| use std::fmt; |
| use rustc_macros::HashStable; |
| use rustc_apfloat::{Float, ieee::{Double, Single}}; |
| |
| use crate::ty::{Ty, InferConst, ParamConst, layout::{HasDataLayout, Size}, subst::SubstsRef}; |
| use crate::ty::PlaceholderConst; |
| use crate::hir::def_id::DefId; |
| |
| use super::{InterpResult, Pointer, PointerArithmetic, Allocation, AllocId, sign_extend, truncate}; |
| |
| /// Represents the result of a raw const operation, pre-validation. |
| #[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash, HashStable)] |
| pub struct RawConst<'tcx> { |
| // the value lives here, at offset 0, and that allocation definitely is a `AllocKind::Memory` |
| // (so you can use `AllocMap::unwrap_memory`). |
| pub alloc_id: AllocId, |
| pub ty: Ty<'tcx>, |
| } |
| |
| /// Represents a constant value in Rust. `Scalar` and `ScalarPair` are optimizations that |
| /// match the `LocalState` optimizations for easy conversions between `Value` and `ConstValue`. |
| #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, |
| RustcEncodable, RustcDecodable, Hash, HashStable)] |
| pub enum ConstValue<'tcx> { |
| /// A const generic parameter. |
| Param(ParamConst), |
| |
| /// Infer the value of the const. |
| Infer(InferConst<'tcx>), |
| |
| /// A placeholder const - universally quantified higher-ranked const. |
| Placeholder(PlaceholderConst), |
| |
| /// Used only for types with `layout::abi::Scalar` ABI and ZSTs. |
| /// |
| /// Not using the enum `Value` to encode that this must not be `Undef`. |
| Scalar(Scalar), |
| |
| /// Used only for `&[u8]` and `&str` |
| Slice { |
| data: &'tcx Allocation, |
| start: usize, |
| end: usize, |
| }, |
| |
| /// A value not represented/representable by `Scalar` or `Slice` |
| ByRef { |
| /// The backing memory of the value, may contain more memory than needed for just the value |
| /// in order to share `Allocation`s between values |
| alloc: &'tcx Allocation, |
| /// Offset into `alloc` |
| offset: Size, |
| }, |
| |
| /// Used in the HIR by using `Unevaluated` everywhere and later normalizing to one of the other |
| /// variants when the code is monomorphic enough for that. |
| Unevaluated(DefId, SubstsRef<'tcx>), |
| } |
| |
| #[cfg(target_arch = "x86_64")] |
| static_assert_size!(ConstValue<'_>, 32); |
| |
| impl<'tcx> ConstValue<'tcx> { |
| #[inline] |
| pub fn try_to_scalar(&self) -> Option<Scalar> { |
| match *self { |
| ConstValue::Param(_) | |
| ConstValue::Infer(_) | |
| ConstValue::Placeholder(_) | |
| ConstValue::ByRef{ .. } | |
| ConstValue::Unevaluated(..) | |
| ConstValue::Slice { .. } => None, |
| ConstValue::Scalar(val) => Some(val), |
| } |
| } |
| |
| #[inline] |
| pub fn try_to_bits(&self, size: Size) -> Option<u128> { |
| self.try_to_scalar()?.to_bits(size).ok() |
| } |
| |
| #[inline] |
| pub fn try_to_ptr(&self) -> Option<Pointer> { |
| self.try_to_scalar()?.to_ptr().ok() |
| } |
| } |
| |
| /// A `Scalar` represents an immediate, primitive value existing outside of a |
| /// `memory::Allocation`. It is in many ways like a small chunk of a `Allocation`, up to 8 bytes in |
| /// size. Like a range of bytes in an `Allocation`, a `Scalar` can either represent the raw bytes |
| /// of a simple value or a pointer into another `Allocation` |
| #[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, |
| RustcEncodable, RustcDecodable, Hash, HashStable)] |
| pub enum Scalar<Tag=(), Id=AllocId> { |
| /// The raw bytes of a simple value. |
| Raw { |
| /// The first `size` bytes of `data` are the value. |
| /// Do not try to read less or more bytes than that. The remaining bytes must be 0. |
| data: u128, |
| size: u8, |
| }, |
| |
| /// A pointer into an `Allocation`. An `Allocation` in the `memory` module has a list of |
| /// relocations, but a `Scalar` is only large enough to contain one, so we just represent the |
| /// relocation and its associated offset together as a `Pointer` here. |
| Ptr(Pointer<Tag, Id>), |
| } |
| |
| #[cfg(target_arch = "x86_64")] |
| static_assert_size!(Scalar, 24); |
| |
| impl<Tag: fmt::Debug, Id: fmt::Debug> fmt::Debug for Scalar<Tag, Id> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| Scalar::Ptr(ptr) => |
| write!(f, "{:?}", ptr), |
| &Scalar::Raw { data, size } => { |
| Scalar::check_data(data, size); |
| if size == 0 { |
| write!(f, "<ZST>") |
| } else { |
| // Format as hex number wide enough to fit any value of the given `size`. |
| // So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014". |
| write!(f, "0x{:>0width$x}", data, width=(size*2) as usize) |
| } |
| } |
| } |
| } |
| } |
| |
| impl<Tag> fmt::Display for Scalar<Tag> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| Scalar::Ptr(_) => write!(f, "a pointer"), |
| Scalar::Raw { data, .. } => write!(f, "{}", data), |
| } |
| } |
| } |
| |
| impl<Tag> From<Single> for Scalar<Tag> { |
| #[inline(always)] |
| fn from(f: Single) -> Self { |
| Scalar::from_f32(f) |
| } |
| } |
| |
| impl<Tag> From<Double> for Scalar<Tag> { |
| #[inline(always)] |
| fn from(f: Double) -> Self { |
| Scalar::from_f64(f) |
| } |
| } |
| |
| impl Scalar<()> { |
| #[inline(always)] |
| fn check_data(data: u128, size: u8) { |
| debug_assert_eq!(truncate(data, Size::from_bytes(size as u64)), data, |
| "Scalar value {:#x} exceeds size of {} bytes", data, size); |
| } |
| |
| /// Tag this scalar with `new_tag` if it is a pointer, leave it unchanged otherwise. |
| /// |
| /// Used by `MemPlace::replace_tag`. |
| #[inline] |
| pub fn with_tag<Tag>(self, new_tag: Tag) -> Scalar<Tag> { |
| match self { |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.with_tag(new_tag)), |
| Scalar::Raw { data, size } => Scalar::Raw { data, size }, |
| } |
| } |
| } |
| |
| impl<'tcx, Tag> Scalar<Tag> { |
| /// Erase the tag from the scalar, if any. |
| /// |
| /// Used by error reporting code to avoid having the error type depend on `Tag`. |
| #[inline] |
| pub fn erase_tag(self) -> Scalar { |
| match self { |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.erase_tag()), |
| Scalar::Raw { data, size } => Scalar::Raw { data, size }, |
| } |
| } |
| |
| #[inline] |
| pub fn ptr_null(cx: &impl HasDataLayout) -> Self { |
| Scalar::Raw { |
| data: 0, |
| size: cx.data_layout().pointer_size.bytes() as u8, |
| } |
| } |
| |
| #[inline] |
| pub fn zst() -> Self { |
| Scalar::Raw { data: 0, size: 0 } |
| } |
| |
| #[inline] |
| pub fn ptr_offset(self, i: Size, cx: &impl HasDataLayout) -> InterpResult<'tcx, Self> { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Ok(Scalar::Raw { |
| data: dl.offset(data as u64, i.bytes())? as u128, |
| size, |
| }) |
| } |
| Scalar::Ptr(ptr) => ptr.offset(i, dl).map(Scalar::Ptr), |
| } |
| } |
| |
| #[inline] |
| pub fn ptr_wrapping_offset(self, i: Size, cx: &impl HasDataLayout) -> Self { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Scalar::Raw { |
| data: dl.overflowing_offset(data as u64, i.bytes()).0 as u128, |
| size, |
| } |
| } |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_offset(i, dl)), |
| } |
| } |
| |
| #[inline] |
| pub fn ptr_signed_offset(self, i: i64, cx: &impl HasDataLayout) -> InterpResult<'tcx, Self> { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(size as u64, dl.pointer_size().bytes()); |
| Ok(Scalar::Raw { |
| data: dl.signed_offset(data as u64, i)? as u128, |
| size, |
| }) |
| } |
| Scalar::Ptr(ptr) => ptr.signed_offset(i, dl).map(Scalar::Ptr), |
| } |
| } |
| |
| #[inline] |
| pub fn ptr_wrapping_signed_offset(self, i: i64, cx: &impl HasDataLayout) -> Self { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Scalar::Raw { |
| data: dl.overflowing_signed_offset(data as u64, i128::from(i)).0 as u128, |
| size, |
| } |
| } |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_signed_offset(i, dl)), |
| } |
| } |
| |
| #[inline] |
| pub fn from_bool(b: bool) -> Self { |
| Scalar::Raw { data: b as u128, size: 1 } |
| } |
| |
| #[inline] |
| pub fn from_char(c: char) -> Self { |
| Scalar::Raw { data: c as u128, size: 4 } |
| } |
| |
| #[inline] |
| pub fn from_uint(i: impl Into<u128>, size: Size) -> Self { |
| let i = i.into(); |
| assert_eq!( |
| truncate(i, size), i, |
| "Unsigned value {:#x} does not fit in {} bits", i, size.bits() |
| ); |
| Scalar::Raw { data: i, size: size.bytes() as u8 } |
| } |
| |
| #[inline] |
| pub fn from_u8(i: u8) -> Self { |
| Scalar::Raw { data: i as u128, size: 1 } |
| } |
| |
| #[inline] |
| pub fn from_u16(i: u16) -> Self { |
| Scalar::Raw { data: i as u128, size: 2 } |
| } |
| |
| #[inline] |
| pub fn from_u32(i: u32) -> Self { |
| Scalar::Raw { data: i as u128, size: 4 } |
| } |
| |
| #[inline] |
| pub fn from_u64(i: u64) -> Self { |
| Scalar::Raw { data: i as u128, size: 8 } |
| } |
| |
| #[inline] |
| pub fn from_int(i: impl Into<i128>, size: Size) -> Self { |
| let i = i.into(); |
| // `into` performed sign extension, we have to truncate |
| let truncated = truncate(i as u128, size); |
| assert_eq!( |
| sign_extend(truncated, size) as i128, i, |
| "Signed value {:#x} does not fit in {} bits", i, size.bits() |
| ); |
| Scalar::Raw { data: truncated, size: size.bytes() as u8 } |
| } |
| |
| #[inline] |
| pub fn from_f32(f: Single) -> Self { |
| // We trust apfloat to give us properly truncated data. |
| Scalar::Raw { data: f.to_bits(), size: 4 } |
| } |
| |
| #[inline] |
| pub fn from_f64(f: Double) -> Self { |
| // We trust apfloat to give us properly truncated data. |
| Scalar::Raw { data: f.to_bits(), size: 8 } |
| } |
| |
| /// This is very rarely the method you want! You should dispatch on the type |
| /// and use `force_bits`/`assert_bits`/`force_ptr`/`assert_ptr`. |
| /// This method only exists for the benefit of low-level memory operations |
| /// as well as the implementation of the `force_*` methods. |
| #[inline] |
| pub fn to_bits_or_ptr( |
| self, |
| target_size: Size, |
| cx: &impl HasDataLayout, |
| ) -> Result<u128, Pointer<Tag>> { |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(target_size.bytes(), size as u64); |
| assert_ne!(size, 0, "you should never look at the bits of a ZST"); |
| Scalar::check_data(data, size); |
| Ok(data) |
| } |
| Scalar::Ptr(ptr) => { |
| assert_eq!(target_size, cx.data_layout().pointer_size); |
| Err(ptr) |
| } |
| } |
| } |
| |
| /// Do not call this method! Use either `assert_bits` or `force_bits`. |
| #[inline] |
| pub fn to_bits(self, target_size: Size) -> InterpResult<'tcx, u128> { |
| match self { |
| Scalar::Raw { data, size } => { |
| assert_eq!(target_size.bytes(), size as u64); |
| assert_ne!(size, 0, "you should never look at the bits of a ZST"); |
| Scalar::check_data(data, size); |
| Ok(data) |
| } |
| Scalar::Ptr(_) => throw_unsup!(ReadPointerAsBytes), |
| } |
| } |
| |
| #[inline(always)] |
| pub fn assert_bits(self, target_size: Size) -> u128 { |
| self.to_bits(target_size).expect("Expected Raw bits but got a Pointer") |
| } |
| |
| /// Do not call this method! Use either `assert_ptr` or `force_ptr`. |
| #[inline] |
| pub fn to_ptr(self) -> InterpResult<'tcx, Pointer<Tag>> { |
| match self { |
| Scalar::Raw { data: 0, .. } => throw_unsup!(InvalidNullPointerUsage), |
| Scalar::Raw { .. } => throw_unsup!(ReadBytesAsPointer), |
| Scalar::Ptr(p) => Ok(p), |
| } |
| } |
| |
| #[inline(always)] |
| pub fn assert_ptr(self) -> Pointer<Tag> { |
| self.to_ptr().expect("Expected a Pointer but got Raw bits") |
| } |
| |
| /// Do not call this method! Dispatch based on the type instead. |
| #[inline] |
| pub fn is_bits(self) -> bool { |
| match self { |
| Scalar::Raw { .. } => true, |
| _ => false, |
| } |
| } |
| |
| /// Do not call this method! Dispatch based on the type instead. |
| #[inline] |
| pub fn is_ptr(self) -> bool { |
| match self { |
| Scalar::Ptr(_) => true, |
| _ => false, |
| } |
| } |
| |
| pub fn to_bool(self) -> InterpResult<'tcx, bool> { |
| match self { |
| Scalar::Raw { data: 0, size: 1 } => Ok(false), |
| Scalar::Raw { data: 1, size: 1 } => Ok(true), |
| _ => throw_unsup!(InvalidBool), |
| } |
| } |
| |
| pub fn to_char(self) -> InterpResult<'tcx, char> { |
| let val = self.to_u32()?; |
| match ::std::char::from_u32(val) { |
| Some(c) => Ok(c), |
| None => throw_unsup!(InvalidChar(val as u128)), |
| } |
| } |
| |
| pub fn to_u8(self) -> InterpResult<'static, u8> { |
| let sz = Size::from_bits(8); |
| let b = self.to_bits(sz)?; |
| Ok(b as u8) |
| } |
| |
| pub fn to_u32(self) -> InterpResult<'static, u32> { |
| let sz = Size::from_bits(32); |
| let b = self.to_bits(sz)?; |
| Ok(b as u32) |
| } |
| |
| pub fn to_u64(self) -> InterpResult<'static, u64> { |
| let sz = Size::from_bits(64); |
| let b = self.to_bits(sz)?; |
| Ok(b as u64) |
| } |
| |
| pub fn to_usize(self, cx: &impl HasDataLayout) -> InterpResult<'static, u64> { |
| let b = self.to_bits(cx.data_layout().pointer_size)?; |
| Ok(b as u64) |
| } |
| |
| pub fn to_i8(self) -> InterpResult<'static, i8> { |
| let sz = Size::from_bits(8); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| Ok(b as i8) |
| } |
| |
| pub fn to_i32(self) -> InterpResult<'static, i32> { |
| let sz = Size::from_bits(32); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| Ok(b as i32) |
| } |
| |
| pub fn to_i64(self) -> InterpResult<'static, i64> { |
| let sz = Size::from_bits(64); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| Ok(b as i64) |
| } |
| |
| pub fn to_isize(self, cx: &impl HasDataLayout) -> InterpResult<'static, i64> { |
| let sz = cx.data_layout().pointer_size; |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| Ok(b as i64) |
| } |
| |
| #[inline] |
| pub fn to_f32(self) -> InterpResult<'static, Single> { |
| // Going through `u32` to check size and truncation. |
| Ok(Single::from_bits(self.to_u32()? as u128)) |
| } |
| |
| #[inline] |
| pub fn to_f64(self) -> InterpResult<'static, Double> { |
| // Going through `u64` to check size and truncation. |
| Ok(Double::from_bits(self.to_u64()? as u128)) |
| } |
| } |
| |
| impl<Tag> From<Pointer<Tag>> for Scalar<Tag> { |
| #[inline(always)] |
| fn from(ptr: Pointer<Tag>) -> Self { |
| Scalar::Ptr(ptr) |
| } |
| } |
| |
| #[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, RustcEncodable, RustcDecodable, Hash)] |
| pub enum ScalarMaybeUndef<Tag=(), Id=AllocId> { |
| Scalar(Scalar<Tag, Id>), |
| Undef, |
| } |
| |
| impl<Tag> From<Scalar<Tag>> for ScalarMaybeUndef<Tag> { |
| #[inline(always)] |
| fn from(s: Scalar<Tag>) -> Self { |
| ScalarMaybeUndef::Scalar(s) |
| } |
| } |
| |
| impl<Tag: fmt::Debug, Id: fmt::Debug> fmt::Debug for ScalarMaybeUndef<Tag, Id> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| ScalarMaybeUndef::Undef => write!(f, "Undef"), |
| ScalarMaybeUndef::Scalar(s) => write!(f, "{:?}", s), |
| } |
| } |
| } |
| |
| impl<Tag> fmt::Display for ScalarMaybeUndef<Tag> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| ScalarMaybeUndef::Undef => write!(f, "uninitialized bytes"), |
| ScalarMaybeUndef::Scalar(s) => write!(f, "{}", s), |
| } |
| } |
| } |
| |
| impl<'tcx, Tag> ScalarMaybeUndef<Tag> { |
| /// Erase the tag from the scalar, if any. |
| /// |
| /// Used by error reporting code to avoid having the error type depend on `Tag`. |
| #[inline] |
| pub fn erase_tag(self) -> ScalarMaybeUndef |
| { |
| match self { |
| ScalarMaybeUndef::Scalar(s) => ScalarMaybeUndef::Scalar(s.erase_tag()), |
| ScalarMaybeUndef::Undef => ScalarMaybeUndef::Undef, |
| } |
| } |
| |
| #[inline] |
| pub fn not_undef(self) -> InterpResult<'static, Scalar<Tag>> { |
| match self { |
| ScalarMaybeUndef::Scalar(scalar) => Ok(scalar), |
| ScalarMaybeUndef::Undef => throw_unsup!(ReadUndefBytes(Size::from_bytes(0))), |
| } |
| } |
| |
| /// Do not call this method! Use either `assert_ptr` or `force_ptr`. |
| #[inline(always)] |
| pub fn to_ptr(self) -> InterpResult<'tcx, Pointer<Tag>> { |
| self.not_undef()?.to_ptr() |
| } |
| |
| /// Do not call this method! Use either `assert_bits` or `force_bits`. |
| #[inline(always)] |
| pub fn to_bits(self, target_size: Size) -> InterpResult<'tcx, u128> { |
| self.not_undef()?.to_bits(target_size) |
| } |
| |
| #[inline(always)] |
| pub fn to_bool(self) -> InterpResult<'tcx, bool> { |
| self.not_undef()?.to_bool() |
| } |
| |
| #[inline(always)] |
| pub fn to_char(self) -> InterpResult<'tcx, char> { |
| self.not_undef()?.to_char() |
| } |
| |
| #[inline(always)] |
| pub fn to_f32(self) -> InterpResult<'tcx, Single> { |
| self.not_undef()?.to_f32() |
| } |
| |
| #[inline(always)] |
| pub fn to_f64(self) -> InterpResult<'tcx, Double> { |
| self.not_undef()?.to_f64() |
| } |
| |
| #[inline(always)] |
| pub fn to_u8(self) -> InterpResult<'tcx, u8> { |
| self.not_undef()?.to_u8() |
| } |
| |
| #[inline(always)] |
| pub fn to_u32(self) -> InterpResult<'tcx, u32> { |
| self.not_undef()?.to_u32() |
| } |
| |
| #[inline(always)] |
| pub fn to_u64(self) -> InterpResult<'tcx, u64> { |
| self.not_undef()?.to_u64() |
| } |
| |
| #[inline(always)] |
| pub fn to_usize(self, cx: &impl HasDataLayout) -> InterpResult<'tcx, u64> { |
| self.not_undef()?.to_usize(cx) |
| } |
| |
| #[inline(always)] |
| pub fn to_i8(self) -> InterpResult<'tcx, i8> { |
| self.not_undef()?.to_i8() |
| } |
| |
| #[inline(always)] |
| pub fn to_i32(self) -> InterpResult<'tcx, i32> { |
| self.not_undef()?.to_i32() |
| } |
| |
| #[inline(always)] |
| pub fn to_i64(self) -> InterpResult<'tcx, i64> { |
| self.not_undef()?.to_i64() |
| } |
| |
| #[inline(always)] |
| pub fn to_isize(self, cx: &impl HasDataLayout) -> InterpResult<'tcx, i64> { |
| self.not_undef()?.to_isize(cx) |
| } |
| } |
| |
| impl_stable_hash_for!(enum crate::mir::interpret::ScalarMaybeUndef { |
| Scalar(v), |
| Undef |
| }); |