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)
}
}
