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use env;
use io::prelude::*;
use io;
use str;
use sync::atomic::{self, Ordering};
use path::{self, Path};
use sys::mutex::Mutex;
use ptr;
pub use sys::backtrace::{
unwind_backtrace,
resolve_symname,
foreach_symbol_fileline,
BacktraceContext
};
#[cfg(target_pointer_width = "64")]
pub const HEX_WIDTH: usize = 18;
#[cfg(target_pointer_width = "32")]
pub const HEX_WIDTH: usize = 10;
#[derive(Debug, Copy, Clone)]
pub struct Frame {
pub exact_position: *const u8,
pub symbol_addr: *const u8,
pub inline_context: u32,
}
const MAX_NB_FRAMES: usize = 100;
pub fn print(w: &mut dyn Write, format: PrintFormat) -> io::Result<()> {
static LOCK: Mutex = Mutex::new();
unsafe {
LOCK.lock();
let res = _print(w, format);
LOCK.unlock();
res
}
}
fn _print(w: &mut dyn Write, format: PrintFormat) -> io::Result<()> {
let mut frames = [Frame {
exact_position: ptr::null(),
symbol_addr: ptr::null(),
inline_context: 0,
}; MAX_NB_FRAMES];
let (nb_frames, context) = unwind_backtrace(&mut frames)?;
let (skipped_before, skipped_after) =
filter_frames(&frames[..nb_frames], format, &context);
if skipped_before + skipped_after > 0 {
writeln!(w, "note: Some details are omitted, \
run with `RUST_BACKTRACE=full` for a verbose backtrace.")?;
}
writeln!(w, "stack backtrace:")?;
let filtered_frames = &frames[..nb_frames - skipped_after];
for (index, frame) in filtered_frames.iter().skip(skipped_before).enumerate() {
resolve_symname(*frame, |symname| {
output(w, index, *frame, symname, format)
}, &context)?;
let has_more_filenames = foreach_symbol_fileline(*frame, |file, line| {
output_fileline(w, file, line, format)
}, &context)?;
if has_more_filenames {
w.write_all(b" <... and possibly more>")?;
}
}
Ok(())
}
fn filter_frames(frames: &[Frame],
format: PrintFormat,
context: &BacktraceContext) -> (usize, usize)
{
if format == PrintFormat::Full {
return (0, 0);
}
let skipped_before = 0;
let skipped_after = frames.len() - frames.iter().position(|frame| {
let mut is_marker = false;
let _ = resolve_symname(*frame, |symname| {
if let Some(mangled_symbol_name) = symname {
if mangled_symbol_name.contains("__rust_begin_short_backtrace") {
is_marker = true;
}
}
Ok(())
}, context);
is_marker
}).unwrap_or(frames.len());
if skipped_before + skipped_after >= frames.len() {
return (0, 0);
}
(skipped_before, skipped_after)
}
#[inline(never)]
pub fn __rust_begin_short_backtrace<F, T>(f: F) -> T
where F: FnOnce() -> T, F: Send, T: Send
{
f()
}
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum PrintFormat {
Short = 2,
Full = 3,
}
pub fn log_enabled() -> Option<PrintFormat> {
static ENABLED: atomic::AtomicIsize = atomic::AtomicIsize::new(0);
match ENABLED.load(Ordering::SeqCst) {
0 => {}
1 => return None,
2 => return Some(PrintFormat::Short),
_ => return Some(PrintFormat::Full),
}
let val = env::var_os("RUST_BACKTRACE").and_then(|x|
if &x == "0" {
None
} else if &x == "full" {
Some(PrintFormat::Full)
} else {
Some(PrintFormat::Short)
}
);
ENABLED.store(match val {
Some(v) => v as isize,
None => 1,
}, Ordering::SeqCst);
val
}
fn output(w: &mut dyn Write, idx: usize, frame: Frame,
s: Option<&str>, format: PrintFormat) -> io::Result<()> {
if format == PrintFormat::Short && frame.exact_position == ptr::null() {
return Ok(());
}
match format {
PrintFormat::Full => write!(w,
" {:2}: {:2$?} - ",
idx,
frame.exact_position,
HEX_WIDTH)?,
PrintFormat::Short => write!(w, " {:2}: ", idx)?,
}
match s {
Some(string) => demangle(w, string, format)?,
None => w.write_all(b"<unknown>")?,
}
w.write_all(b"\n")
}
#[allow(dead_code)]
fn output_fileline(w: &mut dyn Write,
file: &[u8],
line: u32,
format: PrintFormat) -> io::Result<()> {
w.write_all(b"")?;
match format {
PrintFormat::Full => write!(w,
" {:1$}",
"",
HEX_WIDTH)?,
PrintFormat::Short => write!(w, " ")?,
}
let file = str::from_utf8(file).unwrap_or("<unknown>");
let file_path = Path::new(file);
let mut already_printed = false;
if format == PrintFormat::Short && file_path.is_absolute() {
if let Ok(cwd) = env::current_dir() {
if let Ok(stripped) = file_path.strip_prefix(&cwd) {
if let Some(s) = stripped.to_str() {
write!(w, " at .{}{}:{}", path::MAIN_SEPARATOR, s, line)?;
already_printed = true;
}
}
}
}
if !already_printed {
write!(w, " at {}:{}", file, line)?;
}
w.write_all(b"\n")
}
pub fn demangle(writer: &mut dyn Write, mut s: &str, format: PrintFormat) -> io::Result<()> {
let llvm = ".llvm.";
if let Some(i) = s.find(llvm) {
let candidate = &s[i + llvm.len()..];
let all_hex = candidate.chars().all(|c| {
match c {
'A' ..= 'F' | '0' ..= '9' => true,
_ => false,
}
});
if all_hex {
s = &s[..i];
}
}
let mut valid = true;
let mut inner = s;
if s.len() > 4 && s.starts_with("_ZN") && s.ends_with("E") {
inner = &s[3 .. s.len() - 1];
} else if s.len() > 3 && s.starts_with("ZN") && s.ends_with("E") {
inner = &s[2 .. s.len() - 1];
} else {
valid = false;
}
if valid {
let mut chars = inner.chars();
while valid {
let mut i = 0;
for c in chars.by_ref() {
if c.is_numeric() {
i = i * 10 + c as usize - '0' as usize;
} else {
break
}
}
if i == 0 {
valid = chars.next().is_none();
break
} else if chars.by_ref().take(i - 1).count() != i - 1 {
valid = false;
}
}
}
if !valid {
writer.write_all(s.as_bytes())?;
} else {
if format == PrintFormat::Short {
let mut split = inner.rsplitn(2, "17h");
match (split.next(), split.next()) {
(Some(addr), rest) => {
if addr.len() == 16 &&
addr.chars().all(|c| c.is_digit(16))
{
inner = rest.unwrap_or("");
}
}
_ => (),
}
}
let mut first = true;
while !inner.is_empty() {
if !first {
writer.write_all(b"::")?;
} else {
first = false;
}
let mut rest = inner;
while rest.chars().next().unwrap().is_numeric() {
rest = &rest[1..];
}
let i: usize = inner[.. (inner.len() - rest.len())].parse().unwrap();
inner = &rest[i..];
rest = &rest[..i];
if rest.starts_with("_$") {
rest = &rest[1..];
}
while !rest.is_empty() {
if rest.starts_with(".") {
if let Some('.') = rest[1..].chars().next() {
writer.write_all(b"::")?;
rest = &rest[2..];
} else {
writer.write_all(b".")?;
rest = &rest[1..];
}
} else if rest.starts_with("$") {
macro_rules! demangle {
($($pat:expr => $demangled:expr),*) => ({
$(if rest.starts_with($pat) {
writer.write_all($demangled)?;
rest = &rest[$pat.len()..];
} else)*
{
writer.write_all(rest.as_bytes())?;
break;
}
})
}
demangle! (
"$SP$" => b"@",
"$BP$" => b"*",
"$RF$" => b"&",
"$LT$" => b"<",
"$GT$" => b">",
"$LP$" => b"(",
"$RP$" => b")",
"$C$" => b",",
"$u7e$" => b"~",
"$u20$" => b" ",
"$u27$" => b"'",
"$u5b$" => b"[",
"$u5d$" => b"]",
"$u7b$" => b"{",
"$u7d$" => b"}",
"$u3b$" => b";",
"$u2b$" => b"+",
"$u22$" => b"\""
)
} else {
let idx = match rest.char_indices().find(|&(_, c)| c == '$' || c == '.') {
None => rest.len(),
Some((i, _)) => i,
};
writer.write_all(rest[..idx].as_bytes())?;
rest = &rest[idx..];
}
}
}
}
Ok(())
}
#[cfg(test)]
mod tests {
use sys_common;
macro_rules! t { ($a:expr, $b:expr) => ({
let mut m = Vec::new();
sys_common::backtrace::demangle(&mut m,
$a,
super::PrintFormat::Full).unwrap();
assert_eq!(String::from_utf8(m).unwrap(), $b);
}) }
#[test]
fn demangle() {
t!("test", "test");
t!("_ZN4testE", "test");
t!("_ZN4test", "_ZN4test");
t!("_ZN4test1a2bcE", "test::a::bc");
}
#[test]
fn demangle_dollars() {
t!("_ZN4$RP$E", ")");
t!("_ZN8$RF$testE", "&test");
t!("_ZN8$BP$test4foobE", "*test::foob");
t!("_ZN9$u20$test4foobE", " test::foob");
t!("_ZN35Bar$LT$$u5b$u32$u3b$$u20$4$u5d$$GT$E", "Bar<[u32; 4]>");
}
#[test]
fn demangle_many_dollars() {
t!("_ZN13test$u20$test4foobE", "test test::foob");
t!("_ZN12test$BP$test4foobE", "test*test::foob");
}
#[test]
fn demangle_windows() {
t!("ZN4testE", "test");
t!("ZN13test$u20$test4foobE", "test test::foob");
t!("ZN12test$RF$test4foobE", "test&test::foob");
}
#[test]
fn demangle_elements_beginning_with_underscore() {
t!("_ZN13_$LT$test$GT$E", "<test>");
t!("_ZN28_$u7b$$u7b$closure$u7d$$u7d$E", "{{closure}}");
t!("_ZN15__STATIC_FMTSTRE", "__STATIC_FMTSTR");
}
#[test]
fn demangle_trait_impls() {
t!("_ZN71_$LT$Test$u20$$u2b$$u20$$u27$static$u20$as$u20$foo..Bar$LT$Test$GT$$GT$3barE",
"<Test + 'static as foo::Bar<Test>>::bar");
}
}