rust/src/comp/middle/resolve.rs
2011-05-31 01:23:53 -04:00

1298 lines
44 KiB
Rust

import front::ast;
import front::ast::ident;
import front::ast::def;
import front::ast::def_id;
import front::ast::ann;
import front::creader;
import driver::session::session;
import util::common::new_def_hash;
import util::common::new_int_hash;
import util::common::new_uint_hash;
import util::common::new_str_hash;
import util::common::span;
import middle::tstate::ann::ts_ann;
import std::map::hashmap;
import std::list;
import std::list::list;
import std::list::nil;
import std::list::cons;
import std::option;
import std::option::some;
import std::option::none;
import std::str;
import std::vec;
// Resolving happens in two passes. The first pass collects defids of all
// (internal) imports and modules, so that they can be looked up when needed,
// and then uses this information to resolve the imports. The second pass
// locates all names (in expressions, types, and alt patterns) and resolves
// them, storing the resulting def in the AST nodes.
// This module internally uses -1 as a def_id for the top_level module in a
// crate. The parser doesn't assign a def_id to this module.
// (FIXME See https://github.com/graydon/rust/issues/358 for the reason this
// isn't a const.)
tag scope {
scope_crate(@ast::crate);
scope_item(@ast::item);
scope_native_item(@ast::native_item);
scope_loop(@ast::decl); // there's only 1 decl per loop.
scope_block(ast::block);
scope_arm(ast::arm);
}
tag import_state {
todo(@ast::view_item, list[scope]); // only used for explicit imports
resolving(span);
resolved(option::t[def] /* value */,
option::t[def] /* type */,
option::t[def] /* module */);
}
type ext_hash = hashmap[tup(def_id,str,namespace),def];
fn new_ext_hash() -> ext_hash {
fn hash(&tup(def_id,str,namespace) v) -> uint {
ret str::hash(v._1) + util::common::hash_def(v._0) + (alt (v._2) {
case (ns_value) { 1u }
case (ns_type) { 2u }
case (ns_module) { 3u }
});
}
fn eq(&tup(def_id,str,namespace) v1,
&tup(def_id,str,namespace) v2) -> bool {
ret util::common::def_eq(v1._0, v2._0) &&
str::eq(v1._1, v2._1) &&
v1._2 == v2._2;
}
ret std::map::mk_hashmap[tup(def_id,str,namespace),def](hash, eq);
}
tag mod_index_entry {
mie_view_item(@ast::view_item);
mie_item(@ast::item);
mie_native_item(@ast::native_item);
mie_tag_variant(@ast::item /* tag item */, uint /* variant index */);
}
type mod_index = hashmap[ident,list[mod_index_entry]];
type indexed_mod = rec(option::t[ast::_mod] m,
mod_index index, vec[def] glob_imports,
hashmap[str,import_state] glob_imported_names);
/* native modules can't contain tags, and we don't store their ASTs because we
only need to look at them to determine exports, which they can't control.*/
// It should be safe to use index to memoize lookups of globbed names.
type crate_map = hashmap[uint,ast::crate_num];
type def_map = hashmap[uint,def];
type env = rec(crate_map crate_map,
def_map def_map,
hashmap[def_id,@ast::item] ast_map,
hashmap[ast::def_num,import_state] imports,
hashmap[ast::def_num,@indexed_mod] mod_map,
hashmap[def_id,vec[ident]] ext_map,
ext_hash ext_cache,
session sess);
// Used to distinguish between lookups from outside and from inside modules,
// since export restrictions should only be applied for the former.
tag dir { inside; outside; }
tag namespace {
ns_value;
ns_type;
ns_module;
}
fn resolve_crate(session sess, @ast::crate crate) -> def_map {
auto e = @rec(crate_map = new_uint_hash[ast::crate_num](),
def_map = new_uint_hash[def](),
ast_map = new_def_hash[@ast::item](),
imports = new_int_hash[import_state](),
mod_map = new_int_hash[@indexed_mod](),
ext_map = new_def_hash[vec[ident]](),
ext_cache = new_ext_hash(),
sess = sess);
creader::read_crates(sess, e.crate_map, *crate);
map_crate(e, *crate);
resolve_imports(*e);
check_for_collisions(e, *crate);
resolve_names(e, *crate);
ret e.def_map;
}
// Locate all modules and imports and index them, so that the next passes can
// resolve through them.
fn map_crate(&@env e, &ast::crate c) {
// First, find all the modules, and index the names that they contain
auto cell = @mutable nil[scope];
auto index_names =
rec(visit_crate_pre = bind push_env_for_crate(cell, _),
visit_crate_post = bind pop_env_for_crate(cell, _),
visit_view_item_pre = bind index_vi(e, cell, _),
visit_item_pre = bind index_i(e, cell, _),
visit_item_post = bind pop_env_for_item(cell, _)
with walk::default_visitor());
// Register the top-level mod
e.mod_map.insert(-1, @rec(m=some(c.node.module),
index=index_mod(c.node.module),
glob_imports=vec::empty[def](),
glob_imported_names
=new_str_hash[import_state]()));
walk::walk_crate(index_names, c);
fn index_vi(@env e, @mutable list[scope] sc, &@ast::view_item i) {
alt (i.node) {
case (ast::view_item_import(_, ?ids, ?defid)) {
e.imports.insert(defid._1, todo(i, *sc));
}
case (_) {}
}
}
fn index_i(@env e, @mutable list[scope] sc, &@ast::item i) {
push_env_for_item(sc, i);
alt (i.node) {
case (ast::item_mod(_, ?md, ?defid)) {
e.mod_map.insert(defid._1,
@rec(m=some(md), index=index_mod(md),
glob_imports=vec::empty[def](),
glob_imported_names
=new_str_hash[import_state]()));
e.ast_map.insert(defid, i);
}
case (ast::item_native_mod(_, ?nmd, ?defid)) {
e.mod_map.insert(defid._1,
@rec(m=none[ast::_mod],
index=index_nmod(nmd),
glob_imports=vec::empty[def](),
glob_imported_names
=new_str_hash[import_state]()));
e.ast_map.insert(defid, i);
}
case (ast::item_const(_, _, _, ?defid, _)) {
e.ast_map.insert(defid, i);
}
case (ast::item_fn(_, _, _, ?defid, _)) {
e.ast_map.insert(defid, i);
}
case (ast::item_ty(_, _, _, ?defid, _)) {
e.ast_map.insert(defid, i);
}
case (ast::item_tag(_, _, _, ?defid, _)) {
e.ast_map.insert(defid, i);
}
case (ast::item_obj(_, _, _, ?obj_def_ids, _)) {
e.ast_map.insert(obj_def_ids.ty, i);
e.ast_map.insert(obj_def_ids.ctor, i);
}
}
}
// Next, assemble the links for globbed imports.
cell = @mutable nil[scope];
auto link_globs =
rec(visit_crate_pre = bind push_env_for_crate(cell, _),
visit_crate_post = bind pop_env_for_crate(cell, _),
visit_view_item_pre = bind link_glob(e, cell, _),
visit_item_pre = bind push_env_for_item(cell, _),
visit_item_post = bind pop_env_for_item(cell, _)
with walk::default_visitor());
walk::walk_crate(link_globs, c);
fn link_glob(@env e, @mutable list[scope] sc, &@ast::view_item vi) {
fn find_mod(@env e, list[scope] sc) -> @indexed_mod {
alt (sc) {
case (cons(scope_item(?i), ?tl)) {
alt(i.node) {
case (ast::item_mod(_, _, ?defid)) {
ret e.mod_map.get(defid._1);
}
case (ast::item_native_mod(_, _, ?defid)) {
ret e.mod_map.get(defid._1);
}
case (_) {
be find_mod(e, *tl);
}
}
}
case (_) {
ret e.mod_map.get(-1); //top-level
}
}
}
alt (vi.node) {
//if it really is a glob import, that is
case (ast::view_item_import_glob(?path, _)) {
find_mod(e, *sc).glob_imports
+= [follow_import(*e, *sc, path, vi.span)];
}
case (_) {}
}
}
}
fn resolve_imports(&env e) {
for each (@tup(ast::def_num, import_state) it in e.imports.items()) {
alt (it._1) {
case (todo(?item, ?sc)) {
resolve_import(e, item, sc);
}
case (resolved(_, _, _)) {}
}
}
}
fn resolve_names(&@env e, &ast::crate c) {
auto cell = @mutable nil[scope];
auto v = rec(visit_crate_pre = bind push_env_for_crate(cell, _),
visit_crate_post = bind pop_env_for_crate(cell, _),
visit_item_pre = bind push_env_for_item(cell, _),
visit_item_post = bind pop_env_for_item(cell, _),
visit_method_pre = bind push_env_for_method(cell, _),
visit_method_post = bind pop_env_for_method(cell, _),
visit_native_item_pre = bind push_env_for_n_item(cell, _),
visit_native_item_post = bind pop_env_for_n_item(cell, _),
visit_block_pre = bind push_env_for_block(cell, _),
visit_block_post = bind pop_env_for_block(cell, _),
visit_arm_pre = bind walk_arm(e, cell, _),
visit_arm_post = bind pop_env_for_arm(cell, _),
visit_expr_pre = bind walk_expr(e, cell, _),
visit_expr_post = bind pop_env_for_expr(cell, _),
visit_ty_pre = bind walk_ty(e, cell, _)
with walk::default_visitor());
walk::walk_crate(v, c);
fn walk_expr(@env e, @mutable list[scope] sc, &@ast::expr exp) {
push_env_for_expr(sc, exp);
alt (exp.node) {
case (ast::expr_path(?p, ?a)) {
auto df = lookup_path_strict(*e, *sc, exp.span, p.node.idents,
ns_value);
e.def_map.insert(a.id, df);
}
case (_) {}
}
}
fn walk_ty(@env e, @mutable list[scope] sc, &@ast::ty t) {
alt (t.node) {
case (ast::ty_path(?p, ?a)) {
auto new_def = lookup_path_strict(*e, *sc, t.span,
p.node.idents, ns_type);
e.def_map.insert(a.id, new_def);
}
case (_) {}
}
}
fn walk_arm(@env e, @mutable list[scope] sc, &ast::arm a) {
walk_pat(*e, *sc, a.pat);
push_env_for_arm(sc, a);
}
fn walk_pat(&env e, &list[scope] sc, &@ast::pat pat) {
alt (pat.node) {
case (ast::pat_tag(?p, ?children, ?a)) {
auto fnd = lookup_path_strict(e, sc, p.span, p.node.idents,
ns_value);
alt (fnd) {
case (ast::def_variant(?did, ?vid)) {
e.def_map.insert(a.id, fnd);
}
case (_) {
e.sess.span_err(p.span, "not a tag variant: " +
str::connect(p.node.idents, "::"));
fail;
}
}
for (@ast::pat child in children) {
walk_pat(e, sc, child);
}
}
case (_) {}
}
}
}
// Helpers for tracking scope during a walk
fn push_env_for_crate(@mutable list[scope] sc, &ast::crate c) {
*sc = cons[scope](scope_crate(@c), @*sc);
}
fn pop_env_for_crate(@mutable list[scope] sc, &ast::crate c) {
*sc = std::list::cdr(*sc);
}
fn push_env_for_item(@mutable list[scope] sc, &@ast::item i) {
*sc = cons[scope](scope_item(i), @*sc);
}
fn pop_env_for_item(@mutable list[scope] sc, &@ast::item i) {
*sc = std::list::cdr(*sc);
}
fn push_env_for_method(@mutable list[scope] sc, &@ast::method m) {
let vec[ast::ty_param] tp = [];
let @ast::item i = @rec(node=ast::item_fn(m.node.ident,
m.node.meth,
tp,
m.node.id,
m.node.ann),
span=m.span);
*sc = cons[scope](scope_item(i), @*sc);
}
fn pop_env_for_method(@mutable list[scope] sc, &@ast::method m) {
*sc = std::list::cdr(*sc);
}
fn push_env_for_n_item(@mutable list[scope] sc, &@ast::native_item i) {
*sc = cons[scope](scope_native_item(i), @*sc);
}
fn pop_env_for_n_item(@mutable list[scope] sc, &@ast::native_item i) {
*sc = std::list::cdr(*sc);
}
fn push_env_for_block(@mutable list[scope] sc, &ast::block b) {
*sc = cons[scope](scope_block(b), @*sc);
}
fn pop_env_for_block(@mutable list[scope] sc, &ast::block b) {
*sc = std::list::cdr(*sc);
}
fn push_env_for_expr(@mutable list[scope] sc, &@ast::expr x) {
alt (x.node) {
case (ast::expr_for(?d, _, _, _)) {
*sc = cons[scope](scope_loop(d), @*sc);
}
case (ast::expr_for_each(?d, _, _, _)) {
*sc = cons[scope](scope_loop(d), @*sc);
}
case (_) {}
}
}
fn pop_env_for_expr(@mutable list[scope] sc, &@ast::expr x) {
alt (x.node) {
case (ast::expr_for(?d, _, _, _)) {
*sc = std::list::cdr(*sc);
}
case (ast::expr_for_each(?d, _, _, _)) {
*sc = std::list::cdr(*sc);
}
case (_) {}
}
}
fn push_env_for_arm(@mutable list[scope] sc, &ast::arm p) {
*sc = cons[scope](scope_arm(p), @*sc);
}
fn pop_env_for_arm(@mutable list[scope] sc, &ast::arm p) {
*sc = std::list::cdr(*sc);
}
fn follow_import(&env e, &list[scope] sc, vec[ident] path, &span sp)
-> def {
auto path_len = vec::len(path);
auto dcur = lookup_in_scope_strict(e, sc, sp, path.(0), ns_module);
auto i = 1u;
while (true) {
if (i == path_len) { break; }
dcur = lookup_in_mod_strict(e, dcur, sp, path.(i),
ns_module, outside);
i += 1u;
}
alt (dcur) {
case (ast::def_mod(?def_id)) { ret dcur; }
case (ast::def_native_mod(?def_id)) { ret dcur; }
case (_) {
e.sess.span_err(sp, str::connect(path, "::")
+ " does not name a module.");
fail;
}
}
}
// Import resolution
fn resolve_import(&env e, &@ast::view_item it, &list[scope] sc) {
auto defid; auto ids;
alt (it.node) {
case (ast::view_item_import(_, ?_ids, ?_defid)) {
defid = _defid; ids = _ids;
}
}
e.imports.insert(defid._1, resolving(it.span));
auto n_idents = vec::len(ids);
auto end_id = ids.(n_idents - 1u);
if (n_idents == 1u) {
auto next_sc = std::list::cdr(sc);
register(e, defid, it.span, end_id,
lookup_in_scope(e, next_sc, it.span, end_id, ns_value),
lookup_in_scope(e, next_sc, it.span, end_id, ns_type),
lookup_in_scope(e, next_sc, it.span, end_id, ns_module));
} else {
auto dcur = lookup_in_scope_strict(e, sc, it.span, ids.(0),
ns_module);
auto i = 1u;
while (true) {
if (i == n_idents - 1u) {
register(e, defid, it.span, end_id,
lookup_in_mod(e, dcur, it.span, end_id, ns_value,
outside),
lookup_in_mod(e, dcur, it.span, end_id, ns_type,
outside),
lookup_in_mod(e, dcur, it.span, end_id, ns_module,
outside));
break;
} else {
dcur = lookup_in_mod_strict(e, dcur, it.span, ids.(i),
ns_module, outside);
i += 1u;
}
}
}
fn register(&env e, def_id defid, &span sp, &ident id,
&option::t[def] val, &option::t[def] typ,
&option::t[def] md) {
if (option::is_none(val) && option::is_none(typ) &&
option::is_none(md)) {
unresolved(e, sp, id, "import");
}
e.imports.insert(defid._1, resolved(val, typ, md));
}
}
// Utilities
fn ns_name(namespace ns) -> str {
alt (ns) {
case (ns_type) { ret "typename"; }
case (ns_value) { ret "name"; }
case (ns_module) { ret "modulename"; }
}
}
fn unresolved(&env e, &span sp, &ident id, &str kind) {
e.sess.span_err(sp, "unresolved " + kind + ": " + id);
}
// Lookup helpers
fn lookup_path_strict(&env e, &list[scope] sc, &span sp, vec[ident] idents,
namespace ns) -> def {
auto n_idents = vec::len(idents);
auto headns = if (n_idents == 1u) { ns } else { ns_module };
auto dcur = lookup_in_scope_strict(e, sc, sp, idents.(0), headns);
auto i = 1u;
while (i < n_idents) {
auto curns = if (n_idents == i + 1u) { ns } else { ns_module };
dcur = lookup_in_mod_strict(e, dcur, sp, idents.(i), curns, outside);
i += 1u;
}
ret dcur;
}
fn lookup_in_scope_strict(&env e, list[scope] sc, &span sp, &ident id,
namespace ns) -> def {
alt (lookup_in_scope(e, sc, sp, id, ns)) {
case (none) {
unresolved(e, sp, id, ns_name(ns));
fail;
}
case (some(?d)) {
ret d;
}
}
}
fn scope_is_fn(&scope sc) -> bool {
ret alt (sc) {
case (scope_item(?it)) {
alt (it.node) {
case (ast::item_fn(_, _, _, _, _)) { true }
case (_) { false }
}
}
case (scope_native_item(_)) { true }
case (_) { false }
};
}
fn def_is_local(&def d) -> bool {
ret alt (d) {
case (ast::def_arg(_)) { true }
case (ast::def_local(_)) { true }
case (ast::def_binding(_)) { true }
case (_) { false }
};
}
fn def_is_obj_field(&def d) -> bool {
ret alt (d) {
case (ast::def_obj_field(_)) { true }
case (_) { false }
};
}
fn lookup_in_scope(&env e, list[scope] sc, &span sp, &ident id, namespace ns)
-> option::t[def] {
fn in_scope(&env e, &span sp, &ident id, &scope s, namespace ns)
-> option::t[def] {
//not recursing through globs
alt (s) {
case (scope_crate(?c)) {
auto defid = tup(ast::local_crate, -1);
ret lookup_in_local_mod(e, defid, sp, id, ns, inside);
}
case (scope_item(?it)) {
alt (it.node) {
case (ast::item_fn(_, ?f, ?ty_params, _, _)) {
ret lookup_in_fn(id, f.decl, ty_params, ns);
}
case (ast::item_obj(_, ?ob, ?ty_params, _, _)) {
ret lookup_in_obj(id, ob, ty_params, ns);
}
case (ast::item_tag(_, _, ?ty_params, _, _)) {
if (ns == ns_type) {
ret lookup_in_ty_params(id, ty_params);
}
}
case (ast::item_mod(_, _, ?defid)) {
ret lookup_in_local_mod(e, defid, sp, id, ns, inside);
}
case (ast::item_native_mod(_, ?m, ?defid)) {
ret lookup_in_local_native_mod(e, defid, sp, id, ns);
}
case (ast::item_ty(_, _, ?ty_params, _, _)) {
if (ns == ns_type) {
ret lookup_in_ty_params(id, ty_params);
}
}
case (_) {}
}
}
case (scope_native_item(?it)) {
alt (it.node) {
case (ast::native_item_fn(_, _, ?decl, ?ty_params, _, _)){
ret lookup_in_fn(id, decl, ty_params, ns);
}
}
}
case (scope_loop(?d)) {
if (ns == ns_value) {
alt (d.node) {
case (ast::decl_local(?local)) {
if (str::eq(local.ident, id)) {
ret some(ast::def_local(local.id));
}
}
}
}
}
case (scope_block(?b)) {
ret lookup_in_block(id, b.node, ns);
}
case (scope_arm(?a)) {
if (ns == ns_value) {
ret lookup_in_pat(id, *a.pat);
}
}
}
ret none[def];
}
auto left_fn = false;
// Used to determine whether obj fields are in scope
auto left_fn_level2 = false;
while (true) {
alt (sc) {
case (nil) {
ret none[def];
}
case (cons(?hd, ?tl)) {
auto fnd = in_scope(e, sp, id, hd, ns);
if (!option::is_none(fnd)) {
auto df = option::get(fnd);
if ((left_fn && def_is_local(df)) ||
(left_fn_level2 && def_is_obj_field(df))) {
e.sess.span_err
(sp, "attempted dynamic environment-capture");
}
ret fnd;
}
if (left_fn) { left_fn_level2 = true; }
if (ns == ns_value && !left_fn) {
left_fn = scope_is_fn(hd);
}
sc = *tl;
}
}
}
e.sess.bug("reached unreachable code in lookup_in_scope"); // sigh
fail;
}
fn lookup_in_ty_params(&ident id, &vec[ast::ty_param] ty_params)
-> option::t[def] {
auto i = 0u;
for (ast::ty_param tp in ty_params) {
if (str::eq(tp, id)) {
ret some(ast::def_ty_arg(i));
}
i += 1u;
}
ret none[def];
}
fn lookup_in_pat(&ident id, &ast::pat pat) -> option::t[def] {
alt (pat.node) {
case (ast::pat_bind(?name, ?defid, _)) {
if (str::eq(name, id)) { ret some(ast::def_binding(defid)); }
}
case (ast::pat_wild(_)) {}
case (ast::pat_lit(_, _)) {}
case (ast::pat_tag(_, ?pats, _)) {
for (@ast::pat p in pats) {
auto found = lookup_in_pat(id, *p);
if (!option::is_none(found)) { ret found; }
}
}
}
ret none[def];
}
fn lookup_in_fn(&ident id, &ast::fn_decl decl, &vec[ast::ty_param] ty_params,
namespace ns) -> option::t[def] {
alt (ns) {
case (ns_value) {
for (ast::arg a in decl.inputs) {
if (str::eq(a.ident, id)) {
ret some(ast::def_arg(a.id));
}
}
ret none[def];
}
case (ns_type) {
ret lookup_in_ty_params(id, ty_params);
}
case (_) { ret none[def]; }
}
}
fn lookup_in_obj(&ident id, &ast::_obj ob, &vec[ast::ty_param] ty_params,
namespace ns) -> option::t[def] {
alt (ns) {
case (ns_value) {
for (ast::obj_field f in ob.fields) {
if (str::eq(f.ident, id)) {
ret some(ast::def_obj_field(f.id));
}
}
ret none[def];
}
case (ns_type) {
ret lookup_in_ty_params(id, ty_params);
}
case (_) { ret none[def]; }
}
}
fn lookup_in_block(&ident id, &ast::block_ b, namespace ns)
-> option::t[def] {
for (@ast::stmt st in b.stmts) {
alt (st.node) {
case (ast::stmt_decl(?d,_)) {
alt (d.node) {
case (ast::decl_local(?loc)) {
if (ns == ns_value && str::eq(id, loc.ident)) {
ret some(ast::def_local(loc.id));
}
}
case (ast::decl_item(?it)) {
alt (it.node) {
case (ast::item_tag(?name, ?variants, _,
?defid, _)) {
if (ns == ns_type) {
if (str::eq(name, id)) {
ret some(ast::def_ty(defid));
}
} else if (ns == ns_value) {
for (ast::variant v in variants) {
if (str::eq(v.node.name, id)) {
ret some(ast::def_variant(
defid, v.node.id));
}
}
}
}
case (_) {
if (str::eq(ast::item_ident(it), id)) {
auto found = found_def_item(it, ns);
if (!option::is_none(found)) {ret found;}
}
}
}
}
}
}
case (_) {}
}
}
ret none[def];
}
fn found_def_item(&@ast::item i, namespace ns) -> option::t[def] {
alt (i.node) {
case (ast::item_const(_, _, _, ?defid, _)) {
if (ns == ns_value) { ret some(ast::def_const(defid)); }
}
case (ast::item_fn(_, _, _, ?defid, _)) {
if (ns == ns_value) { ret some(ast::def_fn(defid)); }
}
case (ast::item_mod(_, _, ?defid)) {
if (ns == ns_module) { ret some(ast::def_mod(defid)); }
}
case (ast::item_native_mod(_, _, ?defid)) {
if (ns == ns_module) { ret some(ast::def_native_mod(defid)); }
}
case (ast::item_ty(_, _, _, ?defid, _)) {
if (ns == ns_type) { ret some(ast::def_ty(defid)); }
}
case (ast::item_tag(_, _, _, ?defid, _)) {
if (ns == ns_type) { ret some(ast::def_ty(defid)); }
}
case (ast::item_obj(_, _, _, ?odid, _)) {
alt (ns) {
case (ns_value) { ret some(ast::def_obj(odid.ctor)); }
case (ns_type) { ret some(ast::def_obj(odid.ty)); }
case (_) { }
}
}
case (_) { }
}
ret none[def];
}
fn lookup_in_mod_strict(&env e, def m, &span sp, &ident id,
namespace ns, dir dr) -> def {
alt (lookup_in_mod(e, m, sp, id, ns, dr)) {
case (none) {
unresolved(e, sp, id, ns_name(ns));
fail;
}
case (some(?d)) {
ret d;
}
}
}
fn lookup_in_mod(&env e, def m, &span sp, &ident id, namespace ns, dir dr)
-> option::t[def] {
auto defid = ast::def_id_of_def(m);
if (defid._0 != ast::local_crate) {
// examining a module in an external crate
auto cached = e.ext_cache.find(tup(defid,id,ns));
if (!option::is_none(cached)) { ret cached; }
auto path = [id];
if (defid._1 != -1) {
path = e.ext_map.get(defid) + path;
}
auto fnd = lookup_external(e, defid._0, path, ns);
if (!option::is_none(fnd)) {
e.ext_cache.insert(tup(defid,id,ns), option::get(fnd));
}
ret fnd;
}
alt (m) {
case (ast::def_mod(?defid)) {
ret lookup_in_local_mod(e, defid, sp, id, ns, dr);
}
case (ast::def_native_mod(?defid)) {
ret lookup_in_local_native_mod(e, defid, sp, id, ns);
}
}
}
fn found_view_item(&env e, @ast::view_item vi, namespace ns)
-> option::t[def] {
alt (vi.node) {
case (ast::view_item_use(_, _, _, ?ann)) {
ret some(ast::def_mod(tup(e.crate_map.get(ann.id), -1)));
}
case (ast::view_item_import(_, _, ?defid)) {
ret lookup_import(e, defid, ns);
}
case (ast::view_item_import_glob(_, ?defid)) {
ret none[def]; //will be handled in the fallback glob pass
}
}
}
fn lookup_import(&env e, def_id defid, namespace ns) -> option::t[def] {
alt (e.imports.get(defid._1)) {
case (todo(?item, ?sc)) {
resolve_import(e, item, sc);
ret lookup_import(e, defid, ns);
}
case (resolving(?sp)) {
e.sess.span_err(sp, "cyclic import");
}
case (resolved(?val, ?typ, ?md)) {
ret alt (ns) { case (ns_value) { val }
case (ns_type) { typ }
case (ns_module) { md } };
}
}
fail;
}
fn lookup_in_local_native_mod(&env e, def_id defid, &span sp,
&ident id, namespace ns) -> option::t[def] {
ret lookup_in_local_mod(e, defid, sp, id, ns, inside);
}
fn lookup_in_local_mod(&env e, def_id defid, &span sp,
&ident id, namespace ns, dir dr) -> option::t[def] {
auto info = e.mod_map.get(defid._1);
if (dr == outside && !ast::is_exported(id, option::get(info.m))) {
// if we're in a native mod, then dr==inside, so info.m is some _mod
ret none[def]; // name is not visible
}
alt(info.index.find(id)) {
case (none) { }
case (some(?lst)) {
while (true) {
alt (lst) {
case (nil) { break; }
case (cons(?hd, ?tl)) {
auto found = lookup_in_mie(e, hd, ns);
if (!option::is_none(found)) { ret found; }
lst = *tl;
}
}
}
}
}
// not local or explicitly imported; try globs:
ret lookup_glob_in_mod(e, info, sp, id, ns, dr);
}
fn lookup_glob_in_mod(&env e, @indexed_mod info, &span sp,
&ident id, namespace wanted_ns, dir dr)
-> option::t[def] {
fn per_ns(&env e, @indexed_mod info, &span sp, &ident id,
namespace ns, dir dr) -> option::t[def] {
fn l_i_m_r(&env e, &def m, &span sp, &ident id,
namespace ns, dir dr) -> option::t[def] {
be lookup_in_mod(e, m, sp, id, ns, dr);
}
auto matches = vec::filter_map[def, def]
(bind l_i_m_r(e, _, sp, id, ns, dr),
info.glob_imports);
if (vec::len(matches) == 0u) {
ret none[def];
} else if (vec::len(matches) == 1u){
ret some[def](matches.(0));
} else {
for (def match in matches) {
e.sess.span_note(e.ast_map.get
(ast::def_id_of_def(match)).span,
"'" + id + "' is defined here.");
}
e.sess.span_err(sp, "'" + id + "' is glob-imported from" +
" multiple different modules.");
fail;
}
}
// since we don't know what names we have in advance,
// absence takes the place of todo()
if(!info.glob_imported_names.contains_key(id)) {
info.glob_imported_names.insert(id, resolving(sp));
auto val = per_ns(e, info, sp, id, ns_value, dr);
auto typ = per_ns(e, info, sp, id, ns_type, dr);
auto md = per_ns(e, info, sp, id, ns_module, dr);
info.glob_imported_names.insert(id, resolved(val, typ, md));
}
alt (info.glob_imported_names.get(id)) {
case (todo(_,_)) { e.sess.bug("Shouldn't've put a todo in."); }
case (resolving(?sp)) {
ret none[def]; //circularity is okay in import globs
}
case (resolved(?val, ?typ, ?md)) {
ret alt (wanted_ns) { case (ns_value) { val }
case (ns_type) { typ }
case (ns_module) { md } };
}
}
}
fn lookup_in_mie(&env e, &mod_index_entry mie, namespace ns)
-> option::t[def] {
alt (mie) {
case (mie_view_item(?view_item)) {
ret found_view_item(e, view_item, ns);
}
case (mie_item(?item)) {
ret found_def_item(item, ns);
}
case (mie_tag_variant(?item, ?variant_idx)) {
alt (item.node) {
case (ast::item_tag(_, ?variants, _, ?tid, _)) {
if (ns == ns_value) {
auto vid = variants.(variant_idx).node.id;
ret some(ast::def_variant(tid, vid));
} else {
ret none[def];
}
}
}
}
case (mie_native_item(?native_item)) {
alt (native_item.node) {
case (ast::native_item_ty(_, ?id)) {
if (ns == ns_type) {
ret some(ast::def_native_ty(id));
}
}
case (ast::native_item_fn(_, _, _, _, ?id, _)) {
if (ns == ns_value) {
ret some(ast::def_native_fn(id));
}
}
}
}
case (_) {}
}
ret none[def];
}
// Module indexing
fn add_to_index(&hashmap[ident,list[mod_index_entry]] index, &ident id,
&mod_index_entry ent) {
alt (index.find(id)) {
case (none) {
index.insert(id, cons(ent, @nil[mod_index_entry]));
}
case (some(?prev)) {
index.insert(id, cons(ent, @prev));
}
}
}
fn index_mod(&ast::_mod md) -> mod_index {
auto index = new_str_hash[list[mod_index_entry]]();
for (@ast::view_item it in md.view_items) {
alt (it.node) {
case(ast::view_item_use(?id, _, _, _)) {
add_to_index(index, id, mie_view_item(it));
}
case(ast::view_item_import(?def_ident,_,_)) {
add_to_index(index, def_ident, mie_view_item(it));
}
//globbed imports have to be resolved lazily.
case(ast::view_item_import_glob(_,_)) {}
case(ast::view_item_export(_)) {}
}
}
for (@ast::item it in md.items) {
alt (it.node) {
case (ast::item_const(?id, _, _, _, _)) {
add_to_index(index, id, mie_item(it));
}
case (ast::item_fn(?id, _, _, _, _)) {
add_to_index(index, id, mie_item(it));
}
case (ast::item_mod(?id, _, _)) {
add_to_index(index, id, mie_item(it));
}
case (ast::item_native_mod(?id, _, _)) {
add_to_index(index, id, mie_item(it));
}
case (ast::item_ty(?id, _, _, _, _)) {
add_to_index(index, id, mie_item(it));
}
case (ast::item_tag(?id, ?variants, _, _, _)) {
add_to_index(index, id, mie_item(it));
let uint variant_idx = 0u;
for (ast::variant v in variants) {
add_to_index(index, v.node.name,
mie_tag_variant(it, variant_idx));
variant_idx += 1u;
}
}
case (ast::item_obj(?id, _, _, _, _)) {
add_to_index(index, id, mie_item(it));
}
}
}
ret index;
}
fn index_nmod(&ast::native_mod md) -> mod_index {
auto index = new_str_hash[list[mod_index_entry]]();
for (@ast::view_item it in md.view_items) {
alt (it.node) {
case(ast::view_item_import(?def_ident,_,_)) {
add_to_index(index, def_ident, mie_view_item(it));
}
case(ast::view_item_import_glob(_,_)) {}
case(ast::view_item_export(_)) {}
}
}
for (@ast::native_item it in md.items) {
alt (it.node) {
case (ast::native_item_ty(?id, _)) {
add_to_index(index, id, mie_native_item(it));
}
case (ast::native_item_fn(?id, _, _, _, _, _)) {
add_to_index(index, id, mie_native_item(it));
}
}
}
ret index;
}
// External lookups
fn ns_for_def(def d) -> namespace {
ret alt (d) {
case (ast::def_fn(?id)) { ns_value }
case (ast::def_obj(?id)) { ns_value }
case (ast::def_obj_field(?id)) { ns_value }
case (ast::def_mod(?id)) { ns_module }
case (ast::def_native_mod(?id)) { ns_module }
case (ast::def_const(?id)) { ns_value }
case (ast::def_arg(?id)) { ns_value }
case (ast::def_local(?id)) { ns_value }
case (ast::def_variant(_, ?id)) { ns_value }
case (ast::def_ty(?id)) { ns_type }
case (ast::def_binding(?id)) { ns_type }
case (ast::def_use(?id)) { ns_module }
case (ast::def_native_ty(?id)) { ns_type }
case (ast::def_native_fn(?id)) { ns_value }
};
}
fn lookup_external(&env e, int cnum, vec[ident] ids, namespace ns)
-> option::t[def] {
for (def d in creader::lookup_defs(e.sess, cnum, ids)) {
e.ext_map.insert(ast::def_id_of_def(d), ids);
if (ns == ns_for_def(d)) { ret some(d); }
}
ret none[def];
}
// Collision detection
fn check_for_collisions(&@env e, &ast::crate c) {
// Module indices make checking those relatively simple -- just check each
// name for multiple entities in the same namespace.
for each (@tup(ast::def_num, @indexed_mod) m in e.mod_map.items()) {
for each (@tup(ident, list[mod_index_entry]) name in
m._1.index.items()) {
check_mod_name(*e, name._0, name._1);
}
}
// Other scopes have to be checked the hard way.
auto v = rec(visit_item_pre = bind check_item(e, _),
visit_block_pre = bind check_block(e, _),
visit_arm_pre = bind check_arm(e, _)
with walk::default_visitor());
walk::walk_crate(v, c);
}
fn check_mod_name(&env e, &ident name, &list[mod_index_entry] entries) {
auto saw_mod = false; auto saw_type = false; auto saw_value = false;
fn dup(&env e, &span sp, &str word, &ident name) {
e.sess.span_err(sp, "duplicate definition of " + word + name);
}
while (true) {
alt (entries) {
case (cons(?entry, ?rest)) {
if (!option::is_none(lookup_in_mie(e, entry, ns_value))) {
if (saw_value) { dup(e, mie_span(entry), "", name); }
else { saw_value = true; }
}
if (!option::is_none(lookup_in_mie(e, entry, ns_type))) {
if (saw_type) { dup(e, mie_span(entry), "type ", name); }
else { saw_type = true; }
}
if (!option::is_none(lookup_in_mie(e, entry, ns_module))) {
if (saw_mod) { dup(e, mie_span(entry), "module ", name); }
else { saw_mod = true; }
}
entries = *rest;
}
case (nil) { break; }
}
}
}
fn mie_span(&mod_index_entry mie) -> span {
alt (mie) {
case (mie_view_item(?item)) { ret item.span; }
case (mie_item(?item)) { ret item.span; }
case (mie_tag_variant(?item, _)) { ret item.span; }
case (mie_native_item(?item)) { ret item.span; }
}
}
fn check_item(@env e, &@ast::item i) {
alt (i.node) {
case (ast::item_fn(_, ?f, ?ty_params, _, _)) {
check_fn(*e, i.span, f);
ensure_unique(*e, i.span, ty_params, ident_id, "type parameter");
}
case (ast::item_obj(_, ?ob, ?ty_params, _, _)) {
fn field_name(&ast::obj_field field) -> ident {
ret field.ident;
}
ensure_unique(*e, i.span, ob.fields, field_name, "object field");
for (@ast::method m in ob.methods) {
check_fn(*e, m.span, m.node.meth);
}
ensure_unique(*e, i.span, ty_params, ident_id, "type parameter");
}
case (ast::item_tag(_, _, ?ty_params, _, _)) {
ensure_unique(*e, i.span, ty_params, ident_id, "type parameter");
}
case (_) {}
}
}
fn check_arm(@env e, &ast::arm a) {
fn walk_pat(checker ch, &@ast::pat p) {
alt (p.node) {
case (ast::pat_bind(?name, _, _)) {
add_name(ch, p.span, name);
}
case (ast::pat_tag(_, ?children, _)) {
for (@ast::pat child in children) {
walk_pat(ch, child);
}
}
case (_) {}
}
}
walk_pat(checker(*e, "binding"), a.pat);
}
fn check_block(@env e, &ast::block b) {
auto values = checker(*e, "value");
auto types = checker(*e, "type");
auto mods = checker(*e, "module");
for (@ast::stmt st in b.node.stmts) {
alt (st.node) {
case (ast::stmt_decl(?d,_)) {
alt (d.node) {
case (ast::decl_local(?loc)) {
add_name(values, d.span, loc.ident);
}
case (ast::decl_item(?it)) {
alt (it.node) {
case (ast::item_tag(?name, ?variants, _, _, _)) {
add_name(types, it.span, name);
for (ast::variant v in variants) {
add_name(values, v.span, v.node.name);
}
}
case (ast::item_const(?name, _, _, _, _)) {
add_name(values, it.span, name);
}
case (ast::item_fn(?name, _, _, _, _)) {
add_name(values, it.span, name);
}
case (ast::item_mod(?name, _, _)) {
add_name(mods, it.span, name);
}
case (ast::item_native_mod(?name, _, _)) {
add_name(mods, it.span, name);
}
case (ast::item_ty(?name, _, _, _, _)) {
add_name(types, it.span, name);
}
case (ast::item_obj(?name, _, _, _, _)) {
add_name(types, it.span, name);
add_name(values, it.span, name);
}
case (_) { }
}
}
}
}
case (_) {}
}
}
}
fn check_fn(&env e, &span sp, &ast::_fn f) {
fn arg_name(&ast::arg a) -> ident {
ret a.ident;
}
ensure_unique(e, sp, f.decl.inputs, arg_name, "argument");
}
type checker = @rec(mutable vec[ident] seen,
str kind,
session sess);
fn checker(&env e, str kind) -> checker {
let vec[ident] seen = [];
ret @rec(mutable seen=seen, kind=kind, sess=e.sess);
}
fn add_name(&checker ch, &span sp, &ident id) {
for (ident s in ch.seen) {
if (str::eq(s, id)) {
ch.sess.span_err(sp, "duplicate " + ch.kind + " name: " + id);
}
}
vec::push(ch.seen, id);
}
fn ident_id(&ident i) -> ident { ret i; }
fn ensure_unique[T](&env e, &span sp, &vec[T] elts, fn (&T) -> ident id,
&str kind) {
auto ch = checker(e, kind);
for (T elt in elts) {
add_name(ch, sp, id(elt));
}
}
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End: