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;
16 use core::convert::TryInto; // Bindings need at least rustc 1.34
17 use core::ffi::c_void;
19 #[cfg(feature = "std")]
20 pub(crate) use std::io::{self, Cursor, Read};
21 #[cfg(feature = "no-std")]
22 pub(crate) use core2::io::{self, Cursor, Read};
23 #[cfg(feature = "no-std")]
24 use alloc::{boxed::Box, vec::Vec, string::String};
27 /// A dummy struct of which an instance must never exist.
28 /// This corresponds to the Rust type `Infallible`, or, in unstable rust, `!`
29 pub struct NotConstructable {
30 _priv_thing: core::convert::Infallible,
32 impl From<core::convert::Infallible> for NotConstructable {
33 fn from(_: core::convert::Infallible) -> Self { unreachable!(); }
36 /// Integer in the range `0..32`
37 #[derive(PartialEq, Eq, Copy, Clone)]
38 #[allow(non_camel_case_types)]
42 impl From<bech32::u5> for u5 {
43 fn from(o: bech32::u5) -> Self { Self(o.to_u8()) }
45 impl Into<bech32::u5> for u5 {
46 fn into(self) -> bech32::u5 { bech32::u5::try_from_u8(self.0).expect("u5 objects must be in the range 0..32") }
51 /// Represents a valid secp256k1 public key serialized in "compressed form" as a 33 byte array.
52 pub struct PublicKey {
53 /// The bytes of the public key
54 pub compressed_form: [u8; 33],
57 pub(crate) fn from_rust(pk: &SecpPublicKey) -> Self {
59 compressed_form: pk.serialize(),
62 pub(crate) fn into_rust(&self) -> SecpPublicKey {
63 SecpPublicKey::from_slice(&self.compressed_form).unwrap()
65 pub(crate) fn is_null(&self) -> bool { self.compressed_form[..] == [0; 33][..] }
66 pub(crate) fn null() -> Self { Self { compressed_form: [0; 33] } }
71 /// Represents a valid secp256k1 secret key serialized as a 32 byte array.
72 pub struct SecretKey {
73 /// The bytes of the secret key
77 // from_rust isn't implemented for a ref since we just return byte array refs directly
78 pub(crate) fn from_rust(sk: SecpSecretKey) -> Self {
79 let mut bytes = [0; 32];
80 bytes.copy_from_slice(&sk[..]);
83 pub(crate) fn into_rust(&self) -> SecpSecretKey {
84 SecpSecretKey::from_slice(&self.bytes).unwrap()
90 /// Represents a secp256k1 signature serialized as two 32-byte numbers
91 pub struct Signature {
92 /// The bytes of the signature in "compact" form
93 pub compact_form: [u8; 64],
96 pub(crate) fn from_rust(pk: &SecpSignature) -> Self {
98 compact_form: pk.serialize_compact(),
101 pub(crate) fn into_rust(&self) -> SecpSignature {
102 SecpSignature::from_compact(&self.compact_form).unwrap()
104 // The following are used for Option<Signature> which we support, but don't use anymore
105 #[allow(unused)] pub(crate) fn is_null(&self) -> bool { self.compact_form[..] == [0; 64][..] }
106 #[allow(unused)] pub(crate) fn null() -> Self { Self { compact_form: [0; 64] } }
111 /// Represents a secp256k1 signature serialized as two 32-byte numbers as well as a tag which
112 /// allows recovering the exact public key which created the signature given the message.
113 pub struct RecoverableSignature {
114 /// The bytes of the signature in "compact" form plus a "Recovery ID" which allows for
116 pub serialized_form: [u8; 68],
118 impl RecoverableSignature {
119 pub(crate) fn from_rust(pk: &SecpRecoverableSignature) -> Self {
120 let (id, compact_form) = pk.serialize_compact();
121 let mut serialized_form = [0; 68];
122 serialized_form[0..64].copy_from_slice(&compact_form[..]);
123 serialized_form[64..].copy_from_slice(&id.to_i32().to_le_bytes());
124 Self { serialized_form }
126 pub(crate) fn into_rust(&self) -> SecpRecoverableSignature {
128 id.copy_from_slice(&self.serialized_form[64..]);
129 SecpRecoverableSignature::from_compact(&self.serialized_form[0..64],
130 RecoveryId::from_i32(i32::from_le_bytes(id)).expect("Invalid Recovery ID"))
136 #[derive(Copy, Clone)]
137 /// Represents an error returned from libsecp256k1 during validation of some secp256k1 data
138 pub enum Secp256k1Error {
139 /// Signature failed verification
141 /// Badly sized message ("messages" are actually fixed-sized digests; see the MESSAGE_SIZE constant)
149 /// Bad shared secret.
153 /// Invalid tweak for add_assign or mul_assign
155 /// Didn't pass enough memory to context creation with preallocated memory
157 /// Bad set of public keys.
159 /// The only valid parity values are 0 or 1.
162 impl Secp256k1Error {
163 pub(crate) fn from_rust(err: SecpError) -> Self {
165 SecpError::IncorrectSignature => Secp256k1Error::IncorrectSignature,
166 SecpError::InvalidMessage => Secp256k1Error::InvalidMessage,
167 SecpError::InvalidPublicKey => Secp256k1Error::InvalidPublicKey,
168 SecpError::InvalidSignature => Secp256k1Error::InvalidSignature,
169 SecpError::InvalidSecretKey => Secp256k1Error::InvalidSecretKey,
170 SecpError::InvalidSharedSecret => Secp256k1Error::InvalidSharedSecret,
171 SecpError::InvalidRecoveryId => Secp256k1Error::InvalidRecoveryId,
172 SecpError::InvalidTweak => Secp256k1Error::InvalidTweak,
173 SecpError::NotEnoughMemory => Secp256k1Error::NotEnoughMemory,
174 SecpError::InvalidPublicKeySum => Secp256k1Error::InvalidPublicKeySum,
175 SecpError::InvalidParityValue(_) => Secp256k1Error::InvalidParityValue,
178 pub(crate) fn into_rust(self) -> SecpError {
179 let invalid_parity = secp256k1::Parity::from_i32(42).unwrap_err();
181 Secp256k1Error::IncorrectSignature => SecpError::IncorrectSignature,
182 Secp256k1Error::InvalidMessage => SecpError::InvalidMessage,
183 Secp256k1Error::InvalidPublicKey => SecpError::InvalidPublicKey,
184 Secp256k1Error::InvalidSignature => SecpError::InvalidSignature,
185 Secp256k1Error::InvalidSecretKey => SecpError::InvalidSecretKey,
186 Secp256k1Error::InvalidSharedSecret => SecpError::InvalidSharedSecret,
187 Secp256k1Error::InvalidRecoveryId => SecpError::InvalidRecoveryId,
188 Secp256k1Error::InvalidTweak => SecpError::InvalidTweak,
189 Secp256k1Error::NotEnoughMemory => SecpError::NotEnoughMemory,
190 Secp256k1Error::InvalidPublicKeySum => SecpError::InvalidPublicKeySum,
191 Secp256k1Error::InvalidParityValue => SecpError::InvalidParityValue(invalid_parity),
197 #[derive(Copy, Clone)]
198 /// Represents an error returned from the bech32 library during validation of some bech32 data
199 pub enum Bech32Error {
200 /// String does not contain the separator character
202 /// The checksum does not match the rest of the data
204 /// The data or human-readable part is too long or too short
206 /// Some part of the string contains an invalid character
208 /// Some part of the data has an invalid value
210 /// The bit conversion failed due to a padding issue
212 /// The whole string must be of one case
216 pub(crate) fn from_rust(err: bech32::Error) -> Self {
218 bech32::Error::MissingSeparator => Self::MissingSeparator,
219 bech32::Error::InvalidChecksum => Self::InvalidChecksum,
220 bech32::Error::InvalidLength => Self::InvalidLength,
221 bech32::Error::InvalidChar(c) => Self::InvalidChar(c as u32),
222 bech32::Error::InvalidData(d) => Self::InvalidData(d),
223 bech32::Error::InvalidPadding => Self::InvalidPadding,
224 bech32::Error::MixedCase => Self::MixedCase,
227 pub(crate) fn into_rust(self) -> bech32::Error {
229 Self::MissingSeparator => bech32::Error::MissingSeparator,
230 Self::InvalidChecksum => bech32::Error::InvalidChecksum,
231 Self::InvalidLength => bech32::Error::InvalidLength,
232 Self::InvalidChar(c) => bech32::Error::InvalidChar(core::char::from_u32(c).expect("Invalid UTF-8 character in Bech32Error::InvalidChar")),
233 Self::InvalidData(d) => bech32::Error::InvalidData(d),
234 Self::InvalidPadding => bech32::Error::InvalidPadding,
235 Self::MixedCase => bech32::Error::MixedCase,
240 /// Creates a new Bech32Error which has the same data as `orig`
241 pub extern "C" fn Bech32Error_clone(orig: &Bech32Error) -> Bech32Error { orig.clone() }
243 /// Releases any memory held by the given `Bech32Error` (which is currently none)
244 pub extern "C" fn Bech32Error_free(o: Bech32Error) { }
247 #[derive(Clone, Copy, PartialEq)]
248 /// Sub-errors which don't have specific information in them use this type.
250 /// Zero-Sized_types aren't consistent across Rust/C/C++, so we add some size here
255 #[allow(missing_docs)] // If there's no docs upstream, that's good enough for us
256 #[derive(Clone, Copy, PartialEq)]
257 /// Represents an IO Error. Note that some information is lost in the conversion from Rust.
278 #[cfg(feature = "std")]
280 pub(crate) fn from_rust(err: std::io::Error) -> Self {
282 std::io::ErrorKind::NotFound => IOError::NotFound,
283 std::io::ErrorKind::PermissionDenied => IOError::PermissionDenied,
284 std::io::ErrorKind::ConnectionRefused => IOError::ConnectionRefused,
285 std::io::ErrorKind::ConnectionReset => IOError::ConnectionReset,
286 std::io::ErrorKind::ConnectionAborted => IOError::ConnectionAborted,
287 std::io::ErrorKind::NotConnected => IOError::NotConnected,
288 std::io::ErrorKind::AddrInUse => IOError::AddrInUse,
289 std::io::ErrorKind::AddrNotAvailable => IOError::AddrNotAvailable,
290 std::io::ErrorKind::BrokenPipe => IOError::BrokenPipe,
291 std::io::ErrorKind::AlreadyExists => IOError::AlreadyExists,
292 std::io::ErrorKind::WouldBlock => IOError::WouldBlock,
293 std::io::ErrorKind::InvalidInput => IOError::InvalidInput,
294 std::io::ErrorKind::InvalidData => IOError::InvalidData,
295 std::io::ErrorKind::TimedOut => IOError::TimedOut,
296 std::io::ErrorKind::WriteZero => IOError::WriteZero,
297 std::io::ErrorKind::Interrupted => IOError::Interrupted,
298 std::io::ErrorKind::Other => IOError::Other,
299 std::io::ErrorKind::UnexpectedEof => IOError::UnexpectedEof,
303 pub(crate) fn to_rust(&self) -> std::io::Error {
304 std::io::Error::new(match self {
305 IOError::NotFound => std::io::ErrorKind::NotFound,
306 IOError::PermissionDenied => std::io::ErrorKind::PermissionDenied,
307 IOError::ConnectionRefused => std::io::ErrorKind::ConnectionRefused,
308 IOError::ConnectionReset => std::io::ErrorKind::ConnectionReset,
309 IOError::ConnectionAborted => std::io::ErrorKind::ConnectionAborted,
310 IOError::NotConnected => std::io::ErrorKind::NotConnected,
311 IOError::AddrInUse => std::io::ErrorKind::AddrInUse,
312 IOError::AddrNotAvailable => std::io::ErrorKind::AddrNotAvailable,
313 IOError::BrokenPipe => std::io::ErrorKind::BrokenPipe,
314 IOError::AlreadyExists => std::io::ErrorKind::AlreadyExists,
315 IOError::WouldBlock => std::io::ErrorKind::WouldBlock,
316 IOError::InvalidInput => std::io::ErrorKind::InvalidInput,
317 IOError::InvalidData => std::io::ErrorKind::InvalidData,
318 IOError::TimedOut => std::io::ErrorKind::TimedOut,
319 IOError::WriteZero => std::io::ErrorKind::WriteZero,
320 IOError::Interrupted => std::io::ErrorKind::Interrupted,
321 IOError::Other => std::io::ErrorKind::Other,
322 IOError::UnexpectedEof => std::io::ErrorKind::UnexpectedEof,
328 /// A serialized transaction, in (pointer, length) form.
330 /// This type optionally owns its own memory, and thus the semantics around access change based on
331 /// the `data_is_owned` flag. If `data_is_owned` is set, you must call `Transaction_free` to free
332 /// the underlying buffer before the object goes out of scope. If `data_is_owned` is not set, any
333 /// access to the buffer after the scope in which the object was provided to you is invalid. eg,
334 /// access after you return from the call in which a `!data_is_owned` `Transaction` is provided to
335 /// you would be invalid.
337 /// Note that, while it may change in the future, because transactions on the Rust side are stored
338 /// in a deserialized form, all `Transaction`s generated on the Rust side will have `data_is_owned`
339 /// set. Similarly, while it may change in the future, all `Transaction`s you pass to Rust may have
340 /// `data_is_owned` either set or unset at your discretion.
341 pub struct Transaction {
342 /// The serialized transaction data.
344 /// This is non-const for your convenience, an object passed to Rust is never written to.
346 /// The length of the serialized transaction
348 /// Whether the data pointed to by `data` should be freed or not.
349 pub data_is_owned: bool,
352 fn from_vec(vec: Vec<u8>) -> Self {
353 let datalen = vec.len();
354 let data = Box::into_raw(vec.into_boxed_slice());
356 data: unsafe { (*data).as_mut_ptr() },
361 pub(crate) fn into_bitcoin(&self) -> BitcoinTransaction {
362 if self.datalen == 0 { panic!("0-length buffer can never represent a valid Transaction"); }
363 ::bitcoin::consensus::encode::deserialize(unsafe { core::slice::from_raw_parts(self.data, self.datalen) }).unwrap()
365 pub(crate) fn from_bitcoin(btc: &BitcoinTransaction) -> Self {
366 let vec = ::bitcoin::consensus::encode::serialize(btc);
370 impl Drop for Transaction {
372 if self.data_is_owned && self.datalen != 0 {
373 let _ = derived::CVec_u8Z { data: self.data as *mut u8, datalen: self.datalen };
377 impl Clone for Transaction {
378 fn clone(&self) -> Self {
379 let sl = unsafe { core::slice::from_raw_parts(self.data, self.datalen) };
380 let mut v = Vec::new();
381 v.extend_from_slice(&sl);
386 /// Frees the data buffer, if data_is_owned is set and datalen > 0.
387 pub extern "C" fn Transaction_free(_res: Transaction) { }
389 pub(crate) fn bitcoin_to_C_outpoint(outpoint: ::bitcoin::blockdata::transaction::OutPoint) -> crate::lightning::chain::transaction::OutPoint {
390 crate::lightning::chain::transaction::OutPoint_new(ThirtyTwoBytes { data: outpoint.txid.into_inner() }, outpoint.vout.try_into().unwrap())
392 pub(crate) fn C_to_bitcoin_outpoint(outpoint: crate::lightning::chain::transaction::OutPoint) -> ::bitcoin::blockdata::transaction::OutPoint {
394 ::bitcoin::blockdata::transaction::OutPoint {
395 txid: (*outpoint.inner).txid, vout: (*outpoint.inner).index as u32
402 /// A transaction output including a scriptPubKey and value.
403 /// This type *does* own its own memory, so must be free'd appropriately.
405 /// The script_pubkey in this output
406 pub script_pubkey: derived::CVec_u8Z,
407 /// The value, in satoshis, of this output
412 pub(crate) fn into_rust(mut self) -> ::bitcoin::blockdata::transaction::TxOut {
413 ::bitcoin::blockdata::transaction::TxOut {
414 script_pubkey: self.script_pubkey.into_rust().into(),
418 pub(crate) fn from_rust(txout: ::bitcoin::blockdata::transaction::TxOut) -> Self {
420 script_pubkey: derived::CVec_u8Z::from(txout.script_pubkey.into_bytes()),
427 /// Convenience function for constructing a new TxOut
428 pub extern "C" fn TxOut_new(script_pubkey: derived::CVec_u8Z, value: u64) -> TxOut {
429 TxOut { script_pubkey, value }
432 /// Frees the data pointed to by script_pubkey.
433 pub extern "C" fn TxOut_free(_res: TxOut) { }
435 /// Creates a new TxOut which has the same data as `orig` but with a new script buffer.
436 pub extern "C" fn TxOut_clone(orig: &TxOut) -> TxOut { orig.clone() }
439 /// A "slice" referencing some byte array. This is simply a length-tagged pointer which does not
440 /// own the memory pointed to by data.
442 /// A pointer to the byte buffer
444 /// The number of bytes pointed to by `data`.
448 pub(crate) fn from_slice(s: &[u8]) -> Self {
454 pub(crate) fn to_slice(&self) -> &[u8] {
455 if self.datalen == 0 { return &[]; }
456 unsafe { core::slice::from_raw_parts(self.data, self.datalen) }
458 pub(crate) fn to_reader<'a>(&'a self) -> Cursor<&'a [u8]> {
459 let sl = self.to_slice();
462 pub(crate) fn from_vec(v: &derived::CVec_u8Z) -> u8slice {
463 Self::from_slice(v.as_slice())
466 pub(crate) fn reader_to_vec<R: Read>(r: &mut R) -> derived::CVec_u8Z {
467 let mut res = Vec::new();
468 r.read_to_end(&mut res).unwrap();
469 derived::CVec_u8Z::from(res)
473 #[derive(Copy, Clone)]
474 /// Arbitrary 32 bytes, which could represent one of a few different things. You probably want to
475 /// look up the corresponding function in rust-lightning's docs.
476 pub struct ThirtyTwoBytes {
477 /// The thirty-two bytes
480 impl ThirtyTwoBytes {
481 pub(crate) fn null() -> Self {
482 Self { data: [0; 32] }
487 /// A 3-byte byte array.
488 pub struct ThreeBytes { /** The three bytes */ pub data: [u8; 3], }
491 /// A 4-byte byte array.
492 pub struct FourBytes { /** The four bytes */ pub data: [u8; 4], }
495 /// A 12-byte byte array.
496 pub struct TwelveBytes { /** The twelve bytes */ pub data: [u8; 12], }
499 /// A 16-byte byte array.
500 pub struct SixteenBytes { /** The sixteen bytes */ pub data: [u8; 16], }
503 /// A 20-byte byte array.
504 pub struct TwentyBytes { /** The twenty bytes */ pub data: [u8; 20], }
506 pub(crate) struct VecWriter(pub Vec<u8>);
507 impl lightning::util::ser::Writer for VecWriter {
508 fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
509 self.0.extend_from_slice(buf);
513 pub(crate) fn serialize_obj<I: lightning::util::ser::Writeable>(i: &I) -> derived::CVec_u8Z {
514 let mut out = VecWriter(Vec::new());
515 i.write(&mut out).unwrap();
516 derived::CVec_u8Z::from(out.0)
518 pub(crate) fn deserialize_obj<I: lightning::util::ser::Readable>(s: u8slice) -> Result<I, lightning::ln::msgs::DecodeError> {
519 I::read(&mut s.to_slice())
521 pub(crate) fn maybe_deserialize_obj<I: lightning::util::ser::MaybeReadable>(s: u8slice) -> Result<Option<I>, lightning::ln::msgs::DecodeError> {
522 I::read(&mut s.to_slice())
524 pub(crate) fn deserialize_obj_arg<A, I: lightning::util::ser::ReadableArgs<A>>(s: u8slice, args: A) -> Result<I, lightning::ln::msgs::DecodeError> {
525 I::read(&mut s.to_slice(), args)
529 /// A Rust str object, ie a reference to a UTF8-valid string.
530 /// This is *not* null-terminated so cannot be used directly as a C string!
532 /// A pointer to the string's bytes, in UTF8 encoding
533 pub chars: *const u8,
534 /// The number of bytes (not characters!) pointed to by `chars`
536 /// Whether the data pointed to by `chars` should be freed or not.
537 pub chars_is_owned: bool,
539 impl Into<Str> for &'static str {
540 fn into(self) -> Str {
541 Str { chars: self.as_ptr(), len: self.len(), chars_is_owned: false }
544 impl Into<Str> for &mut &'static str {
545 fn into(self) -> Str {
546 let us: &'static str = *self;
552 pub(crate) fn into_str(&self) -> &'static str {
553 if self.len == 0 { return ""; }
554 core::str::from_utf8(unsafe { core::slice::from_raw_parts(self.chars, self.len) }).unwrap()
556 pub(crate) fn into_string(mut self) -> String {
557 let bytes = if self.len == 0 {
559 } else if self.chars_is_owned {
561 Box::from_raw(core::slice::from_raw_parts_mut(unsafe { self.chars as *mut u8 }, self.len))
563 self.chars_is_owned = false;
566 let mut ret = Vec::with_capacity(self.len);
567 ret.extend_from_slice(unsafe { core::slice::from_raw_parts(self.chars, self.len) });
570 String::from_utf8(bytes).unwrap()
573 impl Into<Str> for String {
574 fn into(self) -> Str {
575 let s = Box::leak(self.into_boxed_str());
576 Str { chars: s.as_ptr(), len: s.len(), chars_is_owned: true }
580 fn clone(&self) -> Self {
581 String::from(self.into_str()).into()
587 if self.chars_is_owned && self.len != 0 {
588 let _ = derived::CVec_u8Z { data: self.chars as *mut u8, datalen: self.len };
593 /// Frees the data buffer, if chars_is_owned is set and len > 0.
594 pub extern "C" fn Str_free(_res: Str) { }
596 // Note that the C++ headers memset(0) all the Templ types to avoid deallocation!
597 // Thus, they must gracefully handle being completely null in _free.
599 // TODO: Integer/bool primitives should avoid the pointer indirection for underlying types
600 // everywhere in the containers.
603 pub(crate) union CResultPtr<O, E> {
604 pub(crate) result: *mut O,
605 pub(crate) err: *mut E,
608 pub(crate) struct CResultTempl<O, E> {
609 pub(crate) contents: CResultPtr<O, E>,
610 pub(crate) result_ok: bool,
612 impl<O, E> CResultTempl<O, E> {
613 pub(crate) extern "C" fn ok(o: O) -> Self {
615 contents: CResultPtr {
616 result: Box::into_raw(Box::new(o)),
621 pub(crate) extern "C" fn err(e: E) -> Self {
623 contents: CResultPtr {
624 err: Box::into_raw(Box::new(e)),
630 impl<O, E> Drop for CResultTempl<O, E> {
633 if unsafe { !self.contents.result.is_null() } {
634 unsafe { Box::from_raw(self.contents.result) };
636 } else if unsafe { !self.contents.err.is_null() } {
637 unsafe { Box::from_raw(self.contents.err) };
642 /// Utility to make it easy to set a pointer to null and get its original value in line.
643 pub(crate) trait TakePointer<T> {
644 fn take_ptr(&mut self) -> T;
646 impl<T> TakePointer<*const T> for *const T {
647 fn take_ptr(&mut self) -> *const T {
649 *self = core::ptr::null();
653 impl<T> TakePointer<*mut T> for *mut T {
654 fn take_ptr(&mut self) -> *mut T {
656 *self = core::ptr::null_mut();
662 pub(crate) mod ObjOps {
663 #[cfg(feature = "no-std")]
664 use alloc::boxed::Box;
667 #[must_use = "returns new dangling pointer"]
668 pub(crate) fn heap_alloc<T>(obj: T) -> *mut T {
669 let ptr = Box::into_raw(Box::new(obj));
670 nonnull_ptr_to_inner(ptr)
673 pub(crate) fn nonnull_ptr_to_inner<T>(ptr: *const T) -> *mut T {
674 if core::mem::size_of::<T>() == 0 {
675 // We map `None::<T>` as `T { inner: null, .. }` which works great for all
676 // non-Zero-Sized-Types `T`.
677 // For ZSTs, we need to differentiate between null implying `None` and null implying
678 // `Some` with no allocation.
679 // Thus, for ZSTs, we add one (usually) page here, which should always be aligned.
680 // Note that this relies on undefined behavior! A pointer to NULL may be valid, but a
681 // pointer to NULL + 4096 is almost certainly not. That said, Rust's existing use of
682 // `(*mut T)1` for the pointer we're adding to is also not defined, so we should be
684 // Note that we add 4095 here as at least the Java client assumes that the low bit on
685 // any heap pointer is 0, which is generally provided by malloc, but which is not true
686 // for ZSTs "allocated" by `Box::new`.
687 debug_assert_eq!(ptr as usize, 1);
688 unsafe { (ptr as *mut T).cast::<u8>().add(4096 - 1).cast::<T>() }
690 // In order to get better test coverage, also increment non-ZST pointers with
691 // --cfg=test_mod_pointers, which is set in genbindings.sh for debug builds.
692 #[cfg(test_mod_pointers)]
693 unsafe { (ptr as *mut T).cast::<u8>().add(4096).cast::<T>() }
694 #[cfg(not(test_mod_pointers))]
695 unsafe { ptr as *mut T }
699 /// Invert nonnull_ptr_to_inner
700 pub(crate) fn untweak_ptr<T>(ptr: *mut T) -> *mut T {
701 if core::mem::size_of::<T>() == 0 {
702 unsafe { ptr.cast::<u8>().sub(4096 - 1).cast::<T>() }
704 #[cfg(test_mod_pointers)]
705 unsafe { ptr.cast::<u8>().sub(4096).cast::<T>() }
706 #[cfg(not(test_mod_pointers))]
712 #[cfg(test_mod_pointers)]
714 /// This function exists for memory safety testing purposes. It should never be used in production
716 pub extern "C" fn __unmangle_inner_ptr(ptr: *const c_void) -> *const c_void {
717 if ptr as usize == 1 {
720 unsafe { ptr.cast::<u8>().sub(4096).cast::<c_void>() }
724 pub(crate) struct SmartPtr<T> {
727 impl<T> SmartPtr<T> {
728 pub(crate) fn from_obj(o: T) -> Self {
729 Self { ptr: Box::into_raw(Box::new(o)) }
731 pub(crate) fn null() -> Self {
732 Self { ptr: core::ptr::null_mut() }
735 impl<T> Drop for SmartPtr<T> {
737 if self.ptr != core::ptr::null_mut() {
738 unsafe { Box::from_raw(self.ptr); }
742 impl<T> core::ops::Deref for SmartPtr<T> {
743 type Target = *mut T;
744 fn deref(&self) -> &*mut T {