bjoernager/rust
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Fix two typestate bugs

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* Non-returning calls should set all predicates to be true, not
  just the "this function returns" predicate

* Fixed a bug in the expr_alt case in tstate.states that wasn't updating
  the changed flag properly, then fixed *another* bug that was updating
  it too enthusiastically, but was masked by the first bug.
This commit is contained in:
Tim Chevalier 2011-05-27 17:01:37 -07:00
parent dc9d5e1689
commit 9a24e4f780
1 changed files with 11 additions and 8 deletions
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19
src/comp/middle/tstate/states.rs
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@ -215,10 +215,10 @@ fn find_pre_post_state_expr(&fn_ctxt fcx, &prestate pres, @expr e) -> bool {
auto changed = false;
auto num_local_vars = num_locals(fcx.enclosing);
/*
/*
log_err("states:");
log_expr_err(*e);
log_err(middle::ty::expr_ann(e).id);
aux::log_bitv_err(fcx, expr_poststate(fcx.ccx, e));
*/
/* FIXME could get rid of some of the copy/paste */
@ -236,10 +236,12 @@ fn find_pre_post_state_expr(&fn_ctxt fcx, &prestate pres, @expr e) -> bool {
/* rands go left-to-right */
changed = find_pre_post_state_exprs(fcx,
expr_poststate(fcx.ccx, operator), a, operands) || changed;
/* if this is a failing call, it sets the return value */
/* if this is a failing call, it sets everything as initialized */
alt (controlflow_expr(fcx.ccx, operator)) {
case (noreturn) {
changed = gen_poststate(fcx, a, fcx.id) || changed;
changed = set_poststate_ann(fcx.ccx, a,
false_postcond(num_local_vars))
|| changed;
}
case (_) { }
}
@ -525,16 +527,17 @@ fn find_pre_post_state_expr(&fn_ctxt fcx, &prestate pres, @expr e) -> bool {
for (arm an_alt in alts) {
changed = find_pre_post_state_block(fcx, e_post,
an_alt.block) || changed;
changed = intersect(a_post,
block_poststate(fcx.ccx,
an_alt.block)) || changed;
intersect(a_post, block_poststate(fcx.ccx, an_alt.block));
// We deliberately do *not* update changed here, because we'd
// go into an infinite loop that way, and the change gets made
// after the if expression.
}
}
else {
// No alts; poststate is the poststate of the test
a_post = e_post;
}
changed = extend_poststate_ann(fcx.ccx, a, a_post);
changed = extend_poststate_ann(fcx.ccx, a, a_post) || changed;
ret changed;
}
case (expr_field(?e, _, ?a)) {