librustc: Make a context including the method map in check_alt, in preparation for moving check_legality_of_move_bindings there. rs=refactoring

This commit is contained in:
Patrick Walton 2012-12-05 18:27:04 -08:00
parent 1fc802233b
commit 16506c0250
3 changed files with 103 additions and 87 deletions

View File

@ -249,7 +249,7 @@ fn compile_upto(sess: Session, cfg: ast::crate_cfg,
middle::check_loop::check_crate(ty_cx, crate));
time(time_passes, ~"alt checking", ||
middle::check_alt::check_crate(ty_cx, crate));
middle::check_alt::check_crate(ty_cx, method_map, crate));
time(time_passes, ~"mode computation", ||
middle::mode::compute_modes(ty_cx, method_map, crate));

View File

@ -19,40 +19,49 @@ use pat_util::*;
use syntax::visit;
use middle::ty;
use middle::ty::*;
use middle::typeck::method_map;
use std::map::HashMap;
fn check_crate(tcx: ty::ctxt, crate: @crate) {
struct AltCheckCtxt {
tcx: ty::ctxt,
method_map: method_map,
}
fn check_crate(tcx: ty::ctxt, method_map: method_map, crate: @crate) {
let cx = @AltCheckCtxt { tcx: tcx, method_map: method_map };
visit::visit_crate(*crate, (), visit::mk_vt(@{
visit_expr: |a,b,c| check_expr(tcx, a, b, c),
visit_local: |a,b,c| check_local(tcx, a, b, c),
visit_expr: |a,b,c| check_expr(cx, a, b, c),
visit_local: |a,b,c| check_local(cx, a, b, c),
visit_fn: |kind, decl, body, sp, id, e, v|
check_fn(tcx, kind, decl, body, sp, id, e, v),
check_fn(cx, kind, decl, body, sp, id, e, v),
.. *visit::default_visitor::<()>()
}));
tcx.sess.abort_if_errors();
}
fn check_expr(tcx: ty::ctxt, ex: @expr, &&s: (), v: visit::vt<()>) {
fn check_expr(cx: @AltCheckCtxt, ex: @expr, &&s: (), v: visit::vt<()>) {
visit::visit_expr(ex, s, v);
match ex.node {
expr_match(scrut, ref arms) => {
check_arms(tcx, (*arms));
check_arms(cx, (*arms));
/* Check for exhaustiveness */
// Check for empty enum, because is_useful only works on inhabited
// types.
let pat_ty = node_id_to_type(tcx, scrut.id);
let pat_ty = node_id_to_type(cx.tcx, scrut.id);
if (*arms).is_empty() {
if !type_is_empty(tcx, pat_ty) {
if !type_is_empty(cx.tcx, pat_ty) {
// We know the type is inhabited, so this must be wrong
tcx.sess.span_err(ex.span, fmt!("non-exhaustive patterns: \
type %s is non-empty", ty_to_str(tcx, pat_ty)));
cx.tcx.sess.span_err(ex.span, fmt!("non-exhaustive patterns: \
type %s is non-empty",
ty_to_str(cx.tcx, pat_ty)));
}
// If the type *is* empty, it's vacuously exhaustive
return;
}
match ty::get(pat_ty).sty {
ty_enum(did, _) => {
if (*enum_variants(tcx, did)).is_empty() && (*arms).is_empty() {
if (*enum_variants(cx.tcx, did)).is_empty() &&
(*arms).is_empty() {
return;
}
@ -60,21 +69,21 @@ fn check_expr(tcx: ty::ctxt, ex: @expr, &&s: (), v: visit::vt<()>) {
_ => { /* We assume only enum types can be uninhabited */ }
}
let arms = vec::concat(vec::filter_map((*arms), unguarded_pat));
check_exhaustive(tcx, ex.span, arms);
check_exhaustive(cx, ex.span, arms);
}
_ => ()
}
}
// Check for unreachable patterns
fn check_arms(tcx: ty::ctxt, arms: ~[arm]) {
fn check_arms(cx: @AltCheckCtxt, arms: ~[arm]) {
let mut seen = ~[];
for arms.each |arm| {
for arm.pats.each |pat| {
let v = ~[*pat];
match is_useful(tcx, seen, v) {
match is_useful(cx, seen, v) {
not_useful => {
tcx.sess.span_err(pat.span, ~"unreachable pattern");
cx.tcx.sess.span_err(pat.span, ~"unreachable pattern");
}
_ => ()
}
@ -90,9 +99,9 @@ fn raw_pat(p: @pat) -> @pat {
}
}
fn check_exhaustive(tcx: ty::ctxt, sp: span, pats: ~[@pat]) {
fn check_exhaustive(cx: @AltCheckCtxt, sp: span, pats: ~[@pat]) {
assert(pats.is_not_empty());
let ext = match is_useful(tcx, vec::map(pats, |p| ~[*p]), ~[wild()]) {
let ext = match is_useful(cx, vec::map(pats, |p| ~[*p]), ~[wild()]) {
not_useful => return, // This is good, wildcard pattern isn't reachable
useful_ => None,
useful(ty, ref ctor) => {
@ -107,9 +116,9 @@ fn check_exhaustive(tcx: ty::ctxt, sp: span, pats: ~[@pat]) {
ty::ty_enum(id, _) => {
let vid = match (*ctor) { variant(id) => id,
_ => fail ~"check_exhaustive: non-variant ctor" };
match vec::find(*ty::enum_variants(tcx, id),
match vec::find(*ty::enum_variants(cx.tcx, id),
|v| v.id == vid) {
Some(v) => Some(tcx.sess.str_of(v.name)),
Some(v) => Some(cx.tcx.sess.str_of(v.name)),
None => fail ~"check_exhaustive: bad variant in ctor"
}
}
@ -121,7 +130,7 @@ fn check_exhaustive(tcx: ty::ctxt, sp: span, pats: ~[@pat]) {
Some(ref s) => ~": " + (*s) + ~" not covered",
None => ~""
};
tcx.sess.span_err(sp, msg);
cx.tcx.sess.span_err(sp, msg);
}
type matrix = ~[~[@pat]];
@ -167,34 +176,36 @@ impl ctor : cmp::Eq {
// Note: is_useful doesn't work on empty types, as the paper notes.
// So it assumes that v is non-empty.
fn is_useful(tcx: ty::ctxt, m: matrix, v: ~[@pat]) -> useful {
fn is_useful(cx: @AltCheckCtxt, m: matrix, v: ~[@pat]) -> useful {
if m.len() == 0u { return useful_; }
if m[0].len() == 0u { return not_useful; }
let real_pat = match vec::find(m, |r| r[0].id != 0) {
Some(r) => r[0], None => v[0]
};
let left_ty = if real_pat.id == 0 { ty::mk_nil(tcx) }
else { ty::node_id_to_type(tcx, real_pat.id) };
let left_ty = if real_pat.id == 0 { ty::mk_nil(cx.tcx) }
else { ty::node_id_to_type(cx.tcx, real_pat.id) };
match pat_ctor_id(tcx, v[0]) {
match pat_ctor_id(cx, v[0]) {
None => {
match missing_ctor(tcx, m, left_ty) {
match missing_ctor(cx, m, left_ty) {
None => {
match ty::get(left_ty).sty {
ty::ty_bool => {
match is_useful_specialized(tcx, m, v, val(const_bool(true)),
0u, left_ty){
match is_useful_specialized(cx, m, v,
val(const_bool(true)),
0u, left_ty){
not_useful => {
is_useful_specialized(tcx, m, v, val(const_bool(false)),
is_useful_specialized(cx, m, v,
val(const_bool(false)),
0u, left_ty)
}
ref u => (*u)
}
}
ty::ty_enum(eid, _) => {
for (*ty::enum_variants(tcx, eid)).each |va| {
match is_useful_specialized(tcx, m, v, variant(va.id),
va.args.len(), left_ty) {
for (*ty::enum_variants(cx.tcx, eid)).each |va| {
match is_useful_specialized(cx, m, v, variant(va.id),
va.args.len(), left_ty) {
not_useful => (),
ref u => return (*u)
}
@ -202,14 +213,14 @@ fn is_useful(tcx: ty::ctxt, m: matrix, v: ~[@pat]) -> useful {
not_useful
}
_ => {
let arity = ctor_arity(tcx, single, left_ty);
is_useful_specialized(tcx, m, v, single, arity, left_ty)
let arity = ctor_arity(cx, single, left_ty);
is_useful_specialized(cx, m, v, single, arity, left_ty)
}
}
}
Some(ref ctor) => {
match is_useful(tcx, vec::filter_map(m, |r| default(tcx, *r) ),
vec::tail(v)) {
match is_useful(cx, vec::filter_map(m, |r| default(cx, *r)),
vec::tail(v)) {
useful_ => useful(left_ty, (*ctor)),
ref u => (*u)
}
@ -217,43 +228,43 @@ fn is_useful(tcx: ty::ctxt, m: matrix, v: ~[@pat]) -> useful {
}
}
Some(ref v0_ctor) => {
let arity = ctor_arity(tcx, (*v0_ctor), left_ty);
is_useful_specialized(tcx, m, v, (*v0_ctor), arity, left_ty)
let arity = ctor_arity(cx, (*v0_ctor), left_ty);
is_useful_specialized(cx, m, v, (*v0_ctor), arity, left_ty)
}
}
}
fn is_useful_specialized(tcx: ty::ctxt, m: matrix, v: ~[@pat], ctor: ctor,
fn is_useful_specialized(cx: @AltCheckCtxt, m: matrix, v: ~[@pat], ctor: ctor,
arity: uint, lty: ty::t) -> useful {
let ms = vec::filter_map(m, |r| specialize(tcx, *r, ctor, arity, lty) );
let ms = vec::filter_map(m, |r| specialize(cx, *r, ctor, arity, lty));
let could_be_useful = is_useful(
tcx, ms, specialize(tcx, v, ctor, arity, lty).get());
cx, ms, specialize(cx, v, ctor, arity, lty).get());
match could_be_useful {
useful_ => useful(lty, ctor),
ref u => (*u)
}
}
fn pat_ctor_id(tcx: ty::ctxt, p: @pat) -> Option<ctor> {
fn pat_ctor_id(cx: @AltCheckCtxt, p: @pat) -> Option<ctor> {
let pat = raw_pat(p);
match pat.node {
pat_wild => { None }
pat_ident(_, _, _) | pat_enum(_, _) => {
match tcx.def_map.find(pat.id) {
match cx.tcx.def_map.find(pat.id) {
Some(def_variant(_, id)) => Some(variant(id)),
Some(def_const(did)) => {
let const_expr = lookup_const_by_id(tcx, did).get();
Some(val(eval_const_expr(tcx, const_expr)))
let const_expr = lookup_const_by_id(cx.tcx, did).get();
Some(val(eval_const_expr(cx.tcx, const_expr)))
}
_ => None
}
}
pat_lit(expr) => { Some(val(eval_const_expr(tcx, expr))) }
pat_lit(expr) => { Some(val(eval_const_expr(cx.tcx, expr))) }
pat_range(lo, hi) => {
Some(range(eval_const_expr(tcx, lo), eval_const_expr(tcx, hi)))
Some(range(eval_const_expr(cx.tcx, lo), eval_const_expr(cx.tcx, hi)))
}
pat_struct(*) => {
match tcx.def_map.find(pat.id) {
match cx.tcx.def_map.find(pat.id) {
Some(def_variant(_, id)) => Some(variant(id)),
_ => Some(single)
}
@ -265,12 +276,12 @@ fn pat_ctor_id(tcx: ty::ctxt, p: @pat) -> Option<ctor> {
}
}
fn is_wild(tcx: ty::ctxt, p: @pat) -> bool {
fn is_wild(cx: @AltCheckCtxt, p: @pat) -> bool {
let pat = raw_pat(p);
match pat.node {
pat_wild => { true }
pat_ident(_, _, _) => {
match tcx.def_map.find(pat.id) {
match cx.tcx.def_map.find(pat.id) {
Some(def_variant(_, _)) | Some(def_const(*)) => { false }
_ => { true }
}
@ -279,25 +290,28 @@ fn is_wild(tcx: ty::ctxt, p: @pat) -> bool {
}
}
fn missing_ctor(tcx: ty::ctxt, m: matrix, left_ty: ty::t) -> Option<ctor> {
fn missing_ctor(cx: @AltCheckCtxt,
m: matrix,
left_ty: ty::t)
-> Option<ctor> {
match ty::get(left_ty).sty {
ty::ty_box(_) | ty::ty_uniq(_) | ty::ty_rptr(*) | ty::ty_tup(_) |
ty::ty_rec(_) | ty::ty_class(*) => {
for m.each |r| {
if !is_wild(tcx, r[0]) { return None; }
if !is_wild(cx, r[0]) { return None; }
}
return Some(single);
}
ty::ty_enum(eid, _) => {
let mut found = ~[];
for m.each |r| {
do option::iter(&pat_ctor_id(tcx, r[0])) |id| {
do option::iter(&pat_ctor_id(cx, r[0])) |id| {
if !vec::contains(found, id) {
found.push(*id);
}
}
}
let variants = ty::enum_variants(tcx, eid);
let variants = ty::enum_variants(cx.tcx, eid);
if found.len() != (*variants).len() {
for vec::each(*variants) |v| {
if !found.contains(&(variant(v.id))) {
@ -311,7 +325,7 @@ fn missing_ctor(tcx: ty::ctxt, m: matrix, left_ty: ty::t) -> Option<ctor> {
ty::ty_bool => {
let mut true_found = false, false_found = false;
for m.each |r| {
match pat_ctor_id(tcx, r[0]) {
match pat_ctor_id(cx, r[0]) {
None => (),
Some(val(const_bool(true))) => true_found = true,
Some(val(const_bool(false))) => false_found = true,
@ -326,7 +340,7 @@ fn missing_ctor(tcx: ty::ctxt, m: matrix, left_ty: ty::t) -> Option<ctor> {
}
}
fn ctor_arity(tcx: ty::ctxt, ctor: ctor, ty: ty::t) -> uint {
fn ctor_arity(cx: @AltCheckCtxt, ctor: ctor, ty: ty::t) -> uint {
match ty::get(ty).sty {
ty::ty_tup(fs) => fs.len(),
ty::ty_rec(fs) => fs.len(),
@ -334,12 +348,12 @@ fn ctor_arity(tcx: ty::ctxt, ctor: ctor, ty: ty::t) -> uint {
ty::ty_enum(eid, _) => {
let id = match ctor { variant(id) => id,
_ => fail ~"impossible case" };
match vec::find(*ty::enum_variants(tcx, eid), |v| v.id == id ) {
match vec::find(*ty::enum_variants(cx.tcx, eid), |v| v.id == id ) {
Some(v) => v.args.len(),
None => fail ~"impossible case"
}
}
ty::ty_class(cid, _) => ty::lookup_class_fields(tcx, cid).len(),
ty::ty_class(cid, _) => ty::lookup_class_fields(cx.tcx, cid).len(),
_ => 0u
}
}
@ -348,21 +362,21 @@ fn wild() -> @pat {
@{id: 0, node: pat_wild, span: syntax::ast_util::dummy_sp()}
}
fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
fn specialize(cx: @AltCheckCtxt, r: ~[@pat], ctor_id: ctor, arity: uint,
left_ty: ty::t) -> Option<~[@pat]> {
let r0 = raw_pat(r[0]);
match r0.node {
pat_wild => Some(vec::append(vec::from_elem(arity, wild()),
vec::tail(r))),
pat_ident(_, _, _) => {
match tcx.def_map.find(r0.id) {
match cx.tcx.def_map.find(r0.id) {
Some(def_variant(_, id)) => {
if variant(id) == ctor_id { Some(vec::tail(r)) }
else { None }
}
Some(def_const(did)) => {
let const_expr = lookup_const_by_id(tcx, did).get();
let e_v = eval_const_expr(tcx, const_expr);
let const_expr = lookup_const_by_id(cx.tcx, did).get();
let e_v = eval_const_expr(cx.tcx, const_expr);
let match_ = match ctor_id {
val(ref v) => compare_const_vals(e_v, (*v)) == 0,
range(ref c_lo, ref c_hi) => {
@ -378,7 +392,7 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
}
}
pat_enum(_, args) => {
match tcx.def_map.get(r0.id) {
match cx.tcx.def_map.get(r0.id) {
def_variant(_, id) if variant(id) == ctor_id => {
let args = match args {
Some(args) => args,
@ -414,7 +428,7 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
}
pat_struct(_, flds, _) => {
// Is this a struct or an enum variant?
match tcx.def_map.get(r0.id) {
match cx.tcx.def_map.get(r0.id) {
def_variant(_, variant_id) => {
if variant(variant_id) == ctor_id {
// XXX: Is this right? --pcw
@ -435,11 +449,13 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
match ty::get(left_ty).sty {
ty::ty_class(cid, _) => {
class_id = cid;
class_fields = ty::lookup_class_fields(tcx, class_id);
class_fields = ty::lookup_class_fields(cx.tcx,
class_id);
}
_ => {
tcx.sess.span_bug(r0.span, ~"struct pattern didn't \
resolve to a struct");
cx.tcx.sess.span_bug(r0.span, ~"struct pattern \
didn't resolve to a \
struct");
}
}
let args = vec::map(class_fields, |class_field| {
@ -456,7 +472,7 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
pat_box(a) | pat_uniq(a) | pat_region(a) =>
Some(vec::append(~[a], vec::tail(r))),
pat_lit(expr) => {
let e_v = eval_const_expr(tcx, expr);
let e_v = eval_const_expr(cx.tcx, expr);
let match_ = match ctor_id {
val(ref v) => compare_const_vals(e_v, (*v)) == 0,
range(ref c_lo, ref c_hi) => {
@ -475,8 +491,8 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
single => return Some(vec::tail(r)),
_ => fail ~"type error"
};
let v_lo = eval_const_expr(tcx, lo),
v_hi = eval_const_expr(tcx, hi);
let v_lo = eval_const_expr(cx.tcx, lo),
v_hi = eval_const_expr(cx.tcx, hi);
let match_ = compare_const_vals(c_lo, v_lo) >= 0 &&
compare_const_vals(c_hi, v_hi) <= 0;
if match_ { Some(vec::tail(r)) } else { None }
@ -484,20 +500,20 @@ fn specialize(tcx: ty::ctxt, r: ~[@pat], ctor_id: ctor, arity: uint,
}
}
fn default(tcx: ty::ctxt, r: ~[@pat]) -> Option<~[@pat]> {
if is_wild(tcx, r[0]) { Some(vec::tail(r)) }
fn default(cx: @AltCheckCtxt, r: ~[@pat]) -> Option<~[@pat]> {
if is_wild(cx, r[0]) { Some(vec::tail(r)) }
else { None }
}
fn check_local(tcx: ty::ctxt, loc: @local, &&s: (), v: visit::vt<()>) {
fn check_local(cx: @AltCheckCtxt, loc: @local, &&s: (), v: visit::vt<()>) {
visit::visit_local(loc, s, v);
if is_refutable(tcx, loc.node.pat) {
tcx.sess.span_err(loc.node.pat.span,
if is_refutable(cx, loc.node.pat) {
cx.tcx.sess.span_err(loc.node.pat.span,
~"refutable pattern in local binding");
}
}
fn check_fn(tcx: ty::ctxt,
fn check_fn(cx: @AltCheckCtxt,
kind: visit::fn_kind,
decl: fn_decl,
body: blk,
@ -507,17 +523,17 @@ fn check_fn(tcx: ty::ctxt,
v: visit::vt<()>) {
visit::visit_fn(kind, decl, body, sp, id, s, v);
for decl.inputs.each |input| {
if is_refutable(tcx, input.pat) {
tcx.sess.span_err(input.pat.span,
if is_refutable(cx, input.pat) {
cx.tcx.sess.span_err(input.pat.span,
~"refutable pattern in function argument");
}
}
}
fn is_refutable(tcx: ty::ctxt, pat: &pat) -> bool {
match tcx.def_map.find(pat.id) {
fn is_refutable(cx: @AltCheckCtxt, pat: &pat) -> bool {
match cx.tcx.def_map.find(pat.id) {
Some(def_variant(enum_id, _)) => {
if vec::len(*ty::enum_variants(tcx, enum_id)) != 1u {
if vec::len(*ty::enum_variants(cx.tcx, enum_id)) != 1u {
return true;
}
}
@ -528,22 +544,22 @@ fn is_refutable(tcx: ty::ctxt, pat: &pat) -> bool {
match pat.node {
pat_box(sub) | pat_uniq(sub) | pat_region(sub) |
pat_ident(_, _, Some(sub)) => {
is_refutable(tcx, sub)
is_refutable(cx, sub)
}
pat_wild | pat_ident(_, _, None) => { false }
pat_lit(@{node: expr_lit(@{node: lit_nil, _}), _}) => { false } // "()"
pat_lit(_) | pat_range(_, _) => { true }
pat_rec(fields, _) => {
fields.any(|f| is_refutable(tcx, f.pat))
fields.any(|f| is_refutable(cx, f.pat))
}
pat_struct(_, fields, _) => {
fields.any(|f| is_refutable(tcx, f.pat))
fields.any(|f| is_refutable(cx, f.pat))
}
pat_tup(elts) => {
elts.any(|elt| is_refutable(tcx, *elt))
elts.any(|elt| is_refutable(cx, *elt))
}
pat_enum(_, Some(args)) => {
args.any(|a| is_refutable(tcx, *a))
args.any(|a| is_refutable(cx, *a))
}
pat_enum(_,_) => { false }
}

View File

@ -246,7 +246,7 @@ fn run(repl: Repl, input: ~str) -> Repl {
middle::check_loop::check_crate(ty_cx, crate);
debug!("alt checking");
middle::check_alt::check_crate(ty_cx, crate);
middle::check_alt::check_crate(ty_cx, method_map, crate);
debug!("liveness checking");
let last_use_map = middle::liveness::check_crate(ty_cx,