ptr: split out borrowed pointer utilities

The ptr module is intended to be for raw pointers.

Closes #3111
This commit is contained in:
Daniel Micay 2013-06-02 19:16:40 -04:00
parent 077ca79941
commit 454133127a
8 changed files with 72 additions and 53 deletions

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@ -48,6 +48,7 @@ use core::cast;
use core::unstable::sync::UnsafeAtomicRcBox;
use core::ptr;
use core::task;
use core::borrow;
/// As sync::condvar, a mechanism for unlock-and-descheduling and signaling.
pub struct Condvar<'self> {
@ -425,7 +426,7 @@ impl<T:Const + Owned> RWARC<T> {
// of this cast is removing the mutability.)
let new_data = cast::transmute_immut(data);
// Downgrade ensured the token belonged to us. Just a sanity check.
assert!(ptr::ref_eq(&(*state).data, new_data));
assert!(borrow::ref_eq(&(*state).data, new_data));
// Produce new token
RWReadMode {
data: new_data,

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@ -17,6 +17,7 @@
use core::prelude::*;
use core::borrow;
use core::comm;
use core::ptr;
use core::task;
@ -589,7 +590,7 @@ impl RWlock {
/// To be called inside of the write_downgrade block.
pub fn downgrade<'a>(&self, token: RWlockWriteMode<'a>)
-> RWlockReadMode<'a> {
if !ptr::ref_eq(self, token.lock) {
if !borrow::ref_eq(self, token.lock) {
fail!("Can't downgrade() with a different rwlock's write_mode!");
}
unsafe {

60
src/libstd/borrow.rs Normal file
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@ -0,0 +1,60 @@
// Copyright 2012-2013 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.
//! Borrowed pointer utilities
#[cfg(not(test))]
use prelude::*;
/// Cast a region pointer - &T - to a uint.
#[inline(always)]
pub fn to_uint<T>(thing: &T) -> uint {
thing as *T as uint
}
/// Determine if two borrowed pointers point to the same thing.
#[inline(always)]
pub fn ref_eq<'a, 'b, T>(thing: &'a T, other: &'b T) -> bool {
to_uint(thing) == to_uint(other)
}
// Equality for region pointers
#[cfg(not(test))]
impl<'self, T: Eq> Eq for &'self T {
#[inline(always)]
fn eq(&self, other: & &'self T) -> bool {
*(*self) == *(*other)
}
#[inline(always)]
fn ne(&self, other: & &'self T) -> bool {
*(*self) != *(*other)
}
}
// Comparison for region pointers
#[cfg(not(test))]
impl<'self, T: Ord> Ord for &'self T {
#[inline(always)]
fn lt(&self, other: & &'self T) -> bool {
*(*self) < *(*other)
}
#[inline(always)]
fn le(&self, other: & &'self T) -> bool {
*(*self) <= *(*other)
}
#[inline(always)]
fn ge(&self, other: & &'self T) -> bool {
*(*self) >= *(*other)
}
#[inline(always)]
fn gt(&self, other: & &'self T) -> bool {
*(*self) > *(*other)
}
}

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@ -125,6 +125,7 @@ pub mod ascii;
pub mod ptr;
pub mod owned;
pub mod managed;
pub mod borrow;
/* Core language traits */

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@ -255,18 +255,6 @@ pub fn to_mut_unsafe_ptr<T>(thing: &mut T) -> *mut T {
thing as *mut T
}
/// Cast a region pointer - &T - to a uint.
#[inline(always)]
pub fn to_uint<T>(thing: &T) -> uint {
thing as *T as uint
}
/// Determine if two borrowed pointers point to the same thing.
#[inline(always)]
pub fn ref_eq<'a,'b,T>(thing: &'a T, other: &'b T) -> bool {
to_uint(thing) == to_uint(other)
}
/**
Given a **T (pointer to an array of pointers),
iterate through each *T, up to the provided `len`,
@ -411,40 +399,6 @@ impl<T> Ord for *const T {
}
}
// Equality for region pointers
#[cfg(not(test))]
impl<'self,T:Eq> Eq for &'self T {
#[inline(always)]
fn eq(&self, other: & &'self T) -> bool {
*(*self) == *(*other)
}
#[inline(always)]
fn ne(&self, other: & &'self T) -> bool {
*(*self) != *(*other)
}
}
// Comparison for region pointers
#[cfg(not(test))]
impl<'self,T:Ord> Ord for &'self T {
#[inline(always)]
fn lt(&self, other: & &'self T) -> bool {
*(*self) < *(*other)
}
#[inline(always)]
fn le(&self, other: & &'self T) -> bool {
*(*self) <= *(*other)
}
#[inline(always)]
fn ge(&self, other: & &'self T) -> bool {
*(*self) >= *(*other)
}
#[inline(always)]
fn gt(&self, other: & &'self T) -> bool {
*(*self) > *(*other)
}
}
#[cfg(test)]
pub mod ptr_tests {
use super::*;

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@ -13,6 +13,7 @@
//! local storage, and logging. Even a 'freestanding' Rust would likely want
//! to implement this.
use borrow;
use cast::transmute;
use libc::{c_void, uintptr_t};
use ptr;
@ -64,7 +65,7 @@ impl Task {
// This is just an assertion that `run` was called unsafely
// and this instance of Task is still accessible.
do Local::borrow::<Task> |task| {
assert!(ptr::ref_eq(task, self));
assert!(borrow::ref_eq(task, self));
}
match self.unwinder {
@ -89,7 +90,7 @@ impl Task {
// This is just an assertion that `destroy` was called unsafely
// and this instance of Task is still accessible.
do Local::borrow::<Task> |task| {
assert!(ptr::ref_eq(task, self));
assert!(borrow::ref_eq(task, self));
}
match self.storage {
LocalStorage(ptr, Some(ref dtor)) => {

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@ -8,6 +8,7 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::borrow;
use std::ptr;
fn borrow(x: &int, f: &fn(x: &int)) {
@ -17,7 +18,7 @@ fn borrow(x: &int, f: &fn(x: &int)) {
fn test1(x: @~int) {
do borrow(&*(*x).clone()) |p| {
let x_a = ptr::to_unsafe_ptr(&**x);
assert!((x_a as uint) != ptr::to_uint(p));
assert!((x_a as uint) != borrow::to_uint(p));
assert_eq!(unsafe{*x_a}, *p);
}
}

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@ -8,9 +8,9 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::ptr;
use std::borrow;
pub fn main() {
let x = 3;
debug!("&x=%x", ptr::to_uint(&x));
debug!("&x=%x", borrow::to_uint(&x));
}