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Merged
nunoplopes merged 4 commits into from
May 14, 2026
Merged

Add fwrite in libcc2rs to allow taking its address #95

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334098a
Add fwrite in libcc2rs to allow taking its address
lucic71 May 13, 2026
2a29316
Replace offset with increment for pointer arithmetic
lucic71 May 14, 2026
7f7c788
[unsafe] Replace pointer arithmetic with offset method
lucic71 May 14, 2026
3122126
Delete flushes on fwrite
lucic71 May 14, 2026
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98 changes: 98 additions & 0 deletions libcc2rs/src/io.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -121,6 +121,104 @@ pub fn fread_refcount(a0: AnyPtr, a1: u64, a2: u64, a3: Ptr<::std::fs::File>) ->
(read_bytes / a1 as usize) as u64
}

pub fn fwrite_refcount(a0: AnyPtr, a1: u64, a2: u64, a3: Ptr<::std::fs::File>) -> u64 {
let total = a1.saturating_mul(a2) as usize;
let mut src = a0
.cast::<u8>()
.expect("fwrite: only supporting u8 pointers")
.clone();

let f = (*a3.upgrade().deref())
.try_clone()
.expect("try_clone failed");
let mut writer = std::io::BufWriter::with_capacity(64 * 1024, f);

let mut written_bytes: usize = 0;
let mut buffer: [u8; 8192] = [0; 8192];

while written_bytes < total {
let remaining = total - written_bytes;
let to_fill = std::cmp::min(buffer.len(), remaining);

for b in buffer.iter_mut().take(to_fill) {
*b = src.read();
src = src.offset(1);

@nunoplopes nunoplopes May 13, 2026

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src += 1

@lucic71 lucic71 May 14, 2026

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Done

}

let mut off = 0;
while off < to_fill {
match std::io::Write::write(&mut writer, &buffer[off..to_fill]) {
Ok(0) => break,
Ok(n) => off += n,
Err(ref e) if e.kind() == std::io::ErrorKind::Interrupted => continue,
Err(e) => panic!("Unhandled error in fwrite: {e}"),
}
}

if off == 0 {
break;
}

written_bytes += off;
}

std::io::Write::flush(&mut writer).expect("flush failed");

@nunoplopes nunoplopes May 14, 2026

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I don't think fwrite flushes the stream

@lucic71 lucic71 May 14, 2026 •
edited
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I deleted the flush


(written_bytes / a1 as usize) as u64
}

/// # Safety
///
/// `a0` must point to a readable buffer of at least `a1 * a2` bytes, and `a3`
/// must point to a valid, open `std::fs::File`.
pub unsafe fn fwrite_unsafe(
a0: *const ::std::ffi::c_void,
a1: u64,
a2: u64,
a3: *mut ::std::fs::File,
) -> u64 {
let total = a1.saturating_mul(a2) as usize;
let mut src = a0 as *const u8;

let f = unsafe { (*a3).try_clone().expect("try_clone failed") };
let mut writer = std::io::BufWriter::with_capacity(64 * 1024, f);

let mut written_bytes: usize = 0;
let mut buffer: [u8; 8192] = [0; 8192];

while written_bytes < total {
let remaining = total - written_bytes;
let to_fill = std::cmp::min(buffer.len(), remaining);

for b in buffer.iter_mut().take(to_fill) {
unsafe {
*b = *src;
src = src.offset(1);
}
}

let mut off = 0;
while off < to_fill {
match std::io::Write::write(&mut writer, &buffer[off..to_fill]) {
Ok(0) => break,
Ok(n) => off += n,
Err(ref e) if e.kind() == std::io::ErrorKind::Interrupted => continue,
Err(e) => panic!("Unhandled error in fwrite: {e}"),
}
}

if off == 0 {
break;
}

written_bytes += off;
}

std::io::Write::flush(&mut writer).expect("flush failed");

(written_bytes / a1 as usize) as u64
}

/// # Safety
///
/// `a0` must point to a writable buffer of at least `a1 * a2` bytes, and `a3`
Expand Down
216 changes: 19 additions & 197 deletions rules/stdio/ir_refcount.json
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Original file line number Diff line number Diff line change
Expand Up @@ -503,234 +503,56 @@
"f6": {
"body": [
{
"text": "let total = "
"text": "libcc2rs::fwrite_refcount("
},
{
"method_call": {
"receiver": [
{
"placeholder": {
"arg": 1,
"access": "read"
}
}
],
"body": [
{
"text": ".saturating_mul("
},
{
"placeholder": {
"arg": 2,
"access": "read"
}
},
{
"text": ")"
}
]
}
},
{
"text": " as usize;\n let mut src = "
},
{
"method_call": {
"receiver": [
{
"method_call": {
"receiver": [
{
"method_call": {
"receiver": [
{
"placeholder": {
"arg": 0,
"access": "read"
}
}
],
"body": [
{
"text": ".cast::<u8>()"
}
]
}
}
],
"body": [
{
"text": ".expect(\"fwrite: only supporting u8 pointers\")"
}
]
}
}
],
"body": [
{
"text": ".clone()"
}
]
}
},
{
"text": ";\n\n let mut f = "
},
{
"method_call": {
"receiver": [
{
"method_call": {
"receiver": [
{
"text": "(*"
},
{
"method_call": {
"receiver": [
{
"method_call": {
"receiver": [
{
"placeholder": {
"arg": 3,
"access": "read"
}
}
],
"body": [
{
"text": ".upgrade()"
}
]
}
}
],
"body": [
{
"text": ".deref()"
}
]
}
},
{
"text": ")"
}
],
"body": [
{
"text": ".try_clone()"
}
]
}
}
],
"body": [
{
"text": ".expect(\"try_clone failed\")"
}
]
}
},
{
"text": ";\n let mut writer = std::io::BufWriter::with_capacity(64 * 1024, f);\n\n let mut written_bytes: usize = 0;\n let mut buffer: [u8; 8192] = [0; 8192];\n\n while written_bytes < total {\n let remaining = total - written_bytes;\n let to_fill = std::cmp::min("
},
{
"method_call": {
"receiver": [
{
"text": "buffer"
}
],
"body": [
{
"text": ".len()"
}
]
}
},
{
"text": ", remaining);\n\n for i in 0..to_fill {\n buffer[i] = "
},
{
"method_call": {
"receiver": [
{
"text": "src"
}
],
"body": [
{
"text": ".read()"
}
]
"placeholder": {
"arg": 0,
"access": "read"
}
},
{
"text": ";\n src = "
"text": ", "
},
{
"method_call": {
"receiver": [
{
"text": "src"
}
],
"body": [
{
"text": ".offset(1)"
}
]
"placeholder": {
"arg": 1,
"access": "read"
}
},
{
"text": ";\n }\n\n let mut off = 0;\n while off < to_fill {\n match std::io::Write::write(&mut writer, &buffer[off..to_fill]) {\n Ok(0) => break,\n Ok(n) => off += n,\n Err(ref e) if "
"text": ", "
},
{
"method_call": {
"receiver": [
{
"text": "e"
}
],
"body": [
{
"text": ".kind()"
}
]
"placeholder": {
"arg": 2,
"access": "read"
}
},
{
"text": " == std::io::ErrorKind::Interrupted => continue,\n Err(e) => panic!(\"Unhandled error in fwrite: {e}\"),\n }\n }\n\n if off == 0 {\n break;\n }\n\n written_bytes += off;\n }\n\n "
"text": ", "
},
{
"method_call": {
"receiver": [
{
"text": "std::io::Write::flush(&mut writer)"
"placeholder": {
"arg": 3,
"access": "read"
}
}
],
"body": [
{
"text": ".expect(\"flush failed\")"
"text": ".clone()"
}
]
}
},
{
"text": ";\n\n (written_bytes / "
},
{
"placeholder": {
"arg": 1,
"access": "read"
}
},
{
"text": " as usize) as u64"
"text": ")"
}
],
"multi_statement": true,
"params": {
"a0": {
"type": "AnyPtr"
Expand Down
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