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use self::Fragment::*;
use borrowck::InteriorKind::{InteriorField, InteriorElement};
use borrowck::LoanPath;
use borrowck::LoanPathKind::{LpVar, LpUpvar, LpDowncast, LpExtend};
use borrowck::LoanPathElem::{LpDeref, LpInterior};
use borrowck::move_data::InvalidMovePathIndex;
use borrowck::move_data::{MoveData, MovePathIndex};
use rustc::middle::ty;
use rustc::middle::mem_categorization as mc;
use rustc::util::ppaux::{Repr, UserString};
use std::mem;
use std::rc::Rc;
use syntax::ast;
use syntax::attr::AttrMetaMethods;
use syntax::codemap::Span;
#[derive(PartialEq, Eq, PartialOrd, Ord)]
enum Fragment {
Just(MovePathIndex),
AllButOneFrom(MovePathIndex),
}
impl Fragment {
fn loan_path_repr<'tcx>(&self, move_data: &MoveData<'tcx>, tcx: &ty::ctxt<'tcx>) -> String {
let repr = |mpi| move_data.path_loan_path(mpi).repr(tcx);
match *self {
Just(mpi) => repr(mpi),
AllButOneFrom(mpi) => format!("$(allbutone {})", repr(mpi)),
}
}
fn loan_path_user_string<'tcx>(&self,
move_data: &MoveData<'tcx>,
tcx: &ty::ctxt<'tcx>) -> String {
let user_string = |mpi| move_data.path_loan_path(mpi).user_string(tcx);
match *self {
Just(mpi) => user_string(mpi),
AllButOneFrom(mpi) => format!("$(allbutone {})", user_string(mpi)),
}
}
}
pub struct FragmentSets {
moved_leaf_paths: Vec<MovePathIndex>,
assigned_leaf_paths: Vec<MovePathIndex>,
parents_of_fragments: Vec<MovePathIndex>,
unmoved_fragments: Vec<Fragment>,
}
impl FragmentSets {
pub fn new() -> FragmentSets {
FragmentSets {
unmoved_fragments: Vec::new(),
moved_leaf_paths: Vec::new(),
assigned_leaf_paths: Vec::new(),
parents_of_fragments: Vec::new(),
}
}
pub fn add_move(&mut self, path_index: MovePathIndex) {
self.moved_leaf_paths.push(path_index);
}
pub fn add_assignment(&mut self, path_index: MovePathIndex) {
self.assigned_leaf_paths.push(path_index);
}
}
pub fn instrument_move_fragments<'tcx>(this: &MoveData<'tcx>,
tcx: &ty::ctxt<'tcx>,
sp: Span,
id: ast::NodeId) {
let span_err = tcx.map.attrs(id).iter()
.any(|a| a.check_name("rustc_move_fragments"));
let print = tcx.sess.opts.debugging_opts.print_move_fragments;
if !span_err && !print { return; }
let instrument_all_paths = |kind, vec_rc: &Vec<MovePathIndex>| {
for (i, mpi) in vec_rc.iter().enumerate() {
let render = || this.path_loan_path(*mpi).user_string(tcx);
if span_err {
tcx.sess.span_err(sp, &format!("{}: `{}`", kind, render()));
}
if print {
println!("id:{} {}[{}] `{}`", id, kind, i, render());
}
}
};
let instrument_all_fragments = |kind, vec_rc: &Vec<Fragment>| {
for (i, f) in vec_rc.iter().enumerate() {
let render = || f.loan_path_user_string(this, tcx);
if span_err {
tcx.sess.span_err(sp, &format!("{}: `{}`", kind, render()));
}
if print {
println!("id:{} {}[{}] `{}`", id, kind, i, render());
}
}
};
let fragments = this.fragments.borrow();
instrument_all_paths("moved_leaf_path", &fragments.moved_leaf_paths);
instrument_all_fragments("unmoved_fragment", &fragments.unmoved_fragments);
instrument_all_paths("parent_of_fragments", &fragments.parents_of_fragments);
instrument_all_paths("assigned_leaf_path", &fragments.assigned_leaf_paths);
}
pub fn fixup_fragment_sets<'tcx>(this: &MoveData<'tcx>, tcx: &ty::ctxt<'tcx>) {
let mut fragments = this.fragments.borrow_mut();
let mut unmoved = mem::replace(&mut fragments.unmoved_fragments, vec![]);
let mut parents = mem::replace(&mut fragments.parents_of_fragments, vec![]);
let mut moved = mem::replace(&mut fragments.moved_leaf_paths, vec![]);
let mut assigned = mem::replace(&mut fragments.assigned_leaf_paths, vec![]);
let path_lps = |mpis: &[MovePathIndex]| -> Vec<String> {
mpis.iter().map(|mpi| this.path_loan_path(*mpi).repr(tcx)).collect()
};
let frag_lps = |fs: &[Fragment]| -> Vec<String> {
fs.iter().map(|f| f.loan_path_repr(this, tcx)).collect()
};
moved.sort();
moved.dedup();
debug!("fragments 1 moved: {:?}", path_lps(&moved[..]));
assigned.sort();
assigned.dedup();
debug!("fragments 1 assigned: {:?}", path_lps(&assigned[..]));
for m in &moved {
let mut p = this.path_parent(*m);
while p != InvalidMovePathIndex {
parents.push(p);
p = this.path_parent(p);
}
}
for a in &assigned {
let mut p = this.path_parent(*a);
while p != InvalidMovePathIndex {
parents.push(p);
p = this.path_parent(p);
}
}
parents.sort();
parents.dedup();
debug!("fragments 2 parents: {:?}", path_lps(&parents[..]));
moved.retain(|f| non_member(*f, &parents[..]));
debug!("fragments 3 moved: {:?}", path_lps(&moved[..]));
assigned.retain(|f| non_member(*f, &parents[..]));
debug!("fragments 3 assigned: {:?}", path_lps(&assigned[..]));
for m in &moved {
let lp = this.path_loan_path(*m);
add_fragment_siblings(this, tcx, &mut unmoved, lp, None);
}
for a in &assigned {
let lp = this.path_loan_path(*a);
add_fragment_siblings(this, tcx, &mut unmoved, lp, None);
}
for p in &parents {
let lp = this.path_loan_path(*p);
add_fragment_siblings(this, tcx, &mut unmoved, lp, None);
}
unmoved.sort();
unmoved.dedup();
debug!("fragments 4 unmoved: {:?}", frag_lps(&unmoved[..]));
unmoved.retain(|f| match *f {
AllButOneFrom(_) => true,
Just(mpi) => non_member(mpi, &parents[..]) &&
non_member(mpi, &moved[..]) &&
non_member(mpi, &assigned[..])
});
debug!("fragments 5 unmoved: {:?}", frag_lps(&unmoved[..]));
fragments.unmoved_fragments = unmoved;
fragments.parents_of_fragments = parents;
fragments.moved_leaf_paths = moved;
fragments.assigned_leaf_paths = assigned;
return;
fn non_member(elem: MovePathIndex, set: &[MovePathIndex]) -> bool {
match set.binary_search(&elem) {
Ok(_) => false,
Err(_) => true,
}
}
}
fn add_fragment_siblings<'tcx>(this: &MoveData<'tcx>,
tcx: &ty::ctxt<'tcx>,
gathered_fragments: &mut Vec<Fragment>,
lp: Rc<LoanPath<'tcx>>,
origin_id: Option<ast::NodeId>) {
match lp.kind {
LpVar(_) | LpUpvar(..) => {}
LpDowncast(ref loan_parent, _) => {
add_fragment_siblings(this, tcx, gathered_fragments, loan_parent.clone(), origin_id);
}
LpExtend(ref loan_parent, _, LpDeref(mc::Unique)) => {
add_fragment_siblings(this, tcx, gathered_fragments, loan_parent.clone(), origin_id);
}
LpExtend(_, _, LpDeref(mc::UnsafePtr(..))) |
LpExtend(_, _, LpDeref(mc::Implicit(..))) |
LpExtend(_, _, LpDeref(mc::BorrowedPtr(..))) => {}
LpExtend(_, _, LpInterior(InteriorElement(..))) => {
let mp = this.move_path(tcx, lp.clone());
gathered_fragments.push(AllButOneFrom(mp));
}
LpExtend(ref loan_parent, mc,
LpInterior(InteriorField(ref field_name))) => {
let enum_variant_info = match loan_parent.kind {
LpDowncast(ref loan_parent_2, variant_def_id) =>
Some((variant_def_id, loan_parent_2.clone())),
LpExtend(..) | LpVar(..) | LpUpvar(..) =>
None,
};
add_fragment_siblings_for_extension(
this,
tcx,
gathered_fragments,
loan_parent, mc, field_name, &lp, origin_id, enum_variant_info);
}
}
}
fn add_fragment_siblings_for_extension<'tcx>(this: &MoveData<'tcx>,
tcx: &ty::ctxt<'tcx>,
gathered_fragments: &mut Vec<Fragment>,
parent_lp: &Rc<LoanPath<'tcx>>,
mc: mc::MutabilityCategory,
origin_field_name: &mc::FieldName,
origin_lp: &Rc<LoanPath<'tcx>>,
origin_id: Option<ast::NodeId>,
enum_variant_info: Option<(ast::DefId,
Rc<LoanPath<'tcx>>)>) {
let parent_ty = parent_lp.to_type();
let mut add_fragment_sibling_local = |field_name, variant_did| {
add_fragment_sibling_core(
this, tcx, gathered_fragments, parent_lp.clone(), mc, field_name, origin_lp,
variant_did);
};
match (&parent_ty.sty, enum_variant_info) {
(&ty::ty_tup(ref v), None) => {
let tuple_idx = match *origin_field_name {
mc::PositionalField(tuple_idx) => tuple_idx,
mc::NamedField(_) =>
panic!("tuple type {} should not have named fields.",
parent_ty.repr(tcx)),
};
let tuple_len = v.len();
for i in 0..tuple_len {
if i == tuple_idx { continue }
let field_name = mc::PositionalField(i);
add_fragment_sibling_local(field_name, None);
}
}
(&ty::ty_struct(def_id, ref _substs), None) => {
let fields = ty::lookup_struct_fields(tcx, def_id);
match *origin_field_name {
mc::NamedField(ast_name) => {
for f in &fields {
if f.name == ast_name {
continue;
}
let field_name = mc::NamedField(f.name);
add_fragment_sibling_local(field_name, None);
}
}
mc::PositionalField(tuple_idx) => {
for (i, _f) in fields.iter().enumerate() {
if i == tuple_idx {
continue
}
let field_name = mc::PositionalField(i);
add_fragment_sibling_local(field_name, None);
}
}
}
}
(&ty::ty_enum(enum_def_id, substs), ref enum_variant_info) => {
let variant_info = {
let mut variants = ty::substd_enum_variants(tcx, enum_def_id, substs);
match *enum_variant_info {
Some((variant_def_id, ref _lp2)) =>
variants.iter()
.find(|variant| variant.id == variant_def_id)
.expect("enum_variant_with_id(): no variant exists with that ID")
.clone(),
None => {
assert_eq!(variants.len(), 1);
variants.pop().unwrap()
}
}
};
match *origin_field_name {
mc::NamedField(ast_name) => {
let variant_arg_names = variant_info.arg_names.as_ref().unwrap();
for &variant_arg_name in variant_arg_names {
if variant_arg_name == ast_name {
continue;
}
let field_name = mc::NamedField(variant_arg_name);
add_fragment_sibling_local(field_name, Some(variant_info.id));
}
}
mc::PositionalField(tuple_idx) => {
let variant_arg_types = &variant_info.args;
for (i, _variant_arg_ty) in variant_arg_types.iter().enumerate() {
if tuple_idx == i {
continue;
}
let field_name = mc::PositionalField(i);
add_fragment_sibling_local(field_name, None);
}
}
}
}
ref sty_and_variant_info => {
let msg = format!("type {} ({:?}) is not fragmentable",
parent_ty.repr(tcx), sty_and_variant_info);
let opt_span = origin_id.and_then(|id|tcx.map.opt_span(id));
tcx.sess.opt_span_bug(opt_span, &msg[..])
}
}
}
fn add_fragment_sibling_core<'tcx>(this: &MoveData<'tcx>,
tcx: &ty::ctxt<'tcx>,
gathered_fragments: &mut Vec<Fragment>,
parent: Rc<LoanPath<'tcx>>,
mc: mc::MutabilityCategory,
new_field_name: mc::FieldName,
origin_lp: &Rc<LoanPath<'tcx>>,
enum_variant_did: Option<ast::DefId>) -> MovePathIndex {
let opt_variant_did = match parent.kind {
LpDowncast(_, variant_did) => Some(variant_did),
LpVar(..) | LpUpvar(..) | LpExtend(..) => enum_variant_did,
};
let loan_path_elem = LpInterior(InteriorField(new_field_name));
let new_lp_type = match new_field_name {
mc::NamedField(ast_name) =>
ty::named_element_ty(tcx, parent.to_type(), ast_name, opt_variant_did),
mc::PositionalField(idx) =>
ty::positional_element_ty(tcx, parent.to_type(), idx, opt_variant_did),
};
let new_lp_variant = LpExtend(parent, mc, loan_path_elem);
let new_lp = LoanPath::new(new_lp_variant, new_lp_type.unwrap());
debug!("add_fragment_sibling_core(new_lp={}, origin_lp={})",
new_lp.repr(tcx), origin_lp.repr(tcx));
let mp = this.move_path(tcx, Rc::new(new_lp));
gathered_fragments.push(Just(mp));
mp
}