
-                                build::mk_access(cx, sp,
-                                                 ids_ext(cx, ~[~"tt"]),
-                                                 id_ext(cx, ~"push")),
-                                ~[e_tok]);
+                build::mk_method_call(cx, sp,
+                                      build::mk_path(cx, sp, ids_ext(cx, ~[~"tt"])),
+                                      id_ext(cx, ~"push"),
+                                      ~[e_tok]);
             ~[build::mk_stmt(cx, sp, e_push)]
 
         }
@@ -479,21 +478,17 @@ fn mk_tt(cx: @ext_ctxt, sp: span, tt: &ast::token_tree)
             // tt.push_all_move($ident.to_tokens(ext_cx))
 
             let e_to_toks =
-                build::mk_call_(cx, sp,
-                                build::mk_access
-                                (cx, sp,
-                                 ~[ident],
-                                 id_ext(cx, ~"to_tokens")),
-                                ~[build::mk_path(cx, sp,
-                                        ids_ext(cx, ~[~"ext_cx"]))]);
+                build::mk_method_call(cx, sp,
+                                      build::mk_path(cx, sp, ~[ident]),
+                                      id_ext(cx, ~"to_tokens"),
+                                      ~[build::mk_path(cx, sp,
+                                                       ids_ext(cx, ~[~"ext_cx"]))]);
 
             let e_push =
-                build::mk_call_(cx, sp,
-                                build::mk_access
-                                (cx, sp,
-                                 ids_ext(cx, ~[~"tt"]),
-                                 id_ext(cx, ~"push_all_move")),
-                                ~[e_to_toks]);
+                build::mk_method_call(cx, sp,
+                                      build::mk_path(cx, sp, ids_ext(cx, ~[~"tt"])),
+                                      id_ext(cx, ~"push_all_move"),
+                                      ~[e_to_toks]);
 
             ~[build::mk_stmt(cx, sp, e_push)]
         }
@@ -562,11 +557,10 @@ fn expand_tts(cx: @ext_ctxt,
     // of quotes, for example) but at this point it seems not likely to be
     // worth the hassle.
 
-    let e_sp = build::mk_call_(cx, sp,
-                               build::mk_access(cx, sp,
-                                                ids_ext(cx, ~[~"ext_cx"]),
-                                                id_ext(cx, ~"call_site")),
-                               ~[]);
+    let e_sp = build::mk_method_call(cx, sp,
+                                     build::mk_path(cx, sp, ids_ext(cx, ~[~"ext_cx"])),
+                                     id_ext(cx, ~"call_site"),
+                                     ~[]);
 
     let stmt_let_sp = build::mk_local(cx, sp, false,
                                       id_ext(cx, ~"sp"),
@@ -590,13 +584,13 @@ fn expand_parse_call(cx: @ext_ctxt,
                      tts: &[ast::token_tree]) -> @ast::expr {
     let tts_expr = expand_tts(cx, sp, tts);
 
-    let cfg_call = || build::mk_call_(
-        cx, sp, build::mk_access(cx, sp, ids_ext(cx, ~[~"ext_cx"]),
-                                 id_ext(cx, ~"cfg")), ~[]);
+    let cfg_call = || build::mk_method_call(
+        cx, sp, build::mk_path(cx, sp, ids_ext(cx, ~[~"ext_cx"])),
+        id_ext(cx, ~"cfg"), ~[]);
 
-    let parse_sess_call = || build::mk_call_(
-        cx, sp, build::mk_access(cx, sp, ids_ext(cx, ~[~"ext_cx"]),
-                                 id_ext(cx, ~"parse_sess")), ~[]);
+    let parse_sess_call = || build::mk_method_call(
+        cx, sp, build::mk_path(cx, sp, ids_ext(cx, ~[~"ext_cx"])),
+        id_ext(cx, ~"parse_sess"), ~[]);
 
     let new_parser_call =
         build::mk_call_global(cx, sp,
@@ -609,9 +603,9 @@ fn expand_parse_call(cx: @ext_ctxt,
                                 cfg_call(),
                                 tts_expr]);
 
-    build::mk_call_(cx, sp,
-                    build::mk_access_(cx, sp, new_parser_call,
-                                      id_ext(cx, parse_method)),
-                    arg_exprs)
+    build::mk_method_call(cx, sp,
+                          new_parser_call,
+                          id_ext(cx, parse_method),
+                          arg_exprs)
 }