Move current implementation into `legacy` module.
diff --git a/src/legacy.rs b/src/legacy.rs new file mode 100644 index 0000000..1e1824c --- /dev/null +++ b/src/legacy.rs
@@ -0,0 +1,370 @@ +use core::fmt; + +/// Representation of a demangled symbol name. +pub struct Demangle<'a> { + inner: &'a str, + /// The number of ::-separated elements in the original name. + elements: usize, +} + +/// De-mangles a Rust symbol into a more readable version +/// +/// All Rust symbols by default are mangled as they contain characters that +/// cannot be represented in all object files. The mangling mechanism is similar +/// to C++'s, but Rust has a few specifics to handle items like lifetimes in +/// symbols. +/// +/// This function will take a **mangled** symbol and return a value. When printed, +/// the de-mangled version will be written. If the symbol does not look like +/// a mangled symbol, the original value will be written instead. +/// +/// # Examples +/// +/// ``` +/// use rustc_demangle::demangle; +/// +/// assert_eq!(demangle("_ZN4testE").to_string(), "test"); +/// assert_eq!(demangle("_ZN3foo3barE").to_string(), "foo::bar"); +/// assert_eq!(demangle("foo").to_string(), "foo"); +/// ``` + +// All Rust symbols are in theory lists of "::"-separated identifiers. Some +// assemblers, however, can't handle these characters in symbol names. To get +// around this, we use C++-style mangling. The mangling method is: +// +// 1. Prefix the symbol with "_ZN" +// 2. For each element of the path, emit the length plus the element +// 3. End the path with "E" +// +// For example, "_ZN4testE" => "test" and "_ZN3foo3barE" => "foo::bar". +// +// We're the ones printing our backtraces, so we can't rely on anything else to +// demangle our symbols. It's *much* nicer to look at demangled symbols, so +// this function is implemented to give us nice pretty output. +// +// Note that this demangler isn't quite as fancy as it could be. We have lots +// of other information in our symbols like hashes, version, type information, +// etc. Additionally, this doesn't handle glue symbols at all. +pub fn demangle(s: &str) -> Result<Demangle, ()> { + // First validate the symbol. If it doesn't look like anything we're + // expecting, we just print it literally. Note that we must handle non-Rust + // symbols because we could have any function in the backtrace. + let inner; + 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') { + // On Windows, dbghelp strips leading underscores, so we accept "ZN...E" + // form too. + inner = &s[2..s.len() - 1]; + } else if s.len() > 5 && s.starts_with("__ZN") && s.ends_with('E') { + // On OSX, symbols are prefixed with an extra _ + inner = &s[4..s.len() - 1]; + } else { + return Err(()); + } + + // only work with ascii text + if inner.bytes().any(|c| c & 0x80 != 0) { + return Err(()); + } + + let mut elements = 0; + let mut chars = inner.chars().peekable(); + loop { + let mut i = 0usize; + while let Some(&c) = chars.peek() { + if !c.is_digit(10) { + break + } + chars.next(); + let next = i.checked_mul(10) + .and_then(|i| i.checked_add(c as usize - '0' as usize)); + i = match next { + Some(i) => i, + None => { + return Err(()); + } + }; + } + + if i == 0 { + if !chars.next().is_none() { + return Err(()); + } + break; + } else if chars.by_ref().take(i).count() != i { + return Err(()); + } else { + elements += 1; + } + } + + Ok(Demangle { + inner: inner, + elements: elements, + }) +} + +// Rust hashes are hex digits with an `h` prepended. +fn is_rust_hash(s: &str) -> bool { + s.starts_with('h') && s[1..].chars().all(|c| c.is_digit(16)) +} + +impl<'a> fmt::Display for Demangle<'a> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + // Alright, let's do this. + let mut inner = self.inner; + for element in 0..self.elements { + let mut rest = inner; + while rest.chars().next().unwrap().is_digit(10) { + rest = &rest[1..]; + } + let i: usize = inner[..(inner.len() - rest.len())].parse().unwrap(); + inner = &rest[i..]; + rest = &rest[..i]; + // Skip printing the hash if alternate formatting + // was requested. + if f.alternate() && element+1 == self.elements && is_rust_hash(&rest) { + break; + } + if element != 0 { + try!(f.write_str("::")); + } + if rest.starts_with("_$") { + rest = &rest[1..]; + } + while !rest.is_empty() { + if rest.starts_with('.') { + if let Some('.') = rest[1..].chars().next() { + try!(f.write_str("::")); + rest = &rest[2..]; + } else { + try!(f.write_str(".")); + rest = &rest[1..]; + } + } else if rest.starts_with('$') { + macro_rules! demangle { + ($($pat:expr => $demangled:expr,)*) => ({ + $(if rest.starts_with($pat) { + try!(f.write_str($demangled)); + rest = &rest[$pat.len()..]; + } else)* + { + try!(f.write_str(rest)); + break; + } + + }) + } + + // see src/librustc/back/link.rs for these mappings + demangle! { + "$SP$" => "@", + "$BP$" => "*", + "$RF$" => "&", + "$LT$" => "<", + "$GT$" => ">", + "$LP$" => "(", + "$RP$" => ")", + "$C$" => ",", + + // in theory we can demangle any Unicode code point, but + // for simplicity we just catch the common ones. + "$u7e$" => "~", + "$u20$" => " ", + "$u27$" => "'", + "$u3d$" => "=", + "$u5b$" => "[", + "$u5d$" => "]", + "$u7b$" => "{", + "$u7d$" => "}", + "$u3b$" => ";", + "$u2b$" => "+", + "$u21$" => "!", + "$u22$" => "\"", + } + } else { + let idx = match rest.char_indices().find(|&(_, c)| c == '$' || c == '.') { + None => rest.len(), + Some((i, _)) => i, + }; + try!(f.write_str(&rest[..idx])); + rest = &rest[idx..]; + } + } + } + + Ok(()) + } +} + +#[cfg(test)] +mod tests { + use std::prelude::v1::*; + + macro_rules! t { + ($a:expr, $b:expr) => (assert!(ok($a, $b))) + } + + macro_rules! t_err { + ($a:expr) => (assert!(ok_err($a))) + } + + macro_rules! t_nohash { + ($a:expr, $b:expr) => ({ + assert_eq!(format!("{:#}", ::demangle($a)), $b); + }) + } + + fn ok(sym: &str, expected: &str) -> bool { + match ::try_demangle(sym) { + Ok(s) => { + if s.to_string() == expected { + true + } else { + println!("\n{}\n!=\n{}\n", s, expected); + false + } + } + Err(_) => { + println!("error demangling"); + false + } + } + } + + fn ok_err(sym: &str) -> bool { + match ::try_demangle(sym) { + Ok(_) => { + println!("succeeded in demangling"); + false + } + Err(_) => ::demangle(sym).to_string() == sym, + } + } + + #[test] + fn demangle() { + t_err!("test"); + t!("_ZN4testE", "test"); + t_err!("_ZN4test"); + t!("_ZN4test1a2bcE", "test::a::bc"); + } + + #[test] + fn demangle_dollars() { + t!("_ZN4$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$$GT$E", "Bar<[u32; 4]>"); + } + + #[test] + fn demangle_many_dollars() { + t!("_ZN13test$u20$test4foobE", "test test::foob"); + t!("_ZN12test$BP$test4foobE", "test*test::foob"); + } + + + #[test] + fn demangle_osx() { + t!("__ZN5alloc9allocator6Layout9for_value17h02a996811f781011E", "alloc::allocator::Layout::for_value::h02a996811f781011"); + t!("__ZN38_$LT$core..option..Option$LT$T$GT$$GT$6unwrap18_MSG_FILE_LINE_COL17haf7cb8d5824ee659E", "<core::option::Option<T>>::unwrap::_MSG_FILE_LINE_COL::haf7cb8d5824ee659"); + t!("__ZN4core5slice89_$LT$impl$u20$core..iter..traits..IntoIterator$u20$for$u20$$RF$$u27$a$u20$$u5b$T$u5d$$GT$9into_iter17h450e234d27262170E", "core::slice::<impl core::iter::traits::IntoIterator for &'a [T]>::into_iter::h450e234d27262170"); + } + + #[test] + fn demangle_windows() { + t!("ZN4testE", "test"); + t!("ZN13test$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$3barE", + "<Test + 'static as foo::Bar<Test>>::bar"); + } + + #[test] + fn demangle_without_hash() { + let s = "_ZN3foo17h05af221e174051e9E"; + t!(s, "foo::h05af221e174051e9"); + t_nohash!(s, "foo"); + } + + #[test] + fn demangle_without_hash_edgecases() { + // One element, no hash. + t_nohash!("_ZN3fooE", "foo"); + // Two elements, no hash. + t_nohash!("_ZN3foo3barE", "foo::bar"); + // Longer-than-normal hash. + t_nohash!("_ZN3foo20h05af221e174051e9abcE", "foo"); + // Shorter-than-normal hash. + t_nohash!("_ZN3foo5h05afE", "foo"); + // Valid hash, but not at the end. + t_nohash!("_ZN17h05af221e174051e93fooE", "h05af221e174051e9::foo"); + // Not a valid hash, missing the 'h'. + t_nohash!("_ZN3foo16ffaf221e174051e9E", "foo::ffaf221e174051e9"); + // Not a valid hash, has a non-hex-digit. + t_nohash!("_ZN3foo17hg5af221e174051e9E", "foo::hg5af221e174051e9"); + } + + #[test] + fn demangle_thinlto() { + // One element, no hash. + t!("_ZN3fooE.llvm.9D1C9369", "foo"); + t!("_ZN3fooE.llvm.9D1C9369@@16", "foo"); + t_nohash!("_ZN9backtrace3foo17hbb467fcdaea5d79bE.llvm.A5310EB9", "backtrace::foo"); + } + + #[test] + fn demangle_llvm_ir_branch_labels() { + t!("_ZN4core5slice77_$LT$impl$u20$core..ops..index..IndexMut$LT$I$GT$$u20$for$u20$$u5b$T$u5d$$GT$9index_mut17haf9727c2edfbc47bE.exit.i.i", "core::slice::<impl core::ops::index::IndexMut<I> for [T]>::index_mut::haf9727c2edfbc47b.exit.i.i"); + t_nohash!("_ZN4core5slice77_$LT$impl$u20$core..ops..index..IndexMut$LT$I$GT$$u20$for$u20$$u5b$T$u5d$$GT$9index_mut17haf9727c2edfbc47bE.exit.i.i", "core::slice::<impl core::ops::index::IndexMut<I> for [T]>::index_mut.exit.i.i"); + } + + #[test] + fn demangle_ignores_suffix_that_doesnt_look_like_a_symbol() { + t_err!("_ZN3fooE.llvm moocow"); + } + + #[test] + fn dont_panic() { + ::demangle("_ZN2222222222222222222222EE").to_string(); + ::demangle("_ZN5*70527e27.ll34csaғE").to_string(); + ::demangle("_ZN5*70527a54.ll34_$b.1E").to_string(); + ::demangle("\ + _ZN5~saäb4e\n\ + 2734cOsbE\n\ + 5usage20h)3\0\0\0\0\0\0\07e2734cOsbE\ + ").to_string(); + } + + #[test] + fn invalid_no_chop() { + t_err!("_ZNfooE"); + } + + #[test] + fn handle_assoc_types() { + t!("_ZN151_$LT$alloc..boxed..Box$LT$alloc..boxed..FnBox$LT$A$C$$u20$Output$u3d$R$GT$$u20$$u2b$$u20$$u27$a$GT$$u20$as$u20$core..ops..function..FnOnce$LT$A$GT$$GT$9call_once17h69e8f44b3723e1caE", "<alloc::boxed::Box<alloc::boxed::FnBox<A, Output=R> + 'a> as core::ops::function::FnOnce<A>>::call_once::h69e8f44b3723e1ca"); + } + + #[test] + fn handle_bang() { + t!( + "_ZN88_$LT$core..result..Result$LT$$u21$$C$$u20$E$GT$$u20$as$u20$std..process..Termination$GT$6report17hfc41d0da4a40b3e8E", + "<core::result::Result<!, E> as std::process::Termination>::report::hfc41d0da4a40b3e8" + ); + } +}
diff --git a/src/lib.rs b/src/lib.rs index 12d3ffc..2281b52 100644 --- a/src/lib.rs +++ b/src/lib.rs
@@ -30,25 +30,23 @@ #[macro_use] extern crate std; +mod legacy; + use core::fmt; /// Representation of a demangled symbol name. pub struct Demangle<'a> { + style: Option<DemangleStyle<'a>>, original: &'a str, - inner: &'a str, suffix: &'a str, - valid: bool, - /// The number of ::-separated elements in the original name. - elements: usize, +} + +enum DemangleStyle<'a> { + Legacy(legacy::Demangle<'a>), } /// De-mangles a Rust symbol into a more readable version /// -/// All Rust symbols by default are mangled as they contain characters that -/// cannot be represented in all object files. The mangling mechanism is similar -/// to C++'s, but Rust has a few specifics to handle items like lifetimes in -/// symbols. -/// /// This function will take a **mangled** symbol and return a value. When printed, /// the de-mangled version will be written. If the symbol does not look like /// a mangled symbol, the original value will be written instead. @@ -62,24 +60,6 @@ /// assert_eq!(demangle("_ZN3foo3barE").to_string(), "foo::bar"); /// assert_eq!(demangle("foo").to_string(), "foo"); /// ``` - -// All Rust symbols are in theory lists of "::"-separated identifiers. Some -// assemblers, however, can't handle these characters in symbol names. To get -// around this, we use C++-style mangling. The mangling method is: -// -// 1. Prefix the symbol with "_ZN" -// 2. For each element of the path, emit the length plus the element -// 3. End the path with "E" -// -// For example, "_ZN4testE" => "test" and "_ZN3foo3barE" => "foo::bar". -// -// We're the ones printing our backtraces, so we can't rely on anything else to -// demangle our symbols. It's *much* nicer to look at demangled symbols, so -// this function is implemented to give us nice pretty output. -// -// Note that this demangler isn't quite as fancy as it could be. We have lots -// of other information in our symbols like hashes, version, type information, -// etc. Additionally, this doesn't handle glue symbols at all. pub fn demangle(mut s: &str) -> Demangle { // During ThinLTO LLVM may import and rename internal symbols, so strip out // those endings first as they're one of the last manglings applied to symbol @@ -111,67 +91,14 @@ } } - // First validate the symbol. If it doesn't look like anything we're - // expecting, we just print it literally. Note that we must handle non-Rust - // symbols because we could have any function in the backtrace. - 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') { - // On Windows, dbghelp strips leading underscores, so we accept "ZN...E" - // form too. - inner = &s[2..s.len() - 1]; - } else if s.len() > 5 && s.starts_with("__ZN") && s.ends_with('E') { - // On OSX, symbols are prefixed with an extra _ - inner = &s[4..s.len() - 1]; - } else { - valid = false; - } - - // only work with ascii text - if inner.bytes().any(|c| c & 0x80 != 0) { - valid = false; - } - - let mut elements = 0; - if valid { - let mut chars = inner.chars().peekable(); - while valid { - let mut i = 0usize; - while let Some(&c) = chars.peek() { - if !c.is_digit(10) { - break - } - chars.next(); - let next = i.checked_mul(10) - .and_then(|i| i.checked_add(c as usize - '0' as usize)); - i = match next { - Some(i) => i, - None => { - valid = false; - break - } - }; - } - - if i == 0 { - valid = chars.next().is_none(); - break; - } else if chars.by_ref().take(i).count() != i { - valid = false; - } else { - elements += 1; - } - } - } - + let style = match legacy::demangle(s) { + Ok(d) => Some(DemangleStyle::Legacy(d)), + Err(()) => None, + }; Demangle { - inner: inner, - suffix: suffix, - valid: valid, - elements: elements, + style: style, original: s, + suffix: suffix, } } @@ -197,7 +124,7 @@ /// ``` pub fn try_demangle(s: &str) -> Result<Demangle, TryDemangleError> { let sym = demangle(s); - if sym.valid { + if sym.style.is_some() { Ok(sym) } else { Err(TryDemangleError { _priv: () }) @@ -211,11 +138,6 @@ } } -// Rust hashes are hex digits with an `h` prepended. -fn is_rust_hash(s: &str) -> bool { - s.starts_with('h') && s[1..].chars().all(|c| c.is_digit(16)) -} - fn is_symbol_like(s: &str) -> bool { s.chars().all(|c| { // Once `char::is_ascii_punctuation` and `char::is_ascii_alphanumeric` @@ -247,95 +169,13 @@ impl<'a> fmt::Display for Demangle<'a> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - // Alright, let's do this. - if !self.valid { - return f.write_str(self.original); - } - - let mut inner = self.inner; - for element in 0..self.elements { - let mut rest = inner; - while rest.chars().next().unwrap().is_digit(10) { - rest = &rest[1..]; - } - let i: usize = inner[..(inner.len() - rest.len())].parse().unwrap(); - inner = &rest[i..]; - rest = &rest[..i]; - // Skip printing the hash if alternate formatting - // was requested. - if f.alternate() && element+1 == self.elements && is_rust_hash(&rest) { - break; - } - if element != 0 { - try!(f.write_str("::")); - } - if rest.starts_with("_$") { - rest = &rest[1..]; - } - while !rest.is_empty() { - if rest.starts_with('.') { - if let Some('.') = rest[1..].chars().next() { - try!(f.write_str("::")); - rest = &rest[2..]; - } else { - try!(f.write_str(".")); - rest = &rest[1..]; - } - } else if rest.starts_with('$') { - macro_rules! demangle { - ($($pat:expr => $demangled:expr,)*) => ({ - $(if rest.starts_with($pat) { - try!(f.write_str($demangled)); - rest = &rest[$pat.len()..]; - } else)* - { - try!(f.write_str(rest)); - break; - } - - }) - } - - // see src/librustc/back/link.rs for these mappings - demangle! { - "$SP$" => "@", - "$BP$" => "*", - "$RF$" => "&", - "$LT$" => "<", - "$GT$" => ">", - "$LP$" => "(", - "$RP$" => ")", - "$C$" => ",", - - // in theory we can demangle any Unicode code point, but - // for simplicity we just catch the common ones. - "$u7e$" => "~", - "$u20$" => " ", - "$u27$" => "'", - "$u3d$" => "=", - "$u5b$" => "[", - "$u5d$" => "]", - "$u7b$" => "{", - "$u7d$" => "}", - "$u3b$" => ";", - "$u2b$" => "+", - "$u21$" => "!", - "$u22$" => "\"", - } - } else { - let idx = match rest.char_indices().find(|&(_, c)| c == '$' || c == '.') { - None => rest.len(), - Some((i, _)) => i, - }; - try!(f.write_str(&rest[..idx])); - rest = &rest[idx..]; - } + match self.style { + None => try!(f.write_str(self.original)), + Some(DemangleStyle::Legacy(ref d)) => { + try!(fmt::Display::fmt(d, f)) } } - - try!(f.write_str(self.suffix)); - - Ok(()) + f.write_str(self.suffix) } }