Disallow implicitly binding methods in typechecker. Closes #2189.
This commit is contained in:
Michael Sullivan
parent
e4362a59b9
commit
bf06deafe6
3 changed files with 108 additions and 80 deletions
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@ -814,7 +814,14 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
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fn check_call(fcx: @fn_ctxt, sp: span, call_expr_id: ast::node_id,
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f: @ast::expr, args: ~[@ast::expr]) -> bool {
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let mut bot = check_expr(fcx, f, none);
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// Index expressions need to be handled seperately, to inform
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// them that they appear in call position.
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let mut bot = alt f.node {
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ast::expr_field(base, field, tys) {
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check_field(fcx, f, true, base, field, tys)
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}
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_ { check_expr(fcx, f, none) }
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};
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let fn_ty = fcx.expr_ty(f);
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// Call the generic checker.
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@ -1051,6 +1058,101 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
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is_loop_body, some(fcx));
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}
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// Check field access expressions
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fn check_field(fcx: @fn_ctxt, expr: @ast::expr, is_callee: bool,
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base: @ast::expr, field: ast::ident, tys: ~[@ast::ty])
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-> bool {
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let tcx = fcx.ccx.tcx;
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let bot = check_expr(fcx, base, none);
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let expr_t = structurally_resolved_type(fcx, expr.span,
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fcx.expr_ty(base));
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let base_t = do_autoderef(fcx, expr.span, expr_t);
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let mut handled = false;
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let n_tys = vec::len(tys);
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alt structure_of(fcx, expr.span, base_t) {
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ty::ty_rec(fields) {
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alt ty::field_idx(field, fields) {
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some(ix) {
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if n_tys > 0u {
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tcx.sess.span_err(expr.span,
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"can't provide type parameters \
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to a field access");
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}
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fcx.write_ty(expr.id, fields[ix].mt.ty);
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handled = true;
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}
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_ {}
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}
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}
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ty::ty_class(base_id, substs) {
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// This is just for fields -- the same code handles
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// methods in both classes and traits
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// (1) verify that the class id actually has a field called
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// field
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#debug("class named %s", ty_to_str(tcx, base_t));
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/*
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check whether this is a self-reference or not, which
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determines whether we look at all fields or only public
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ones
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*/
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let cls_items = if self_ref(fcx, base.id) {
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// base expr is "self" -- consider all fields
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ty::lookup_class_fields(tcx, base_id)
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}
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else {
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lookup_public_fields(tcx, base_id)
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};
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alt lookup_field_ty(tcx, base_id, cls_items, field, substs) {
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some(field_ty) {
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// (2) look up what field's type is, and return it
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fcx.write_ty(expr.id, field_ty);
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handled = true;
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}
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none {}
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}
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}
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_ {}
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}
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if !handled {
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let tps = vec::map(tys, |ty| fcx.to_ty(ty));
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let is_self_ref = self_ref(fcx, base.id);
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// this will be the call or block that immediately
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// encloses the method call
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let borrow_scope = fcx.tcx().region_map.get(expr.id);
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let lkup = method::lookup(fcx, expr, base, borrow_scope,
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expr.id, field, expr_t, tps,
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is_self_ref);
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alt lkup.method() {
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some(entry) {
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fcx.ccx.method_map.insert(expr.id, entry);
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// If we have resolved to a method but this is not in
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// a callee position, error
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if !is_callee {
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tcx.sess.span_err(
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expr.span,
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"attempted to take value of method \
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(try writing an anonymous function)");
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}
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}
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none {
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let t_err = fcx.infcx.resolve_type_vars_if_possible(expr_t);
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let msg = #fmt["attempted access of field `%s` on type `%s`, \
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but no public field or method with that name \
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was found",
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*field, fcx.infcx.ty_to_str(t_err)];
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tcx.sess.span_err(expr.span, msg);
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// NB: Adding a bogus type to allow typechecking to continue
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fcx.write_ty(expr.id, fcx.infcx.next_ty_var());
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}
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}
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}
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ret bot;
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}
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let tcx = fcx.ccx.tcx;
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let id = expr.id;
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@ -1489,84 +1591,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
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}
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}
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ast::expr_field(base, field, tys) {
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bot |= check_expr(fcx, base, none);
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let expr_t = structurally_resolved_type(fcx, expr.span,
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fcx.expr_ty(base));
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let base_t = do_autoderef(fcx, expr.span, expr_t);
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let mut handled = false;
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let n_tys = vec::len(tys);
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alt structure_of(fcx, expr.span, base_t) {
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ty::ty_rec(fields) {
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alt ty::field_idx(field, fields) {
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some(ix) {
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if n_tys > 0u {
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tcx.sess.span_err(expr.span,
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"can't provide type parameters \
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to a field access");
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}
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fcx.write_ty(id, fields[ix].mt.ty);
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handled = true;
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}
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_ {}
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}
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}
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ty::ty_class(base_id, substs) {
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// This is just for fields -- the same code handles
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// methods in both classes and traits
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// (1) verify that the class id actually has a field called
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// field
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#debug("class named %s", ty_to_str(tcx, base_t));
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/*
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check whether this is a self-reference or not, which
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determines whether we look at all fields or only public
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ones
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*/
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let cls_items = if self_ref(fcx, base.id) {
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// base expr is "self" -- consider all fields
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ty::lookup_class_fields(tcx, base_id)
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}
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else {
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lookup_public_fields(tcx, base_id)
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};
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alt lookup_field_ty(tcx, base_id, cls_items, field, substs) {
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some(field_ty) {
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// (2) look up what field's type is, and return it
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fcx.write_ty(id, field_ty);
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handled = true;
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}
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none {}
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}
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}
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_ {}
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}
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if !handled {
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let tps = vec::map(tys, |ty| fcx.to_ty(ty));
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let is_self_ref = self_ref(fcx, base.id);
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// this will be the call or block that immediately
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// encloses the method call
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let borrow_scope = fcx.tcx().region_map.get(expr.id);
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let lkup = method::lookup(fcx, expr, base, borrow_scope,
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expr.id, field, expr_t, tps,
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is_self_ref);
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alt lkup.method() {
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some(entry) {
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fcx.ccx.method_map.insert(id, entry);
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}
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none {
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let t_err = fcx.infcx.resolve_type_vars_if_possible(expr_t);
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let msg = #fmt["attempted access of field `%s` on type `%s`, \
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but no public field or method with that name \
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was found",
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*field, fcx.infcx.ty_to_str(t_err)];
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tcx.sess.span_err(expr.span, msg);
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// NB: Adding a bogus type to allow typechecking to continue
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fcx.write_ty(id, fcx.infcx.next_ty_var());
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}
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}
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}
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bot = check_field(fcx, expr, false, base, field, tys);
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}
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ast::expr_index(base, idx) {
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bot |= check_expr(fcx, base, none);
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@ -11,5 +11,5 @@ class cat {
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fn main() {
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let nyan : cat = cat(52u, 99);
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nyan.speak = fn@() { #debug["meow"]; }; //~ ERROR assigning to method
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nyan.speak = fn@() { #debug["meow"]; }; //~ ERROR attempted to take value of method
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}
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3
src/test/compile-fail/implicit-method-bind.rs
Normal file
3
src/test/compile-fail/implicit-method-bind.rs
Normal file
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@ -0,0 +1,3 @@
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fn main() {
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let _f = 10.times; //~ ERROR attempted to take value of method
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}
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