106 lines
2.9 KiB
Rust
106 lines
2.9 KiB
Rust
#[doc = "Unsafe pointer utility functions"];
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export addr_of;
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export mut_addr_of;
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export offset;
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export mut_offset;
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export null;
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export memcpy;
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export memmove;
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import libc::c_void;
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#[nolink]
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#[abi = "cdecl"]
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native mod libc_ {
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#[rust_stack]
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fn memcpy(dest: *c_void, src: *c_void, n: libc::size_t) -> *c_void;
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#[rust_stack]
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fn memmove(dest: *c_void, src: *c_void, n: libc::size_t) -> *c_void;
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}
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#[abi = "rust-intrinsic"]
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native mod rusti {
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fn addr_of<T>(val: T) -> *T;
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}
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#[doc = "Get an unsafe pointer to a value"]
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#[inline(always)]
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fn addr_of<T>(val: T) -> *T { rusti::addr_of(val) }
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#[doc = "Get an unsafe mut pointer to a value"]
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#[inline(always)]
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fn mut_addr_of<T>(val: T) -> *mut T unsafe {
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unsafe::reinterpret_cast(rusti::addr_of(val))
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}
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#[doc = "Calculate the offset from a pointer"]
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#[inline(always)]
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fn offset<T>(ptr: *T, count: uint) -> *T unsafe {
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(ptr as uint + count * sys::size_of::<T>()) as *T
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}
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#[doc = "Calculate the offset from a mut pointer"]
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#[inline(always)]
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fn mut_offset<T>(ptr: *mut T, count: uint) -> *mut T {
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(ptr as uint + count * sys::size_of::<T>()) as *mut T
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}
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#[doc = "Create an unsafe null pointer"]
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#[inline(always)]
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fn null<T>() -> *T unsafe { ret unsafe::reinterpret_cast(0u); }
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#[doc = "
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Copies data from one location to another
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Copies `count` elements (not bytes) from `src` to `dst`. The source
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and destination may not overlap.
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"]
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#[inline(always)]
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unsafe fn memcpy<T>(dst: *T, src: *T, count: uint) {
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let n = count * sys::size_of::<T>();
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libc_::memcpy(dst as *c_void, src as *c_void, n);
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}
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#[doc = "
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Copies data from one location to another
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Copies `count` elements (not bytes) from `src` to `dst`. The source
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and destination may overlap.
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"]
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#[inline(always)]
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unsafe fn memmove<T>(dst: *T, src: *T, count: uint) {
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let n = count * sys::size_of::<T>();
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libc_::memmove(dst as *c_void, src as *c_void, n);
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}
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#[test]
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fn test() unsafe {
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type pair = {mut fst: int, mut snd: int};
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let p = {mut fst: 10, mut snd: 20};
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let pptr: *mut pair = mut_addr_of(p);
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let iptr: *mut int = unsafe::reinterpret_cast(pptr);
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assert (*iptr == 10);;
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*iptr = 30;
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assert (*iptr == 30);
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assert (p.fst == 30);;
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*pptr = {mut fst: 50, mut snd: 60};
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assert (*iptr == 50);
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assert (p.fst == 50);
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assert (p.snd == 60);
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let v0 = [32000u16, 32001u16, 32002u16];
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let v1 = [0u16, 0u16, 0u16];
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ptr::memcpy(ptr::offset(vec::unsafe::to_ptr(v1), 1u),
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ptr::offset(vec::unsafe::to_ptr(v0), 1u), 1u);
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assert (v1[0] == 0u16 && v1[1] == 32001u16 && v1[2] == 0u16);
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ptr::memcpy(vec::unsafe::to_ptr(v1),
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ptr::offset(vec::unsafe::to_ptr(v0), 2u), 1u);
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assert (v1[0] == 32002u16 && v1[1] == 32001u16 && v1[2] == 0u16);
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ptr::memcpy(ptr::offset(vec::unsafe::to_ptr(v1), 2u),
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vec::unsafe::to_ptr(v0), 1u);
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assert (v1[0] == 32002u16 && v1[1] == 32001u16 && v1[2] == 32000u16);
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} |