mathieu/granite-rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Remove map_layouts.

Browse source 
As per the `FIXME` comment, it's an abstraction that makes the code
harder to read.
This commit is contained in:
Nicholas Nethercote 2023-10-06 11:20:02 +11:00
parent 409193654d
commit 449b84cb99
1 changed files with 33 additions and 57 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

90
compiler/rustc_transmute/src/maybe_transmutable/mod.rs
View file

@ -32,26 +32,6 @@ where
) -> Self {
Self { src, dst, scope, assume, context }
}
// FIXME(bryangarza): Delete this when all usages are removed
pub(crate) fn map_layouts<F, M>(
self,
f: F,
) -> Result<MaybeTransmutableQuery<M, C>, Answer<<C as QueryContext>::Ref>>
where
F: FnOnce(
L,
L,
<C as QueryContext>::Scope,
&C,
) -> Result<(M, M), Answer<<C as QueryContext>::Ref>>,
{
let Self { src, dst, scope, assume, context } = self;
let (src, dst) = f(src, dst, scope, &context)?;
Ok(MaybeTransmutableQuery { src, dst, scope, assume, context })
}
}
// FIXME: Nix this cfg, so we can write unit tests independently of rustc
@ -107,42 +87,42 @@ where
#[instrument(level = "debug", skip(self), fields(src = ?self.src, dst = ?self.dst))]
pub(crate) fn answer(self) -> Answer<<C as QueryContext>::Ref> {
let assume_visibility = self.assume.safety;
// FIXME(bryangarza): Refactor this code to get rid of `map_layouts`
let query_or_answer = self.map_layouts(|src, dst, scope, context| {
// Remove all `Def` nodes from `src`, without checking their visibility.
let src = src.prune(&|def| true);
trace!(?src, "pruned src");
let Self { src, dst, scope, assume, context } = self;
// Remove all `Def` nodes from `dst`, additionally...
let dst = if assume_visibility {
// ...if visibility is assumed, don't check their visibility.
dst.prune(&|def| true)
} else {
// ...otherwise, prune away all unreachable paths through the `Dst` layout.
dst.prune(&|def| context.is_accessible_from(def, scope))
};
// Remove all `Def` nodes from `src`, without checking their visibility.
let src = src.prune(&|def| true);
trace!(?dst, "pruned dst");
trace!(?src, "pruned src");
// Convert `src` from a tree-based representation to an NFA-based representation.
// If the conversion fails because `src` is uninhabited, conclude that the transmutation
// is acceptable, because instances of the `src` type do not exist.
let src = Nfa::from_tree(src).map_err(|Uninhabited| Answer::Yes)?;
// Remove all `Def` nodes from `dst`, additionally...
let dst = if assume_visibility {
// ...if visibility is assumed, don't check their visibility.
dst.prune(&|def| true)
} else {
// ...otherwise, prune away all unreachable paths through the `Dst` layout.
dst.prune(&|def| context.is_accessible_from(def, scope))
};
// Convert `dst` from a tree-based representation to an NFA-based representation.
// If the conversion fails because `src` is uninhabited, conclude that the transmutation
// is unacceptable, because instances of the `dst` type do not exist.
let dst =
Nfa::from_tree(dst).map_err(|Uninhabited| Answer::No(Reason::DstIsPrivate))?;
trace!(?dst, "pruned dst");
Ok((src, dst))
});
// Convert `src` from a tree-based representation to an NFA-based representation.
// If the conversion fails because `src` is uninhabited, conclude that the transmutation
// is acceptable, because instances of the `src` type do not exist.
let src = match Nfa::from_tree(src) {
Ok(src) => src,
Err(Uninhabited) => return Answer::Yes,
};
match query_or_answer {
Ok(query) => query.answer(),
Err(answer) => answer,
}
// Convert `dst` from a tree-based representation to an NFA-based representation.
// If the conversion fails because `src` is uninhabited, conclude that the transmutation
// is unacceptable, because instances of the `dst` type do not exist.
let dst = match Nfa::from_tree(dst) {
Ok(dst) => dst,
Err(Uninhabited) => return Answer::No(Reason::DstIsPrivate),
};
MaybeTransmutableQuery { src, dst, scope, assume, context }.answer()
}
}
@ -156,14 +136,10 @@ where
#[inline(always)]
#[instrument(level = "debug", skip(self), fields(src = ?self.src, dst = ?self.dst))]
pub(crate) fn answer(self) -> Answer<<C as QueryContext>::Ref> {
// FIXME(bryangarza): Refactor this code to get rid of `map_layouts`
let query_or_answer = self
.map_layouts(|src, dst, scope, context| Ok((Dfa::from_nfa(src), Dfa::from_nfa(dst))));
match query_or_answer {
Ok(query) => query.answer(),
Err(answer) => answer,
}
let Self { src, dst, scope, assume, context } = self;
let src = Dfa::from_nfa(src);
let dst = Dfa::from_nfa(dst);
MaybeTransmutableQuery { src, dst, scope, assume, context }.answer()
}
}