solana_define_syscall/
lib.rs

1#[cfg(target_feature = "static-syscalls")]
2#[macro_export]
3macro_rules! define_syscall {
4    (fn $name:ident($($arg:ident: $typ:ty),*) -> $ret:ty) => {
5        #[inline]
6        pub unsafe fn $name($($arg: $typ),*) -> $ret {
7            // this enum is used to force the hash to be computed in a const context
8            #[repr(usize)]
9            enum Syscall {
10                Code = $crate::sys_hash(stringify!($name)),
11            }
12
13            let syscall: extern "C" fn($($arg: $typ),*) -> $ret = core::mem::transmute(Syscall::Code);
14            syscall($($arg),*)
15        }
16
17    };
18    (fn $name:ident($($arg:ident: $typ:ty),*)) => {
19        define_syscall!(fn $name($($arg: $typ),*) -> ());
20    }
21}
22
23#[cfg(not(target_feature = "static-syscalls"))]
24#[macro_export]
25macro_rules! define_syscall {
26    (fn $name:ident($($arg:ident: $typ:ty),*) -> $ret:ty) => {
27        extern "C" {
28            pub fn $name($($arg: $typ),*) -> $ret;
29        }
30    };
31    (fn $name:ident($($arg:ident: $typ:ty),*)) => {
32        define_syscall!(fn $name($($arg: $typ),*) -> ());
33    }
34}
35
36#[cfg(target_feature = "static-syscalls")]
37pub const fn sys_hash(name: &str) -> usize {
38    murmur3_32(name.as_bytes(), 0) as usize
39}
40
41#[cfg(target_feature = "static-syscalls")]
42const fn murmur3_32(buf: &[u8], seed: u32) -> u32 {
43    const fn pre_mix(buf: [u8; 4]) -> u32 {
44        u32::from_le_bytes(buf)
45            .wrapping_mul(0xcc9e2d51)
46            .rotate_left(15)
47            .wrapping_mul(0x1b873593)
48    }
49
50    let mut hash = seed;
51
52    let mut i = 0;
53    while i < buf.len() / 4 {
54        let buf = [buf[i * 4], buf[i * 4 + 1], buf[i * 4 + 2], buf[i * 4 + 3]];
55        hash ^= pre_mix(buf);
56        hash = hash.rotate_left(13);
57        hash = hash.wrapping_mul(5).wrapping_add(0xe6546b64);
58
59        i += 1;
60    }
61
62    match buf.len() % 4 {
63        0 => {}
64        1 => {
65            hash = hash ^ pre_mix([buf[i * 4], 0, 0, 0]);
66        }
67        2 => {
68            hash = hash ^ pre_mix([buf[i * 4], buf[i * 4 + 1], 0, 0]);
69        }
70        3 => {
71            hash = hash ^ pre_mix([buf[i * 4], buf[i * 4 + 1], buf[i * 4 + 2], 0]);
72        }
73        _ => { /* unreachable!() */ }
74    }
75
76    hash = hash ^ buf.len() as u32;
77    hash = hash ^ (hash.wrapping_shr(16));
78    hash = hash.wrapping_mul(0x85ebca6b);
79    hash = hash ^ (hash.wrapping_shr(13));
80    hash = hash.wrapping_mul(0xc2b2ae35);
81    hash = hash ^ (hash.wrapping_shr(16));
82
83    hash
84}
solana_define_syscall/lib.rs

solana_define_syscall/
lib.rs
