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
|
import syntax::ast::*;
import syntax::visit;
import driver::session::session;
type ctx = {in_loop: bool, can_ret: bool};
fn check_crate(tcx: ty::ctxt, crate: @crate) {
visit::visit_crate(*crate, {in_loop: false,can_ret: true}, visit::mk_vt(@{
visit_item: {|i, _cx, v|
visit::visit_item(i, {in_loop: false, can_ret: true}, v);
},
visit_expr: {|e: @expr, cx: ctx, v: visit::vt<ctx>|
alt e.node {
expr_while(e, b) | expr_do_while(b, e) {
v.visit_expr(e, cx, v);
v.visit_block(b, {in_loop: true with cx}, v);
}
expr_loop(b) {
v.visit_block(b, {in_loop: true with cx}, v);
}
expr_fn(_, _, _, _) {
visit::visit_expr(e, {in_loop: false, can_ret: true}, v);
}
expr_fn_block(_, b) {
v.visit_block(b, {in_loop: false, can_ret: false}, v);
}
expr_loop_body(@{node: expr_fn_block(_, b), _}) {
let blk = is_blockish(ty::ty_fn_proto(ty::expr_ty(tcx, e)));
v.visit_block(b, {in_loop: true, can_ret: blk}, v);
}
expr_break {
if !cx.in_loop {
tcx.sess.span_err(e.span, "`break` outside of loop");
}
}
expr_cont {
if !cx.in_loop {
tcx.sess.span_err(e.span, "`cont` outside of loop");
}
}
expr_ret(oe) {
if !cx.can_ret {
tcx.sess.span_err(e.span, "`ret` in block function");
}
visit::visit_expr_opt(oe, cx, v);
}
expr_be(re) {
if !cx.can_ret {
tcx.sess.span_err(e.span, "`be` in block function");
}
v.visit_expr(re, cx, v);
}
_ { visit::visit_expr(e, cx, v); }
}
}
with *visit::default_visitor()
}));
}
|
