1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
import option::{some, none};
import syntax::{visit, ast_util};
import syntax::ast::*;
import syntax::codemap::span;
// Kind analysis pass. There are three kinds:
//
// sendable: scalar types, and unique types containing only sendable types
// copyable: boxes, objects, closures, and uniques containing copyable types
// noncopyable: resources, or unique types containing resources
//
// This pass ensures that type parameters are only instantiated with types
// whose kinds are equal or less general than the way the type parameter was
// annotated (with the `send` or `copy` keyword).
//
// It also verifies that noncopyable kinds are not copied. Sendability is not
// applied, since none of our language primitives send. Instead, the sending
// primitives in the stdlib are explicitly annotated to only take sendable
// types.
fn kind_to_str(k: kind) -> str {
alt k {
kind_sendable. { "sendable" }
kind_copyable. { "copyable" }
kind_noncopyable. { "noncopyable" }
}
}
type rval_map = std::map::hashmap<node_id, ()>;
type ctx = {tcx: ty::ctxt,
rval_map: rval_map,
method_map: typeck::method_map,
last_uses: last_use::last_uses};
fn check_crate(tcx: ty::ctxt, method_map: typeck::method_map,
last_uses: last_use::last_uses, crate: @crate)
-> rval_map {
let ctx = {tcx: tcx,
rval_map: std::map::new_int_hash(),
method_map: method_map,
last_uses: last_uses};
let visit = visit::mk_vt(@{
visit_expr: check_expr,
visit_stmt: check_stmt
with *visit::default_visitor()
});
visit::visit_crate(*crate, ctx, visit);
tcx.sess.abort_if_errors();
ret ctx.rval_map;
}
fn check_expr(e: @expr, cx: ctx, v: visit::vt<ctx>) {
fn check_free_vars(e: @expr,
cx: ctx,
check_fn: fn(ctx, ty::t, sp: span)) {
for free in *freevars::get_freevars(cx.tcx, e.id) {
let id = ast_util::def_id_of_def(free).node;
let ty = ty::node_id_to_type(cx.tcx, id);
check_fn(cx, ty, e.span);
}
}
alt e.node {
expr_assign(_, ex) | expr_assign_op(_, _, ex) |
expr_block({node: {expr: some(ex), _}, _}) |
expr_unary(box(_), ex) | expr_unary(uniq(_), ex) { maybe_copy(cx, ex); }
expr_ret(some(ex)) { maybe_copy(cx, ex); }
expr_copy(expr) { check_copy_ex(cx, expr, false); }
// Vector add copies.
expr_binary(add., ls, rs) { maybe_copy(cx, ls); maybe_copy(cx, rs); }
expr_rec(fields, def) {
for field in fields { maybe_copy(cx, field.node.expr); }
alt def {
some(ex) {
// All noncopyable fields must be overridden
let t = ty::expr_ty(cx.tcx, ex);
let ty_fields = alt ty::struct(cx.tcx, t) { ty::ty_rec(f) { f } };
for tf in ty_fields {
if !vec::any(fields, {|f| f.node.ident == tf.ident}) &&
!kind_can_be_copied(ty::type_kind(cx.tcx, tf.mt.ty)) {
cx.tcx.sess.span_err(ex.span,
"copying a noncopyable value");
}
}
}
_ {}
}
}
expr_tup(exprs) | expr_vec(exprs, _) {
for expr in exprs { maybe_copy(cx, expr); }
}
expr_bind(_, args) {
for a in args { alt a { some(ex) { maybe_copy(cx, ex); } _ {} } }
}
expr_call(f, args, _) {
let i = 0u;
for arg_t in ty::ty_fn_args(cx.tcx, ty::expr_ty(cx.tcx, f)) {
alt arg_t.mode { by_copy. { maybe_copy(cx, args[i]); } _ {} }
i += 1u;
}
}
expr_path(_) {
let substs = ty::node_id_to_ty_param_substs_opt_and_ty(cx.tcx, e.id);
alt substs.substs {
some(ts) {
let did = ast_util::def_id_of_def(cx.tcx.def_map.get(e.id));
let kinds = ty::lookup_item_type(cx.tcx, did).kinds, i = 0u;
for ty in ts {
let kind = ty::type_kind(cx.tcx, ty);
if !ty::kind_lteq(kinds[i], kind) {
cx.tcx.sess.span_err(e.span, "instantiating a " +
kind_to_str(kinds[i]) +
" type parameter with a "
+ kind_to_str(kind) + " type");
}
i += 1u;
}
}
none. {}
}
}
expr_fn({proto: proto_send., _}, captures) { // NDM captures
check_free_vars(e, cx, check_send);
}
expr_fn({proto: proto_shared(_), _}, captures) { // NDM captures
check_free_vars(e, cx, check_copy);
}
expr_ternary(_, a, b) { maybe_copy(cx, a); maybe_copy(cx, b); }
_ { }
}
visit::visit_expr(e, cx, v);
}
fn check_stmt(stmt: @stmt, cx: ctx, v: visit::vt<ctx>) {
alt stmt.node {
stmt_decl(@{node: decl_local(locals), _}, _) {
for (_, local) in locals {
alt local.node.init {
some({op: init_assign., expr}) { maybe_copy(cx, expr); }
_ {}
}
}
}
_ {}
}
visit::visit_stmt(stmt, cx, v);
}
fn maybe_copy(cx: ctx, ex: @expr) {
check_copy_ex(cx, ex, true);
}
fn check_copy_ex(cx: ctx, ex: @expr, _warn: bool) {
if ty::expr_is_lval(cx.method_map, cx.tcx, ex) &&
!cx.last_uses.contains_key(ex.id) {
let ty = ty::expr_ty(cx.tcx, ex);
check_copy(cx, ty, ex.span);
// FIXME turn this on again once vector types are no longer unique.
// Right now, it is too annoying to be useful.
/* if warn && ty::type_is_unique(cx.tcx, ty) {
cx.tcx.sess.span_warn(ex.span, "copying a unique value");
}*/
}
}
fn check_copy(cx: ctx, ty: ty::t, sp: span) {
if !kind_can_be_copied(ty::type_kind(cx.tcx, ty)) {
cx.tcx.sess.span_err(sp, "copying a noncopyable value");
}
}
fn check_send(cx: ctx, ty: ty::t, sp: span) {
if !kind_can_be_sent(ty::type_kind(cx.tcx, ty)) {
cx.tcx.sess.span_err(sp, "not a sendable value");
}
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//
|
