| // Copyright 2018 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use std::fmt; |
| |
| use crate::ty::{Ty, subst::Substs, layout::{HasDataLayout, Size}}; |
| use crate::hir::def_id::DefId; |
| |
| use super::{EvalResult, 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)] |
| 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 which |
| /// matches the LocalValue optimizations for easy conversions between Value and ConstValue. |
| #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord, RustcEncodable, RustcDecodable, Hash)] |
| pub enum ConstValue<'tcx> { |
| /// Never returned from the `const_eval` query, but the HIR contains these frequently in order |
| /// to allow HIR creation to happen for everything before needing to be able to run constant |
| /// evaluation |
| /// FIXME: The query should then return a type that does not even have this variant. |
| Unevaluated(DefId, &'tcx Substs<'tcx>), |
| |
| /// 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 *fat pointers* with layout::abi::ScalarPair |
| /// |
| /// Needed for pattern matching code related to slices and strings. |
| ScalarPair(Scalar, Scalar), |
| |
| /// An allocation + offset into the allocation. |
| /// Invariant: The AllocId matches the allocation. |
| ByRef(AllocId, &'tcx Allocation, Size), |
| } |
| |
| impl<'tcx> ConstValue<'tcx> { |
| #[inline] |
| pub fn try_to_scalar(&self) -> Option<Scalar> { |
| match *self { |
| ConstValue::Unevaluated(..) | |
| ConstValue::ByRef(..) | |
| ConstValue::ScalarPair(..) => 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() |
| } |
| |
| #[inline] |
| pub fn new_slice( |
| val: Scalar, |
| len: u64, |
| cx: &impl HasDataLayout |
| ) -> Self { |
| ConstValue::ScalarPair(val, Scalar::Bits { |
| bits: len as u128, |
| size: cx.data_layout().pointer_size.bytes() as u8, |
| }) |
| } |
| |
| #[inline] |
| pub fn new_dyn_trait(val: Scalar, vtable: Pointer) -> Self { |
| ConstValue::ScalarPair(val, Scalar::Ptr(vtable)) |
| } |
| } |
| |
| /// 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, Debug, Eq, PartialEq, Ord, PartialOrd, RustcEncodable, RustcDecodable, Hash)] |
| pub enum Scalar<Tag=(), Id=AllocId> { |
| /// The raw bytes of a simple value. |
| Bits { |
| /// The first `size` bytes are the value. |
| /// Do not try to read less or more bytes that that. The remaining bytes must be 0. |
| size: u8, |
| bits: u128, |
| }, |
| |
| /// 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>), |
| } |
| |
| 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::Bits { bits, .. } => write!(f, "{}", bits), |
| } |
| } |
| } |
| |
| impl<'tcx> Scalar<()> { |
| #[inline] |
| pub fn with_default_tag<Tag>(self) -> Scalar<Tag> |
| where Tag: Default |
| { |
| match self { |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.with_default_tag()), |
| Scalar::Bits { bits, size } => Scalar::Bits { bits, size }, |
| } |
| } |
| } |
| |
| impl<'tcx, Tag> Scalar<Tag> { |
| #[inline] |
| pub fn erase_tag(self) -> Scalar { |
| match self { |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.erase_tag()), |
| Scalar::Bits { bits, size } => Scalar::Bits { bits, size }, |
| } |
| } |
| |
| #[inline] |
| pub fn with_tag(self, new_tag: Tag) -> Self { |
| match self { |
| Scalar::Ptr(ptr) => Scalar::Ptr(Pointer { tag: new_tag, ..ptr }), |
| Scalar::Bits { bits, size } => Scalar::Bits { bits, size }, |
| } |
| } |
| |
| #[inline] |
| pub fn ptr_null(cx: &impl HasDataLayout) -> Self { |
| Scalar::Bits { |
| bits: 0, |
| size: cx.data_layout().pointer_size.bytes() as u8, |
| } |
| } |
| |
| #[inline] |
| pub fn zst() -> Self { |
| Scalar::Bits { bits: 0, size: 0 } |
| } |
| |
| #[inline] |
| pub fn ptr_offset(self, i: Size, cx: &impl HasDataLayout) -> EvalResult<'tcx, Self> { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Bits { bits, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Ok(Scalar::Bits { |
| bits: dl.offset(bits 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::Bits { bits, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Scalar::Bits { |
| bits: dl.overflowing_offset(bits 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) -> EvalResult<'tcx, Self> { |
| let dl = cx.data_layout(); |
| match self { |
| Scalar::Bits { bits, size } => { |
| assert_eq!(size as u64, dl.pointer_size().bytes()); |
| Ok(Scalar::Bits { |
| bits: dl.signed_offset(bits 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::Bits { bits, size } => { |
| assert_eq!(size as u64, dl.pointer_size.bytes()); |
| Scalar::Bits { |
| bits: dl.overflowing_signed_offset(bits as u64, i128::from(i)).0 as u128, |
| size, |
| } |
| } |
| Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_signed_offset(i, dl)), |
| } |
| } |
| |
| /// Returns this pointers offset from the allocation base, or from NULL (for |
| /// integer pointers). |
| #[inline] |
| pub fn get_ptr_offset(self, cx: &impl HasDataLayout) -> Size { |
| match self { |
| Scalar::Bits { bits, size } => { |
| assert_eq!(size as u64, cx.pointer_size().bytes()); |
| Size::from_bytes(bits as u64) |
| } |
| Scalar::Ptr(ptr) => ptr.offset, |
| } |
| } |
| |
| #[inline] |
| pub fn is_null_ptr(self, cx: &impl HasDataLayout) -> bool { |
| match self { |
| Scalar::Bits { bits, size } => { |
| assert_eq!(size as u64, cx.data_layout().pointer_size.bytes()); |
| bits == 0 |
| }, |
| Scalar::Ptr(_) => false, |
| } |
| } |
| |
| #[inline] |
| pub fn from_bool(b: bool) -> Self { |
| Scalar::Bits { bits: b as u128, size: 1 } |
| } |
| |
| #[inline] |
| pub fn from_char(c: char) -> Self { |
| Scalar::Bits { bits: c as u128, size: 4 } |
| } |
| |
| #[inline] |
| pub fn from_uint(i: impl Into<u128>, size: Size) -> Self { |
| let i = i.into(); |
| debug_assert_eq!(truncate(i, size), i, |
| "Unsigned value {} does not fit in {} bits", i, size.bits()); |
| Scalar::Bits { bits: i, size: size.bytes() as u8 } |
| } |
| |
| #[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); |
| debug_assert_eq!(sign_extend(truncated, size) as i128, i, |
| "Signed value {} does not fit in {} bits", i, size.bits()); |
| Scalar::Bits { bits: truncated, size: size.bytes() as u8 } |
| } |
| |
| #[inline] |
| pub fn from_f32(f: f32) -> Self { |
| Scalar::Bits { bits: f.to_bits() as u128, size: 4 } |
| } |
| |
| #[inline] |
| pub fn from_f64(f: f64) -> Self { |
| Scalar::Bits { bits: f.to_bits() as u128, size: 8 } |
| } |
| |
| #[inline] |
| pub fn to_bits(self, target_size: Size) -> EvalResult<'tcx, u128> { |
| match self { |
| Scalar::Bits { bits, size } => { |
| assert_eq!(target_size.bytes(), size as u64); |
| assert_ne!(size, 0, "to_bits cannot be used with zsts"); |
| Ok(bits) |
| } |
| Scalar::Ptr(_) => err!(ReadPointerAsBytes), |
| } |
| } |
| |
| #[inline] |
| pub fn to_ptr(self) -> EvalResult<'tcx, Pointer<Tag>> { |
| match self { |
| Scalar::Bits { bits: 0, .. } => err!(InvalidNullPointerUsage), |
| Scalar::Bits { .. } => err!(ReadBytesAsPointer), |
| Scalar::Ptr(p) => Ok(p), |
| } |
| } |
| |
| #[inline] |
| pub fn is_bits(self) -> bool { |
| match self { |
| Scalar::Bits { .. } => true, |
| _ => false, |
| } |
| } |
| |
| #[inline] |
| pub fn is_ptr(self) -> bool { |
| match self { |
| Scalar::Ptr(_) => true, |
| _ => false, |
| } |
| } |
| |
| pub fn to_bool(self) -> EvalResult<'tcx, bool> { |
| match self { |
| Scalar::Bits { bits: 0, size: 1 } => Ok(false), |
| Scalar::Bits { bits: 1, size: 1 } => Ok(true), |
| _ => err!(InvalidBool), |
| } |
| } |
| |
| pub fn to_char(self) -> EvalResult<'tcx, char> { |
| let val = self.to_u32()?; |
| match ::std::char::from_u32(val) { |
| Some(c) => Ok(c), |
| None => err!(InvalidChar(val as u128)), |
| } |
| } |
| |
| pub fn to_u8(self) -> EvalResult<'static, u8> { |
| let sz = Size::from_bits(8); |
| let b = self.to_bits(sz)?; |
| assert_eq!(b as u8 as u128, b); |
| Ok(b as u8) |
| } |
| |
| pub fn to_u32(self) -> EvalResult<'static, u32> { |
| let sz = Size::from_bits(32); |
| let b = self.to_bits(sz)?; |
| assert_eq!(b as u32 as u128, b); |
| Ok(b as u32) |
| } |
| |
| pub fn to_u64(self) -> EvalResult<'static, u64> { |
| let sz = Size::from_bits(64); |
| let b = self.to_bits(sz)?; |
| assert_eq!(b as u64 as u128, b); |
| Ok(b as u64) |
| } |
| |
| pub fn to_usize(self, cx: &impl HasDataLayout) -> EvalResult<'static, u64> { |
| let b = self.to_bits(cx.data_layout().pointer_size)?; |
| assert_eq!(b as u64 as u128, b); |
| Ok(b as u64) |
| } |
| |
| pub fn to_i8(self) -> EvalResult<'static, i8> { |
| let sz = Size::from_bits(8); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| assert_eq!(b as i8 as i128, b); |
| Ok(b as i8) |
| } |
| |
| pub fn to_i32(self) -> EvalResult<'static, i32> { |
| let sz = Size::from_bits(32); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| assert_eq!(b as i32 as i128, b); |
| Ok(b as i32) |
| } |
| |
| pub fn to_i64(self) -> EvalResult<'static, i64> { |
| let sz = Size::from_bits(64); |
| let b = self.to_bits(sz)?; |
| let b = sign_extend(b, sz) as i128; |
| assert_eq!(b as i64 as i128, b); |
| Ok(b as i64) |
| } |
| |
| pub fn to_isize(self, cx: &impl HasDataLayout) -> EvalResult<'static, i64> { |
| let b = self.to_bits(cx.data_layout().pointer_size)?; |
| let b = sign_extend(b, cx.data_layout().pointer_size) as i128; |
| assert_eq!(b as i64 as i128, b); |
| Ok(b as i64) |
| } |
| |
| #[inline] |
| pub fn to_f32(self) -> EvalResult<'static, f32> { |
| Ok(f32::from_bits(self.to_u32()?)) |
| } |
| |
| #[inline] |
| pub fn to_f64(self) -> EvalResult<'static, f64> { |
| Ok(f64::from_bits(self.to_u64()?)) |
| } |
| } |
| |
| impl<Tag> From<Pointer<Tag>> for Scalar<Tag> { |
| #[inline(always)] |
| fn from(ptr: Pointer<Tag>) -> Self { |
| Scalar::Ptr(ptr) |
| } |
| } |
| |
| #[derive(Clone, Copy, Debug, 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::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> ScalarMaybeUndef<()> { |
| #[inline] |
| pub fn with_default_tag<Tag>(self) -> ScalarMaybeUndef<Tag> |
| where Tag: Default |
| { |
| match self { |
| ScalarMaybeUndef::Scalar(s) => ScalarMaybeUndef::Scalar(s.with_default_tag()), |
| ScalarMaybeUndef::Undef => ScalarMaybeUndef::Undef, |
| } |
| } |
| } |
| |
| impl<'tcx, Tag> ScalarMaybeUndef<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) -> EvalResult<'static, Scalar<Tag>> { |
| match self { |
| ScalarMaybeUndef::Scalar(scalar) => Ok(scalar), |
| ScalarMaybeUndef::Undef => err!(ReadUndefBytes(Size::from_bytes(0))), |
| } |
| } |
| |
| #[inline(always)] |
| pub fn to_ptr(self) -> EvalResult<'tcx, Pointer<Tag>> { |
| self.not_undef()?.to_ptr() |
| } |
| |
| #[inline(always)] |
| pub fn to_bits(self, target_size: Size) -> EvalResult<'tcx, u128> { |
| self.not_undef()?.to_bits(target_size) |
| } |
| |
| #[inline(always)] |
| pub fn to_bool(self) -> EvalResult<'tcx, bool> { |
| self.not_undef()?.to_bool() |
| } |
| |
| #[inline(always)] |
| pub fn to_char(self) -> EvalResult<'tcx, char> { |
| self.not_undef()?.to_char() |
| } |
| |
| #[inline(always)] |
| pub fn to_f32(self) -> EvalResult<'tcx, f32> { |
| self.not_undef()?.to_f32() |
| } |
| |
| #[inline(always)] |
| pub fn to_f64(self) -> EvalResult<'tcx, f64> { |
| self.not_undef()?.to_f64() |
| } |
| |
| #[inline(always)] |
| pub fn to_u8(self) -> EvalResult<'tcx, u8> { |
| self.not_undef()?.to_u8() |
| } |
| |
| #[inline(always)] |
| pub fn to_u32(self) -> EvalResult<'tcx, u32> { |
| self.not_undef()?.to_u32() |
| } |
| |
| #[inline(always)] |
| pub fn to_u64(self) -> EvalResult<'tcx, u64> { |
| self.not_undef()?.to_u64() |
| } |
| |
| #[inline(always)] |
| pub fn to_usize(self, cx: &impl HasDataLayout) -> EvalResult<'tcx, u64> { |
| self.not_undef()?.to_usize(cx) |
| } |
| |
| #[inline(always)] |
| pub fn to_i8(self) -> EvalResult<'tcx, i8> { |
| self.not_undef()?.to_i8() |
| } |
| |
| #[inline(always)] |
| pub fn to_i32(self) -> EvalResult<'tcx, i32> { |
| self.not_undef()?.to_i32() |
| } |
| |
| #[inline(always)] |
| pub fn to_i64(self) -> EvalResult<'tcx, i64> { |
| self.not_undef()?.to_i64() |
| } |
| |
| #[inline(always)] |
| pub fn to_isize(self, cx: &impl HasDataLayout) -> EvalResult<'tcx, i64> { |
| self.not_undef()?.to_isize(cx) |
| } |
| } |
| |
| impl_stable_hash_for!(enum ::mir::interpret::ScalarMaybeUndef { |
| Scalar(v), |
| Undef |
| }); |