Obliterate the callee_id hack

Exprs that could be applications of overloaded operators
(expr_unary, expr_binary, expr_index) relied on the previous node ID
being "reserved" to carry extra typechecking info. This was
incredibly error-prone. Fixed it; now all exprs have two node IDs
(which will be wasted in some cases; future work could make this
an option instead if the extra int field ends up being a performance
problem).

Closes #2804

src/rustc/front/test.rs

@@ -283,9 +283,11 @@ fn mk_test_desc_vec(cx: test_ctxt) -> @ast::expr {
     }
 
     let inner_expr = @{id: cx.sess.next_node_id(),
+                       callee_id: cx.sess.next_node_id(),
                        node: ast::expr_vec(descs, ast::m_imm),
                        span: dummy_sp()};
     ret @{id: cx.sess.next_node_id(),
+          callee_id: cx.sess.next_node_id(),
           node: ast::expr_vstore(inner_expr, ast::vstore_uniq),
           span: dummy_sp()};
 }
@@ -300,6 +302,7 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
         nospan(ast::lit_str(@ast_util::path_name_i(path)));
     let name_expr: ast::expr =
         {id: cx.sess.next_node_id(),
+         callee_id: cx.sess.next_node_id(),
          node: ast::expr_lit(@name_lit),
          span: span};
 
@@ -310,6 +313,7 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
 
     let fn_expr: ast::expr =
         {id: cx.sess.next_node_id(),
+         callee_id: cx.sess.next_node_id(),
          node: ast::expr_path(fn_path),
          span: span};
 
@@ -322,6 +326,7 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
 
     let ignore_expr: ast::expr =
         {id: cx.sess.next_node_id(),
+         callee_id: cx.sess.next_node_id(),
          node: ast::expr_lit(@ignore_lit),
          span: span};
 
@@ -332,6 +337,7 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
 
     let fail_expr: ast::expr =
         {id: cx.sess.next_node_id(),
+         callee_id: cx.sess.next_node_id(),
          node: ast::expr_lit(@fail_lit),
          span: span};
 
@@ -342,7 +348,8 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
         ast::expr_rec(~[name_field, fn_field, ignore_field, fail_field],
             option::none);
     let desc_rec: ast::expr =
-        {id: cx.sess.next_node_id(), node: desc_rec_, span: span};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: desc_rec_, span: span};
     ret @desc_rec;
 }
 
@@ -354,6 +361,7 @@ fn mk_test_wrapper(cx: test_ctxt,
                    span: span) -> @ast::expr {
     let call_expr: ast::expr = {
         id: cx.sess.next_node_id(),
+        callee_id: cx.sess.next_node_id(),
         node: ast::expr_call(@fn_path_expr, ~[], false),
         span: span
     };
@@ -379,6 +387,7 @@ fn mk_test_wrapper(cx: test_ctxt,
 
     let wrapper_expr: ast::expr = {
         id: cx.sess.next_node_id(),
+        callee_id: cx.sess.next_node_id(),
         node: ast::expr_fn(ast::proto_bare, wrapper_decl,
                            wrapper_body, @~[]),
         span: span
@@ -444,7 +453,8 @@ fn mk_test_main_call(cx: test_ctxt) -> @ast::expr {
     let args_path_expr_: ast::expr_ = ast::expr_path(args_path);
 
     let args_path_expr: ast::expr =
-        {id: cx.sess.next_node_id(), node: args_path_expr_, span: dummy_sp()};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: args_path_expr_, span: dummy_sp()};
 
     // Call __test::test to generate the vector of test_descs
     let test_path = path_node(~[@"tests"]);
@@ -452,12 +462,14 @@ fn mk_test_main_call(cx: test_ctxt) -> @ast::expr {
     let test_path_expr_: ast::expr_ = ast::expr_path(test_path);
 
     let test_path_expr: ast::expr =
-        {id: cx.sess.next_node_id(), node: test_path_expr_, span: dummy_sp()};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: test_path_expr_, span: dummy_sp()};
 
     let test_call_expr_ = ast::expr_call(@test_path_expr, ~[], false);
 
     let test_call_expr: ast::expr =
-        {id: cx.sess.next_node_id(), node: test_call_expr_, span: dummy_sp()};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: test_call_expr_, span: dummy_sp()};
 
     // Call std::test::test_main
     let test_main_path = path_node(mk_path(cx, ~[@"test", @"test_main"]));
@@ -465,16 +477,16 @@ fn mk_test_main_call(cx: test_ctxt) -> @ast::expr {
     let test_main_path_expr_: ast::expr_ = ast::expr_path(test_main_path);
 
     let test_main_path_expr: ast::expr =
-        {id: cx.sess.next_node_id(), node: test_main_path_expr_,
-         span: dummy_sp()};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: test_main_path_expr_, span: dummy_sp()};
 
     let test_main_call_expr_: ast::expr_ =
         ast::expr_call(@test_main_path_expr,
                        ~[@args_path_expr, @test_call_expr], false);
 
     let test_main_call_expr: ast::expr =
-        {id: cx.sess.next_node_id(), node: test_main_call_expr_,
-         span: dummy_sp()};
+        {id: cx.sess.next_node_id(), callee_id: cx.sess.next_node_id(),
+         node: test_main_call_expr_, span: dummy_sp()};
 
     ret @test_main_call_expr;
 }

src/rustc/middle/borrowck.rs

@@ -159,7 +159,6 @@ import std::list::{list, cons, nil};
 import result::{result, ok, err, extensions};
 import syntax::print::pprust;
 import util::common::indenter;
-import ast_util::op_expr_callee_id;
 import ty::to_str;
 import driver::session::session;
 import dvec::{dvec, extensions};

src/rustc/middle/borrowck/check_loans.rs

@@ -616,7 +616,7 @@ fn check_loans_in_expr(expr: @ast::expr,
       if self.bccx.method_map.contains_key(expr.id) {
         self.check_call(expr,
                         none,
-                        ast_util::op_expr_callee_id(expr),
+                        expr.callee_id,
                         expr.span,
                         ~[rval]);
       }
@@ -624,7 +624,7 @@ fn check_loans_in_expr(expr: @ast::expr,
       if self.bccx.method_map.contains_key(expr.id) {
         self.check_call(expr,
                         none,
-                        ast_util::op_expr_callee_id(expr),
+                        expr.callee_id,
                         expr.span,
                         ~[]);
       }

src/rustc/middle/lint.rs

@@ -405,6 +405,7 @@ fn check_item_path_statement(cx: ty::ctxt, it: @ast::item) {
         visit_stmt: fn@(s: @ast::stmt) {
             alt s.node {
               ast::stmt_semi(@{id: id,
+                               callee_id: _,
                                node: ast::expr_path(@path),
                                span: _}, _) {
                 cx.sess.span_lint(

src/rustc/middle/trans/base.rs

@@ -1475,12 +1475,12 @@ fn trans_unary(bcx: block, op: ast::unop, e: @ast::expr,
     // Check for user-defined method call
     alt bcx.ccx().maps.method_map.find(un_expr.id) {
       some(mentry) {
-        let callee_id = ast_util::op_expr_callee_id(un_expr);
-        let fty = node_id_type(bcx, callee_id);
+        let fty = node_id_type(bcx, un_expr.callee_id);
         ret trans_call_inner(
             bcx, un_expr.info(), fty,
             expr_ty(bcx, un_expr),
-            |bcx| impl::trans_method_callee(bcx, callee_id, e, mentry),
+            |bcx| impl::trans_method_callee(bcx, un_expr.callee_id, e,
+                                            mentry),
             arg_exprs(~[]), dest);
       }
       _ {}
@@ -1703,10 +1703,9 @@ fn trans_assign_op(bcx: block, ex: @ast::expr, op: ast::binop,
     alt bcx.ccx().maps.method_map.find(ex.id) {
       some(origin) {
         let bcx = lhs_res.bcx;
-        let callee_id = ast_util::op_expr_callee_id(ex);
         #debug["user-defined method callee_id: %s",
-               ast_map::node_id_to_str(bcx.tcx().items, callee_id)];
-        let fty = node_id_type(bcx, callee_id);
+               ast_map::node_id_to_str(bcx.tcx().items, ex.callee_id)];
+        let fty = node_id_type(bcx, ex.callee_id);
 
         let dty = expr_ty(bcx, dst);
         let target = alloc_ty(bcx, dty);
@@ -1717,7 +1716,7 @@ fn trans_assign_op(bcx: block, ex: @ast::expr, op: ast::binop,
             |bcx| {
                 // FIXME (#2528): provide the already-computed address, not
                 // the expr.
-                impl::trans_method_callee(bcx, callee_id, dst, origin)
+                impl::trans_method_callee(bcx, ex.callee_id, dst, origin)
             },
             arg_exprs(~[src]), save_in(target));
 
@@ -1851,13 +1850,12 @@ fn trans_binary(bcx: block, op: ast::binop, lhs: @ast::expr,
     // User-defined operators
     alt bcx.ccx().maps.method_map.find(ex.id) {
       some(origin) {
-        let callee_id = ast_util::op_expr_callee_id(ex);
-        let fty = node_id_type(bcx, callee_id);
+        let fty = node_id_type(bcx, ex.callee_id);
         ret trans_call_inner(
             bcx, ex.info(), fty,
             expr_ty(bcx, ex),
             |bcx| {
-                impl::trans_method_callee(bcx, callee_id, lhs, origin)
+                impl::trans_method_callee(bcx, ex.callee_id, lhs, origin)
             },
             arg_exprs(~[rhs]), dest);
       }
@@ -3597,12 +3595,12 @@ fn trans_expr(bcx: block, e: @ast::expr, dest: dest) -> block {
             // If it is here, it's not an lval, so this is a user-defined
             // index op
             let origin = bcx.ccx().maps.method_map.get(e.id);
-            let callee_id = ast_util::op_expr_callee_id(e);
-            let fty = node_id_type(bcx, callee_id);
+            let fty = node_id_type(bcx, e.callee_id);
             ret trans_call_inner(
                 bcx, e.info(), fty,
                 expr_ty(bcx, e),
-                |bcx| impl::trans_method_callee(bcx, callee_id, base, origin),
+                |bcx| impl::trans_method_callee(bcx, e.callee_id, base,
+                                                origin),
                 arg_exprs(~[idx]), dest);
           }
 

src/rustc/middle/typeck/check.rs

@@ -893,13 +893,12 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                         self_ex: @ast::expr, self_t: ty::t,
                         opname: str, args: ~[@ast::expr])
         -> option<(ty::t, bool)> {
-        let callee_id = ast_util::op_expr_callee_id(op_ex);
         let lkup = method::lookup(fcx, op_ex, self_ex, op_ex.id,
-                                  callee_id, @opname, self_t, ~[], false);
+                     op_ex.callee_id, @opname, self_t, ~[], false);
         alt lkup.method() {
           some(origin) {
             let {fty: method_ty, bot: bot} = {
-                let method_ty = fcx.node_ty(callee_id);
+                let method_ty = fcx.node_ty(op_ex.callee_id);
                 check_call_inner(fcx, op_ex.span, op_ex.id,
                                  method_ty, args)
             };
@@ -1963,7 +1962,9 @@ fn check_constraints(fcx: @fn_ctxt, cs: ~[@ast::constr],
                     }
                     ast::carg_lit(l) {
                       let tmp_node_id = fcx.ccx.tcx.sess.next_node_id();
-                      {id: tmp_node_id, node: ast::expr_lit(l), span: a.span}
+                      {id: tmp_node_id,
+                       callee_id: fcx.ccx.tcx.sess.next_node_id(),
+                       node: ast::expr_lit(l), span: a.span}
                     }
                     ast::carg_ident(i) {
                       if i < num_args {
@@ -1976,6 +1977,7 @@ fn check_constraints(fcx: @fn_ctxt, cs: ~[@ast::constr],
                               (arg_occ_node_id,
                                ast::def_arg(args[i].id, args[i].mode));
                           {id: arg_occ_node_id,
+                           callee_id: fcx.ccx.tcx.sess.next_node_id(),
                            node: ast::expr_path(p),
                            span: a.span}
                       } else {
@@ -1987,11 +1989,14 @@ fn check_constraints(fcx: @fn_ctxt, cs: ~[@ast::constr],
                   });
         }
         let p_op: ast::expr_ = ast::expr_path(c.node.path);
-        let oper: @ast::expr = @{id: c.node.id, node: p_op, span: c.span};
+        let oper: @ast::expr = @{id: c.node.id,
+             callee_id: fcx.ccx.tcx.sess.next_node_id(),
+             node: p_op, span: c.span};
         // Another ephemeral expr
         let call_expr_id = fcx.ccx.tcx.sess.next_node_id();
         let call_expr =
             @{id: call_expr_id,
+              callee_id: fcx.ccx.tcx.sess.next_node_id(),
               node: ast::expr_call(oper, c_args, false),
               span: c.span};
         check_pred_expr(fcx, call_expr);

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

@@ -415,7 +415,7 @@ class lookup {
         let all_substs = {tps: vec::append(cand.self_substs.tps, m_substs)
                           with cand.self_substs};
 
-        self.fcx.write_ty_substs(self.node_id, cand.fty, all_substs);
+         self.fcx.write_ty_substs(self.node_id, cand.fty, all_substs);
 
         ret cand.entry;
     }

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

@@ -233,7 +233,7 @@ fn resolve_expr(ex: @ast::expr, &&fcx: @fn_ctxt, v: visit::vt<@fn_ctxt>) {
             if has_trait_bounds(*bounds) {
                 let callee_id = alt ex.node {
                   ast::expr_field(_, _, _) { ex.id }
-                  _ { ast_util::op_expr_callee_id(ex) }
+                  _ { ex.callee_id }
                 };
                 let substs = fcx.node_ty_substs(callee_id);
                 let iscs = cx.impl_map.get(ex.id);

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

@@ -105,8 +105,7 @@ fn visit_expr(e: @ast::expr, wbcx: wb_ctxt, v: wb_vt) {
 
       ast::expr_binary(*) | ast::expr_unary(*) | ast::expr_assign_op(*)
         | ast::expr_index(*) {
-        maybe_resolve_type_vars_for_node(wbcx, e.span,
-                                         ast_util::op_expr_callee_id(e));
+        maybe_resolve_type_vars_for_node(wbcx, e.span, e.callee_id);
       }
 
       _ { }