bjoernager/rust
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compiler: Add is_uninhabited and use LayoutS accessors

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This reduces the need of the compiler to peek on the fields of LayoutS.
This commit is contained in:
Jubilee Young 2024-10-27 21:34:49 -07:00
parent 5f5c243ca0
commit 88a9edc091
20 changed files with 40 additions and 37 deletions
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4
compiler/rustc_codegen_ssa/src/mir/block.rs
View file

@ -438,7 +438,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
_ => bug!("C-variadic function must have a `VaList` place"),
}
}
if self.fn_abi.ret.layout.abi.is_uninhabited() {
if self.fn_abi.ret.layout.is_uninhabited() {
// Functions with uninhabited return values are marked `noreturn`,
// so we should make sure that we never actually do.
// We play it safe by using a well-defined `abort`, but we could go for immediate UB
@ -774,7 +774,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
Some(if do_panic {
let msg_str = with_no_visible_paths!({
with_no_trimmed_paths!({
if layout.abi.is_uninhabited() {
if layout.is_uninhabited() {
// Use this error even for the other intrinsics as it is more precise.
format!("attempted to instantiate uninhabited type `{ty}`")
} else if requirement == ValidityRequirement::Zero {

6
compiler/rustc_codegen_ssa/src/mir/place.rs
View file

@ -55,7 +55,7 @@ impl<V: CodegenObject> PlaceValue<V> {
/// Creates a `PlaceRef` to this location with the given type.
pub fn with_type<'tcx>(self, layout: TyAndLayout<'tcx>) -> PlaceRef<'tcx, V> {
assert!(
layout.is_unsized() || layout.abi.is_uninhabited() || self.llextra.is_none(),
layout.is_unsized() || layout.is_uninhabited() || self.llextra.is_none(),
"Had pointer metadata {:?} for sized type {layout:?}",
self.llextra,
);
@ -239,7 +239,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
let dl = &bx.tcx().data_layout;
let cast_to_layout = bx.cx().layout_of(cast_to);
let cast_to = bx.cx().immediate_backend_type(cast_to_layout);
if self.layout.abi.is_uninhabited() {
if self.layout.is_uninhabited() {
return bx.cx().const_poison(cast_to);
}
let (tag_scalar, tag_encoding, tag_field) = match self.layout.variants {
@ -358,7 +358,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
bx: &mut Bx,
variant_index: VariantIdx,
) {
if self.layout.for_variant(bx.cx(), variant_index).abi.is_uninhabited() {
if self.layout.for_variant(bx.cx(), variant_index).is_uninhabited() {
// We play it safe by using a well-defined `abort`, but we could go for immediate UB
// if that turns out to be helpful.
bx.abort();

8
compiler/rustc_codegen_ssa/src/mir/rvalue.rs
View file

@ -203,10 +203,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
) -> Option<OperandValue<Bx::Value>> {
// Check for transmutes that are always UB.
if operand.layout.size != cast.size
|| operand.layout.abi.is_uninhabited()
|| cast.abi.is_uninhabited()
|| operand.layout.is_uninhabited()
|| cast.is_uninhabited()
{
if !operand.layout.abi.is_uninhabited() {
if !operand.layout.is_uninhabited() {
// Since this is known statically and the input could have existed
// without already having hit UB, might as well trap for it.
bx.abort();
@ -555,7 +555,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
assert!(bx.cx().is_backend_immediate(cast));
let to_backend_ty = bx.cx().immediate_backend_type(cast);
if operand.layout.abi.is_uninhabited() {
if operand.layout.is_uninhabited() {
let val = OperandValue::Immediate(bx.cx().const_poison(to_backend_ty));
return OperandRef { val, layout: cast };
}