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import syntax::visit;
import syntax::ast::*;
import driver::session::session;
type ctx = {tcx: ty::ctxt, mut allow_block: bool};
fn check_crate(tcx: ty::ctxt, crate: @crate) {
let cx = {tcx: tcx, mut allow_block: false};
let v = visit::mk_vt(@{visit_expr: visit_expr
with *visit::default_visitor()});
visit::visit_crate(*crate, cx, v);
}
fn visit_expr(ex: @expr, cx: ctx, v: visit::vt<ctx>) {
if !cx.allow_block {
alt ty::get(ty::expr_ty(cx.tcx, ex)).struct {
ty::ty_fn({proto: p, _}) if is_blockish(p) {
cx.tcx.sess.span_err(ex.span,
"expressions with stack closure type \
can only appear in callee or (by-ref) argument position");
}
_ {}
}
}
let outer = cx.allow_block;
alt ex.node {
expr_call(f, args, _) {
cx.allow_block = true;
v.visit_expr(f, cx, v);
let mut i = 0u;
for ty::ty_fn_args(ty::expr_ty(cx.tcx, f)).each |arg_t| {
cx.allow_block = (ty::arg_mode(cx.tcx, arg_t) == by_ref);
v.visit_expr(args[i], cx, v);
i += 1u;
}
}
expr_loop_body(body) | expr_do_body(body) {
cx.allow_block = true;
v.visit_expr(body, cx, v);
}
_ {
cx.allow_block = false;
visit::visit_expr(ex, cx, v);
}
}
cx.allow_block = outer;
}
|
