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import syntax::ast::*;
import syntax::visit;
import option::*;
import aux::*;
import tstate::ann::{pre_and_post, precond, postcond, prestate, poststate,
relax_prestate, relax_precond, relax_poststate,
pps_len, true_precond,
difference, union, clone,
set_in_postcond, set_in_poststate, set_in_poststate_,
clear_in_poststate, clear_in_prestate,
clear_in_poststate_};
import tritv::*;
import util::common::*;
import driver::session::session;
import std::map::hashmap;
fn bit_num(fcx: fn_ctxt, c: tsconstr) -> uint {
let d = tsconstr_to_def_id(c);
assert (fcx.enclosing.constrs.contains_key(d));
let rslt = fcx.enclosing.constrs.get(d);
alt c {
ninit(_, _) {
alt rslt {
cinit(n, _, _) { ret n; }
_ {
fcx.ccx.tcx.sess.bug("bit_num: asked for init constraint," +
" found a pred constraint");
}
}
}
npred(_, _, args) {
alt rslt {
cpred(_, descs) { ret match_args(fcx, descs, args); }
_ {
fcx.ccx.tcx.sess.bug("bit_num: asked for pred constraint," +
" found an init constraint");
}
}
}
}
}
fn promises(fcx: fn_ctxt, p: poststate, c: tsconstr) -> bool {
ret promises_(bit_num(fcx, c), p);
}
fn promises_(n: uint, p: poststate) -> bool { ret tritv_get(p, n) == ttrue; }
// v "happens after" u
fn seq_trit(u: trit, v: trit) -> trit {
alt v { ttrue { ttrue } tfalse { tfalse } dont_care { u } }
}
// idea: q "happens after" p -- so if something is
// 1 in q and 0 in p, it's 1 in the result; however,
// if it's 0 in q and 1 in p, it's 0 in the result
fn seq_tritv(p: postcond, q: postcond) {
let mut i = 0u;
assert (p.nbits == q.nbits);
while i < p.nbits {
tritv_set(i, p, seq_trit(tritv_get(p, i), tritv_get(q, i)));
i += 1u;
}
}
fn seq_postconds(fcx: fn_ctxt, ps: [postcond]) -> postcond {
let sz = vec::len(ps);
if sz >= 1u {
let prev = tritv_clone(ps[0]);
for p: postcond in vec::slice(ps, 1u, sz) { seq_tritv(prev, p); }
ret prev;
} else { ret ann::empty_poststate(num_constraints(fcx.enclosing)); }
}
// Given a list of pres and posts for exprs e0 ... en,
// return the precondition for evaluating each expr in order.
// So, if e0's post is {x} and e1's pre is {x, y, z}, the entire
// precondition shouldn't include x.
fn seq_preconds(fcx: fn_ctxt, pps: [pre_and_post]) -> precond {
let sz: uint = vec::len(pps);
let num_vars: uint = num_constraints(fcx.enclosing);
fn seq_preconds_go(fcx: fn_ctxt, pps: [pre_and_post], first: pre_and_post)
-> precond {
let sz: uint = vec::len(pps);
if sz >= 1u {
let second = pps[0];
assert (pps_len(second) == num_constraints(fcx.enclosing));
let second_pre = clone(second.precondition);
difference(second_pre, first.postcondition);
let next_first = clone(first.precondition);
union(next_first, second_pre);
let next_first_post = clone(first.postcondition);
seq_tritv(next_first_post, second.postcondition);
ret seq_preconds_go(fcx, vec::slice(pps, 1u, sz),
@{precondition: next_first,
postcondition: next_first_post});
} else { ret first.precondition; }
}
if sz >= 1u {
let first = pps[0];
assert (pps_len(first) == num_vars);
ret seq_preconds_go(fcx, vec::slice(pps, 1u, sz), first);
} else { ret true_precond(num_vars); }
}
fn intersect_states(p: prestate, q: prestate) -> prestate {
let rslt = tritv_clone(p);
tritv_intersect(rslt, q);
ret rslt;
}
fn gen(fcx: fn_ctxt, id: node_id, c: tsconstr) -> bool {
ret set_in_postcond(bit_num(fcx, c),
node_id_to_ts_ann(fcx.ccx, id).conditions);
}
fn declare_var(fcx: fn_ctxt, c: tsconstr, pre: prestate) -> prestate {
let rslt = clone(pre);
relax_prestate(bit_num(fcx, c), rslt);
// idea is this is scoped
relax_poststate(bit_num(fcx, c), rslt);
ret rslt;
}
fn relax_precond_expr(e: @expr, cx: relax_ctxt, vt: visit::vt<relax_ctxt>) {
relax_precond(cx.i as uint, expr_precond(cx.fcx.ccx, e));
visit::visit_expr(e, cx, vt);
}
fn relax_precond_stmt(s: @stmt, cx: relax_ctxt, vt: visit::vt<relax_ctxt>) {
relax_precond(cx.i as uint, stmt_precond(cx.fcx.ccx, *s));
visit::visit_stmt(s, cx, vt);
}
type relax_ctxt = {fcx: fn_ctxt, i: node_id};
fn relax_precond_block_inner(b: blk, cx: relax_ctxt,
vt: visit::vt<relax_ctxt>) {
relax_precond(cx.i as uint, block_precond(cx.fcx.ccx, b));
visit::visit_block(b, cx, vt);
}
fn relax_precond_block(fcx: fn_ctxt, i: node_id, b: blk) {
let cx = {fcx: fcx, i: i};
let visitor = visit::default_visitor::<relax_ctxt>();
let visitor =
@{visit_block: relax_precond_block_inner,
visit_expr: relax_precond_expr,
visit_stmt: relax_precond_stmt,
visit_item:
fn@(_i: @item, _cx: relax_ctxt, _vt: visit::vt<relax_ctxt>) { },
visit_fn: bind do_nothing(_, _, _, _, _, _, _)
with *visitor};
let v1 = visit::mk_vt(visitor);
v1.visit_block(b, cx, v1);
}
fn gen_poststate(fcx: fn_ctxt, id: node_id, c: tsconstr) -> bool {
#debug("gen_poststate");
ret set_in_poststate(bit_num(fcx, c),
node_id_to_ts_ann(fcx.ccx, id).states);
}
fn kill_prestate(fcx: fn_ctxt, id: node_id, c: tsconstr) -> bool {
ret clear_in_prestate(bit_num(fcx, c),
node_id_to_ts_ann(fcx.ccx, id).states);
}
fn kill_all_prestate(fcx: fn_ctxt, id: node_id) {
tritv::tritv_kill(node_id_to_ts_ann(fcx.ccx, id).states.prestate);
}
fn kill_poststate(fcx: fn_ctxt, id: node_id, c: tsconstr) -> bool {
#debug("kill_poststate");
ret clear_in_poststate(bit_num(fcx, c),
node_id_to_ts_ann(fcx.ccx, id).states);
}
fn clear_in_poststate_expr(fcx: fn_ctxt, e: @expr, t: poststate) {
alt e.node {
expr_path(p) {
alt vec::last_opt(p.node.idents) {
some(i) {
alt local_node_id_to_def(fcx, e.id) {
some(def_local(nid, _)) {
clear_in_poststate_(bit_num(fcx, ninit(nid, i)), t);
}
some(_) {/* ignore args (for now...) */ }
_ {
fcx.ccx.tcx.sess.bug("clear_in_poststate_expr: \
unbound var");
}
}
}
_ { fcx.ccx.tcx.sess.bug("clear_in_poststate_expr"); }
}
}
_ {/* do nothing */ }
}
}
fn kill_poststate_(fcx: fn_ctxt, c: tsconstr, post: poststate) -> bool {
#debug("kill_poststate_");
ret clear_in_poststate_(bit_num(fcx, c), post);
}
fn set_in_poststate_ident(fcx: fn_ctxt, id: node_id, ident: ident,
t: poststate) -> bool {
ret set_in_poststate_(bit_num(fcx, ninit(id, ident)), t);
}
fn set_in_prestate_constr(fcx: fn_ctxt, c: tsconstr, t: prestate) -> bool {
ret set_in_poststate_(bit_num(fcx, c), t);
}
fn clear_in_poststate_ident(fcx: fn_ctxt, id: node_id, ident: ident,
parent: node_id) -> bool {
ret kill_poststate(fcx, parent, ninit(id, ident));
}
fn clear_in_prestate_ident(fcx: fn_ctxt, id: node_id, ident: ident,
parent: node_id) -> bool {
ret kill_prestate(fcx, parent, ninit(id, ident));
}
fn clear_in_poststate_ident_(fcx: fn_ctxt, id: node_id, ident: ident,
post: poststate) -> bool {
ret kill_poststate_(fcx, ninit(id, ident), post);
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//
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