Skip to content

CTFE: tweak aggregate rvalue handling #89370

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Oct 1, 2021
Merged

CTFE: tweak aggregate rvalue handling #89370

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
35f74c2
remove outdated comment
RalfJung Sep 29, 2021
268bb46
CTFE: extra assertions for Aggregate rvalues; remove unnecessarily ea…
RalfJung Sep 29, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 9 additions & 8 deletions compiler/rustc_const_eval/src/interpret/step.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -197,12 +197,17 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}

Aggregate(ref kind, ref operands) => {
// active_field_index is for union initialization.
let (dest, active_field_index) = match **kind {
mir::AggregateKind::Adt(adt_def, variant_index, _, _, active_field_index) => {
self.write_discriminant(variant_index, &dest)?;
if adt_def.is_enum() {
(self.place_downcast(&dest, variant_index)?, active_field_index)
assert!(active_field_index.is_none());
(self.place_downcast(&dest, variant_index)?, None)
} else {
if active_field_index.is_some() {
assert_eq!(operands.len(), 1);
}
(dest, active_field_index)
}
}
Expand All @@ -211,12 +216,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {

for (i, operand) in operands.iter().enumerate() {
let op = self.eval_operand(operand, None)?;
// Ignore zero-sized fields.
if !op.layout.is_zst() {
let field_index = active_field_index.unwrap_or(i);
let field_dest = self.place_field(&dest, field_index)?;
self.copy_op(&op, &field_dest)?;
}
let field_index = active_field_index.unwrap_or(i);
let field_dest = self.place_field(&dest, field_index)?;
self.copy_op(&op, &field_dest)?;
}
}

Expand Down Expand Up @@ -253,7 +255,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}

Len(place) => {
// FIXME(CTFE): don't allow computing the length of arrays in const eval
let src = self.eval_place(place)?;
let mplace = self.force_allocation(&src)?;
let len = mplace.len(self)?;
Expand Down