Skip to content

Commit

Permalink
Improved the mapping handling. Closes rust-lang#17.
Browse files Browse the repository at this point in the history 
This uses the newly added crate tracking to make errors more
discoverable and code more obvious in it's current behaviour.
  • Loading branch information
@ibabushkin
ibabushkin committed Jul 23, 2017
1 parent 363a56b commit d594407
Show file tree
Hide file tree
Showing 3 changed files with 66 additions and 42 deletions.
60 changes: 49 additions & 11 deletions src/semcheck/mapping.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ use rustc::hir::def::{Def, Export};
use rustc::hir::def_id::{CrateNum, DefId};
use rustc::ty::TypeParameterDef;

use std::collections::{BTreeSet, HashMap, VecDeque};
use std::collections::{BTreeSet, HashMap, HashSet, VecDeque};

use syntax::ast::Name;

Expand All @@ -23,6 +23,8 @@ pub struct IdMapping {
new_crate: CrateNum,
/// Toplevel items' old `DefId` mapped to old and new `Def`.
toplevel_mapping: HashMap<DefId, (Def, Def)>,
/// The set of toplevel items that have been removed.
removed_items: HashSet<DefId>,
/// Trait items' old `DefId` mapped to old and new `Def`.
trait_item_mapping: HashMap<DefId, (Def, Def, DefId)>,
/// Other items' old `DefId` mapped to new `DefId`.
Expand All @@ -39,6 +41,7 @@ impl IdMapping {
old_crate: old_crate,
new_crate: new_crate,
toplevel_mapping: HashMap::new(),
removed_items: HashSet::new(),
trait_item_mapping: HashMap::new(),
internal_mapping: HashMap::new(),
child_mapping: HashMap::new(),
Expand All @@ -48,19 +51,30 @@ impl IdMapping {

/// Register two exports representing the same item across versions.
pub fn add_export(&mut self, old: Def, new: Def) -> bool {
if self.toplevel_mapping.contains_key(&old.def_id()) {
let old_def_id = old.def_id();

if !self.in_old_crate(old_def_id) || self.toplevel_mapping.contains_key(&old_def_id) {
return false;
}

self.toplevel_mapping
.insert(old.def_id(), (old, new));
.insert(old_def_id, (old, new));

true
}

/// Register that an old item has no corresponding new item.
pub fn add_removal(&mut self, old: DefId) {
self.removed_items.insert(old);
}

/// Add any trait item's old and new `DefId`s.
pub fn add_trait_item(&mut self, old: Def, new: Def, trait_def_id: DefId) {
self.trait_item_mapping.insert(old.def_id(), (old, new, trait_def_id));
let old_def_id = old.def_id();

assert!(self.in_old_crate(old_def_id));

self.trait_item_mapping.insert(old_def_id, (old, new, trait_def_id));
}

/// Add any other item's old and new `DefId`s.
Expand All @@ -70,12 +84,14 @@ impl IdMapping {
old,
self.internal_mapping[&old],
new);
assert!(self.in_old_crate(old));

self.internal_mapping.insert(old, new);
}

/// Add any other item's old and new `DefId`s, together with a parent entry.
pub fn add_subitem(&mut self, parent: DefId, old: DefId, new: DefId) {
// NB: we rely on the assers in `add_internal_item` here.
self.add_internal_item(old, new);
self.child_mapping
.entry(parent)
Expand All @@ -85,29 +101,49 @@ impl IdMapping {

/// Record that a `DefId` represents a new type parameter.
pub fn add_type_param(&mut self, new: TypeParameterDef) {
assert!(self.in_new_crate(new.def_id));
self.type_params.insert(new.def_id, new);
}

/// Get the type parameter represented by a given `DefId`.
pub fn get_type_param(&self, def_id: &DefId) -> TypeParameterDef {
self.type_params[def_id]
pub fn get_type_param(&self, did: &DefId) -> TypeParameterDef {
self.type_params[did]
}

/// Check whether a `DefId` represents a newly added defaulted type parameter.
pub fn is_defaulted_type_param(&self, new: &DefId) -> bool {
// TODO?
self.type_params
.get(new)
.map_or(false, |def| def.has_default)
}

/// Get the new `DefId` associated with the given old one.
pub fn get_new_id(&self, old: DefId) -> DefId {
if let Some(new) = self.toplevel_mapping.get(&old) {
new.1.def_id()
} else if let Some(new) = self.trait_item_mapping.get(&old) {
new.1.def_id()
assert!(!self.in_new_crate(old));

if self.in_old_crate(old) && !self.removed_items.contains(&old) {
if let Some(new) = self.toplevel_mapping.get(&old) {
new.1.def_id()
} else if let Some(new) = self.trait_item_mapping.get(&old) {
new.1.def_id()
} else {
self.internal_mapping[&old]
}
} else {
old
}
}

/// Get the new `DefId` associated with the given old one, respecting possibly removed
/// traits that are a parent of the given `DefId`.
pub fn get_new_trait_item_id(&self, old: DefId, trait_id: DefId) -> DefId {
assert!(!self.in_new_crate(trait_id));

if !self.removed_items.contains(&trait_id) {
self.get_new_id(old)
} else {
self.internal_mapping[&old]
old
}
}

Expand Down Expand Up @@ -148,10 +184,12 @@ impl IdMapping {
.map(|m| m.iter().map(move |old| (*old, self.internal_mapping[old])))
}

/// Check whether a `DefId` belongs to an item in the old crate.
pub fn in_old_crate(&self, did: DefId) -> bool {
self.old_crate == did.krate
}

/// Check whether a `DefId` belongs to an item in the new crate.
pub fn in_new_crate(&self, did: DefId) -> bool {
self.new_crate == did.krate
}
Expand Down
17 changes: 8 additions & 9 deletions src/semcheck/mismatch.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,14 +111,12 @@ impl<'a, 'gcx, 'tcx> TypeRelation<'a, 'gcx, 'tcx> for Mismatch<'a, 'gcx, 'tcx> {
.collect();

for field in a_adt.all_fields().filter(|f| f.vis == Public) {
if self.id_mapping.contains_id(field.did) {
let a_field_ty = field.ty(self.tcx, a_substs);
let b_field_ty =
b_fields[&self.id_mapping.get_new_id(field.did)]
.ty(self.tcx, b_substs);

let _ = self.relate(&a_field_ty, &b_field_ty)?;
}
let a_field_ty = field.ty(self.tcx, a_substs);
let b_field_ty =
b_fields[&self.id_mapping.get_new_id(field.did)]
.ty(self.tcx, b_substs);

let _ = self.relate(&a_field_ty, &b_field_ty)?;
}

Some((a_def.did, b_def.did))
Expand Down Expand Up @@ -188,7 +186,8 @@ impl<'a, 'gcx, 'tcx> TypeRelation<'a, 'gcx, 'tcx> for Mismatch<'a, 'gcx, 'tcx> {
};

if let Some((old_def_id, new_def_id)) = matching {
if !self.id_mapping.contains_id(old_def_id) && self.id_mapping.in_old_crate(old_def_id) {
if !self.id_mapping.contains_id(old_def_id) &&
self.id_mapping.in_old_crate(old_def_id) {
self.id_mapping.add_internal_item(old_def_id, new_def_id);
self.item_queue.push_back((old_def_id, new_def_id));
}
Expand Down
31 changes: 9 additions & 22 deletions src/semcheck/traverse.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -261,6 +261,7 @@ fn diff_structure<'a, 'tcx>(changes: &mut ChangeSet,
changes.new_path_change(n_def_id, o.ident.name, tcx.def_span(n_def_id));
changes.add_path_removal(n_def_id, o.span);
} else {
id_mapping.add_removal(o_def_id);
changes.new_path_change(o_def_id, o.ident.name, tcx.def_span(o_def_id));
changes.add_path_removal(o_def_id, o.span);
}
Expand Down Expand Up @@ -732,7 +733,7 @@ fn fold_to_new<'a, 'tcx, T>(id_mapping: &IdMapping,

old.fold_with(&mut BottomUpFolder { tcx: tcx, fldop: |ty| {
match ty.sty {
TyAdt(&AdtDef { ref did, .. }, substs) if id_mapping.contains_id(*did) => {
TyAdt(&AdtDef { ref did, .. }, substs) if id_mapping.in_old_crate(*did) => {
let new_def_id = id_mapping.get_new_id(*did);
let new_adt = tcx.adt_def(new_def_id);
tcx.mk_adt(new_adt, substs)
Expand All @@ -747,23 +748,15 @@ fn fold_to_new<'a, 'tcx, T>(id_mapping: &IdMapping,
let new_preds = tcx.mk_existential_predicates(preds.iter().map(|p| {
match *p.skip_binder() {
Trait(ExistentialTraitRef { def_id: did, substs }) => {
let new_def_id = if id_mapping.contains_id(did) {
id_mapping.get_new_id(did)
} else {
did
};
let new_def_id = id_mapping.get_new_id(did);

Trait(ExistentialTraitRef {
def_id: new_def_id,
substs: substs
})
},
Projection(ExistentialProjection { item_def_id, substs, ty }) => {
let new_def_id = if id_mapping.contains_id(item_def_id) {
id_mapping.get_new_id(item_def_id)
} else {
item_def_id
};
let new_def_id = id_mapping.get_new_id(item_def_id);

Projection(ExistentialProjection {
item_def_id: new_def_id,
Expand All @@ -772,23 +765,17 @@ fn fold_to_new<'a, 'tcx, T>(id_mapping: &IdMapping,
})
},
AutoTrait(did) => {
if id_mapping.contains_id(did) {
AutoTrait(id_mapping.get_new_id(did))
} else {
AutoTrait(did)
}
AutoTrait(id_mapping.get_new_id(did))
},
}
}));

tcx.mk_dynamic(Binder(new_preds), region)
},
TyProjection(proj) => {
let new_def_id = if id_mapping.contains_id(proj.item_def_id) {
id_mapping.get_new_id(proj.item_def_id)
} else {
proj.item_def_id
};
let trait_def_id = tcx.associated_item(proj.item_def_id).container.id();
let new_def_id =
id_mapping.get_new_trait_item_id(proj.item_def_id, trait_def_id);

tcx.mk_projection(new_def_id, proj.substs)
},
Expand All @@ -798,7 +785,7 @@ fn fold_to_new<'a, 'tcx, T>(id_mapping: &IdMapping,
TyParam(param) => {
if param.idx != 0 { // `Self` is special
let old_did = index_map[&param.idx];
if id_mapping.contains_id(old_did) {
if id_mapping.in_old_crate(old_did) {
let new_def_id = id_mapping.get_new_id(old_did);
tcx.mk_param_from_def(&id_mapping.get_type_param(&new_def_id))
} else {
Expand Down

0 comments on commit d594407

Please sign in to comment.