1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
// 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.
#![allow(dead_code)]
use alloc::{GlobalAlloc, Layout, System};
use cmp;
use ptr;
// The minimum alignment guaranteed by the architecture. This value is used to
// add fast paths for low alignment values.
#[cfg(all(any(target_arch = "x86",
target_arch = "arm",
target_arch = "mips",
target_arch = "powerpc",
target_arch = "powerpc64",
target_arch = "asmjs",
target_arch = "wasm32")))]
pub const MIN_ALIGN: usize = 8;
#[cfg(all(any(target_arch = "x86_64",
target_arch = "aarch64",
target_arch = "mips64",
target_arch = "s390x",
target_arch = "sparc64")))]
pub const MIN_ALIGN: usize = 16;
pub unsafe fn realloc_fallback(
alloc: &System,
ptr: *mut u8,
old_layout: Layout,
new_size: usize,
) -> *mut u8 {
// Docs for GlobalAlloc::realloc require this to be valid:
let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
let new_ptr = GlobalAlloc::alloc(alloc, new_layout);
if !new_ptr.is_null() {
let size = cmp::min(old_layout.size(), new_size);
ptr::copy_nonoverlapping(ptr, new_ptr, size);
GlobalAlloc::dealloc(alloc, ptr, old_layout);
}
new_ptr
}
|
