2012-07-04 16:53:12 -05:00
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//! Unsafe pointer utility functions
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2012-03-10 02:04:09 -06:00
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export addr_of;
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2012-08-02 16:23:04 -05:00
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export assimilate;
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2012-03-10 02:04:09 -06:00
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export mut_addr_of;
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export offset;
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2012-06-02 21:03:28 -05:00
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export const_offset;
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2012-03-10 02:04:09 -06:00
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export mut_offset;
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export null;
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2012-04-04 00:32:55 -05:00
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export is_null;
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export is_not_null;
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2012-03-10 02:04:09 -06:00
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export memcpy;
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export memmove;
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2012-06-13 18:14:01 -05:00
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export memset;
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2012-08-02 16:23:04 -05:00
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export to_uint;
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2012-08-11 14:42:58 -05:00
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export ref_eq;
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2012-04-15 02:40:47 -05:00
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export buf_len;
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export position;
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2012-07-11 17:00:40 -05:00
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export ptr;
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2012-03-10 02:04:09 -06:00
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2012-06-04 19:26:17 -05:00
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import libc::{c_void, size_t};
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2011-12-13 18:25:51 -06:00
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2012-03-22 06:30:10 -05:00
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#[nolink]
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#[abi = "cdecl"]
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2012-07-03 18:11:00 -05:00
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extern mod libc_ {
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2012-03-22 07:44:16 -05:00
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#[rust_stack]
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2012-03-22 06:30:10 -05:00
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fn memcpy(dest: *c_void, src: *c_void, n: libc::size_t) -> *c_void;
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2012-03-22 07:44:16 -05:00
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#[rust_stack]
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2012-03-22 06:30:10 -05:00
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fn memmove(dest: *c_void, src: *c_void, n: libc::size_t) -> *c_void;
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2012-06-13 18:14:01 -05:00
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#[rust_stack]
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fn memset(dest: *c_void, c: libc::c_int, len: libc::size_t) -> *c_void;
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2012-03-22 06:30:10 -05:00
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}
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2012-03-23 09:05:16 -05:00
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#[abi = "rust-intrinsic"]
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2012-07-03 18:11:00 -05:00
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extern mod rusti {
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2011-12-13 18:25:51 -06:00
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fn addr_of<T>(val: T) -> *T;
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}
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2012-07-04 16:53:12 -05:00
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/// Get an unsafe pointer to a value
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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-06-07 09:18:24 -05:00
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pure fn addr_of<T>(val: T) -> *T { unchecked { rusti::addr_of(val) } }
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2011-12-13 18:25:51 -06:00
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2012-07-04 16:53:12 -05:00
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/// Get an unsafe mut pointer to a value
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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-06-24 22:18:18 -05:00
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pure fn mut_addr_of<T>(val: T) -> *mut T {
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unsafe {
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unsafe::reinterpret_cast(rusti::addr_of(val))
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}
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2011-12-13 18:25:51 -06:00
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}
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2012-07-04 16:53:12 -05:00
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/// Calculate the offset from a pointer
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2012-03-02 22:06:08 -06:00
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#[inline(always)]
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2012-06-24 22:18:18 -05:00
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fn offset<T>(ptr: *T, count: uint) -> *T {
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unsafe {
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(ptr as uint + count * sys::size_of::<T>()) as *T
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}
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2011-12-13 18:25:51 -06:00
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}
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2012-07-04 16:53:12 -05:00
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/// Calculate the offset from a const pointer
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2012-06-02 21:03:28 -05:00
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#[inline(always)]
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2012-06-24 22:18:18 -05:00
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fn const_offset<T>(ptr: *const T, count: uint) -> *const T {
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unsafe {
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(ptr as uint + count * sys::size_of::<T>()) as *T
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}
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2012-06-02 21:03:28 -05:00
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}
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2012-07-04 16:53:12 -05:00
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/// Calculate the offset from a mut pointer
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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-03-26 20:35:18 -05:00
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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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2011-12-13 18:25:51 -06:00
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}
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2012-07-04 16:53:12 -05:00
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/// Return the offset of the first null pointer in `buf`.
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2012-04-11 17:46:51 -05:00
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#[inline(always)]
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unsafe fn buf_len<T>(buf: **T) -> uint {
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2012-06-30 18:19:07 -05:00
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position(buf, |i| i == null())
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2012-04-11 17:46:51 -05:00
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}
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2012-07-04 16:53:12 -05:00
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/// Return the first offset `i` such that `f(buf[i]) == true`.
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2012-04-11 17:46:51 -05:00
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#[inline(always)]
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unsafe fn position<T>(buf: *T, f: fn(T) -> bool) -> uint {
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let mut i = 0u;
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loop {
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2012-08-01 19:30:05 -05:00
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if f(*offset(buf, i)) { return i; }
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2012-04-11 17:46:51 -05:00
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else { i += 1u; }
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}
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}
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2011-12-13 18:25:51 -06:00
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2012-07-04 16:53:12 -05:00
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/// Create an unsafe null pointer
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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-06-24 22:18:18 -05:00
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pure fn null<T>() -> *T { unsafe { unsafe::reinterpret_cast(0u) } }
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2012-04-03 23:56:16 -05:00
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2012-07-04 16:53:12 -05:00
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/// Returns true if the pointer is equal to the null pointer.
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2012-04-03 23:56:16 -05:00
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pure fn is_null<T>(ptr: *const T) -> bool { ptr == null() }
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2012-07-04 16:53:12 -05:00
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/// Returns true if the pointer is not equal to the null pointer.
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2012-04-03 23:56:16 -05:00
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pure fn is_not_null<T>(ptr: *const T) -> bool { !is_null(ptr) }
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2012-01-17 19:28:21 -06:00
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2012-07-04 16:53:12 -05:00
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/**
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* Copies data from one location to another
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*
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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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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-02-07 15:21:11 -06:00
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unsafe fn memcpy<T>(dst: *T, src: *T, count: uint) {
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2012-03-22 06:30:10 -05:00
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let n = count * sys::size_of::<T>();
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2012-06-04 19:26:17 -05:00
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libc_::memcpy(dst as *c_void, src as *c_void, n as size_t);
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2012-02-07 15:21:11 -06:00
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}
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2012-02-07 12:50:42 -06:00
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2012-07-04 16:53:12 -05:00
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/**
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* Copies data from one location to another
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*
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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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2012-03-06 13:20:43 -06:00
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#[inline(always)]
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2012-02-07 15:21:11 -06:00
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unsafe fn memmove<T>(dst: *T, src: *T, count: uint) {
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2012-03-22 06:30:10 -05:00
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let n = count * sys::size_of::<T>();
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2012-06-04 19:26:17 -05:00
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libc_::memmove(dst as *c_void, src as *c_void, n as size_t);
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2012-02-07 15:21:11 -06:00
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}
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2012-02-07 12:50:42 -06:00
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2012-06-13 18:14:01 -05:00
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#[inline(always)]
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unsafe fn memset<T>(dst: *mut T, c: int, count: uint) {
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let n = count * sys::size_of::<T>();
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libc_::memset(dst as *c_void, c as libc::c_int, n as size_t);
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}
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2012-08-02 16:23:04 -05:00
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/**
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Transform a region pointer - &T - to an unsafe pointer - *T.
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This is safe, but is implemented with an unsafe block due to
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reinterpret_cast.
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("assimilate" because it makes the pointer forget its region.)
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*/
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#[inline(always)]
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fn assimilate<T>(thing: &T) -> *T unsafe {
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unsafe::reinterpret_cast(thing)
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}
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/**
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Cast a region pointer - &T - to a uint.
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This is safe, but is implemented with an unsafe block due to
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reinterpret_cast.
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(I couldn't think of a cutesy name for this one.)
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*/
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#[inline(always)]
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fn to_uint<T>(thing: &T) -> uint unsafe {
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unsafe::reinterpret_cast(thing)
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}
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2012-08-11 14:42:58 -05:00
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/// Determine if two borrowed pointers point to the same thing.
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#[inline(always)]
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fn ref_eq<T>(thing: &T, other: &T) -> bool {
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to_uint(thing) == to_uint(other)
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}
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2012-07-11 14:45:54 -05:00
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trait ptr {
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pure fn is_null() -> bool;
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pure fn is_not_null() -> bool;
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}
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2012-07-04 16:53:12 -05:00
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/// Extension methods for pointers
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2012-08-07 20:10:06 -05:00
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impl<T> *T: ptr {
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2012-07-04 16:53:12 -05:00
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/// Returns true if the pointer is equal to the null pointer.
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2012-05-02 23:12:16 -05:00
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pure fn is_null() -> bool { is_null(self) }
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2012-04-15 23:46:29 -05:00
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2012-07-04 16:53:12 -05:00
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/// Returns true if the pointer is not equal to the null pointer.
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2012-05-02 23:12:16 -05:00
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pure fn is_not_null() -> bool { is_not_null(self) }
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2012-04-15 23:46:29 -05:00
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}
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2012-01-17 19:28:21 -06:00
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#[test]
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2012-06-24 22:18:18 -05:00
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fn test() {
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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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2012-06-29 18:26:56 -05:00
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let v0 = ~[32000u16, 32001u16, 32002u16];
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let v1 = ~[0u16, 0u16, 0u16];
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2012-06-24 22:18:18 -05:00
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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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}
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2012-04-11 17:46:51 -05:00
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}
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#[test]
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2012-06-24 22:18:18 -05:00
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fn test_position() {
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2012-04-11 17:46:51 -05:00
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import str::as_c_str;
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import libc::c_char;
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2012-07-14 00:57:48 -05:00
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let s = ~"hello";
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2012-06-24 22:18:18 -05:00
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unsafe {
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2012-06-30 18:19:07 -05:00
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assert 2u == as_c_str(s, |p| position(p, |c| c == 'l' as c_char));
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assert 4u == as_c_str(s, |p| position(p, |c| c == 'o' as c_char));
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assert 5u == as_c_str(s, |p| position(p, |c| c == 0 as c_char));
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2012-06-24 22:18:18 -05:00
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}
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2012-04-11 17:46:51 -05:00
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}
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#[test]
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2012-06-24 22:18:18 -05:00
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fn test_buf_len() {
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2012-07-14 00:57:48 -05:00
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let s0 = ~"hello";
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let s1 = ~"there";
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let s2 = ~"thing";
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2012-06-30 18:19:07 -05:00
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do str::as_c_str(s0) |p0| {
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do str::as_c_str(s1) |p1| {
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do str::as_c_str(s2) |p2| {
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2012-06-29 18:26:56 -05:00
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let v = ~[p0, p1, p2, null()];
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2012-07-24 14:35:34 -05:00
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do vec::as_buf(v) |vp, len| {
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2012-06-24 22:18:18 -05:00
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assert unsafe { buf_len(vp) } == 3u;
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2012-07-24 14:35:34 -05:00
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assert len == 4u;
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2012-04-11 17:46:51 -05:00
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}
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}
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}
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}
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2012-04-15 02:40:47 -05:00
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}
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2012-07-31 19:30:38 -05:00
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#[test]
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fn test_is_null() {
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let p: *int = ptr::null();
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assert p.is_null();
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assert !p.is_not_null();
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let q = ptr::offset(p, 1u);
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assert !q.is_null();
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assert q.is_not_null();
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2012-08-11 14:42:58 -05:00
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}
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