1#![forbid(unsafe_op_in_unsafe_fn)]
2
3use crate::alloc::{GlobalAlloc, Layout, System};
4use crate::ptr;
5
6// The minimum alignment guaranteed by the architecture. This value is used to
7// add fast paths for low alignment values.
8#[allow(dead_code)]
9const MIN_ALIGN: usize = if cfg!(any(
10 all(target_arch = "riscv32", any(target_os = "espidf", target_os = "zkvm")),
11 all(target_arch = "xtensa", target_os = "espidf"),
12)) {
13 // The allocator on the esp-idf and zkvm platforms guarantees 4 byte alignment.
14 4
15} else if cfg!(any(
16 target_arch = "x86",
17 target_arch = "arm",
18 target_arch = "m68k",
19 target_arch = "csky",
20 target_arch = "loongarch32",
21 target_arch = "mips",
22 target_arch = "mips32r6",
23 target_arch = "powerpc",
24 target_arch = "powerpc64",
25 target_arch = "sparc",
26 target_arch = "wasm32",
27 target_arch = "hexagon",
28 target_arch = "riscv32",
29 target_arch = "xtensa",
30)) {
31 8
32} else if cfg!(any(
33 target_arch = "x86_64",
34 target_arch = "aarch64",
35 target_arch = "arm64ec",
36 target_arch = "loongarch64",
37 target_arch = "mips64",
38 target_arch = "mips64r6",
39 target_arch = "s390x",
40 target_arch = "sparc64",
41 target_arch = "riscv64",
42 target_arch = "wasm64",
43)) {
44 16
45} else {
46 panic!("add a value for MIN_ALIGN")
47};
48
49#[allow(dead_code)]
50unsafe fn realloc_fallback(
51 alloc: &System,
52 ptr: *mut u8,
53 old_layout: Layout,
54 new_size: usize,
55) -> *mut u8 {
56 // SAFETY: Docs for GlobalAlloc::realloc require this to be valid
57 unsafe {
58 let new_layout: Layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
59
60 let new_ptr: *mut u8 = GlobalAlloc::alloc(self:alloc, new_layout);
61 if !new_ptr.is_null() {
62 let size: usize = usize::min(self:old_layout.size(), other:new_size);
63 ptr::copy_nonoverlapping(src:ptr, dst:new_ptr, count:size);
64 GlobalAlloc::dealloc(self:alloc, ptr, old_layout);
65 }
66
67 new_ptr
68 }
69}
70
71cfg_if::cfg_if! {
72 if #[cfg(any(
73 target_family = "unix",
74 target_os = "wasi",
75 target_os = "teeos",
76 target_os = "trusty",
77 ))] {
78 mod unix;
79 } else if #[cfg(target_os = "windows")] {
80 mod windows;
81 } else if #[cfg(target_os = "hermit")] {
82 mod hermit;
83 } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
84 mod sgx;
85 } else if #[cfg(target_os = "solid_asp3")] {
86 mod solid;
87 } else if #[cfg(target_os = "uefi")] {
88 mod uefi;
89 } else if #[cfg(target_family = "wasm")] {
90 mod wasm;
91 } else if #[cfg(target_os = "xous")] {
92 mod xous;
93 } else if #[cfg(target_os = "zkvm")] {
94 mod zkvm;
95 }
96}
97