Make lookup non recursive and instead move the recursion just to

find_final_def. Use the fact that the recursion is in a simpler function to
detected import loops and exit.
This commit is contained in:
Rafael Ávila de Espíndola 2011-01-13 23:19:42 -05:00 committed by Graydon Hoare
parent f3c3fc0353
commit bdcb9d9b53
2 changed files with 90 additions and 60 deletions

View File

@ -405,6 +405,7 @@ TEST_XFAILS_BOOT := $(TASK_XFAILS) \
test/compile-fail/import.rs \
test/compile-fail/import2.rs \
test/compile-fail/import3.rs \
test/compile-fail/import4.rs \
test/compile-fail/bad-recv.rs \
test/compile-fail/bad-send.rs \
test/compile-fail/infinite-vec-type-recursion.rs \
@ -485,6 +486,7 @@ TEST_XFAILS_RUSTC := $(filter-out \
import.rs \
import2.rs \
import3.rs \
import4.rs \
while-type-error.rs \
), \
$(wildcard test/*/*.rs test/*/*.rc))

View File

@ -25,17 +25,20 @@ tag scope {
type env = rec(list[scope] scopes,
session.session sess);
type import_map = std.map.hashmap[ast.def_id,def_wrap];
type import_map = std.map.hashmap[ast.def_id,def];
// A simple wrapper over defs that stores a bit more information about modules
// and uses so that we can use the regular lookup_name when resolving imports.
tag def_wrap {
def_wrap_use(@ast.view_item);
def_wrap_import(@ast.view_item);
def_wrap_mod(@ast.item);
def_wrap_other(def);
}
fn unwrap_def(option.t[def_wrap] d_) -> option.t[def] {
fn lookup_name(&env e, import_map index,
ast.ident i) -> option.t[def] {
auto d_ = lookup_name_wrapped(e, i);
alt (d_) {
case (none[def_wrap]) {
ret none[def];
@ -48,7 +51,13 @@ fn unwrap_def(option.t[def_wrap] d_) -> option.t[def] {
ret some[def](ast.def_use(id));
}
}
fail;
}
case (def_wrap_import(?it)) {
alt (it.node) {
case (ast.view_item_import(_, ?id)) {
ret index.find(id);
}
}
}
case (def_wrap_mod(?i)) {
alt (i.node) {
@ -56,7 +65,6 @@ fn unwrap_def(option.t[def_wrap] d_) -> option.t[def] {
ret some[def](ast.def_mod(id));
}
}
fail;
}
case (def_wrap_other(?d)) {
ret some[def](d);
@ -64,46 +72,72 @@ fn unwrap_def(option.t[def_wrap] d_) -> option.t[def] {
}
}
}
fail;
}
// Follow the path of an import and return what it ultimately points to.
fn find_final_def(&env e, &span sp, vec[ident] idents) -> option.t[def_wrap] {
auto len = _vec.len[ident](idents);
auto first = idents.(0);
auto d_ = lookup_name(e, none[import_map], first);
if (len == 1u) {
ret d_;
}
alt (d_) {
case (none[def_wrap]) {
e.sess.span_err(sp, "unresolved name: " + first);
ret d_;
fn find_final_def(&env e, &span sp, vec[ident] idents) -> def_wrap {
fn found_something(&env e, std.map.hashmap[ast.def_id, bool] pending,
&span sp, vec[ident] idents, def_wrap d) -> def_wrap {
alt (d) {
case (def_wrap_import(?imp)) {
alt (imp.node) {
case (ast.view_item_import(?new_idents, ?d)) {
if (pending.contains_key(d)) {
e.sess.span_err(sp,
"recursive import");
fail;
}
pending.insert(d, true);
auto x = inner(e, pending, sp, new_idents);
ret found_something(e, pending, sp, idents, x);
}
}
}
case (_) {
}
}
case (some[def_wrap](?d)) {
alt (d) {
case (def_wrap_mod(?i)) {
auto new_idents = _vec.slice[ident](idents, 1u, len);
auto tmp_e = rec(scopes = nil[scope],
sess = e.sess);
auto new_e = update_env_for_item(tmp_e, i);
ret find_final_def(new_e, sp, new_idents);
}
case (def_wrap_use(?c)) {
e.sess.span_err(sp, "Crate access is not implemented");
}
case (_) {
e.sess.span_err(sp, first + " is not a module or crate");
}
auto len = _vec.len[ident](idents);
if (len == 1u) {
ret d;
}
alt (d) {
case (def_wrap_mod(?i)) {
auto new_idents = _vec.slice[ident](idents, 1u, len);
auto tmp_e = rec(scopes = nil[scope],
sess = e.sess);
auto new_e = update_env_for_item(tmp_e, i);
ret inner(new_e, pending, sp, new_idents);
}
case (def_wrap_use(?c)) {
e.sess.span_err(sp, "Crate access is not implemented");
}
case (_) {
auto first = idents.(0);
e.sess.span_err(sp, first + " is not a module or crate");
}
}
fail;
}
fn inner(&env e, std.map.hashmap[ast.def_id, bool] pending,
&span sp, vec[ident] idents) -> def_wrap {
auto first = idents.(0);
auto d_ = lookup_name_wrapped(e, first);
alt (d_) {
case (none[def_wrap]) {
e.sess.span_err(sp, "unresolved name: " + first);
fail;
}
case (some[def_wrap](?d)) {
ret found_something(e, pending, sp, idents, d);
}
}
}
fail;
auto pending = new_def_hash[bool]();
ret inner(e, pending, sp, idents);
}
fn lookup_name(&env e, option.t[import_map] index,
ast.ident i) -> option.t[def_wrap] {
fn lookup_name_wrapped(&env e, ast.ident i) -> option.t[def_wrap] {
// log "resolving name " + i;
@ -147,33 +181,24 @@ fn lookup_name(&env e, option.t[import_map] index,
ret none[def_wrap];
}
fn found_def_view(&env e, option.t[import_map] index,
@ast.view_item i) -> option.t[def_wrap] {
fn found_def_view(&env e, @ast.view_item i) -> option.t[def_wrap] {
alt (i.node) {
case (ast.view_item_use(_, _, ?id)) {
ret some[def_wrap](def_wrap_use(i));
}
case (ast.view_item_import(?idents,?d)) {
alt (index) {
case (some[import_map](?idx)) {
ret idx.find(d);
}
case (none[import_map]) {
ret find_final_def(e, i.span, idents);
}
}
ret some[def_wrap](def_wrap_import(i));
}
}
fail;
}
fn check_mod(&env e, option.t[import_map] index, ast.ident i,
ast._mod m) -> option.t[def_wrap] {
fn check_mod(&env e, ast.ident i, ast._mod m) -> option.t[def_wrap] {
alt (m.index.find(i)) {
case (some[ast.mod_index_entry](?ent)) {
alt (ent) {
case (ast.mie_view_item(?view_item)) {
ret found_def_view(e, index, view_item);
ret found_def_view(e, view_item);
}
case (ast.mie_item(?item)) {
ret found_def_item(item);
@ -199,12 +224,11 @@ fn lookup_name(&env e, option.t[import_map] index,
}
fn in_scope(ast.ident i, env e, option.t[import_map] index,
&scope s) -> option.t[def_wrap] {
fn in_scope(ast.ident i, env e, &scope s) -> option.t[def_wrap] {
alt (s) {
case (scope_crate(?c)) {
ret check_mod(e, index, i, c.node.module);
ret check_mod(e, i, c.node.module);
}
case (scope_item(?it)) {
@ -238,7 +262,7 @@ fn lookup_name(&env e, option.t[import_map] index,
}
}
case (ast.item_mod(_, ?m, _)) {
ret check_mod(e, index, i, m);
ret check_mod(e, i, m);
}
case (_) { /* fall through */ }
}
@ -267,14 +291,14 @@ fn lookup_name(&env e, option.t[import_map] index,
}
ret std.list.find[scope,def_wrap](e.scopes,
bind in_scope(i, e, index, _));
bind in_scope(i, e, _));
}
fn fold_pat_tag(&env e, &span sp, import_map index, ident i,
vec[@ast.pat] args, option.t[ast.variant_def] old_def,
ann a) -> @ast.pat {
auto new_def;
alt (unwrap_def(lookup_name(e, some(index), i))) {
alt (lookup_name(e, index, i)) {
case (some[def](?d)) {
alt (d) {
case (ast.def_variant(?did, ?vid)) {
@ -327,7 +351,7 @@ fn fold_expr_path(&env e, &span sp, import_map index,
check (n_idents != 0u);
auto id0 = p.node.idents.(0);
auto d_ = unwrap_def(lookup_name(e, some(index), id0));
auto d_ = lookup_name(e, index, id0);
alt (d_) {
case (some[def](_)) {
@ -362,11 +386,15 @@ fn fold_view_item_import(&env e, &span sp,
auto last_id = is.(len - 1u);
auto d = find_final_def(e, sp, is);
alt (d) {
case (none[def_wrap]) {
e.sess.span_err(sp, "unresolved name: " + last_id);
case (def_wrap_mod(?m)) {
alt (m.node) {
case (ast.item_mod(_, _, ?id)) {
index.insert(id, ast.def_mod(id));
}
}
}
case (some[def_wrap](?d2)) {
index.insert(id, d2);
case (def_wrap_other(?target_def)) {
index.insert(id, target_def);
}
}
@ -387,7 +415,7 @@ fn fold_ty_path(&env e, &span sp, import_map index, ast.path p,
e.sess.unimpl("resolving path ty with ty params");
}
auto d_ = unwrap_def(lookup_name(e, some(index), p.node.idents.(0)));
auto d_ = lookup_name(e, index, p.node.idents.(0));
alt (d_) {
case (some[def](?d)) {
@ -421,7 +449,7 @@ fn resolve_crate(session.session sess, @ast.crate crate) -> @ast.crate {
let fold.ast_fold[env] fld = fold.new_identity_fold[env]();
auto import_index = new_def_hash[def_wrap]();
auto import_index = new_def_hash[def]();
fld = @rec( fold_pat_tag = bind fold_pat_tag(_,_,import_index,_,_,_,_),
fold_expr_path = bind fold_expr_path(_,_,import_index,_,_,_),
fold_view_item_import