1 //! This module contains standard C-mapped types for types not in the original crate.
3 /// Auto-generated C-mapped types for templated containers
6 use bitcoin::Transaction as BitcoinTransaction;
7 use bitcoin::hashes::Hash;
8 use bitcoin::secp256k1::PublicKey as SecpPublicKey;
9 use bitcoin::secp256k1::SecretKey as SecpSecretKey;
10 use bitcoin::secp256k1::ecdsa::Signature as SecpSignature;
11 use bitcoin::secp256k1::Error as SecpError;
12 use bitcoin::secp256k1::ecdsa::RecoveryId;
13 use bitcoin::secp256k1::ecdsa::RecoverableSignature as SecpRecoverableSignature;
14 use bitcoin::secp256k1::Scalar as SecpScalar;
16 use bitcoin::util::address;
18 use core::convert::TryInto; // Bindings need at least rustc 1.34
19 use core::ffi::c_void;
21 #[cfg(feature = "std")]
22 pub(crate) use std::io::{self, Cursor, Read};
23 #[cfg(feature = "no-std")]
24 pub(crate) use core2::io::{self, Cursor, Read};
25 #[cfg(feature = "no-std")]
26 use alloc::{boxed::Box, vec::Vec, string::String};
28 use core::convert::TryFrom;
31 /// A dummy struct of which an instance must never exist.
32 /// This corresponds to the Rust type `Infallible`, or, in unstable rust, `!`
33 pub struct NotConstructable {
34 _priv_thing: core::convert::Infallible,
36 impl From<core::convert::Infallible> for NotConstructable {
37 fn from(_: core::convert::Infallible) -> Self { unreachable!(); }
40 /// Integer in the range `0..32`
41 #[derive(PartialEq, Eq, Copy, Clone)]
42 #[allow(non_camel_case_types)]
46 impl From<bech32::u5> for u5 {
47 fn from(o: bech32::u5) -> Self { Self(o.to_u8()) }
49 impl Into<bech32::u5> for u5 {
50 fn into(self) -> bech32::u5 { bech32::u5::try_from_u8(self.0).expect("u5 objects must be in the range 0..32") }
53 /// Integer in the range `0..=16`
54 #[derive(PartialEq, Eq, Copy, Clone)]
56 pub struct WitnessVersion(u8);
58 impl From<address::WitnessVersion> for WitnessVersion {
59 fn from(o: address::WitnessVersion) -> Self { Self(o.to_num()) }
61 impl Into<address::WitnessVersion> for WitnessVersion {
62 fn into(self) -> address::WitnessVersion {
63 address::WitnessVersion::try_from(self.0).expect("WitnessVersion objects must be in the range 0..=16")
69 /// Represents a valid secp256k1 public key serialized in "compressed form" as a 33 byte array.
70 pub struct PublicKey {
71 /// The bytes of the public key
72 pub compressed_form: [u8; 33],
75 pub(crate) fn from_rust(pk: &SecpPublicKey) -> Self {
77 compressed_form: pk.serialize(),
80 pub(crate) fn into_rust(&self) -> SecpPublicKey {
81 SecpPublicKey::from_slice(&self.compressed_form).unwrap()
83 pub(crate) fn is_null(&self) -> bool { self.compressed_form[..] == [0; 33][..] }
84 pub(crate) fn null() -> Self { Self { compressed_form: [0; 33] } }
89 /// Represents a valid secp256k1 secret key serialized as a 32 byte array.
90 pub struct SecretKey {
91 /// The bytes of the secret key
95 // from_rust isn't implemented for a ref since we just return byte array refs directly
96 pub(crate) fn from_rust(sk: SecpSecretKey) -> Self {
97 let mut bytes = [0; 32];
98 bytes.copy_from_slice(&sk[..]);
101 pub(crate) fn into_rust(&self) -> SecpSecretKey {
102 SecpSecretKey::from_slice(&self.bytes).unwrap()
108 /// Represents a secp256k1 signature serialized as two 32-byte numbers
109 pub struct Signature {
110 /// The bytes of the signature in "compact" form
111 pub compact_form: [u8; 64],
114 pub(crate) fn from_rust(pk: &SecpSignature) -> Self {
116 compact_form: pk.serialize_compact(),
119 pub(crate) fn into_rust(&self) -> SecpSignature {
120 SecpSignature::from_compact(&self.compact_form).unwrap()
122 // The following are used for Option<Signature> which we support, but don't use anymore
123 #[allow(unused)] pub(crate) fn is_null(&self) -> bool { self.compact_form[..] == [0; 64][..] }
124 #[allow(unused)] pub(crate) fn null() -> Self { Self { compact_form: [0; 64] } }
129 /// Represents a secp256k1 signature serialized as two 32-byte numbers as well as a tag which
130 /// allows recovering the exact public key which created the signature given the message.
131 pub struct RecoverableSignature {
132 /// The bytes of the signature in "compact" form plus a "Recovery ID" which allows for
134 pub serialized_form: [u8; 68],
136 impl RecoverableSignature {
137 pub(crate) fn from_rust(pk: &SecpRecoverableSignature) -> Self {
138 let (id, compact_form) = pk.serialize_compact();
139 let mut serialized_form = [0; 68];
140 serialized_form[0..64].copy_from_slice(&compact_form[..]);
141 serialized_form[64..].copy_from_slice(&id.to_i32().to_le_bytes());
142 Self { serialized_form }
144 pub(crate) fn into_rust(&self) -> SecpRecoverableSignature {
146 id.copy_from_slice(&self.serialized_form[64..]);
147 SecpRecoverableSignature::from_compact(&self.serialized_form[0..64],
148 RecoveryId::from_i32(i32::from_le_bytes(id)).expect("Invalid Recovery ID"))
155 /// Represents a scalar value between zero and the secp256k1 curve order, in big endian.
156 pub struct BigEndianScalar {
157 /// The bytes of the scalar value.
158 pub big_endian_bytes: [u8; 32],
160 impl BigEndianScalar {
161 pub(crate) fn from_rust(scalar: &SecpScalar) -> Self {
162 Self { big_endian_bytes: scalar.to_be_bytes() }
164 pub(crate) fn into_rust(&self) -> SecpScalar {
165 SecpScalar::from_be_bytes(self.big_endian_bytes).expect("Scalar greater than the curve order")
170 #[derive(Copy, Clone)]
171 /// Represents an error returned from libsecp256k1 during validation of some secp256k1 data
172 pub enum Secp256k1Error {
173 /// Signature failed verification
175 /// Badly sized message ("messages" are actually fixed-sized digests; see the MESSAGE_SIZE constant)
183 /// Bad shared secret.
187 /// Invalid tweak for add_assign or mul_assign
189 /// Didn't pass enough memory to context creation with preallocated memory
191 /// Bad set of public keys.
193 /// The only valid parity values are 0 or 1.
196 impl Secp256k1Error {
197 pub(crate) fn from_rust(err: SecpError) -> Self {
199 SecpError::IncorrectSignature => Secp256k1Error::IncorrectSignature,
200 SecpError::InvalidMessage => Secp256k1Error::InvalidMessage,
201 SecpError::InvalidPublicKey => Secp256k1Error::InvalidPublicKey,
202 SecpError::InvalidSignature => Secp256k1Error::InvalidSignature,
203 SecpError::InvalidSecretKey => Secp256k1Error::InvalidSecretKey,
204 SecpError::InvalidSharedSecret => Secp256k1Error::InvalidSharedSecret,
205 SecpError::InvalidRecoveryId => Secp256k1Error::InvalidRecoveryId,
206 SecpError::InvalidTweak => Secp256k1Error::InvalidTweak,
207 SecpError::NotEnoughMemory => Secp256k1Error::NotEnoughMemory,
208 SecpError::InvalidPublicKeySum => Secp256k1Error::InvalidPublicKeySum,
209 SecpError::InvalidParityValue(_) => Secp256k1Error::InvalidParityValue,
212 pub(crate) fn into_rust(self) -> SecpError {
213 let invalid_parity = secp256k1::Parity::from_i32(42).unwrap_err();
215 Secp256k1Error::IncorrectSignature => SecpError::IncorrectSignature,
216 Secp256k1Error::InvalidMessage => SecpError::InvalidMessage,
217 Secp256k1Error::InvalidPublicKey => SecpError::InvalidPublicKey,
218 Secp256k1Error::InvalidSignature => SecpError::InvalidSignature,
219 Secp256k1Error::InvalidSecretKey => SecpError::InvalidSecretKey,
220 Secp256k1Error::InvalidSharedSecret => SecpError::InvalidSharedSecret,
221 Secp256k1Error::InvalidRecoveryId => SecpError::InvalidRecoveryId,
222 Secp256k1Error::InvalidTweak => SecpError::InvalidTweak,
223 Secp256k1Error::NotEnoughMemory => SecpError::NotEnoughMemory,
224 Secp256k1Error::InvalidPublicKeySum => SecpError::InvalidPublicKeySum,
225 Secp256k1Error::InvalidParityValue => SecpError::InvalidParityValue(invalid_parity),
231 #[derive(Copy, Clone)]
232 /// Represents an error returned from the bech32 library during validation of some bech32 data
233 pub enum Bech32Error {
234 /// String does not contain the separator character
236 /// The checksum does not match the rest of the data
238 /// The data or human-readable part is too long or too short
240 /// Some part of the string contains an invalid character
242 /// Some part of the data has an invalid value
244 /// The bit conversion failed due to a padding issue
246 /// The whole string must be of one case
250 pub(crate) fn from_rust(err: bech32::Error) -> Self {
252 bech32::Error::MissingSeparator => Self::MissingSeparator,
253 bech32::Error::InvalidChecksum => Self::InvalidChecksum,
254 bech32::Error::InvalidLength => Self::InvalidLength,
255 bech32::Error::InvalidChar(c) => Self::InvalidChar(c as u32),
256 bech32::Error::InvalidData(d) => Self::InvalidData(d),
257 bech32::Error::InvalidPadding => Self::InvalidPadding,
258 bech32::Error::MixedCase => Self::MixedCase,
261 pub(crate) fn into_rust(self) -> bech32::Error {
263 Self::MissingSeparator => bech32::Error::MissingSeparator,
264 Self::InvalidChecksum => bech32::Error::InvalidChecksum,
265 Self::InvalidLength => bech32::Error::InvalidLength,
266 Self::InvalidChar(c) => bech32::Error::InvalidChar(core::char::from_u32(c).expect("Invalid UTF-8 character in Bech32Error::InvalidChar")),
267 Self::InvalidData(d) => bech32::Error::InvalidData(d),
268 Self::InvalidPadding => bech32::Error::InvalidPadding,
269 Self::MixedCase => bech32::Error::MixedCase,
274 /// Creates a new Bech32Error which has the same data as `orig`
275 pub extern "C" fn Bech32Error_clone(orig: &Bech32Error) -> Bech32Error { orig.clone() }
277 /// Releases any memory held by the given `Bech32Error` (which is currently none)
278 pub extern "C" fn Bech32Error_free(o: Bech32Error) { }
281 #[derive(Clone, Copy, PartialEq)]
282 /// Sub-errors which don't have specific information in them use this type.
284 /// Zero-Sized_types aren't consistent across Rust/C/C++, so we add some size here
289 #[allow(missing_docs)] // If there's no docs upstream, that's good enough for us
290 #[derive(Clone, Copy, PartialEq)]
291 /// Represents an IO Error. Note that some information is lost in the conversion from Rust.
313 pub(crate) fn from_rust(err: io::Error) -> Self {
315 io::ErrorKind::NotFound => IOError::NotFound,
316 io::ErrorKind::PermissionDenied => IOError::PermissionDenied,
317 io::ErrorKind::ConnectionRefused => IOError::ConnectionRefused,
318 io::ErrorKind::ConnectionReset => IOError::ConnectionReset,
319 io::ErrorKind::ConnectionAborted => IOError::ConnectionAborted,
320 io::ErrorKind::NotConnected => IOError::NotConnected,
321 io::ErrorKind::AddrInUse => IOError::AddrInUse,
322 io::ErrorKind::AddrNotAvailable => IOError::AddrNotAvailable,
323 io::ErrorKind::BrokenPipe => IOError::BrokenPipe,
324 io::ErrorKind::AlreadyExists => IOError::AlreadyExists,
325 io::ErrorKind::WouldBlock => IOError::WouldBlock,
326 io::ErrorKind::InvalidInput => IOError::InvalidInput,
327 io::ErrorKind::InvalidData => IOError::InvalidData,
328 io::ErrorKind::TimedOut => IOError::TimedOut,
329 io::ErrorKind::WriteZero => IOError::WriteZero,
330 io::ErrorKind::Interrupted => IOError::Interrupted,
331 io::ErrorKind::Other => IOError::Other,
332 io::ErrorKind::UnexpectedEof => IOError::UnexpectedEof,
336 pub(crate) fn to_rust(&self) -> io::Error {
337 io::Error::new(match self {
338 IOError::NotFound => io::ErrorKind::NotFound,
339 IOError::PermissionDenied => io::ErrorKind::PermissionDenied,
340 IOError::ConnectionRefused => io::ErrorKind::ConnectionRefused,
341 IOError::ConnectionReset => io::ErrorKind::ConnectionReset,
342 IOError::ConnectionAborted => io::ErrorKind::ConnectionAborted,
343 IOError::NotConnected => io::ErrorKind::NotConnected,
344 IOError::AddrInUse => io::ErrorKind::AddrInUse,
345 IOError::AddrNotAvailable => io::ErrorKind::AddrNotAvailable,
346 IOError::BrokenPipe => io::ErrorKind::BrokenPipe,
347 IOError::AlreadyExists => io::ErrorKind::AlreadyExists,
348 IOError::WouldBlock => io::ErrorKind::WouldBlock,
349 IOError::InvalidInput => io::ErrorKind::InvalidInput,
350 IOError::InvalidData => io::ErrorKind::InvalidData,
351 IOError::TimedOut => io::ErrorKind::TimedOut,
352 IOError::WriteZero => io::ErrorKind::WriteZero,
353 IOError::Interrupted => io::ErrorKind::Interrupted,
354 IOError::Other => io::ErrorKind::Other,
355 IOError::UnexpectedEof => io::ErrorKind::UnexpectedEof,
361 /// A serialized transaction, in (pointer, length) form.
363 /// This type optionally owns its own memory, and thus the semantics around access change based on
364 /// the `data_is_owned` flag. If `data_is_owned` is set, you must call `Transaction_free` to free
365 /// the underlying buffer before the object goes out of scope. If `data_is_owned` is not set, any
366 /// access to the buffer after the scope in which the object was provided to you is invalid. eg,
367 /// access after you return from the call in which a `!data_is_owned` `Transaction` is provided to
368 /// you would be invalid.
370 /// Note that, while it may change in the future, because transactions on the Rust side are stored
371 /// in a deserialized form, all `Transaction`s generated on the Rust side will have `data_is_owned`
372 /// set. Similarly, while it may change in the future, all `Transaction`s you pass to Rust may have
373 /// `data_is_owned` either set or unset at your discretion.
374 pub struct Transaction {
375 /// The serialized transaction data.
377 /// This is non-const for your convenience, an object passed to Rust is never written to.
379 /// The length of the serialized transaction
381 /// Whether the data pointed to by `data` should be freed or not.
382 pub data_is_owned: bool,
385 fn from_vec(vec: Vec<u8>) -> Self {
386 let datalen = vec.len();
387 let data = Box::into_raw(vec.into_boxed_slice());
389 data: unsafe { (*data).as_mut_ptr() },
394 pub(crate) fn into_bitcoin(&self) -> BitcoinTransaction {
395 if self.datalen == 0 { panic!("0-length buffer can never represent a valid Transaction"); }
396 ::bitcoin::consensus::encode::deserialize(unsafe { core::slice::from_raw_parts(self.data, self.datalen) }).unwrap()
398 pub(crate) fn from_bitcoin(btc: &BitcoinTransaction) -> Self {
399 let vec = ::bitcoin::consensus::encode::serialize(btc);
403 impl Drop for Transaction {
405 if self.data_is_owned && self.datalen != 0 {
406 let _ = derived::CVec_u8Z { data: self.data as *mut u8, datalen: self.datalen };
410 impl Clone for Transaction {
411 fn clone(&self) -> Self {
412 let sl = unsafe { core::slice::from_raw_parts(self.data, self.datalen) };
413 let mut v = Vec::new();
414 v.extend_from_slice(&sl);
419 /// Frees the data buffer, if data_is_owned is set and datalen > 0.
420 pub extern "C" fn Transaction_free(_res: Transaction) { }
422 pub(crate) fn bitcoin_to_C_outpoint(outpoint: ::bitcoin::blockdata::transaction::OutPoint) -> crate::lightning::chain::transaction::OutPoint {
423 crate::lightning::chain::transaction::OutPoint_new(ThirtyTwoBytes { data: outpoint.txid.into_inner() }, outpoint.vout.try_into().unwrap())
425 pub(crate) fn C_to_bitcoin_outpoint(outpoint: crate::lightning::chain::transaction::OutPoint) -> ::bitcoin::blockdata::transaction::OutPoint {
427 ::bitcoin::blockdata::transaction::OutPoint {
428 txid: (*outpoint.inner).txid, vout: (*outpoint.inner).index as u32
435 /// A transaction output including a scriptPubKey and value.
436 /// This type *does* own its own memory, so must be free'd appropriately.
438 /// The script_pubkey in this output
439 pub script_pubkey: derived::CVec_u8Z,
440 /// The value, in satoshis, of this output
445 pub(crate) fn into_rust(mut self) -> ::bitcoin::blockdata::transaction::TxOut {
446 ::bitcoin::blockdata::transaction::TxOut {
447 script_pubkey: self.script_pubkey.into_rust().into(),
451 pub(crate) fn from_rust(txout: ::bitcoin::blockdata::transaction::TxOut) -> Self {
453 script_pubkey: derived::CVec_u8Z::from(txout.script_pubkey.into_bytes()),
460 /// Convenience function for constructing a new TxOut
461 pub extern "C" fn TxOut_new(script_pubkey: derived::CVec_u8Z, value: u64) -> TxOut {
462 TxOut { script_pubkey, value }
465 /// Frees the data pointed to by script_pubkey.
466 pub extern "C" fn TxOut_free(_res: TxOut) { }
468 /// Creates a new TxOut which has the same data as `orig` but with a new script buffer.
469 pub extern "C" fn TxOut_clone(orig: &TxOut) -> TxOut { orig.clone() }
472 /// A "slice" referencing some byte array. This is simply a length-tagged pointer which does not
473 /// own the memory pointed to by data.
475 /// A pointer to the byte buffer
477 /// The number of bytes pointed to by `data`.
481 pub(crate) fn from_slice(s: &[u8]) -> Self {
487 pub(crate) fn to_slice(&self) -> &[u8] {
488 if self.datalen == 0 { return &[]; }
489 unsafe { core::slice::from_raw_parts(self.data, self.datalen) }
491 pub(crate) fn to_reader<'a>(&'a self) -> Cursor<&'a [u8]> {
492 let sl = self.to_slice();
495 pub(crate) fn from_vec(v: &derived::CVec_u8Z) -> u8slice {
496 Self::from_slice(v.as_slice())
499 pub(crate) fn reader_to_vec<R: Read>(r: &mut R) -> derived::CVec_u8Z {
500 let mut res = Vec::new();
501 r.read_to_end(&mut res).unwrap();
502 derived::CVec_u8Z::from(res)
506 #[derive(Copy, Clone)]
507 /// Arbitrary 32 bytes, which could represent one of a few different things. You probably want to
508 /// look up the corresponding function in rust-lightning's docs.
509 pub struct ThirtyTwoBytes {
510 /// The thirty-two bytes
513 impl ThirtyTwoBytes {
514 pub(crate) fn null() -> Self {
515 Self { data: [0; 32] }
520 /// A 3-byte byte array.
521 pub struct ThreeBytes { /** The three bytes */ pub data: [u8; 3], }
524 /// A 4-byte byte array.
525 pub struct FourBytes { /** The four bytes */ pub data: [u8; 4], }
528 /// A 12-byte byte array.
529 pub struct TwelveBytes { /** The twelve bytes */ pub data: [u8; 12], }
532 /// A 16-byte byte array.
533 pub struct SixteenBytes { /** The sixteen bytes */ pub data: [u8; 16], }
536 /// A 20-byte byte array.
537 pub struct TwentyBytes { /** The twenty bytes */ pub data: [u8; 20], }
539 pub(crate) struct VecWriter(pub Vec<u8>);
540 impl lightning::util::ser::Writer for VecWriter {
541 fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
542 self.0.extend_from_slice(buf);
546 pub(crate) fn serialize_obj<I: lightning::util::ser::Writeable>(i: &I) -> derived::CVec_u8Z {
547 let mut out = VecWriter(Vec::new());
548 i.write(&mut out).unwrap();
549 derived::CVec_u8Z::from(out.0)
551 pub(crate) fn deserialize_obj<I: lightning::util::ser::Readable>(s: u8slice) -> Result<I, lightning::ln::msgs::DecodeError> {
552 I::read(&mut s.to_slice())
554 pub(crate) fn maybe_deserialize_obj<I: lightning::util::ser::MaybeReadable>(s: u8slice) -> Result<Option<I>, lightning::ln::msgs::DecodeError> {
555 I::read(&mut s.to_slice())
557 pub(crate) fn deserialize_obj_arg<A, I: lightning::util::ser::ReadableArgs<A>>(s: u8slice, args: A) -> Result<I, lightning::ln::msgs::DecodeError> {
558 I::read(&mut s.to_slice(), args)
562 /// A Rust str object, ie a reference to a UTF8-valid string.
563 /// This is *not* null-terminated so cannot be used directly as a C string!
565 /// A pointer to the string's bytes, in UTF8 encoding
566 pub chars: *const u8,
567 /// The number of bytes (not characters!) pointed to by `chars`
569 /// Whether the data pointed to by `chars` should be freed or not.
570 pub chars_is_owned: bool,
572 impl Into<Str> for &'static str {
573 fn into(self) -> Str {
574 Str { chars: self.as_ptr(), len: self.len(), chars_is_owned: false }
577 impl Into<Str> for &mut &'static str {
578 fn into(self) -> Str {
579 let us: &'static str = *self;
585 pub(crate) fn into_str(&self) -> &'static str {
586 if self.len == 0 { return ""; }
587 core::str::from_utf8(unsafe { core::slice::from_raw_parts(self.chars, self.len) }).unwrap()
589 pub(crate) fn into_string(mut self) -> String {
590 let bytes = if self.len == 0 {
592 } else if self.chars_is_owned {
594 Box::from_raw(core::slice::from_raw_parts_mut(unsafe { self.chars as *mut u8 }, self.len))
596 self.chars_is_owned = false;
599 let mut ret = Vec::with_capacity(self.len);
600 ret.extend_from_slice(unsafe { core::slice::from_raw_parts(self.chars, self.len) });
603 String::from_utf8(bytes).unwrap()
606 impl Into<Str> for String {
607 fn into(self) -> Str {
608 let s = Box::leak(self.into_boxed_str());
609 Str { chars: s.as_ptr(), len: s.len(), chars_is_owned: true }
613 fn clone(&self) -> Self {
614 String::from(self.into_str()).into()
620 if self.chars_is_owned && self.len != 0 {
621 let _ = derived::CVec_u8Z { data: self.chars as *mut u8, datalen: self.len };
626 /// Frees the data buffer, if chars_is_owned is set and len > 0.
627 pub extern "C" fn Str_free(_res: Str) { }
629 // Note that the C++ headers memset(0) all the Templ types to avoid deallocation!
630 // Thus, they must gracefully handle being completely null in _free.
632 // TODO: Integer/bool primitives should avoid the pointer indirection for underlying types
633 // everywhere in the containers.
636 pub(crate) union CResultPtr<O, E> {
637 pub(crate) result: *mut O,
638 pub(crate) err: *mut E,
641 pub(crate) struct CResultTempl<O, E> {
642 pub(crate) contents: CResultPtr<O, E>,
643 pub(crate) result_ok: bool,
645 impl<O, E> CResultTempl<O, E> {
646 pub(crate) extern "C" fn ok(o: O) -> Self {
648 contents: CResultPtr {
649 result: Box::into_raw(Box::new(o)),
654 pub(crate) extern "C" fn err(e: E) -> Self {
656 contents: CResultPtr {
657 err: Box::into_raw(Box::new(e)),
663 impl<O, E> Drop for CResultTempl<O, E> {
666 if unsafe { !self.contents.result.is_null() } {
667 unsafe { Box::from_raw(self.contents.result) };
669 } else if unsafe { !self.contents.err.is_null() } {
670 unsafe { Box::from_raw(self.contents.err) };
675 /// Utility to make it easy to set a pointer to null and get its original value in line.
676 pub(crate) trait TakePointer<T> {
677 fn take_ptr(&mut self) -> T;
679 impl<T> TakePointer<*const T> for *const T {
680 fn take_ptr(&mut self) -> *const T {
682 *self = core::ptr::null();
686 impl<T> TakePointer<*mut T> for *mut T {
687 fn take_ptr(&mut self) -> *mut T {
689 *self = core::ptr::null_mut();
695 pub(crate) mod ObjOps {
696 #[cfg(feature = "no-std")]
697 use alloc::boxed::Box;
700 #[must_use = "returns new dangling pointer"]
701 pub(crate) fn heap_alloc<T>(obj: T) -> *mut T {
702 let ptr = Box::into_raw(Box::new(obj));
703 nonnull_ptr_to_inner(ptr)
706 pub(crate) fn nonnull_ptr_to_inner<T>(ptr: *const T) -> *mut T {
707 if core::mem::size_of::<T>() == 0 {
708 // We map `None::<T>` as `T { inner: null, .. }` which works great for all
709 // non-Zero-Sized-Types `T`.
710 // For ZSTs, we need to differentiate between null implying `None` and null implying
711 // `Some` with no allocation.
712 // Thus, for ZSTs, we add one (usually) page here, which should always be aligned.
713 // Note that this relies on undefined behavior! A pointer to NULL may be valid, but a
714 // pointer to NULL + 4096 is almost certainly not. That said, Rust's existing use of
715 // `(*mut T)1` for the pointer we're adding to is also not defined, so we should be
717 // Note that we add 4095 here as at least the Java client assumes that the low bit on
718 // any heap pointer is 0, which is generally provided by malloc, but which is not true
719 // for ZSTs "allocated" by `Box::new`.
720 debug_assert_eq!(ptr as usize, 1);
721 unsafe { (ptr as *mut T).cast::<u8>().add(4096 - 1).cast::<T>() }
723 // In order to get better test coverage, also increment non-ZST pointers with
724 // --cfg=test_mod_pointers, which is set in genbindings.sh for debug builds.
725 #[cfg(test_mod_pointers)]
726 unsafe { (ptr as *mut T).cast::<u8>().add(4096).cast::<T>() }
727 #[cfg(not(test_mod_pointers))]
728 unsafe { ptr as *mut T }
732 /// Invert nonnull_ptr_to_inner
733 pub(crate) fn untweak_ptr<T>(ptr: *mut T) -> *mut T {
734 if core::mem::size_of::<T>() == 0 {
735 unsafe { ptr.cast::<u8>().sub(4096 - 1).cast::<T>() }
737 #[cfg(test_mod_pointers)]
738 unsafe { ptr.cast::<u8>().sub(4096).cast::<T>() }
739 #[cfg(not(test_mod_pointers))]
745 #[cfg(test_mod_pointers)]
747 /// This function exists for memory safety testing purposes. It should never be used in production
749 pub extern "C" fn __unmangle_inner_ptr(ptr: *const c_void) -> *const c_void {
750 if ptr as usize == 1 {
753 unsafe { ptr.cast::<u8>().sub(4096).cast::<c_void>() }
757 pub(crate) struct SmartPtr<T> {
760 impl<T> SmartPtr<T> {
761 pub(crate) fn from_obj(o: T) -> Self {
762 Self { ptr: Box::into_raw(Box::new(o)) }
764 pub(crate) fn null() -> Self {
765 Self { ptr: core::ptr::null_mut() }
768 impl<T> Drop for SmartPtr<T> {
770 if self.ptr != core::ptr::null_mut() {
771 unsafe { Box::from_raw(self.ptr); }
775 impl<T> core::ops::Deref for SmartPtr<T> {
776 type Target = *mut T;
777 fn deref(&self) -> &*mut T {