1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! rustc compiler intrinsics.
13 //! The corresponding definitions are in librustc_trans/trans/intrinsic.rs.
17 //! The volatile intrinsics provide operations intended to act on I/O
18 //! memory, which are guaranteed to not be reordered by the compiler
19 //! across other volatile intrinsics. See the LLVM documentation on
22 //! [volatile]: http://llvm.org/docs/LangRef.html#volatile-memory-accesses
26 //! The atomic intrinsics provide common atomic operations on machine
27 //! words, with multiple possible memory orderings. They obey the same
28 //! semantics as C++11. See the LLVM documentation on [[atomics]].
30 //! [atomics]: http://llvm.org/docs/Atomics.html
32 //! A quick refresher on memory ordering:
34 //! * Acquire - a barrier for acquiring a lock. Subsequent reads and writes
35 //! take place after the barrier.
36 //! * Release - a barrier for releasing a lock. Preceding reads and writes
37 //! take place before the barrier.
38 //! * Sequentially consistent - sequentially consistent operations are
39 //! guaranteed to happen in order. This is the standard mode for working
40 //! with atomic types and is equivalent to Java's `volatile`.
42 #![unstable(feature = "core_intrinsics",
43 reason = "intrinsics are unlikely to ever be stabilized, instead \
44 they should be used through stabilized interfaces \
45 in the rest of the standard library",
47 #![allow(missing_docs)]
51 extern "rust-intrinsic" {
53 // NB: These intrinsics take raw pointers because they mutate aliased
54 // memory, which is not valid for either `&` or `&mut`.
56 pub fn atomic_cxchg<T>(dst: *mut T, old: T, src: T) -> T;
57 pub fn atomic_cxchg_acq<T>(dst: *mut T, old: T, src: T) -> T;
58 pub fn atomic_cxchg_rel<T>(dst: *mut T, old: T, src: T) -> T;
59 pub fn atomic_cxchg_acqrel<T>(dst: *mut T, old: T, src: T) -> T;
60 pub fn atomic_cxchg_relaxed<T>(dst: *mut T, old: T, src: T) -> T;
62 pub fn atomic_load<T>(src: *const T) -> T;
63 pub fn atomic_load_acq<T>(src: *const T) -> T;
64 pub fn atomic_load_relaxed<T>(src: *const T) -> T;
65 pub fn atomic_load_unordered<T>(src: *const T) -> T;
67 pub fn atomic_store<T>(dst: *mut T, val: T);
68 pub fn atomic_store_rel<T>(dst: *mut T, val: T);
69 pub fn atomic_store_relaxed<T>(dst: *mut T, val: T);
70 pub fn atomic_store_unordered<T>(dst: *mut T, val: T);
72 pub fn atomic_xchg<T>(dst: *mut T, src: T) -> T;
73 pub fn atomic_xchg_acq<T>(dst: *mut T, src: T) -> T;
74 pub fn atomic_xchg_rel<T>(dst: *mut T, src: T) -> T;
75 pub fn atomic_xchg_acqrel<T>(dst: *mut T, src: T) -> T;
76 pub fn atomic_xchg_relaxed<T>(dst: *mut T, src: T) -> T;
78 pub fn atomic_xadd<T>(dst: *mut T, src: T) -> T;
79 pub fn atomic_xadd_acq<T>(dst: *mut T, src: T) -> T;
80 pub fn atomic_xadd_rel<T>(dst: *mut T, src: T) -> T;
81 pub fn atomic_xadd_acqrel<T>(dst: *mut T, src: T) -> T;
82 pub fn atomic_xadd_relaxed<T>(dst: *mut T, src: T) -> T;
84 pub fn atomic_xsub<T>(dst: *mut T, src: T) -> T;
85 pub fn atomic_xsub_acq<T>(dst: *mut T, src: T) -> T;
86 pub fn atomic_xsub_rel<T>(dst: *mut T, src: T) -> T;
87 pub fn atomic_xsub_acqrel<T>(dst: *mut T, src: T) -> T;
88 pub fn atomic_xsub_relaxed<T>(dst: *mut T, src: T) -> T;
90 pub fn atomic_and<T>(dst: *mut T, src: T) -> T;
91 pub fn atomic_and_acq<T>(dst: *mut T, src: T) -> T;
92 pub fn atomic_and_rel<T>(dst: *mut T, src: T) -> T;
93 pub fn atomic_and_acqrel<T>(dst: *mut T, src: T) -> T;
94 pub fn atomic_and_relaxed<T>(dst: *mut T, src: T) -> T;
96 pub fn atomic_nand<T>(dst: *mut T, src: T) -> T;
97 pub fn atomic_nand_acq<T>(dst: *mut T, src: T) -> T;
98 pub fn atomic_nand_rel<T>(dst: *mut T, src: T) -> T;
99 pub fn atomic_nand_acqrel<T>(dst: *mut T, src: T) -> T;
100 pub fn atomic_nand_relaxed<T>(dst: *mut T, src: T) -> T;
102 pub fn atomic_or<T>(dst: *mut T, src: T) -> T;
103 pub fn atomic_or_acq<T>(dst: *mut T, src: T) -> T;
104 pub fn atomic_or_rel<T>(dst: *mut T, src: T) -> T;
105 pub fn atomic_or_acqrel<T>(dst: *mut T, src: T) -> T;
106 pub fn atomic_or_relaxed<T>(dst: *mut T, src: T) -> T;
108 pub fn atomic_xor<T>(dst: *mut T, src: T) -> T;
109 pub fn atomic_xor_acq<T>(dst: *mut T, src: T) -> T;
110 pub fn atomic_xor_rel<T>(dst: *mut T, src: T) -> T;
111 pub fn atomic_xor_acqrel<T>(dst: *mut T, src: T) -> T;
112 pub fn atomic_xor_relaxed<T>(dst: *mut T, src: T) -> T;
114 pub fn atomic_max<T>(dst: *mut T, src: T) -> T;
115 pub fn atomic_max_acq<T>(dst: *mut T, src: T) -> T;
116 pub fn atomic_max_rel<T>(dst: *mut T, src: T) -> T;
117 pub fn atomic_max_acqrel<T>(dst: *mut T, src: T) -> T;
118 pub fn atomic_max_relaxed<T>(dst: *mut T, src: T) -> T;
120 pub fn atomic_min<T>(dst: *mut T, src: T) -> T;
121 pub fn atomic_min_acq<T>(dst: *mut T, src: T) -> T;
122 pub fn atomic_min_rel<T>(dst: *mut T, src: T) -> T;
123 pub fn atomic_min_acqrel<T>(dst: *mut T, src: T) -> T;
124 pub fn atomic_min_relaxed<T>(dst: *mut T, src: T) -> T;
126 pub fn atomic_umin<T>(dst: *mut T, src: T) -> T;
127 pub fn atomic_umin_acq<T>(dst: *mut T, src: T) -> T;
128 pub fn atomic_umin_rel<T>(dst: *mut T, src: T) -> T;
129 pub fn atomic_umin_acqrel<T>(dst: *mut T, src: T) -> T;
130 pub fn atomic_umin_relaxed<T>(dst: *mut T, src: T) -> T;
132 pub fn atomic_umax<T>(dst: *mut T, src: T) -> T;
133 pub fn atomic_umax_acq<T>(dst: *mut T, src: T) -> T;
134 pub fn atomic_umax_rel<T>(dst: *mut T, src: T) -> T;
135 pub fn atomic_umax_acqrel<T>(dst: *mut T, src: T) -> T;
136 pub fn atomic_umax_relaxed<T>(dst: *mut T, src: T) -> T;
139 extern "rust-intrinsic" {
141 pub fn atomic_fence();
142 pub fn atomic_fence_acq();
143 pub fn atomic_fence_rel();
144 pub fn atomic_fence_acqrel();
146 /// A compiler-only memory barrier.
148 /// Memory accesses will never be reordered across this barrier by the
149 /// compiler, but no instructions will be emitted for it. This is
150 /// appropriate for operations on the same thread that may be preempted,
151 /// such as when interacting with signal handlers.
152 pub fn atomic_singlethreadfence();
153 pub fn atomic_singlethreadfence_acq();
154 pub fn atomic_singlethreadfence_rel();
155 pub fn atomic_singlethreadfence_acqrel();
157 /// Aborts the execution of the process.
160 /// Tells LLVM that this point in the code is not reachable,
161 /// enabling further optimizations.
163 /// NB: This is very different from the `unreachable!()` macro!
164 pub fn unreachable() -> !;
166 /// Informs the optimizer that a condition is always true.
167 /// If the condition is false, the behavior is undefined.
169 /// No code is generated for this intrinsic, but the optimizer will try
170 /// to preserve it (and its condition) between passes, which may interfere
171 /// with optimization of surrounding code and reduce performance. It should
172 /// not be used if the invariant can be discovered by the optimizer on its
173 /// own, or if it does not enable any significant optimizations.
174 pub fn assume(b: bool);
176 /// Executes a breakpoint trap, for inspection by a debugger.
179 /// The size of a type in bytes.
181 /// This is the exact number of bytes in memory taken up by a
182 /// value of the given type. In other words, a memset of this size
183 /// would *exactly* overwrite a value. When laid out in vectors
184 /// and structures there may be additional padding between
186 pub fn size_of<T>() -> usize;
188 /// Moves a value to an uninitialized memory location.
190 /// Drop glue is not run on the destination.
191 pub fn move_val_init<T>(dst: *mut T, src: T);
193 pub fn min_align_of<T>() -> usize;
194 pub fn pref_align_of<T>() -> usize;
196 pub fn size_of_val<T: ?Sized>(_: &T) -> usize;
197 pub fn min_align_of_val<T: ?Sized>(_: &T) -> usize;
199 /// Executes the destructor (if any) of the pointed-to value.
201 /// This has two use cases:
203 /// * It is *required* to use `drop_in_place` to drop unsized types like
204 /// trait objects, because they can't be read out onto the stack and
205 /// dropped normally.
207 /// * It is friendlier to the optimizer to do this over `ptr::read` when
208 /// dropping manually allocated memory (e.g. when writing Box/Rc/Vec),
209 /// as the compiler doesn't need to prove that it's sound to elide the
212 /// # Undefined Behavior
214 /// This has all the same safety problems as `ptr::read` with respect to
215 /// invalid pointers, types, and double drops.
216 #[unstable(feature = "drop_in_place", reason = "just exposed, needs FCP", issue = "27908")]
217 pub fn drop_in_place<T: ?Sized>(to_drop: *mut T);
219 /// Gets a static string slice containing the name of a type.
220 pub fn type_name<T: ?Sized>() -> &'static str;
222 /// Gets an identifier which is globally unique to the specified type. This
223 /// function will return the same value for a type regardless of whichever
224 /// crate it is invoked in.
225 pub fn type_id<T: ?Sized + 'static>() -> u64;
227 /// Creates a value initialized to so that its drop flag,
228 /// if any, says that it has been dropped.
230 /// `init_dropped` is unsafe because it returns a datum with all
231 /// of its bytes set to the drop flag, which generally does not
232 /// correspond to a valid value.
234 /// This intrinsic is likely to be deprecated in the future when
235 /// Rust moves to non-zeroing dynamic drop (and thus removes the
236 /// embedded drop flags that are being established by this
238 pub fn init_dropped<T>() -> T;
240 /// Creates a value initialized to zero.
242 /// `init` is unsafe because it returns a zeroed-out datum,
243 /// which is unsafe unless T is `Copy`. Also, even if T is
244 /// `Copy`, an all-zero value may not correspond to any legitimate
245 /// state for the type in question.
246 pub fn init<T>() -> T;
248 /// Creates an uninitialized value.
250 /// `uninit` is unsafe because there is no guarantee of what its
251 /// contents are. In particular its drop-flag may be set to any
252 /// state, which means it may claim either dropped or
253 /// undropped. In the general case one must use `ptr::write` to
254 /// initialize memory previous set to the result of `uninit`.
255 pub fn uninit<T>() -> T;
257 /// Moves a value out of scope without running drop glue.
258 pub fn forget<T>(_: T) -> ();
260 /// Unsafely transforms a value of one type into a value of another type.
262 /// Both types must have the same size.
269 /// let array: &[u8] = unsafe { mem::transmute("Rust") };
270 /// assert_eq!(array, [82, 117, 115, 116]);
272 #[stable(feature = "rust1", since = "1.0.0")]
273 pub fn transmute<T, U>(e: T) -> U;
275 /// Gives the address for the return value of the enclosing function.
277 /// Using this intrinsic in a function that does not use an out pointer
278 /// will trigger a compiler error.
279 pub fn return_address() -> *const u8;
281 /// Returns `true` if the actual type given as `T` requires drop
282 /// glue; returns `false` if the actual type provided for `T`
283 /// implements `Copy`.
285 /// If the actual type neither requires drop glue nor implements
286 /// `Copy`, then may return `true` or `false`.
287 pub fn needs_drop<T>() -> bool;
289 /// Calculates the offset from a pointer.
291 /// This is implemented as an intrinsic to avoid converting to and from an
292 /// integer, since the conversion would throw away aliasing information.
296 /// Both the starting and resulting pointer must be either in bounds or one
297 /// byte past the end of an allocated object. If either pointer is out of
298 /// bounds or arithmetic overflow occurs then any further use of the
299 /// returned value will result in undefined behavior.
300 pub fn offset<T>(dst: *const T, offset: isize) -> *const T;
302 /// Calculates the offset from a pointer, potentially wrapping.
304 /// This is implemented as an intrinsic to avoid converting to and from an
305 /// integer, since the conversion inhibits certain optimizations.
309 /// Unlike the `offset` intrinsic, this intrinsic does not restrict the
310 /// resulting pointer to point into or one byte past the end of an allocated
311 /// object, and it wraps with two's complement arithmetic. The resulting
312 /// value is not necessarily valid to be used to actually access memory.
313 pub fn arith_offset<T>(dst: *const T, offset: isize) -> *const T;
315 /// Copies `count * size_of<T>` bytes from `src` to `dst`. The source
316 /// and destination may *not* overlap.
318 /// `copy_nonoverlapping` is semantically equivalent to C's `memcpy`.
322 /// Beyond requiring that the program must be allowed to access both regions
323 /// of memory, it is Undefined Behavior for source and destination to
324 /// overlap. Care must also be taken with the ownership of `src` and
325 /// `dst`. This method semantically moves the values of `src` into `dst`.
326 /// However it does not drop the contents of `dst`, or prevent the contents
327 /// of `src` from being dropped or used.
331 /// A safe swap function:
337 /// # #[allow(dead_code)]
338 /// fn swap<T>(x: &mut T, y: &mut T) {
340 /// // Give ourselves some scratch space to work with
341 /// let mut t: T = mem::uninitialized();
343 /// // Perform the swap, `&mut` pointers never alias
344 /// ptr::copy_nonoverlapping(x, &mut t, 1);
345 /// ptr::copy_nonoverlapping(y, x, 1);
346 /// ptr::copy_nonoverlapping(&t, y, 1);
348 /// // y and t now point to the same thing, but we need to completely forget `tmp`
349 /// // because it's no longer relevant.
354 #[stable(feature = "rust1", since = "1.0.0")]
355 pub fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
357 /// Copies `count * size_of<T>` bytes from `src` to `dst`. The source
358 /// and destination may overlap.
360 /// `copy` is semantically equivalent to C's `memmove`.
364 /// Care must be taken with the ownership of `src` and `dst`.
365 /// This method semantically moves the values of `src` into `dst`.
366 /// However it does not drop the contents of `dst`, or prevent the contents of `src`
367 /// from being dropped or used.
371 /// Efficiently create a Rust vector from an unsafe buffer:
376 /// # #[allow(dead_code)]
377 /// unsafe fn from_buf_raw<T>(ptr: *const T, elts: usize) -> Vec<T> {
378 /// let mut dst = Vec::with_capacity(elts);
379 /// dst.set_len(elts);
380 /// ptr::copy(ptr, dst.as_mut_ptr(), elts);
385 #[stable(feature = "rust1", since = "1.0.0")]
386 pub fn copy<T>(src: *const T, dst: *mut T, count: usize);
388 /// Invokes memset on the specified pointer, setting `count * size_of::<T>()`
389 /// bytes of memory starting at `dst` to `val`.
390 #[stable(feature = "rust1", since = "1.0.0")]
391 pub fn write_bytes<T>(dst: *mut T, val: u8, count: usize);
393 /// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with
394 /// a size of `count` * `size_of::<T>()` and an alignment of
395 /// `min_align_of::<T>()`
397 /// The volatile parameter is set to `true`, so it will not be optimized out.
398 pub fn volatile_copy_nonoverlapping_memory<T>(dst: *mut T, src: *const T,
400 /// Equivalent to the appropriate `llvm.memmove.p0i8.0i8.*` intrinsic, with
401 /// a size of `count` * `size_of::<T>()` and an alignment of
402 /// `min_align_of::<T>()`
404 /// The volatile parameter is set to `true`, so it will not be optimized out.
405 pub fn volatile_copy_memory<T>(dst: *mut T, src: *const T, count: usize);
406 /// Equivalent to the appropriate `llvm.memset.p0i8.*` intrinsic, with a
407 /// size of `count` * `size_of::<T>()` and an alignment of
408 /// `min_align_of::<T>()`.
410 /// The volatile parameter is set to `true`, so it will not be optimized out.
411 pub fn volatile_set_memory<T>(dst: *mut T, val: u8, count: usize);
413 /// Perform a volatile load from the `src` pointer.
414 pub fn volatile_load<T>(src: *const T) -> T;
415 /// Perform a volatile store to the `dst` pointer.
416 pub fn volatile_store<T>(dst: *mut T, val: T);
418 /// Returns the square root of an `f32`
419 pub fn sqrtf32(x: f32) -> f32;
420 /// Returns the square root of an `f64`
421 pub fn sqrtf64(x: f64) -> f64;
423 /// Raises an `f32` to an integer power.
424 pub fn powif32(a: f32, x: i32) -> f32;
425 /// Raises an `f64` to an integer power.
426 pub fn powif64(a: f64, x: i32) -> f64;
428 /// Returns the sine of an `f32`.
429 pub fn sinf32(x: f32) -> f32;
430 /// Returns the sine of an `f64`.
431 pub fn sinf64(x: f64) -> f64;
433 /// Returns the cosine of an `f32`.
434 pub fn cosf32(x: f32) -> f32;
435 /// Returns the cosine of an `f64`.
436 pub fn cosf64(x: f64) -> f64;
438 /// Raises an `f32` to an `f32` power.
439 pub fn powf32(a: f32, x: f32) -> f32;
440 /// Raises an `f64` to an `f64` power.
441 pub fn powf64(a: f64, x: f64) -> f64;
443 /// Returns the exponential of an `f32`.
444 pub fn expf32(x: f32) -> f32;
445 /// Returns the exponential of an `f64`.
446 pub fn expf64(x: f64) -> f64;
448 /// Returns 2 raised to the power of an `f32`.
449 pub fn exp2f32(x: f32) -> f32;
450 /// Returns 2 raised to the power of an `f64`.
451 pub fn exp2f64(x: f64) -> f64;
453 /// Returns the natural logarithm of an `f32`.
454 pub fn logf32(x: f32) -> f32;
455 /// Returns the natural logarithm of an `f64`.
456 pub fn logf64(x: f64) -> f64;
458 /// Returns the base 10 logarithm of an `f32`.
459 pub fn log10f32(x: f32) -> f32;
460 /// Returns the base 10 logarithm of an `f64`.
461 pub fn log10f64(x: f64) -> f64;
463 /// Returns the base 2 logarithm of an `f32`.
464 pub fn log2f32(x: f32) -> f32;
465 /// Returns the base 2 logarithm of an `f64`.
466 pub fn log2f64(x: f64) -> f64;
468 /// Returns `a * b + c` for `f32` values.
469 pub fn fmaf32(a: f32, b: f32, c: f32) -> f32;
470 /// Returns `a * b + c` for `f64` values.
471 pub fn fmaf64(a: f64, b: f64, c: f64) -> f64;
473 /// Returns the absolute value of an `f32`.
474 pub fn fabsf32(x: f32) -> f32;
475 /// Returns the absolute value of an `f64`.
476 pub fn fabsf64(x: f64) -> f64;
478 /// Copies the sign from `y` to `x` for `f32` values.
479 pub fn copysignf32(x: f32, y: f32) -> f32;
480 /// Copies the sign from `y` to `x` for `f64` values.
481 pub fn copysignf64(x: f64, y: f64) -> f64;
483 /// Returns the largest integer less than or equal to an `f32`.
484 pub fn floorf32(x: f32) -> f32;
485 /// Returns the largest integer less than or equal to an `f64`.
486 pub fn floorf64(x: f64) -> f64;
488 /// Returns the smallest integer greater than or equal to an `f32`.
489 pub fn ceilf32(x: f32) -> f32;
490 /// Returns the smallest integer greater than or equal to an `f64`.
491 pub fn ceilf64(x: f64) -> f64;
493 /// Returns the integer part of an `f32`.
494 pub fn truncf32(x: f32) -> f32;
495 /// Returns the integer part of an `f64`.
496 pub fn truncf64(x: f64) -> f64;
498 /// Returns the nearest integer to an `f32`. May raise an inexact floating-point exception
499 /// if the argument is not an integer.
500 pub fn rintf32(x: f32) -> f32;
501 /// Returns the nearest integer to an `f64`. May raise an inexact floating-point exception
502 /// if the argument is not an integer.
503 pub fn rintf64(x: f64) -> f64;
505 /// Returns the nearest integer to an `f32`.
506 pub fn nearbyintf32(x: f32) -> f32;
507 /// Returns the nearest integer to an `f64`.
508 pub fn nearbyintf64(x: f64) -> f64;
510 /// Returns the nearest integer to an `f32`. Rounds half-way cases away from zero.
511 pub fn roundf32(x: f32) -> f32;
512 /// Returns the nearest integer to an `f64`. Rounds half-way cases away from zero.
513 pub fn roundf64(x: f64) -> f64;
515 /// Returns the number of bits set in an integer type `T`
516 pub fn ctpop<T>(x: T) -> T;
518 /// Returns the number of leading bits unset in an integer type `T`
519 pub fn ctlz<T>(x: T) -> T;
521 /// Returns the number of trailing bits unset in an integer type `T`
522 pub fn cttz<T>(x: T) -> T;
524 /// Reverses the bytes in an integer type `T`.
525 pub fn bswap<T>(x: T) -> T;
527 /// Performs checked integer addition.
528 pub fn add_with_overflow<T>(x: T, y: T) -> (T, bool);
530 /// Performs checked integer subtraction
531 pub fn sub_with_overflow<T>(x: T, y: T) -> (T, bool);
533 /// Performs checked integer multiplication
534 pub fn mul_with_overflow<T>(x: T, y: T) -> (T, bool);
536 /// Performs an unchecked division, resulting in undefined behavior
537 /// where y = 0 or x = `T::min_value()` and y = -1
538 pub fn unchecked_div<T>(x: T, y: T) -> T;
539 /// Returns the remainder of an unchecked division, resulting in
540 /// undefined behavior where y = 0 or x = `T::min_value()` and y = -1
541 pub fn unchecked_rem<T>(x: T, y: T) -> T;
543 /// Returns (a + b) mod 2^N, where N is the width of T in bits.
544 pub fn overflowing_add<T>(a: T, b: T) -> T;
545 /// Returns (a - b) mod 2^N, where N is the width of T in bits.
546 pub fn overflowing_sub<T>(a: T, b: T) -> T;
547 /// Returns (a * b) mod 2^N, where N is the width of T in bits.
548 pub fn overflowing_mul<T>(a: T, b: T) -> T;
550 /// Returns the value of the discriminant for the variant in 'v',
551 /// cast to a `u64`; if `T` has no discriminant, returns 0.
552 pub fn discriminant_value<T>(v: &T) -> u64;
554 /// Rust's "try catch" construct which invokes the function pointer `f` with
555 /// the data pointer `data`.
557 /// The third pointer is a target-specific data pointer which is filled in
558 /// with the specifics of the exception that occurred. For examples on Unix
559 /// platforms this is a `*mut *mut T` which is filled in by the compiler and
560 /// on MSVC it's `*mut [usize; 2]`. For more information see the compiler's
561 /// source as well as std's catch implementation.
563 pub fn try(f: fn(*mut u8), data: *mut u8, local_ptr: *mut u8) -> i32;
565 pub fn try(f: fn(*mut u8), data: *mut u8) -> *mut u8;