rustc: Add support of warning on unused imports

Fixes issue #889
This commit is contained in:
Haitao Li 2011-11-10 23:31:55 +08:00 committed by Brian Anderson
parent f705f68121
commit 9bc2f1800d
2 changed files with 54 additions and 9 deletions

View File

@ -50,7 +50,9 @@ tag import_state {
resolving(span); resolving(span);
resolved(option::t<def>, /* value */ resolved(option::t<def>, /* value */
option::t<def>, /* type */ option::t<def>, /* type */
option::t<def>); /* module */ option::t<def>, /* module */
/* used for reporting unused import warning */
ast::ident, codemap::span);
} }
type ext_hash = hashmap<{did: def_id, ident: str, ns: namespace}, def>; type ext_hash = hashmap<{did: def_id, ident: str, ns: namespace}, def>;
@ -106,6 +108,7 @@ type env =
mod_map: hashmap<ast::node_id, @indexed_mod>, mod_map: hashmap<ast::node_id, @indexed_mod>,
ext_map: hashmap<def_id, [ident]>, ext_map: hashmap<def_id, [ident]>,
ext_cache: ext_hash, ext_cache: ext_hash,
mutable used_imports: option::t<[ast::node_id]>,
mutable reported: [{ident: str, sc: scope}], mutable reported: [{ident: str, sc: scope}],
mutable currently_resolving: node_id, mutable currently_resolving: node_id,
sess: session}; sess: session};
@ -127,6 +130,7 @@ fn resolve_crate(sess: session, amap: ast_map::map, crate: @ast::crate) ->
mod_map: new_int_hash::<@indexed_mod>(), mod_map: new_int_hash::<@indexed_mod>(),
ext_map: new_def_hash::<[ident]>(), ext_map: new_def_hash::<[ident]>(),
ext_cache: new_ext_hash(), ext_cache: new_ext_hash(),
mutable used_imports: none,
mutable reported: [], mutable reported: [],
mutable currently_resolving: -1, mutable currently_resolving: -1,
sess: sess}; sess: sess};
@ -134,11 +138,12 @@ fn resolve_crate(sess: session, amap: ast_map::map, crate: @ast::crate) ->
resolve_imports(*e); resolve_imports(*e);
check_for_collisions(e, *crate); check_for_collisions(e, *crate);
check_bad_exports(e); check_bad_exports(e);
e.used_imports = some([]);
resolve_names(e, crate); resolve_names(e, crate);
check_unused_imports(e);
ret {def_map: e.def_map, ext_map: e.ext_map}; ret {def_map: e.def_map, ext_map: e.ext_map};
} }
// Locate all modules and imports and index them, so that the next passes can // Locate all modules and imports and index them, so that the next passes can
// resolve through them. // resolve through them.
fn map_crate(e: @env, c: @ast::crate) { fn map_crate(e: @env, c: @ast::crate) {
@ -239,12 +244,26 @@ fn resolve_imports(e: env) {
todo(node_id, name, path, span, scopes) { todo(node_id, name, path, span, scopes) {
resolve_import(e, local_def(node_id), name, path, span, scopes); resolve_import(e, local_def(node_id), name, path, span, scopes);
} }
resolved(_, _, _) { } resolved(_, _, _, _, _) { }
} }
}; };
e.sess.abort_if_errors(); e.sess.abort_if_errors();
} }
fn check_unused_imports(e: @env) {
let used = option::get(e.used_imports);
e.imports.items {|k, v|
alt v {
resolved(val, ty, md, name, sp) {
if !vec::member(k, used) {
e.sess.span_warn(sp, "unused import " + name);
}
}
_ { }
}
};
}
fn resolve_names(e: @env, c: @ast::crate) { fn resolve_names(e: @env, c: @ast::crate) {
let v = let v =
@{visit_native_item: visit_native_item_with_scope, @{visit_native_item: visit_native_item_with_scope,
@ -439,7 +458,7 @@ fn resolve_import(e: env, defid: ast::def_id, name: ast::ident,
if is_none(val) && is_none(typ) && is_none(md) { if is_none(val) && is_none(typ) && is_none(md) {
unresolved_err(e, sc, sp, name, "import"); unresolved_err(e, sc, sp, name, "import");
} else { } else {
e.imports.insert(id, resolved(val, typ, md)); e.imports.insert(id, resolved(val, typ, md, name, sp));
} }
} }
// This function has cleanup code at the end. Do not return without going // This function has cleanup code at the end. Do not return without going
@ -483,8 +502,8 @@ fn resolve_import(e: env, defid: ast::def_id, name: ast::ident,
// resolved state, to avoid having it reported later as a cyclic // resolved state, to avoid having it reported later as a cyclic
// import // import
alt e.imports.find(defid.node) { alt e.imports.find(defid.node) {
some(resolving(_)) { some(resolving(sp)) {
e.imports.insert(defid.node, resolved(none, none, none)); e.imports.insert(defid.node, resolved(none, none, none, "", sp));
} }
_ { } _ { }
} }
@ -931,7 +950,14 @@ fn lookup_import(e: env, defid: def_id, ns: namespace) -> option::t<def> {
} }
ret none; ret none;
} }
resolved(val, typ, md) { resolved(val, typ, md, _, _) {
alt e.used_imports {
none. { }
some(lst_) {
let lst = lst_ + [defid.node];
e.used_imports = option::some(lst);
}
}
ret alt ns { ns_value. { val } ns_type. { typ } ns_module. { md } }; ret alt ns { ns_value. { val } ns_type. { typ } ns_module. { md } };
} }
} }
@ -1008,7 +1034,7 @@ fn lookup_glob_in_mod(e: env, info: @indexed_mod, sp: span, id: ident,
let val = per_ns(e, info, sp, id, ns_value, dr); let val = per_ns(e, info, sp, id, ns_value, dr);
let typ = per_ns(e, info, sp, id, ns_type, dr); let typ = per_ns(e, info, sp, id, ns_type, dr);
let md = per_ns(e, info, sp, id, ns_module, dr); let md = per_ns(e, info, sp, id, ns_module, dr);
info.glob_imported_names.insert(id, resolved(val, typ, md)); info.glob_imported_names.insert(id, resolved(val, typ, md, id, sp));
} }
alt info.glob_imported_names.get(id) { alt info.glob_imported_names.get(id) {
todo(_, _, _, _, _) { e.sess.bug("Shouldn't've put a todo in."); } todo(_, _, _, _, _) { e.sess.bug("Shouldn't've put a todo in."); }
@ -1016,7 +1042,7 @@ fn lookup_glob_in_mod(e: env, info: @indexed_mod, sp: span, id: ident,
ret none::<def>; //circularity is okay in import globs ret none::<def>; //circularity is okay in import globs
} }
resolved(val, typ, md) { resolved(val, typ, md, _, _) {
ret alt wanted_ns { ret alt wanted_ns {
ns_value. { val } ns_value. { val }
ns_type. { typ } ns_type. { typ }

View File

@ -0,0 +1,19 @@
// error-pattern:unused import
import cal = bar::c::cc;
mod foo {
type point = {x: int, y: int};
type square = {p: point, h: uint, w: uint};
}
mod bar {
mod c {
import foo::point;
import foo::square;
fn cc(p: point) -> str { ret 2 * (p.x + p.y); }
}
}
fn main() {
cal({x:3, y:9});
}