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|
use itertools::Itertools;
use super::query_context::test::{Def, UltraMinimal};
use crate::{Answer, Assume, Reason, layout};
type Tree = layout::Tree<Def, !>;
type Dfa = layout::Dfa<!>;
trait Representation {
fn is_transmutable(src: Self, dst: Self, assume: Assume) -> Answer<!>;
}
impl Representation for Tree {
fn is_transmutable(src: Self, dst: Self, assume: Assume) -> Answer<!> {
crate::maybe_transmutable::MaybeTransmutableQuery::new(src, dst, assume, UltraMinimal)
.answer()
}
}
impl Representation for Dfa {
fn is_transmutable(src: Self, dst: Self, assume: Assume) -> Answer<!> {
crate::maybe_transmutable::MaybeTransmutableQuery::new(src, dst, assume, UltraMinimal)
.answer()
}
}
fn is_transmutable<R: Representation + Clone>(
src: &R,
dst: &R,
assume: Assume,
) -> crate::Answer<!> {
let src = src.clone();
let dst = dst.clone();
// The only dimension of the transmutability analysis we want to test
// here is the safety analysis. To ensure this, we disable all other
// toggleable aspects of the transmutability analysis.
R::is_transmutable(src, dst, assume)
}
mod safety {
use super::*;
use crate::Answer;
const DST_HAS_SAFETY_INVARIANTS: Answer<!> =
Answer::No(crate::Reason::DstMayHaveSafetyInvariants);
#[test]
fn src_safe_dst_safe() {
let src = Tree::Def(Def::NoSafetyInvariants).then(Tree::u8());
let dst = Tree::Def(Def::NoSafetyInvariants).then(Tree::u8());
assert_eq!(is_transmutable(&src, &dst, Assume::default()), Answer::Yes);
assert_eq!(
is_transmutable(&src, &dst, Assume { safety: true, ..Assume::default() }),
Answer::Yes
);
}
#[test]
fn src_safe_dst_unsafe() {
let src = Tree::Def(Def::NoSafetyInvariants).then(Tree::u8());
let dst = Tree::Def(Def::HasSafetyInvariants).then(Tree::u8());
assert_eq!(is_transmutable(&src, &dst, Assume::default()), DST_HAS_SAFETY_INVARIANTS);
assert_eq!(
is_transmutable(&src, &dst, Assume { safety: true, ..Assume::default() }),
Answer::Yes
);
}
#[test]
fn src_unsafe_dst_safe() {
let src = Tree::Def(Def::HasSafetyInvariants).then(Tree::u8());
let dst = Tree::Def(Def::NoSafetyInvariants).then(Tree::u8());
assert_eq!(is_transmutable(&src, &dst, Assume::default()), Answer::Yes);
assert_eq!(
is_transmutable(&src, &dst, Assume { safety: true, ..Assume::default() }),
Answer::Yes
);
}
#[test]
fn src_unsafe_dst_unsafe() {
let src = Tree::Def(Def::HasSafetyInvariants).then(Tree::u8());
let dst = Tree::Def(Def::HasSafetyInvariants).then(Tree::u8());
assert_eq!(is_transmutable(&src, &dst, Assume::default()), DST_HAS_SAFETY_INVARIANTS);
assert_eq!(
is_transmutable(&src, &dst, Assume { safety: true, ..Assume::default() }),
Answer::Yes
);
}
}
mod bool {
use super::*;
#[test]
fn should_permit_identity_transmutation_tree() {
let src = Tree::bool();
assert_eq!(is_transmutable(&src, &src, Assume::default()), Answer::Yes);
assert_eq!(
is_transmutable(&src, &src, Assume { validity: true, ..Assume::default() }),
Answer::Yes
);
}
#[test]
fn should_permit_identity_transmutation_dfa() {
let src = Dfa::bool();
assert_eq!(is_transmutable(&src, &src, Assume::default()), Answer::Yes);
assert_eq!(
is_transmutable(&src, &src, Assume { validity: true, ..Assume::default() }),
Answer::Yes
);
}
#[test]
fn should_permit_validity_expansion_and_reject_contraction() {
let b0 = layout::Tree::<Def, !>::from_bits(0);
let b1 = layout::Tree::<Def, !>::from_bits(1);
let b2 = layout::Tree::<Def, !>::from_bits(2);
let alts = [b0, b1, b2];
let into_layout = |alts: Vec<_>| {
alts.into_iter().fold(layout::Tree::<Def, !>::uninhabited(), layout::Tree::<Def, !>::or)
};
let into_set = |alts: Vec<_>| {
#[cfg(feature = "rustc")]
let mut set = rustc_data_structures::fx::FxIndexSet::default();
#[cfg(not(feature = "rustc"))]
let mut set = std::collections::HashSet::new();
set.extend(alts);
set
};
for src_alts in alts.clone().into_iter().powerset() {
let src_layout = into_layout(src_alts.clone());
let src_set = into_set(src_alts.clone());
for dst_alts in alts.clone().into_iter().powerset().filter(|alts| !alts.is_empty()) {
let dst_layout = into_layout(dst_alts.clone());
let dst_set = into_set(dst_alts.clone());
if src_set.is_subset(&dst_set) {
assert_eq!(
Answer::Yes,
is_transmutable(&src_layout, &dst_layout, Assume::default()),
"{:?} SHOULD be transmutable into {:?}",
src_layout,
dst_layout
);
} else if !src_set.is_disjoint(&dst_set) {
assert_eq!(
Answer::Yes,
is_transmutable(
&src_layout,
&dst_layout,
Assume { validity: true, ..Assume::default() }
),
"{:?} SHOULD be transmutable (assuming validity) into {:?}",
src_layout,
dst_layout
);
} else {
assert_eq!(
Answer::No(Reason::DstIsBitIncompatible),
is_transmutable(&src_layout, &dst_layout, Assume::default()),
"{:?} should NOT be transmutable into {:?}",
src_layout,
dst_layout
);
}
}
}
}
}
mod union {
use super::*;
#[test]
fn union() {
let [a, b, c, d] = [0, 1, 2, 3];
let s = Dfa::from_edges(a, d, &[(a, 0, b), (b, 0, d), (a, 1, c), (c, 1, d)]);
let t = Dfa::from_edges(a, c, &[(a, 1, b), (b, 0, c)]);
let mut ctr = 0;
let new_state = || {
let state = crate::layout::dfa::State(ctr);
ctr += 1;
state
};
let u = s.clone().union(t.clone(), new_state);
let expected_u =
Dfa::from_edges(b, a, &[(b, 0, c), (b, 1, d), (d, 1, a), (d, 0, a), (c, 0, a)]);
assert_eq!(u, expected_u);
assert_eq!(is_transmutable(&s, &u, Assume::default()), Answer::Yes);
assert_eq!(is_transmutable(&t, &u, Assume::default()), Answer::Yes);
}
}
|
