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;
15 use bitcoin::util::address;
17 use core::convert::TryInto; // Bindings need at least rustc 1.34
18 use core::ffi::c_void;
20 #[cfg(feature = "std")]
21 pub(crate) use std::io::{self, Cursor, Read};
22 #[cfg(feature = "no-std")]
23 pub(crate) use core2::io::{self, Cursor, Read};
24 #[cfg(feature = "no-std")]
25 use alloc::{boxed::Box, vec::Vec, string::String};
28 /// A dummy struct of which an instance must never exist.
29 /// This corresponds to the Rust type `Infallible`, or, in unstable rust, `!`
30 pub struct NotConstructable {
31 _priv_thing: core::convert::Infallible,
33 impl From<core::convert::Infallible> for NotConstructable {
34 fn from(_: core::convert::Infallible) -> Self { unreachable!(); }
37 /// Integer in the range `0..32`
38 #[derive(PartialEq, Eq, Copy, Clone)]
39 #[allow(non_camel_case_types)]
43 impl From<bech32::u5> for u5 {
44 fn from(o: bech32::u5) -> Self { Self(o.to_u8()) }
46 impl Into<bech32::u5> for u5 {
47 fn into(self) -> bech32::u5 { bech32::u5::try_from_u8(self.0).expect("u5 objects must be in the range 0..32") }
50 /// Integer in the range `0..=16`
51 #[derive(PartialEq, Eq, Copy, Clone)]
53 pub struct WitnessVersion(u8);
55 impl From<address::WitnessVersion> for WitnessVersion {
56 fn from(o: address::WitnessVersion) -> Self { Self(o.into_num()) }
58 impl Into<address::WitnessVersion> for WitnessVersion {
59 fn into(self) -> address::WitnessVersion { address::WitnessVersion::from_num(self.0).expect("WitnessVersion objects must be in the range 0..=16") }
64 /// Represents a valid secp256k1 public key serialized in "compressed form" as a 33 byte array.
65 pub struct PublicKey {
66 /// The bytes of the public key
67 pub compressed_form: [u8; 33],
70 pub(crate) fn from_rust(pk: &SecpPublicKey) -> Self {
72 compressed_form: pk.serialize(),
75 pub(crate) fn into_rust(&self) -> SecpPublicKey {
76 SecpPublicKey::from_slice(&self.compressed_form).unwrap()
78 pub(crate) fn is_null(&self) -> bool { self.compressed_form[..] == [0; 33][..] }
79 pub(crate) fn null() -> Self { Self { compressed_form: [0; 33] } }
84 /// Represents a valid secp256k1 secret key serialized as a 32 byte array.
85 pub struct SecretKey {
86 /// The bytes of the secret key
90 // from_rust isn't implemented for a ref since we just return byte array refs directly
91 pub(crate) fn from_rust(sk: SecpSecretKey) -> Self {
92 let mut bytes = [0; 32];
93 bytes.copy_from_slice(&sk[..]);
96 pub(crate) fn into_rust(&self) -> SecpSecretKey {
97 SecpSecretKey::from_slice(&self.bytes).unwrap()
103 /// Represents a secp256k1 signature serialized as two 32-byte numbers
104 pub struct Signature {
105 /// The bytes of the signature in "compact" form
106 pub compact_form: [u8; 64],
109 pub(crate) fn from_rust(pk: &SecpSignature) -> Self {
111 compact_form: pk.serialize_compact(),
114 pub(crate) fn into_rust(&self) -> SecpSignature {
115 SecpSignature::from_compact(&self.compact_form).unwrap()
117 // The following are used for Option<Signature> which we support, but don't use anymore
118 #[allow(unused)] pub(crate) fn is_null(&self) -> bool { self.compact_form[..] == [0; 64][..] }
119 #[allow(unused)] pub(crate) fn null() -> Self { Self { compact_form: [0; 64] } }
124 /// Represents a secp256k1 signature serialized as two 32-byte numbers as well as a tag which
125 /// allows recovering the exact public key which created the signature given the message.
126 pub struct RecoverableSignature {
127 /// The bytes of the signature in "compact" form plus a "Recovery ID" which allows for
129 pub serialized_form: [u8; 68],
131 impl RecoverableSignature {
132 pub(crate) fn from_rust(pk: &SecpRecoverableSignature) -> Self {
133 let (id, compact_form) = pk.serialize_compact();
134 let mut serialized_form = [0; 68];
135 serialized_form[0..64].copy_from_slice(&compact_form[..]);
136 serialized_form[64..].copy_from_slice(&id.to_i32().to_le_bytes());
137 Self { serialized_form }
139 pub(crate) fn into_rust(&self) -> SecpRecoverableSignature {
141 id.copy_from_slice(&self.serialized_form[64..]);
142 SecpRecoverableSignature::from_compact(&self.serialized_form[0..64],
143 RecoveryId::from_i32(i32::from_le_bytes(id)).expect("Invalid Recovery ID"))
149 #[derive(Copy, Clone)]
150 /// Represents an error returned from libsecp256k1 during validation of some secp256k1 data
151 pub enum Secp256k1Error {
152 /// Signature failed verification
154 /// Badly sized message ("messages" are actually fixed-sized digests; see the MESSAGE_SIZE constant)
162 /// Bad shared secret.
166 /// Invalid tweak for add_assign or mul_assign
168 /// Didn't pass enough memory to context creation with preallocated memory
170 /// Bad set of public keys.
172 /// The only valid parity values are 0 or 1.
175 impl Secp256k1Error {
176 pub(crate) fn from_rust(err: SecpError) -> Self {
178 SecpError::IncorrectSignature => Secp256k1Error::IncorrectSignature,
179 SecpError::InvalidMessage => Secp256k1Error::InvalidMessage,
180 SecpError::InvalidPublicKey => Secp256k1Error::InvalidPublicKey,
181 SecpError::InvalidSignature => Secp256k1Error::InvalidSignature,
182 SecpError::InvalidSecretKey => Secp256k1Error::InvalidSecretKey,
183 SecpError::InvalidSharedSecret => Secp256k1Error::InvalidSharedSecret,
184 SecpError::InvalidRecoveryId => Secp256k1Error::InvalidRecoveryId,
185 SecpError::InvalidTweak => Secp256k1Error::InvalidTweak,
186 SecpError::NotEnoughMemory => Secp256k1Error::NotEnoughMemory,
187 SecpError::InvalidPublicKeySum => Secp256k1Error::InvalidPublicKeySum,
188 SecpError::InvalidParityValue(_) => Secp256k1Error::InvalidParityValue,
191 pub(crate) fn into_rust(self) -> SecpError {
192 let invalid_parity = secp256k1::Parity::from_i32(42).unwrap_err();
194 Secp256k1Error::IncorrectSignature => SecpError::IncorrectSignature,
195 Secp256k1Error::InvalidMessage => SecpError::InvalidMessage,
196 Secp256k1Error::InvalidPublicKey => SecpError::InvalidPublicKey,
197 Secp256k1Error::InvalidSignature => SecpError::InvalidSignature,
198 Secp256k1Error::InvalidSecretKey => SecpError::InvalidSecretKey,
199 Secp256k1Error::InvalidSharedSecret => SecpError::InvalidSharedSecret,
200 Secp256k1Error::InvalidRecoveryId => SecpError::InvalidRecoveryId,
201 Secp256k1Error::InvalidTweak => SecpError::InvalidTweak,
202 Secp256k1Error::NotEnoughMemory => SecpError::NotEnoughMemory,
203 Secp256k1Error::InvalidPublicKeySum => SecpError::InvalidPublicKeySum,
204 Secp256k1Error::InvalidParityValue => SecpError::InvalidParityValue(invalid_parity),
210 #[derive(Copy, Clone)]
211 /// Represents an error returned from the bech32 library during validation of some bech32 data
212 pub enum Bech32Error {
213 /// String does not contain the separator character
215 /// The checksum does not match the rest of the data
217 /// The data or human-readable part is too long or too short
219 /// Some part of the string contains an invalid character
221 /// Some part of the data has an invalid value
223 /// The bit conversion failed due to a padding issue
225 /// The whole string must be of one case
229 pub(crate) fn from_rust(err: bech32::Error) -> Self {
231 bech32::Error::MissingSeparator => Self::MissingSeparator,
232 bech32::Error::InvalidChecksum => Self::InvalidChecksum,
233 bech32::Error::InvalidLength => Self::InvalidLength,
234 bech32::Error::InvalidChar(c) => Self::InvalidChar(c as u32),
235 bech32::Error::InvalidData(d) => Self::InvalidData(d),
236 bech32::Error::InvalidPadding => Self::InvalidPadding,
237 bech32::Error::MixedCase => Self::MixedCase,
240 pub(crate) fn into_rust(self) -> bech32::Error {
242 Self::MissingSeparator => bech32::Error::MissingSeparator,
243 Self::InvalidChecksum => bech32::Error::InvalidChecksum,
244 Self::InvalidLength => bech32::Error::InvalidLength,
245 Self::InvalidChar(c) => bech32::Error::InvalidChar(core::char::from_u32(c).expect("Invalid UTF-8 character in Bech32Error::InvalidChar")),
246 Self::InvalidData(d) => bech32::Error::InvalidData(d),
247 Self::InvalidPadding => bech32::Error::InvalidPadding,
248 Self::MixedCase => bech32::Error::MixedCase,
253 /// Creates a new Bech32Error which has the same data as `orig`
254 pub extern "C" fn Bech32Error_clone(orig: &Bech32Error) -> Bech32Error { orig.clone() }
256 /// Releases any memory held by the given `Bech32Error` (which is currently none)
257 pub extern "C" fn Bech32Error_free(o: Bech32Error) { }
260 #[derive(Clone, Copy, PartialEq)]
261 /// Sub-errors which don't have specific information in them use this type.
263 /// Zero-Sized_types aren't consistent across Rust/C/C++, so we add some size here
268 #[allow(missing_docs)] // If there's no docs upstream, that's good enough for us
269 #[derive(Clone, Copy, PartialEq)]
270 /// Represents an IO Error. Note that some information is lost in the conversion from Rust.
291 #[cfg(feature = "std")]
293 pub(crate) fn from_rust(err: std::io::Error) -> Self {
295 std::io::ErrorKind::NotFound => IOError::NotFound,
296 std::io::ErrorKind::PermissionDenied => IOError::PermissionDenied,
297 std::io::ErrorKind::ConnectionRefused => IOError::ConnectionRefused,
298 std::io::ErrorKind::ConnectionReset => IOError::ConnectionReset,
299 std::io::ErrorKind::ConnectionAborted => IOError::ConnectionAborted,
300 std::io::ErrorKind::NotConnected => IOError::NotConnected,
301 std::io::ErrorKind::AddrInUse => IOError::AddrInUse,
302 std::io::ErrorKind::AddrNotAvailable => IOError::AddrNotAvailable,
303 std::io::ErrorKind::BrokenPipe => IOError::BrokenPipe,
304 std::io::ErrorKind::AlreadyExists => IOError::AlreadyExists,
305 std::io::ErrorKind::WouldBlock => IOError::WouldBlock,
306 std::io::ErrorKind::InvalidInput => IOError::InvalidInput,
307 std::io::ErrorKind::InvalidData => IOError::InvalidData,
308 std::io::ErrorKind::TimedOut => IOError::TimedOut,
309 std::io::ErrorKind::WriteZero => IOError::WriteZero,
310 std::io::ErrorKind::Interrupted => IOError::Interrupted,
311 std::io::ErrorKind::Other => IOError::Other,
312 std::io::ErrorKind::UnexpectedEof => IOError::UnexpectedEof,
316 pub(crate) fn to_rust(&self) -> std::io::Error {
317 std::io::Error::new(match self {
318 IOError::NotFound => std::io::ErrorKind::NotFound,
319 IOError::PermissionDenied => std::io::ErrorKind::PermissionDenied,
320 IOError::ConnectionRefused => std::io::ErrorKind::ConnectionRefused,
321 IOError::ConnectionReset => std::io::ErrorKind::ConnectionReset,
322 IOError::ConnectionAborted => std::io::ErrorKind::ConnectionAborted,
323 IOError::NotConnected => std::io::ErrorKind::NotConnected,
324 IOError::AddrInUse => std::io::ErrorKind::AddrInUse,
325 IOError::AddrNotAvailable => std::io::ErrorKind::AddrNotAvailable,
326 IOError::BrokenPipe => std::io::ErrorKind::BrokenPipe,
327 IOError::AlreadyExists => std::io::ErrorKind::AlreadyExists,
328 IOError::WouldBlock => std::io::ErrorKind::WouldBlock,
329 IOError::InvalidInput => std::io::ErrorKind::InvalidInput,
330 IOError::InvalidData => std::io::ErrorKind::InvalidData,
331 IOError::TimedOut => std::io::ErrorKind::TimedOut,
332 IOError::WriteZero => std::io::ErrorKind::WriteZero,
333 IOError::Interrupted => std::io::ErrorKind::Interrupted,
334 IOError::Other => std::io::ErrorKind::Other,
335 IOError::UnexpectedEof => std::io::ErrorKind::UnexpectedEof,
341 /// A serialized transaction, in (pointer, length) form.
343 /// This type optionally owns its own memory, and thus the semantics around access change based on
344 /// the `data_is_owned` flag. If `data_is_owned` is set, you must call `Transaction_free` to free
345 /// the underlying buffer before the object goes out of scope. If `data_is_owned` is not set, any
346 /// access to the buffer after the scope in which the object was provided to you is invalid. eg,
347 /// access after you return from the call in which a `!data_is_owned` `Transaction` is provided to
348 /// you would be invalid.
350 /// Note that, while it may change in the future, because transactions on the Rust side are stored
351 /// in a deserialized form, all `Transaction`s generated on the Rust side will have `data_is_owned`
352 /// set. Similarly, while it may change in the future, all `Transaction`s you pass to Rust may have
353 /// `data_is_owned` either set or unset at your discretion.
354 pub struct Transaction {
355 /// The serialized transaction data.
357 /// This is non-const for your convenience, an object passed to Rust is never written to.
359 /// The length of the serialized transaction
361 /// Whether the data pointed to by `data` should be freed or not.
362 pub data_is_owned: bool,
365 fn from_vec(vec: Vec<u8>) -> Self {
366 let datalen = vec.len();
367 let data = Box::into_raw(vec.into_boxed_slice());
369 data: unsafe { (*data).as_mut_ptr() },
374 pub(crate) fn into_bitcoin(&self) -> BitcoinTransaction {
375 if self.datalen == 0 { panic!("0-length buffer can never represent a valid Transaction"); }
376 ::bitcoin::consensus::encode::deserialize(unsafe { core::slice::from_raw_parts(self.data, self.datalen) }).unwrap()
378 pub(crate) fn from_bitcoin(btc: &BitcoinTransaction) -> Self {
379 let vec = ::bitcoin::consensus::encode::serialize(btc);
383 impl Drop for Transaction {
385 if self.data_is_owned && self.datalen != 0 {
386 let _ = derived::CVec_u8Z { data: self.data as *mut u8, datalen: self.datalen };
390 impl Clone for Transaction {
391 fn clone(&self) -> Self {
392 let sl = unsafe { core::slice::from_raw_parts(self.data, self.datalen) };
393 let mut v = Vec::new();
394 v.extend_from_slice(&sl);
399 /// Frees the data buffer, if data_is_owned is set and datalen > 0.
400 pub extern "C" fn Transaction_free(_res: Transaction) { }
402 pub(crate) fn bitcoin_to_C_outpoint(outpoint: ::bitcoin::blockdata::transaction::OutPoint) -> crate::lightning::chain::transaction::OutPoint {
403 crate::lightning::chain::transaction::OutPoint_new(ThirtyTwoBytes { data: outpoint.txid.into_inner() }, outpoint.vout.try_into().unwrap())
405 pub(crate) fn C_to_bitcoin_outpoint(outpoint: crate::lightning::chain::transaction::OutPoint) -> ::bitcoin::blockdata::transaction::OutPoint {
407 ::bitcoin::blockdata::transaction::OutPoint {
408 txid: (*outpoint.inner).txid, vout: (*outpoint.inner).index as u32
415 /// A transaction output including a scriptPubKey and value.
416 /// This type *does* own its own memory, so must be free'd appropriately.
418 /// The script_pubkey in this output
419 pub script_pubkey: derived::CVec_u8Z,
420 /// The value, in satoshis, of this output
425 pub(crate) fn into_rust(mut self) -> ::bitcoin::blockdata::transaction::TxOut {
426 ::bitcoin::blockdata::transaction::TxOut {
427 script_pubkey: self.script_pubkey.into_rust().into(),
431 pub(crate) fn from_rust(txout: ::bitcoin::blockdata::transaction::TxOut) -> Self {
433 script_pubkey: derived::CVec_u8Z::from(txout.script_pubkey.into_bytes()),
440 /// Convenience function for constructing a new TxOut
441 pub extern "C" fn TxOut_new(script_pubkey: derived::CVec_u8Z, value: u64) -> TxOut {
442 TxOut { script_pubkey, value }
445 /// Frees the data pointed to by script_pubkey.
446 pub extern "C" fn TxOut_free(_res: TxOut) { }
448 /// Creates a new TxOut which has the same data as `orig` but with a new script buffer.
449 pub extern "C" fn TxOut_clone(orig: &TxOut) -> TxOut { orig.clone() }
452 /// A "slice" referencing some byte array. This is simply a length-tagged pointer which does not
453 /// own the memory pointed to by data.
455 /// A pointer to the byte buffer
457 /// The number of bytes pointed to by `data`.
461 pub(crate) fn from_slice(s: &[u8]) -> Self {
467 pub(crate) fn to_slice(&self) -> &[u8] {
468 if self.datalen == 0 { return &[]; }
469 unsafe { core::slice::from_raw_parts(self.data, self.datalen) }
471 pub(crate) fn to_reader<'a>(&'a self) -> Cursor<&'a [u8]> {
472 let sl = self.to_slice();
475 pub(crate) fn from_vec(v: &derived::CVec_u8Z) -> u8slice {
476 Self::from_slice(v.as_slice())
479 pub(crate) fn reader_to_vec<R: Read>(r: &mut R) -> derived::CVec_u8Z {
480 let mut res = Vec::new();
481 r.read_to_end(&mut res).unwrap();
482 derived::CVec_u8Z::from(res)
486 #[derive(Copy, Clone)]
487 /// Arbitrary 32 bytes, which could represent one of a few different things. You probably want to
488 /// look up the corresponding function in rust-lightning's docs.
489 pub struct ThirtyTwoBytes {
490 /// The thirty-two bytes
493 impl ThirtyTwoBytes {
494 pub(crate) fn null() -> Self {
495 Self { data: [0; 32] }
500 /// A 3-byte byte array.
501 pub struct ThreeBytes { /** The three bytes */ pub data: [u8; 3], }
504 /// A 4-byte byte array.
505 pub struct FourBytes { /** The four bytes */ pub data: [u8; 4], }
508 /// A 12-byte byte array.
509 pub struct TwelveBytes { /** The twelve bytes */ pub data: [u8; 12], }
512 /// A 16-byte byte array.
513 pub struct SixteenBytes { /** The sixteen bytes */ pub data: [u8; 16], }
516 /// A 20-byte byte array.
517 pub struct TwentyBytes { /** The twenty bytes */ pub data: [u8; 20], }
519 pub(crate) struct VecWriter(pub Vec<u8>);
520 impl lightning::util::ser::Writer for VecWriter {
521 fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
522 self.0.extend_from_slice(buf);
526 pub(crate) fn serialize_obj<I: lightning::util::ser::Writeable>(i: &I) -> derived::CVec_u8Z {
527 let mut out = VecWriter(Vec::new());
528 i.write(&mut out).unwrap();
529 derived::CVec_u8Z::from(out.0)
531 pub(crate) fn deserialize_obj<I: lightning::util::ser::Readable>(s: u8slice) -> Result<I, lightning::ln::msgs::DecodeError> {
532 I::read(&mut s.to_slice())
534 pub(crate) fn maybe_deserialize_obj<I: lightning::util::ser::MaybeReadable>(s: u8slice) -> Result<Option<I>, lightning::ln::msgs::DecodeError> {
535 I::read(&mut s.to_slice())
537 pub(crate) fn deserialize_obj_arg<A, I: lightning::util::ser::ReadableArgs<A>>(s: u8slice, args: A) -> Result<I, lightning::ln::msgs::DecodeError> {
538 I::read(&mut s.to_slice(), args)
542 /// A Rust str object, ie a reference to a UTF8-valid string.
543 /// This is *not* null-terminated so cannot be used directly as a C string!
545 /// A pointer to the string's bytes, in UTF8 encoding
546 pub chars: *const u8,
547 /// The number of bytes (not characters!) pointed to by `chars`
549 /// Whether the data pointed to by `chars` should be freed or not.
550 pub chars_is_owned: bool,
552 impl Into<Str> for &'static str {
553 fn into(self) -> Str {
554 Str { chars: self.as_ptr(), len: self.len(), chars_is_owned: false }
557 impl Into<Str> for &mut &'static str {
558 fn into(self) -> Str {
559 let us: &'static str = *self;
565 pub(crate) fn into_str(&self) -> &'static str {
566 if self.len == 0 { return ""; }
567 core::str::from_utf8(unsafe { core::slice::from_raw_parts(self.chars, self.len) }).unwrap()
569 pub(crate) fn into_string(mut self) -> String {
570 let bytes = if self.len == 0 {
572 } else if self.chars_is_owned {
574 Box::from_raw(core::slice::from_raw_parts_mut(unsafe { self.chars as *mut u8 }, self.len))
576 self.chars_is_owned = false;
579 let mut ret = Vec::with_capacity(self.len);
580 ret.extend_from_slice(unsafe { core::slice::from_raw_parts(self.chars, self.len) });
583 String::from_utf8(bytes).unwrap()
586 impl Into<Str> for String {
587 fn into(self) -> Str {
588 let s = Box::leak(self.into_boxed_str());
589 Str { chars: s.as_ptr(), len: s.len(), chars_is_owned: true }
593 fn clone(&self) -> Self {
594 String::from(self.into_str()).into()
600 if self.chars_is_owned && self.len != 0 {
601 let _ = derived::CVec_u8Z { data: self.chars as *mut u8, datalen: self.len };
606 /// Frees the data buffer, if chars_is_owned is set and len > 0.
607 pub extern "C" fn Str_free(_res: Str) { }
609 // Note that the C++ headers memset(0) all the Templ types to avoid deallocation!
610 // Thus, they must gracefully handle being completely null in _free.
612 // TODO: Integer/bool primitives should avoid the pointer indirection for underlying types
613 // everywhere in the containers.
616 pub(crate) union CResultPtr<O, E> {
617 pub(crate) result: *mut O,
618 pub(crate) err: *mut E,
621 pub(crate) struct CResultTempl<O, E> {
622 pub(crate) contents: CResultPtr<O, E>,
623 pub(crate) result_ok: bool,
625 impl<O, E> CResultTempl<O, E> {
626 pub(crate) extern "C" fn ok(o: O) -> Self {
628 contents: CResultPtr {
629 result: Box::into_raw(Box::new(o)),
634 pub(crate) extern "C" fn err(e: E) -> Self {
636 contents: CResultPtr {
637 err: Box::into_raw(Box::new(e)),
643 impl<O, E> Drop for CResultTempl<O, E> {
646 if unsafe { !self.contents.result.is_null() } {
647 unsafe { Box::from_raw(self.contents.result) };
649 } else if unsafe { !self.contents.err.is_null() } {
650 unsafe { Box::from_raw(self.contents.err) };
655 /// Utility to make it easy to set a pointer to null and get its original value in line.
656 pub(crate) trait TakePointer<T> {
657 fn take_ptr(&mut self) -> T;
659 impl<T> TakePointer<*const T> for *const T {
660 fn take_ptr(&mut self) -> *const T {
662 *self = core::ptr::null();
666 impl<T> TakePointer<*mut T> for *mut T {
667 fn take_ptr(&mut self) -> *mut T {
669 *self = core::ptr::null_mut();
675 pub(crate) mod ObjOps {
676 #[cfg(feature = "no-std")]
677 use alloc::boxed::Box;
680 #[must_use = "returns new dangling pointer"]
681 pub(crate) fn heap_alloc<T>(obj: T) -> *mut T {
682 let ptr = Box::into_raw(Box::new(obj));
683 nonnull_ptr_to_inner(ptr)
686 pub(crate) fn nonnull_ptr_to_inner<T>(ptr: *const T) -> *mut T {
687 if core::mem::size_of::<T>() == 0 {
688 // We map `None::<T>` as `T { inner: null, .. }` which works great for all
689 // non-Zero-Sized-Types `T`.
690 // For ZSTs, we need to differentiate between null implying `None` and null implying
691 // `Some` with no allocation.
692 // Thus, for ZSTs, we add one (usually) page here, which should always be aligned.
693 // Note that this relies on undefined behavior! A pointer to NULL may be valid, but a
694 // pointer to NULL + 4096 is almost certainly not. That said, Rust's existing use of
695 // `(*mut T)1` for the pointer we're adding to is also not defined, so we should be
697 // Note that we add 4095 here as at least the Java client assumes that the low bit on
698 // any heap pointer is 0, which is generally provided by malloc, but which is not true
699 // for ZSTs "allocated" by `Box::new`.
700 debug_assert_eq!(ptr as usize, 1);
701 unsafe { (ptr as *mut T).cast::<u8>().add(4096 - 1).cast::<T>() }
703 // In order to get better test coverage, also increment non-ZST pointers with
704 // --cfg=test_mod_pointers, which is set in genbindings.sh for debug builds.
705 #[cfg(test_mod_pointers)]
706 unsafe { (ptr as *mut T).cast::<u8>().add(4096).cast::<T>() }
707 #[cfg(not(test_mod_pointers))]
708 unsafe { ptr as *mut T }
712 /// Invert nonnull_ptr_to_inner
713 pub(crate) fn untweak_ptr<T>(ptr: *mut T) -> *mut T {
714 if core::mem::size_of::<T>() == 0 {
715 unsafe { ptr.cast::<u8>().sub(4096 - 1).cast::<T>() }
717 #[cfg(test_mod_pointers)]
718 unsafe { ptr.cast::<u8>().sub(4096).cast::<T>() }
719 #[cfg(not(test_mod_pointers))]
725 #[cfg(test_mod_pointers)]
727 /// This function exists for memory safety testing purposes. It should never be used in production
729 pub extern "C" fn __unmangle_inner_ptr(ptr: *const c_void) -> *const c_void {
730 if ptr as usize == 1 {
733 unsafe { ptr.cast::<u8>().sub(4096).cast::<c_void>() }
737 pub(crate) struct SmartPtr<T> {
740 impl<T> SmartPtr<T> {
741 pub(crate) fn from_obj(o: T) -> Self {
742 Self { ptr: Box::into_raw(Box::new(o)) }
744 pub(crate) fn null() -> Self {
745 Self { ptr: core::ptr::null_mut() }
748 impl<T> Drop for SmartPtr<T> {
750 if self.ptr != core::ptr::null_mut() {
751 unsafe { Box::from_raw(self.ptr); }
755 impl<T> core::ops::Deref for SmartPtr<T> {
756 type Target = *mut T;
757 fn deref(&self) -> &*mut T {