From 2f4e57f87af72f3c14ec6dc48557d88f54ee3b24 Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Wed, 26 Jun 2019 21:20:48 +0200
Subject: [PATCH] Fix data race inside puts(...) & add dbg!() macro
---
src/header/stdio/mod.rs | 23 ++++++++++++++---------
src/macros.rs | 19 +++++++++++++++++++
2 files changed, 33 insertions(+), 9 deletions(-)
diff --git a/src/header/stdio/mod.rs b/src/header/stdio/mod.rs
index dd1fad2fe..7059ad05c 100644
--- a/src/header/stdio/mod.rs
+++ b/src/header/stdio/mod.rs
@@ -61,7 +61,6 @@ impl<'a> DerefMut for Buffer<'a> {
/// This struct gets exposed to the C API.
pub struct FILE {
- // Can't use spin crate because *_unlocked functions are things in C :(
lock: Mutex<()>,
file: File,
@@ -417,8 +416,10 @@ pub unsafe extern "C" fn fputc(c: c_int, stream: *mut FILE) -> c_int {
/// Insert a string into a stream
#[no_mangle]
pub unsafe extern "C" fn fputs(s: *const c_char, stream: *mut FILE) -> c_int {
- let len = strlen(s);
- (fwrite(s as *const c_void, 1, len, stream) == len) as c_int - 1
+ let mut stream = (*stream).lock();
+ let buf = slice::from_raw_parts(s as *mut u8, strlen(s));
+
+ if stream.write_all(&buf).is_ok() { 0 } else { -1 }
}
/// Read `nitems` of size `size` into `ptr` from `stream`
@@ -577,7 +578,7 @@ pub unsafe extern "C" fn fwrite(
return 0;
}
let mut stream = (*stream).lock();
- let buf = slice::from_raw_parts_mut(ptr as *mut u8, size as usize * nitems as usize);
+ let buf = slice::from_raw_parts(ptr as *const u8, size as usize * nitems as usize);
let mut written = 0;
while written < buf.len() {
match stream.write(&buf[written..]) {
@@ -798,12 +799,16 @@ pub unsafe extern "C" fn putchar_unlocked(c: c_int) -> c_int {
/// Put a string `s` into `stdout`
#[no_mangle]
pub unsafe extern "C" fn puts(s: *const c_char) -> c_int {
- let ret = (fputs(s, stdout) > 0) || (putchar_unlocked(b'\n' as c_int) > 0);
- if ret {
- 0
- } else {
- -1
+ let mut stream = (&mut *stdout).lock();
+ let buf = slice::from_raw_parts(s as *mut u8, strlen(s));
+
+ if stream.write_all(&buf).is_err() {
+ return -1;
}
+ if stream.write(&[b'\n']).is_err() {
+ return -1;
+ }
+ 0
}
/// Put an integer `w` into `stream`
diff --git a/src/macros.rs b/src/macros.rs
index e9ca07c16..f870522b9 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -42,6 +42,25 @@ macro_rules! eprintln {
($fmt:expr, $($arg:tt)*) => (eprint!(concat!($fmt, "\n"), $($arg)*));
}
+/// Lifted from libstd
+#[macro_export]
+macro_rules! dbg {
+ () => {
+ eprintln!("[{}:{}]", file!(), line!());
+ };
+ ($val:expr) => {
+ // Use of `match` here is intentional because it affects the lifetimes
+ // of temporaries - https://stackoverflow.com/a/48732525/1063961
+ match $val {
+ tmp => {
+ eprintln!("[{}:{}] {} = {:#?}",
+ file!(), line!(), stringify!($val), &tmp);
+ tmp
+ }
+ }
+ }
+}
+
#[macro_export]
#[cfg(not(feature = "trace"))]
macro_rules! trace {
--
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