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ScalarInt: size mismatches are a bug, do not delay the panic

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This commit is contained in:
Ralf Jung
2024-06-08 16:13:45 +02:00
parent 13423befc4
commit 3c57ea0df7
45 changed files with 247 additions and 313 deletions
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15
compiler/rustc_const_eval/src/interpret/discriminant.rs
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@@ -123,14 +123,14 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
// (`tag_bits` itself is only used for error messages below.)
let tag_bits = tag_val
.to_scalar()
.try_to_int()
.try_to_scalar_int()
.map_err(|dbg_val| err_ub!(InvalidTag(dbg_val)))?
.assert_bits(tag_layout.size);
.to_bits(tag_layout.size);
// Cast bits from tag layout to discriminant layout.
// After the checks we did above, this cannot fail, as
// discriminants are int-like.
let discr_val = self.int_to_int_or_float(&tag_val, discr_layout).unwrap();
let discr_bits = discr_val.to_scalar().assert_bits(discr_layout.size);
let discr_bits = discr_val.to_scalar().to_bits(discr_layout.size)?;
// Convert discriminant to variant index, and catch invalid discriminants.
let index = match *ty.kind() {
ty::Adt(adt, _) => {
@@ -152,7 +152,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
// discriminant (encoded in niche/tag) and variant index are the same.
let variants_start = niche_variants.start().as_u32();
let variants_end = niche_variants.end().as_u32();
let variant = match tag_val.try_to_int() {
let variant = match tag_val.try_to_scalar_int() {
Err(dbg_val) => {
// So this is a pointer then, and casting to an int failed.
// Can only happen during CTFE.
@@ -167,7 +167,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
untagged_variant
}
Ok(tag_bits) => {
let tag_bits = tag_bits.assert_bits(tag_layout.size);
let tag_bits = tag_bits.to_bits(tag_layout.size);
// We need to use machine arithmetic to get the relative variant idx:
// variant_index_relative = tag_val - niche_start_val
let tag_val = ImmTy::from_uint(tag_bits, tag_layout);
@@ -175,7 +175,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
let variant_index_relative_val =
self.binary_op(mir::BinOp::Sub, &tag_val, &niche_start_val)?;
let variant_index_relative =
variant_index_relative_val.to_scalar().assert_bits(tag_val.layout.size);
variant_index_relative_val.to_scalar().to_bits(tag_val.layout.size)?;
// Check if this is in the range that indicates an actual discriminant.
if variant_index_relative <= u128::from(variants_end - variants_start) {
let variant_index_relative = u32::try_from(variant_index_relative)
@@ -294,8 +294,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
ImmTy::from_uint(variant_index_relative, tag_layout);
let tag = self
.binary_op(mir::BinOp::Add, &variant_index_relative_val, &niche_start_val)?
.to_scalar()
.assert_int();
.to_scalar_int()?;
Ok(Some((tag, tag_field)))
}
}