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pub use Integer::*;
pub use Primitive::*;
use crate::json::{Json, ToJson};
use std::fmt;
use std::ops::Deref;
use rustc_macros::HashStable_Generic;
pub mod call;
pub use rustc_abi::*;
impl ToJson for Endian {
fn to_json(&self) -> Json {
self.as_str().to_json()
}
}
/// The layout of a type, alongside the type itself.
/// Provides various type traversal APIs (e.g., recursing into fields).
///
/// Note that the layout is NOT guaranteed to always be identical
/// to that obtained from `layout_of(ty)`, as we need to produce
/// layouts for which Rust types do not exist, such as enum variants
/// or synthetic fields of enums (i.e., discriminants) and fat pointers.
#[derive(Copy, Clone, PartialEq, Eq, Hash, HashStable_Generic)]
pub struct TyAndLayout<'a, Ty> {
pub ty: Ty,
pub layout: Layout<'a>,
}
impl<'a, Ty: fmt::Display> fmt::Debug for TyAndLayout<'a, Ty> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// Print the type in a readable way, not its debug representation.
f.debug_struct("TyAndLayout")
.field("ty", &format_args!("{}", self.ty))
.field("layout", &self.layout)
.finish()
}
}
impl<'a, Ty> Deref for TyAndLayout<'a, Ty> {
type Target = &'a LayoutS;
fn deref(&self) -> &&'a LayoutS {
&self.layout.0.0
}
}
/// Trait that needs to be implemented by the higher-level type representation
/// (e.g. `rustc_middle::ty::Ty`), to provide `rustc_target::abi` functionality.
pub trait TyAbiInterface<'a, C>: Sized + std::fmt::Debug {
fn ty_and_layout_for_variant(
this: TyAndLayout<'a, Self>,
cx: &C,
variant_index: VariantIdx,
) -> TyAndLayout<'a, Self>;
fn ty_and_layout_field(this: TyAndLayout<'a, Self>, cx: &C, i: usize) -> TyAndLayout<'a, Self>;
fn ty_and_layout_pointee_info_at(
this: TyAndLayout<'a, Self>,
cx: &C,
offset: Size,
) -> Option<PointeeInfo>;
fn is_adt(this: TyAndLayout<'a, Self>) -> bool;
fn is_never(this: TyAndLayout<'a, Self>) -> bool;
fn is_tuple(this: TyAndLayout<'a, Self>) -> bool;
fn is_unit(this: TyAndLayout<'a, Self>) -> bool;
fn is_transparent(this: TyAndLayout<'a, Self>) -> bool;
}
impl<'a, Ty> TyAndLayout<'a, Ty> {
pub fn for_variant<C>(self, cx: &C, variant_index: VariantIdx) -> Self
where
Ty: TyAbiInterface<'a, C>,
{
Ty::ty_and_layout_for_variant(self, cx, variant_index)
}
pub fn field<C>(self, cx: &C, i: usize) -> Self
where
Ty: TyAbiInterface<'a, C>,
{
Ty::ty_and_layout_field(self, cx, i)
}
pub fn pointee_info_at<C>(self, cx: &C, offset: Size) -> Option<PointeeInfo>
where
Ty: TyAbiInterface<'a, C>,
{
Ty::ty_and_layout_pointee_info_at(self, cx, offset)
}
pub fn is_single_fp_element<C>(self, cx: &C) -> bool
where
Ty: TyAbiInterface<'a, C>,
C: HasDataLayout,
{
match self.abi {
Abi::Scalar(scalar) => matches!(scalar.primitive(), F32 | F64),
Abi::Aggregate { .. } => {
if self.fields.count() == 1 && self.fields.offset(0).bytes() == 0 {
self.field(cx, 0).is_single_fp_element(cx)
} else {
false
}
}
_ => false,
}
}
pub fn is_adt<C>(self) -> bool
where
Ty: TyAbiInterface<'a, C>,
{
Ty::is_adt(self)
}
pub fn is_never<C>(self) -> bool
where
Ty: TyAbiInterface<'a, C>,
{
Ty::is_never(self)
}
pub fn is_tuple<C>(self) -> bool
where
Ty: TyAbiInterface<'a, C>,
{
Ty::is_tuple(self)
}
pub fn is_unit<C>(self) -> bool
where
Ty: TyAbiInterface<'a, C>,
{
Ty::is_unit(self)
}
pub fn is_transparent<C>(self) -> bool
where
Ty: TyAbiInterface<'a, C>,
{
Ty::is_transparent(self)
}
pub fn offset_of_subfield<C>(self, cx: &C, indices: impl Iterator<Item = usize>) -> Size
where
Ty: TyAbiInterface<'a, C>,
{
let mut layout = self;
let mut offset = Size::ZERO;
for index in indices {
offset += layout.fields.offset(index);
layout = layout.field(cx, index);
assert!(
layout.is_sized(),
"offset of unsized field (type {:?}) cannot be computed statically",
layout.ty
);
}
offset
}
/// Finds the one field that is not a 1-ZST.
/// Returns `None` if there are multiple non-1-ZST fields or only 1-ZST-fields.
pub fn non_1zst_field<C>(&self, cx: &C) -> Option<(usize, Self)>
where
Ty: TyAbiInterface<'a, C> + Copy,
{
let mut found = None;
for field_idx in 0..self.fields.count() {
let field = self.field(cx, field_idx);
if field.is_1zst() {
continue;
}
if found.is_some() {
// More than one non-1-ZST field.
return None;
}
found = Some((field_idx, field));
}
found
}
}
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