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 = "mips",
21 target_arch = "mips32r6",
22 target_arch = "powerpc",
23 target_arch = "powerpc64",
24 target_arch = "sparc",
25 target_arch = "wasm32",
26 target_arch = "hexagon",
27 target_arch = "riscv32",
28 target_arch = "xtensa",
29)) {
30 8
31} else if cfg!(any(
32 target_arch = "x86_64",
33 target_arch = "aarch64",
34 target_arch = "arm64ec",
35 target_arch = "loongarch64",
36 target_arch = "mips64",
37 target_arch = "mips64r6",
38 target_arch = "s390x",
39 target_arch = "sparc64",
40 target_arch = "riscv64",
41 target_arch = "wasm64",
42)) {
43 16
44} else {
45 panic!("add a value for MIN_ALIGN")
46};
47
48#[allow(dead_code)]
49unsafe fn realloc_fallback(
50 alloc: &System,
51 ptr: *mut u8,
52 old_layout: Layout,
53 new_size: usize,
54) -> *mut u8 {
55 // SAFETY: Docs for GlobalAlloc::realloc require this to be valid
56 unsafe {
57 let new_layout: Layout = Layout::from_size_align_unchecked(new_size, old_layout.align());
58
59 let new_ptr: *mut u8 = GlobalAlloc::alloc(self:alloc, new_layout);
60 if !new_ptr.is_null() {
61 let size: usize = usize::min(self:old_layout.size(), other:new_size);
62 ptr::copy_nonoverlapping(src:ptr, dst:new_ptr, count:size);
63 GlobalAlloc::dealloc(self:alloc, ptr, old_layout);
64 }
65
66 new_ptr
67 }
68}
69
70cfg_if::cfg_if! {
71 if #[cfg(any(
72 target_family = "unix",
73 target_os = "wasi",
74 target_os = "teeos",
75 target_os = "trusty",
76 ))] {
77 mod unix;
78 } else if #[cfg(target_os = "windows")] {
79 mod windows;
80 } else if #[cfg(target_os = "hermit")] {
81 mod hermit;
82 } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
83 mod sgx;
84 } else if #[cfg(target_os = "solid_asp3")] {
85 mod solid;
86 } else if #[cfg(target_os = "uefi")] {
87 mod uefi;
88 } else if #[cfg(target_family = "wasm")] {
89 mod wasm;
90 } else if #[cfg(target_os = "xous")] {
91 mod xous;
92 } else if #[cfg(target_os = "zkvm")] {
93 mod zkvm;
94 }
95}
96