From f7449a21140c109567fa6c756dab2b1b0711a414 Mon Sep 17 00:00:00 2001
From: iximeow <me@iximeow.net>
Date: Sun, 3 May 2020 12:29:24 -0700
Subject: add AddressDiff, CHANGELOG, and bump to 0.0.4
---
src/address/mod.rs | 218 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 214 insertions(+), 4 deletions(-)
(limited to 'src/address')
diff --git a/src/address/mod.rs b/src/address/mod.rs
index edda85d..d3f5113 100644
--- a/src/address/mod.rs
+++ b/src/address/mod.rs
@@ -10,17 +10,227 @@ use num_traits::{Bounded, WrappingAdd, WrappingSub, CheckedAdd, CheckedSub};
#[cfg(feature="use-serde")]
use serde::{Deserialize, Serialize};
+#[cfg(feature="use-serde")]
+pub trait AddressDiffAmount: Copy + Clone + PartialEq + PartialOrd + Eq + Ord + identities::Zero + identities::One + Serialize + for<'de> Deserialize<'de> {}
+#[cfg(not(feature="use-serde"))]
+pub trait AddressDiffAmount: Copy + Clone + PartialEq + PartialOrd + Eq + Ord + identities::Zero + identities::One {}
+
+impl AddressDiffAmount for u64 {}
+impl AddressDiffAmount for u32 {}
+impl AddressDiffAmount for u16 {}
+impl AddressDiffAmount for usize {}
+
+/// a struct describing the differece between some pair of `A: Address`. this is primarily useful
+/// in describing the size of an instruction, or the relative offset of a branch.
+///
+/// for any address type `A`, the following must hold:
+/// ```rust
+/// use yaxpeax_arch::AddressBase;
+/// fn diff_check<A: AddressBase + core::fmt::Debug>(left: A, right: A) {
+/// let diff = left.diff(&right);
+/// if let Some(offset) = diff {
+/// assert_eq!(left.wrapping_offset(offset), right);
+/// }
+/// }
+/// ```
+///
+/// which is to say, `yaxpeax` assumes associativity holds when `diff` yields a `Some`.
+#[cfg(feature="use-serde")]
+#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Serialize, Deserialize)]
+pub struct AddressDiff<T: AddressDiffAmount> {
+ // the AddressDiffAmount trait fools `Deserialize`'s proc macro, so we have to explicitly write
+ // the bound serde should use.
+ #[serde(bound(deserialize = "T: AddressDiffAmount"))]
+ amount: T,
+}
+/// a struct describing the differece between some pair of `A: Address`. this is primarily useful
+/// in describing the size of an instruction, or the relative offset of a branch.
+///
+/// for any address type `A`, the following must hold:
+/// ```rust
+/// use yaxpeax_arch::AddressBase;
+/// fn diff_check<A: AddressBase + core::fmt::Debug>(left: A, right: A) {
+/// let diff = left.diff(&right);
+/// if let Some(offset) = diff {
+/// assert_eq!(left.wrapping_offset(offset), right);
+/// }
+/// }
+/// ```
+///
+/// which is to say, `yaxpeax` assumes associativity holds when `diff` yields a `Some`.
+#[cfg(not(feature="use-serde"))]
+#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord)]
+pub struct AddressDiff<T: AddressDiffAmount> {
+ amount: T,
+}
+
+impl<T: AddressDiffAmount> AddressDiff<T> {
+ pub fn from_const(amount: T) -> Self {
+ AddressDiff { amount }
+ }
+}
+
+impl<T: AddressDiffAmount + fmt::Debug> fmt::Debug for AddressDiff<T> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "AddressDiff({:?})", self.amount)
+ }
+}
+
+impl<T: AddressDiffAmount> AddressDiff<T> {
+ pub fn one() -> Self {
+ AddressDiff {
+ amount: T::one(),
+ }
+ }
+
+ pub fn zero() -> Self {
+ AddressDiff {
+ amount: T::zero(),
+ }
+ }
+}
+
+impl Sub<AddressDiff<u16>> for u16 {
+ type Output = Self;
+
+ fn sub(self, other: AddressDiff<Self>) -> Self::Output {
+ self - other.amount
+ }
+}
+
+impl Sub<AddressDiff<u32>> for u32 {
+ type Output = Self;
+
+ fn sub(self, other: AddressDiff<Self>) -> Self::Output {
+ self - other.amount
+ }
+}
+
+impl Sub<AddressDiff<u64>> for u64 {
+ type Output = Self;
+
+ fn sub(self, other: AddressDiff<Self>) -> Self::Output {
+ self - other.amount
+ }
+}
+
+impl Sub<AddressDiff<usize>> for usize {
+ type Output = Self;
+
+ fn sub(self, other: AddressDiff<Self>) -> Self::Output {
+ self - other.amount
+ }
+}
+
+impl Add<AddressDiff<u16>> for u16 {
+ type Output = Self;
+
+ fn add(self, other: AddressDiff<Self>) -> Self::Output {
+ self + other.amount
+ }
+}
+
+impl Add<AddressDiff<u32>> for u32 {
+ type Output = Self;
+
+ fn add(self, other: AddressDiff<Self>) -> Self::Output {
+ self + other.amount
+ }
+}
+
+impl Add<AddressDiff<u64>> for u64 {
+ type Output = Self;
+
+ fn add(self, other: AddressDiff<Self>) -> Self::Output {
+ self + other.amount
+ }
+}
+
+impl Add<AddressDiff<usize>> for usize {
+ type Output = Self;
+
+ fn add(self, other: AddressDiff<Self>) -> Self::Output {
+ self + other.amount
+ }
+}
+
+impl SubAssign<AddressDiff<u16>> for u16 {
+ fn sub_assign(&mut self, other: AddressDiff<Self>) {
+ *self -= other.amount;
+ }
+}
+
+impl SubAssign<AddressDiff<u32>> for u32 {
+ fn sub_assign(&mut self, other: AddressDiff<Self>) {
+ *self -= other.amount;
+ }
+}
+
+impl SubAssign<AddressDiff<u64>> for u64 {
+ fn sub_assign(&mut self, other: AddressDiff<Self>) {
+ *self -= other.amount;
+ }
+}
+
+impl SubAssign<AddressDiff<usize>> for usize {
+ fn sub_assign(&mut self, other: AddressDiff<Self>) {
+ *self -= other.amount;
+ }
+}
+
+impl AddAssign<AddressDiff<u16>> for u16 {
+ fn add_assign(&mut self, other: AddressDiff<Self>) {
+ *self += other.amount;
+ }
+}
+
+impl AddAssign<AddressDiff<u32>> for u32 {
+ fn add_assign(&mut self, other: AddressDiff<Self>) {
+ *self += other.amount;
+ }
+}
+
+impl AddAssign<AddressDiff<u64>> for u64 {
+ fn add_assign(&mut self, other: AddressDiff<Self>) {
+ *self += other.amount;
+ }
+}
+
+impl AddAssign<AddressDiff<usize>> for usize {
+ fn add_assign(&mut self, other: AddressDiff<Self>) {
+ *self += other.amount;
+ }
+}
+
pub trait AddressBase where Self:
AddressDisplay +
Copy + Clone + Sized + Hash +
Ord + Eq + PartialEq + Bounded +
- Add<Output=Self> + Sub<Output=Self> +
- AddAssign + SubAssign +
+ Add<AddressDiff<Self>, Output=Self> + Sub<AddressDiff<Self>, Output=Self> +
+ AddAssign<AddressDiff<Self>> + SubAssign<AddressDiff<Self>> +
WrappingAdd + WrappingSub +
CheckedAdd + CheckedSub +
- Hash +
- identities::One + identities::Zero {
+ identities::Zero +
+ AddressDiffAmount +
+ Hash {
fn to_linear(&self) -> usize;
+
+ /// compute the `AddressDiff` beetween `self` and `other`.
+ ///
+ /// may return `None` if the two addresses aren't comparable. for example, if a pair of
+ /// addresses are a data-space address and code-space address, there may be no scalar that can
+ /// describe the difference between them.
+ fn diff(&self, other: &Self) -> Option<AddressDiff<Self>> {
+ Some(AddressDiff { amount: self.wrapping_sub(other) })
+ }
+
+ fn wrapping_offset(&self, other: AddressDiff<Self>) -> Self {
+ self.wrapping_add(&other.amount)
+ }
+
+ fn checked_offset(&self, other: AddressDiff<Self>) -> Option<Self> {
+ self.checked_add(&other.amount)
+ }
}
#[cfg(all(feature="use-serde", feature="address-parse"))]
--
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