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Merged
youknowone merged 2 commits into from
Feb 3, 2026
Merged

Switch to Cell::update, slice::{split_first_chunk,split_off}, where appropriate #6974

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11b1e43
Use Cell::update, slice::{split_first_chunk,split_off}
coolreader18 Jan 30, 2026
95164a1
Use more array -> slice methods
coolreader18 Jan 30, 2026
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2 changes: 1 addition & 1 deletion crates/common/src/lock/cell_lock.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,7 @@ unsafe impl RawRwLock for RawCellRwLock {

#[inline]
unsafe fn unlock_shared(&self) {
self.state.set(self.state.get() - ONE_READER)
self.state.update(|x| x - ONE_READER)
}

#[inline]
Expand Down
10 changes: 7 additions & 3 deletions crates/compiler-core/src/marshal.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -158,13 +158,17 @@ impl Read for &[u8] {
fn read_slice(&mut self, n: u32) -> Result<&[u8]> {
self.read_slice_borrow(n)
}

fn read_array<const N: usize>(&mut self) -> Result<&[u8; N]> {
let (chunk, rest) = self.split_first_chunk::<N>().ok_or(MarshalError::Eof)?;
*self = rest;
Ok(chunk)
}
}

impl<'a> ReadBorrowed<'a> for &'a [u8] {
fn read_slice_borrow(&mut self, n: u32) -> Result<&'a [u8]> {
let data = self.get(..n as usize).ok_or(MarshalError::Eof)?;
*self = &self[n as usize..];
Ok(data)
self.split_off(..n as usize).ok_or(MarshalError::Eof)
}
}

Expand Down
2 changes: 1 addition & 1 deletion crates/vm/src/codecs.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -476,7 +476,7 @@ impl<'a> DecodeErrorHandler<PyDecodeContext<'a>> for SurrogatePass {
let p = &s[byte_range.start..];

fn slice<const N: usize>(p: &[u8]) -> Option<[u8; N]> {
p.get(..N).map(|x| x.try_into().unwrap())
p.first_chunk().copied()
}

let c = match standard_encoding {
Expand Down
27 changes: 11 additions & 16 deletions crates/vm/src/stdlib/ctypes/array.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -712,27 +712,22 @@ impl PyCArray {
}
Some("f") => {
// c_float
if offset + 4 <= buffer.len() {
let bytes: [u8; 4] = buffer[offset..offset + 4].try_into().unwrap();
let val = f32::from_ne_bytes(bytes);
Ok(vm.ctx.new_float(val as f64).into())
} else {
Ok(vm.ctx.new_float(0.0).into())
}
let val = buffer[offset..]
.first_chunk::<4>()
.copied()
.map_or(0.0, f32::from_ne_bytes);
Ok(vm.ctx.new_float(val as f64).into())
}
Some("d") | Some("g") => {
// c_double / c_longdouble - read f64 from first 8 bytes
if offset + 8 <= buffer.len() {
let bytes: [u8; 8] = buffer[offset..offset + 8].try_into().unwrap();
let val = f64::from_ne_bytes(bytes);
Ok(vm.ctx.new_float(val).into())
} else {
Ok(vm.ctx.new_float(0.0).into())
}
let val = buffer[offset..]
.first_chunk::<8>()
.copied()
.map_or(0.0, f64::from_ne_bytes);
Ok(vm.ctx.new_float(val).into())
}
_ => {
if offset + element_size <= buffer.len() {
let bytes = &buffer[offset..offset + element_size];
if let Some(bytes) = buffer[offset..].get(..element_size) {
Ok(Self::bytes_to_int(bytes, element_size, type_code, vm))
} else {
Ok(vm.ctx.new_int(0).into())
Expand Down
73 changes: 25 additions & 48 deletions crates/vm/src/stdlib/ctypes/base.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1836,71 +1836,53 @@ pub(super) fn buffer_to_ffi_value(type_code: &str, buffer: &[u8]) -> FfiArgValue
FfiArgValue::U8(v)
}
"h" => {
let v = if buffer.len() >= 2 {
i16::from_ne_bytes(buffer[..2].try_into().unwrap())
} else {
0
};
let v = buffer.first_chunk().copied().map_or(0, i16::from_ne_bytes);
FfiArgValue::I16(v)
}
"H" => {
let v = if buffer.len() >= 2 {
u16::from_ne_bytes(buffer[..2].try_into().unwrap())
} else {
0
};
let v = buffer.first_chunk().copied().map_or(0, u16::from_ne_bytes);
FfiArgValue::U16(v)
}
"i" => {
let v = if buffer.len() >= 4 {
i32::from_ne_bytes(buffer[..4].try_into().unwrap())
} else {
0
};
let v = buffer.first_chunk().copied().map_or(0, i32::from_ne_bytes);
FfiArgValue::I32(v)
}
"I" => {
let v = if buffer.len() >= 4 {
u32::from_ne_bytes(buffer[..4].try_into().unwrap())
} else {
0
};
let v = buffer.first_chunk().copied().map_or(0, u32::from_ne_bytes);
FfiArgValue::U32(v)
}
"l" | "q" => {
let v = if buffer.len() >= 8 {
i64::from_ne_bytes(buffer[..8].try_into().unwrap())
} else if buffer.len() >= 4 {
i32::from_ne_bytes(buffer[..4].try_into().unwrap()) as i64
let v = if let Some(&bytes) = buffer.first_chunk::<8>() {
i64::from_ne_bytes(bytes)
} else if let Some(&bytes) = buffer.first_chunk::<4>() {
i32::from_ne_bytes(bytes).into()
} else {
0
};
FfiArgValue::I64(v)
}
"L" | "Q" => {
let v = if buffer.len() >= 8 {
u64::from_ne_bytes(buffer[..8].try_into().unwrap())
} else if buffer.len() >= 4 {
u32::from_ne_bytes(buffer[..4].try_into().unwrap()) as u64
let v = if let Some(&bytes) = buffer.first_chunk::<8>() {
u64::from_ne_bytes(bytes)
} else if let Some(&bytes) = buffer.first_chunk::<4>() {
u32::from_ne_bytes(bytes).into()
} else {
0
};
FfiArgValue::U64(v)
}
"f" => {
let v = if buffer.len() >= 4 {
f32::from_ne_bytes(buffer[..4].try_into().unwrap())
} else {
0.0
};
let v = buffer
.first_chunk::<4>()
.copied()
.map_or(0.0, f32::from_ne_bytes);
FfiArgValue::F32(v)
}
"d" | "g" => {
let v = if buffer.len() >= 8 {
f64::from_ne_bytes(buffer[..8].try_into().unwrap())
} else {
0.0
};
let v = buffer
.first_chunk::<8>()
.copied()
.map_or(0.0, f64::from_ne_bytes);
FfiArgValue::F64(v)
}
"z" | "Z" | "P" | "O" => FfiArgValue::Pointer(read_ptr_from_buffer(buffer)),
Expand All @@ -1910,11 +1892,7 @@ pub(super) fn buffer_to_ffi_value(type_code: &str, buffer: &[u8]) -> FfiArgValue
}
"u" => {
// wchar_t - 4 bytes on most platforms
let v = if buffer.len() >= 4 {
u32::from_ne_bytes(buffer[..4].try_into().unwrap())
} else {
0
};
let v = buffer.first_chunk().copied().map_or(0, u32::from_ne_bytes);
FfiArgValue::U32(v)
}
_ => FfiArgValue::Pointer(0),
Expand Down Expand Up @@ -2135,11 +2113,10 @@ pub(super) fn get_usize_attr(
#[inline]
pub(super) fn read_ptr_from_buffer(buffer: &[u8]) -> usize {
const PTR_SIZE: usize = core::mem::size_of::<usize>();
if buffer.len() >= PTR_SIZE {
usize::from_ne_bytes(buffer[..PTR_SIZE].try_into().unwrap())
} else {
0
}
buffer
.first_chunk::<PTR_SIZE>()
.copied()
.map_or(0, usize::from_ne_bytes)
}

/// Check if a type is a "simple instance" (direct subclass of a simple type)
Expand Down
6 changes: 2 additions & 4 deletions crates/vm/src/stdlib/ctypes/function.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -567,10 +567,8 @@ fn extract_ptr_from_arg(arg: &PyObject, vm: &VirtualMachine) -> PyResult<usize>
}
if let Some(simple) = arg.downcast_ref::<PyCSimple>() {
let buffer = simple.0.buffer.read();
if buffer.len() >= core::mem::size_of::<usize>() {
return Ok(usize::from_ne_bytes(
buffer[..core::mem::size_of::<usize>()].try_into().unwrap(),
));
if let Some(&bytes) = buffer.first_chunk::<{ size_of::<usize>() }>() {
return Ok(usize::from_ne_bytes(bytes));
}
Comment on lines +570 to 572
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@coderabbitai coderabbitai bot Feb 3, 2026

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⚠️ Potential issue | 🔴 Critical

Unqualified size_of will cause a compilation error.

size_of is not imported and needs to be fully qualified. The rest of the file uses core::mem::size_of consistently (e.g., lines 138, 145, 157, 502).

🐛 Proposed fix 
-        if let Some(&bytes) = buffer.first_chunk::<{ size_of::<usize>() }>() {
+        if let Some(&bytes) = buffer.first_chunk::<{ core::mem::size_of::<usize>() }>() {
             return Ok(usize::from_ne_bytes(bytes));
         }
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
if let Some(&bytes) = buffer.first_chunk::<{ size_of::<usize>() }>() {
return Ok(usize::from_ne_bytes(bytes));
}
if let Some(&bytes) = buffer.first_chunk::<{ core::mem::size_of::<usize>() }>() {
return Ok(usize::from_ne_bytes(bytes));
}
🤖 Prompt for AI Agents 
In `@crates/vm/src/stdlib/ctypes/function.rs` around lines 570 - 572, The call to
buffer.first_chunk::<{ size_of::<usize>() }>() uses an unqualified size_of and
will fail to compile; update that generic const to use the fully qualified
core::mem::size_of (or add a use) so it becomes buffer.first_chunk::<{
core::mem::size_of::<usize>() }>() and ensure the surrounding code that returns
usize::from_ne_bytes(bytes) remains unchanged.

}
if let Some(cdata) = arg.downcast_ref::<PyCData>() {
Expand Down
101 changes: 37 additions & 64 deletions crates/vm/src/stdlib/ctypes/simple.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -419,13 +419,10 @@ impl PyCSimpleType {
if let Some(funcptr) = value.downcast_ref::<PyCFuncPtr>() {
let ptr_val = {
let buffer = funcptr._base.buffer.read();
if buffer.len() >= core::mem::size_of::<usize>() {
usize::from_ne_bytes(
buffer[..core::mem::size_of::<usize>()].try_into().unwrap(),
)
} else {
0
}
buffer
.first_chunk::<{ size_of::<usize>() }>()
.copied()
.map_or(0, usize::from_ne_bytes)
};
return Ok(CArgObject {
tag: b'P',
Expand All @@ -442,13 +439,10 @@ impl PyCSimpleType {
if matches!(value_type_code.as_deref(), Some("z") | Some("Z")) {
let ptr_val = {
let buffer = simple.0.buffer.read();
if buffer.len() >= core::mem::size_of::<usize>() {
usize::from_ne_bytes(
buffer[..core::mem::size_of::<usize>()].try_into().unwrap(),
)
} else {
0
}
buffer
.first_chunk::<{ size_of::<usize>() }>()
.copied()
.map_or(0, usize::from_ne_bytes)
};
return Ok(CArgObject {
tag: b'Z',
Expand Down Expand Up @@ -1360,68 +1354,47 @@ impl PyCSimple {
let buffer = self.0.buffer.read();
let bytes: &[u8] = &buffer;

if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::u8().as_raw_ptr()) {
if !bytes.is_empty() {
return Some(FfiArgValue::U8(bytes[0]));
}
let ret = if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::u8().as_raw_ptr()) {
let byte = *bytes.first()?;
FfiArgValue::U8(byte)
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::i8().as_raw_ptr()) {
if !bytes.is_empty() {
return Some(FfiArgValue::I8(bytes[0] as i8));
}
let byte = *bytes.first()?;
FfiArgValue::I8(byte as i8)
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::u16().as_raw_ptr()) {
if bytes.len() >= 2 {
return Some(FfiArgValue::U16(u16::from_ne_bytes([bytes[0], bytes[1]])));
}
let bytes = *bytes.first_chunk::<2>()?;
FfiArgValue::U16(u16::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::i16().as_raw_ptr()) {
if bytes.len() >= 2 {
return Some(FfiArgValue::I16(i16::from_ne_bytes([bytes[0], bytes[1]])));
}
let bytes = *bytes.first_chunk::<2>()?;
FfiArgValue::I16(i16::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::u32().as_raw_ptr()) {
if bytes.len() >= 4 {
return Some(FfiArgValue::U32(u32::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3],
])));
}
let bytes = *bytes.first_chunk::<4>()?;
FfiArgValue::U32(u32::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::i32().as_raw_ptr()) {
if bytes.len() >= 4 {
return Some(FfiArgValue::I32(i32::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3],
])));
}
let bytes = *bytes.first_chunk::<4>()?;
FfiArgValue::I32(i32::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::u64().as_raw_ptr()) {
if bytes.len() >= 8 {
return Some(FfiArgValue::U64(u64::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7],
])));
}
let bytes = *bytes.first_chunk::<8>()?;
FfiArgValue::U64(u64::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::i64().as_raw_ptr()) {
if bytes.len() >= 8 {
return Some(FfiArgValue::I64(i64::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7],
])));
}
let bytes = *bytes.first_chunk::<8>()?;
FfiArgValue::I64(i64::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::f32().as_raw_ptr()) {
if bytes.len() >= 4 {
return Some(FfiArgValue::F32(f32::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3],
])));
}
let bytes = *bytes.first_chunk::<4>()?;
FfiArgValue::F32(f32::from_ne_bytes(bytes))
} else if core::ptr::eq(ty.as_raw_ptr(), libffi::middle::Type::f64().as_raw_ptr()) {
if bytes.len() >= 8 {
return Some(FfiArgValue::F64(f64::from_ne_bytes([
bytes[0], bytes[1], bytes[2], bytes[3], bytes[4], bytes[5], bytes[6], bytes[7],
])));
}
let bytes = *bytes.first_chunk::<8>()?;
FfiArgValue::F64(f64::from_ne_bytes(bytes))
} else if core::ptr::eq(
ty.as_raw_ptr(),
libffi::middle::Type::pointer().as_raw_ptr(),
) && bytes.len() >= core::mem::size_of::<usize>()
{
let val =
usize::from_ne_bytes(bytes[..core::mem::size_of::<usize>()].try_into().unwrap());
return Some(FfiArgValue::Pointer(val));
}
None
) {
let bytes = *buffer.first_chunk::<{ size_of::<usize>() }>()?;
let val = usize::from_ne_bytes(bytes);
FfiArgValue::Pointer(val)
} else {
return None;
};
Some(ret)
}
}

Expand Down
12 changes: 4 additions & 8 deletions crates/vm/src/stdlib/io.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2506,15 +2506,11 @@ mod _io {
return None;
}
buf.resize(Self::BYTE_LEN, 0);
let buf: &[u8; Self::BYTE_LEN] = buf.as_slice().try_into().unwrap();
let buf: &[u8; Self::BYTE_LEN] = buf.as_array()?;
macro_rules! get_field {
($t:ty, $off:ident) => {{
<$t>::from_ne_bytes(
buf[Self::$off..][..core::mem::size_of::<$t>()]
.try_into()
.unwrap(),
)
}};
($t:ty, $off:ident) => {
<$t>::from_ne_bytes(*buf[Self::$off..].first_chunk().unwrap())
};
Comment on lines +2509 to +2513
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⚠️ Potential issue | 🟡 Minor

🧩 Analysis chain

🏁 Script executed:

find . -name "Cargo.toml" -type f | head -20

Repository: RustPython/RustPython

Length of output: 639

🏁 Script executed:

cat Cargo.toml | grep -A 5 -B 5 "rust-version\|package.version"

Repository: RustPython/RustPython

Length of output: 700

🏁 Script executed:

find . -name "rust-toolchain*" -type f

Repository: RustPython/RustPython

Length of output: 86

🏁 Script executed:

rg -n "rust-version" --type toml

Repository: RustPython/RustPython

Length of output: 1141

🏁 Script executed:

cat rust-toolchain.toml

Repository: RustPython/RustPython

Length of output: 95

🏁 Script executed:

rg -n "as_array|first_chunk" crates/vm/src/stdlib/io.rs -B 3 -A 3

Repository: RustPython/RustPython

Length of output: 480

🏁 Script executed:

cd crates/vm && cargo clippy --lib 2>&1 | head -100

Repository: RustPython/RustPython

Length of output: 204

🏁 Script executed:

cd crates/vm && cargo fmt -- --check 2>&1 | grep -A 5 "io.rs"

Repository: RustPython/RustPython

Length of output: 47

🌐 Web query:

as_array() first_chunk() Rust stabilization version 1.76 1.77

💡 Result:

  • first_chunk() (and related first_chunk_mut, split_first_chunk, etc.) was stabilized in Rust 1.77.0. [1]
  • as_array() (and as_mut_array()) is not from 1.76/1.77; slice::as_array was stabilized much later, in Rust 1.93.0. [2]

Sources: [1] [2]

MSRV and API compatibility confirmed; ensure linting and formatting checks are clean.

The repository's MSRV (1.93.0) supports both slice APIs: as_array() was stabilized in Rust 1.93.0, and first_chunk() in Rust 1.77.0. No toolchain compatibility issues.

Per coding guidelines, run cargo fmt and cargo clippy to verify formatting and linting are clean before submission.

🤖 Prompt for AI Agents 
In `@crates/vm/src/stdlib/io.rs` around lines 2509 - 2513, Confirm formatting and
linting are clean: run cargo fmt and cargo clippy, and ensure the slice APIs
used in get_field (the as_array() call on buf, the first_chunk() usage, and the
BYTE_LEN constant on the type implementing this method) are correct per MSRV
1.93.0; if clippy flags any style or safety issues around the macro get_field or
the unchecked unwrap() on first_chunk(), address them (e.g., handle the Option
instead of unwrap or add a clear comment/expect) so the build and lint checks
pass.

}
Some(Self {
start_pos: get_field!(Offset, START_POS_OFF),
Expand Down
22 changes: 10 additions & 12 deletions crates/vm/src/stdlib/winreg.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -905,20 +905,18 @@ mod winreg {
match typ {
REG_DWORD => {
// If there isn’t enough data, return 0.
if ret_data.len() < std::mem::size_of::<u32>() {
Ok(vm.ctx.new_int(0).into())
} else {
let val = u32::from_ne_bytes(ret_data[..4].try_into().unwrap());
Ok(vm.ctx.new_int(val).into())
}
let val = ret_data
.first_chunk::<4>()
.copied()
.map_or(0, u32::from_ne_bytes);
Ok(vm.ctx.new_int(val).into())
}
REG_QWORD => {
if ret_data.len() < std::mem::size_of::<u64>() {
Ok(vm.ctx.new_int(0).into())
} else {
let val = u64::from_ne_bytes(ret_data[..8].try_into().unwrap());
Ok(vm.ctx.new_int(val).into())
}
let val = ret_data
.first_chunk::<8>()
.copied()
.map_or(0, u64::from_ne_bytes);
Ok(vm.ctx.new_int(val).into())
}
REG_SZ | REG_EXPAND_SZ => {
let u16_slice = bytes_as_wide_slice(ret_data);
Expand Down
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