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author
Ariel Ben-Yehuda
committed
kill the fake provided method stubs
this simplifies the code while reducing the size of libcore.rlib by 3.3 MiB (~1M of which is bloat a separate patch of mine removes too), while reducing rustc memory usage on small crates by 18MiB. This also simplifies the code considerably.
1 parent 3e6d724 commit 709ce9f

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14 files changed

+139
-334
lines changed

14 files changed

+139
-334
lines changed

‎src/librustc/metadata/common.rs

+1-1
Original file line numberDiff line numberDiff line change
@@ -180,7 +180,7 @@ pub const tag_mod_child: usize = 0x7b;
180180
pub const tag_misc_info: usize = 0x108; // top-level only
181181
pub const tag_misc_info_crate_items: usize = 0x7c;
182182

183-
pub const tag_item_method_provided_source: usize = 0x7d;
183+
// GAP 0x7d
184184
pub const tag_item_impl_vtables: usize = 0x7e;
185185

186186
pub const tag_impls: usize = 0x109; // top-level only

‎src/librustc/metadata/decoder.rs

+25-30
Original file line numberDiff line numberDiff line change
@@ -187,12 +187,6 @@ fn item_def_id(d: rbml::Doc, cdata: Cmd) -> DefId {
187187
translated_def_id(cdata, reader::get_doc(d, tag_def_id))
188188
}
189189

190-
fn get_provided_source(d: rbml::Doc, cdata: Cmd) -> Option<DefId> {
191-
reader::maybe_get_doc(d, tag_item_method_provided_source).map(|doc| {
192-
translated_def_id(cdata, doc)
193-
})
194-
}
195-
196190
fn reexports<'a>(d: rbml::Doc<'a>) -> reader::TaggedDocsIterator<'a> {
197191
reader::tagged_docs(d, tag_items_data_item_reexport)
198192
}
@@ -276,11 +270,14 @@ fn item_to_def_like(cdata: Cmd, item: rbml::Doc, did: DefId) -> DefLike {
276270
match fam {
277271
Constant => {
278272
// Check whether we have an associated const item.
279-
if item_sort(item) == Some('C') {
280-
DlDef(def::DefAssociatedConst(did))
281-
} else {
282-
// Regular const item.
283-
DlDef(def::DefConst(did))
273+
match item_sort(item) {
274+
Some('C') | Some('c') => {
275+
DlDef(def::DefAssociatedConst(did))
276+
}
277+
_ => {
278+
// Regular const item.
279+
DlDef(def::DefConst(did))
280+
}
284281
}
285282
}
286283
ImmStatic => DlDef(def::DefStatic(did, false)),
@@ -818,7 +815,7 @@ pub fn get_impl_items(cdata: Cmd, impl_id: ast::NodeId)
818815
reader::tagged_docs(cdata.lookup_item(impl_id), tag_item_impl_item).map(|doc| {
819816
let def_id = item_def_id(doc, cdata);
820817
match item_sort(doc) {
821-
Some('C') => ty::ConstTraitItemId(def_id),
818+
Some('C') | Some('c') => ty::ConstTraitItemId(def_id),
822819
Some('r') | Some('p') => ty::MethodTraitItemId(def_id),
823820
Some('t') => ty::TypeTraitItemId(def_id),
824821
_ => panic!("unknown impl item sort"),
@@ -864,24 +861,22 @@ pub fn get_impl_or_trait_item<'tcx>(intr: Rc<IdentInterner>,
864861
let vis = item_visibility(item_doc);
865862

866863
match item_sort(item_doc) {
867-
Some('C') => {
864+
sort @ Some('C') | sort @ Some('c') => {
868865
let ty = doc_type(item_doc, tcx, cdata);
869-
let default = get_provided_source(item_doc, cdata);
870866
ty::ConstTraitItem(Rc::new(ty::AssociatedConst {
871867
name: name,
872868
ty: ty,
873869
vis: vis,
874870
def_id: def_id,
875871
container: container,
876-
default: default,
872+
has_value: sort == Some('C')
877873
}))
878874
}
879875
Some('r') | Some('p') => {
880876
let generics = doc_generics(item_doc, tcx, cdata, tag_method_ty_generics);
881877
let predicates = doc_predicates(item_doc, tcx, cdata, tag_method_ty_generics);
882878
let fty = doc_method_fty(item_doc, tcx, cdata);
883879
let explicit_self = get_explicit_self(item_doc);
884-
let provided_source = get_provided_source(item_doc, cdata);
885880

886881
ty::MethodTraitItem(Rc::new(ty::Method::new(name,
887882
generics,
@@ -890,8 +885,7 @@ pub fn get_impl_or_trait_item<'tcx>(intr: Rc<IdentInterner>,
890885
explicit_self,
891886
vis,
892887
def_id,
893-
container,
894-
provided_source)))
888+
container)))
895889
}
896890
Some('t') => {
897891
let ty = maybe_doc_type(item_doc, tcx, cdata);
@@ -913,7 +907,7 @@ pub fn get_trait_item_def_ids(cdata: Cmd, id: ast::NodeId)
913907
reader::tagged_docs(item, tag_item_trait_item).map(|mth| {
914908
let def_id = item_def_id(mth, cdata);
915909
match item_sort(mth) {
916-
Some('C') => ty::ConstTraitItemId(def_id),
910+
Some('C') | Some('c') => ty::ConstTraitItemId(def_id),
917911
Some('r') | Some('p') => ty::MethodTraitItemId(def_id),
918912
Some('t') => ty::TypeTraitItemId(def_id),
919913
_ => panic!("unknown trait item sort"),
@@ -967,18 +961,19 @@ pub fn get_associated_consts<'tcx>(intr: Rc<IdentInterner>,
967961
let did = item_def_id(ac_id, cdata);
968962
let ac_doc = cdata.lookup_item(did.node);
969963

970-
if item_sort(ac_doc) == Some('C') {
971-
let trait_item = get_impl_or_trait_item(intr.clone(),
972-
cdata,
973-
did.node,
974-
tcx);
975-
if let ty::ConstTraitItem(ref ac) = trait_item {
976-
Some((*ac).clone())
977-
} else {
978-
None
964+
match item_sort(ac_doc) {
965+
Some('C') | Some('c') => {
966+
let trait_item = get_impl_or_trait_item(intr.clone(),
967+
cdata,
968+
did.node,
969+
tcx);
970+
if let ty::ConstTraitItem(ref ac) = trait_item {
971+
Some((*ac).clone())
972+
} else {
973+
None
974+
}
979975
}
980-
} else {
981-
None
976+
_ => None
982977
}
983978
})
984979
}).collect()

‎src/librustc/metadata/encoder.rs

+7-13
Original file line numberDiff line numberDiff line change
@@ -609,13 +609,6 @@ fn encode_parent_sort(rbml_w: &mut Encoder, sort: char) {
609609
rbml_w.wr_tagged_u8(tag_item_trait_parent_sort, sort as u8);
610610
}
611611

612-
fn encode_provided_source(rbml_w: &mut Encoder,
613-
source_opt: Option<DefId>) {
614-
if let Some(source) = source_opt {
615-
rbml_w.wr_tagged_u64(tag_item_method_provided_source, def_to_u64(source));
616-
}
617-
}
618-
619612
fn encode_field<'a, 'tcx>(ecx: &EncodeContext<'a, 'tcx>,
620613
rbml_w: &mut Encoder,
621614
field: ty::FieldDef<'tcx>,
@@ -776,7 +769,6 @@ fn encode_method_ty_fields<'a, 'tcx>(ecx: &EncodeContext<'a, 'tcx>,
776769
}
777770
_ => encode_family(rbml_w, METHOD_FAMILY)
778771
}
779-
encode_provided_source(rbml_w, method_ty.provided_source);
780772
}
781773

782774
fn encode_info_for_associated_const(ecx: &EncodeContext,
@@ -795,7 +787,6 @@ fn encode_info_for_associated_const(ecx: &EncodeContext,
795787
encode_name(rbml_w, associated_const.name);
796788
encode_visibility(rbml_w, associated_const.vis);
797789
encode_family(rbml_w, 'C');
798-
encode_provided_source(rbml_w, associated_const.default);
799790

800791
encode_parent_item(rbml_w, DefId::local(parent_id));
801792
encode_item_sort(rbml_w, 'C');
@@ -1367,13 +1358,10 @@ fn encode_info_for_item(ecx: &EncodeContext,
13671358
encode_def_id(rbml_w, associated_const.def_id);
13681359
encode_visibility(rbml_w, associated_const.vis);
13691360

1370-
encode_provided_source(rbml_w, associated_const.default);
1371-
13721361
let elem = ast_map::PathName(associated_const.name);
13731362
encode_path(rbml_w,
13741363
path.clone().chain(Some(elem)));
13751364

1376-
encode_item_sort(rbml_w, 'C');
13771365
encode_family(rbml_w, 'C');
13781366

13791367
encode_bounds_and_type_for_item(rbml_w, ecx,
@@ -1429,7 +1417,13 @@ fn encode_info_for_item(ecx: &EncodeContext,
14291417
let trait_item = &*ms[i];
14301418
encode_attributes(rbml_w, &trait_item.attrs);
14311419
match trait_item.node {
1432-
hir::ConstTraitItem(_, _) => {
1420+
hir::ConstTraitItem(_, ref default) => {
1421+
if default.is_some() {
1422+
encode_item_sort(rbml_w, 'C');
1423+
} else {
1424+
encode_item_sort(rbml_w, 'c');
1425+
}
1426+
14331427
encode_inlined_item(ecx, rbml_w,
14341428
InlinedItemRef::TraitItem(def_id, trait_item));
14351429
}

‎src/librustc/middle/ty/context.rs

-3
Original file line numberDiff line numberDiff line change
@@ -235,8 +235,6 @@ pub struct ctxt<'tcx> {
235235
pub ty_param_defs: RefCell<NodeMap<ty::TypeParameterDef<'tcx>>>,
236236
pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
237237
pub lang_items: middle::lang_items::LanguageItems,
238-
/// A mapping of fake provided method def_ids to the default implementation
239-
pub provided_method_sources: RefCell<DefIdMap<DefId>>,
240238

241239
/// Maps from def-id of a type or region parameter to its
242240
/// (inferred) variance.
@@ -471,7 +469,6 @@ impl<'tcx> ctxt<'tcx> {
471469
ty_param_defs: RefCell::new(NodeMap()),
472470
normalized_cache: RefCell::new(FnvHashMap()),
473471
lang_items: lang_items,
474-
provided_method_sources: RefCell::new(DefIdMap()),
475472
inherent_impls: RefCell::new(DefIdMap()),
476473
impl_items: RefCell::new(DefIdMap()),
477474
used_unsafe: RefCell::new(NodeSet()),

‎src/librustc/middle/ty/mod.rs

+5-21
Original file line numberDiff line numberDiff line change
@@ -235,9 +235,6 @@ pub struct Method<'tcx> {
235235
pub vis: hir::Visibility,
236236
pub def_id: DefId,
237237
pub container: ImplOrTraitItemContainer,
238-
239-
// If this method is provided, we need to know where it came from
240-
pub provided_source: Option<DefId>
241238
}
242239

243240
impl<'tcx> Method<'tcx> {
@@ -248,8 +245,7 @@ impl<'tcx> Method<'tcx> {
248245
explicit_self: ExplicitSelfCategory,
249246
vis: hir::Visibility,
250247
def_id: DefId,
251-
container: ImplOrTraitItemContainer,
252-
provided_source: Option<DefId>)
248+
container: ImplOrTraitItemContainer)
253249
-> Method<'tcx> {
254250
Method {
255251
name: name,
@@ -260,7 +256,6 @@ impl<'tcx> Method<'tcx> {
260256
vis: vis,
261257
def_id: def_id,
262258
container: container,
263-
provided_source: provided_source
264259
}
265260
}
266261

@@ -293,7 +288,7 @@ pub struct AssociatedConst<'tcx> {
293288
pub vis: hir::Visibility,
294289
pub def_id: DefId,
295290
pub container: ImplOrTraitItemContainer,
296-
pub default: Option<DefId>,
291+
pub has_value: bool
297292
}
298293

299294
#[derive(Clone, Copy, Debug)]
@@ -2105,10 +2100,6 @@ impl<'tcx> ctxt<'tcx> {
21052100
}
21062101
}
21072102

2108-
pub fn provided_source(&self, id: DefId) -> Option<DefId> {
2109-
self.provided_method_sources.borrow().get(&id).cloned()
2110-
}
2111-
21122103
pub fn provided_trait_methods(&self, id: DefId) -> Vec<Rc<Method<'tcx>>> {
21132104
if id.is_local() {
21142105
if let ItemTrait(_, _, _, ref ms) = self.map.expect_item(id.node).node {
@@ -2477,16 +2468,9 @@ impl<'tcx> ctxt<'tcx> {
24772468
// the map. This is a bit unfortunate.
24782469
for impl_item_def_id in &impl_items {
24792470
let method_def_id = impl_item_def_id.def_id();
2480-
match self.impl_or_trait_item(method_def_id) {
2481-
MethodTraitItem(method) => {
2482-
if let Some(source) = method.provided_source {
2483-
self.provided_method_sources
2484-
.borrow_mut()
2485-
.insert(method_def_id, source);
2486-
}
2487-
}
2488-
_ => {}
2489-
}
2471+
// load impl items eagerly for convenience
2472+
// FIXME: we may want to load these lazily
2473+
self.impl_or_trait_item(method_def_id);
24902474
}
24912475

24922476
// Store the implementation info.

‎src/librustc/middle/ty/util.rs

+54-1
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@ use back::svh::Svh;
1414
use middle::const_eval::{self, ConstVal, ErrKind};
1515
use middle::const_eval::EvalHint::UncheckedExprHint;
1616
use middle::def_id::DefId;
17-
use middle::subst;
17+
use middle::subst::{self, Subst, Substs};
1818
use middle::infer;
1919
use middle::pat_util;
2020
use middle::traits;
@@ -26,6 +26,7 @@ use util::num::ToPrimitive;
2626

2727
use std::cmp;
2828
use std::hash::{Hash, SipHasher, Hasher};
29+
use std::rc::Rc;
2930
use syntax::ast::{self, Name};
3031
use syntax::attr::{self, AttrMetaMethods, SignedInt, UnsignedInt};
3132
use syntax::codemap::Span;
@@ -646,6 +647,58 @@ impl<'tcx> ty::ctxt<'tcx> {
646647
}
647648
}
648649

650+
#[derive(Debug)]
651+
pub struct ImplMethod<'tcx> {
652+
pub method: Rc<ty::Method<'tcx>>,
653+
pub substs: Substs<'tcx>,
654+
pub is_provided: bool
655+
}
656+
657+
impl<'tcx> ty::ctxt<'tcx> {
658+
#[inline(never)] // is this perfy enough?
659+
pub fn get_impl_method(&self,
660+
impl_def_id: DefId,
661+
substs: Substs<'tcx>,
662+
name: Name)
663+
-> ImplMethod<'tcx>
664+
{
665+
// there don't seem to be nicer accessors to these:
666+
let impl_or_trait_items_map = self.impl_or_trait_items.borrow();
667+
668+
for impl_item in &self.impl_items.borrow()[&impl_def_id] {
669+
if let ty::MethodTraitItem(ref meth) =
670+
impl_or_trait_items_map[&impl_item.def_id()] {
671+
if meth.name == name {
672+
return ImplMethod {
673+
method: meth.clone(),
674+
substs: substs,
675+
is_provided: false
676+
}
677+
}
678+
}
679+
}
680+
681+
// It is not in the impl - get the default from the trait.
682+
let trait_ref = self.impl_trait_ref(impl_def_id).unwrap();
683+
for trait_item in self.trait_items(trait_ref.def_id).iter() {
684+
if let &ty::MethodTraitItem(ref meth) = trait_item {
685+
if meth.name == name {
686+
let impl_to_trait_substs = self
687+
.make_substs_for_receiver_types(&trait_ref, meth);
688+
return ImplMethod {
689+
method: meth.clone(),
690+
substs: impl_to_trait_substs.subst(self, &substs),
691+
is_provided: true
692+
}
693+
}
694+
}
695+
}
696+
697+
self.sess.bug(&format!("method {:?} not found in {:?}",
698+
name, impl_def_id))
699+
}
700+
}
701+
649702
impl<'tcx> ty::TyS<'tcx> {
650703
fn impls_bound<'a>(&'tcx self, param_env: &ParameterEnvironment<'a,'tcx>,
651704
bound: ty::BuiltinBound,

‎src/librustc_privacy/lib.rs

-13
Original file line numberDiff line numberDiff line change
@@ -725,19 +725,6 @@ impl<'a, 'tcx> PrivacyVisitor<'a, 'tcx> {
725725
span: Span,
726726
method_id: DefId,
727727
name: ast::Name) {
728-
// If the method is a default method, we need to use the def_id of
729-
// the default implementation.
730-
let method_id = match self.tcx.impl_or_trait_item(method_id) {
731-
ty::MethodTraitItem(method_type) => {
732-
method_type.provided_source.unwrap_or(method_id)
733-
}
734-
_ => {
735-
self.tcx.sess
736-
.span_bug(span,
737-
"got non-method item in check_static_method")
738-
}
739-
};
740-
741728
self.report_error(self.ensure_public(span,
742729
method_id,
743730
None,

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