| use core::char; |
| 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, &str), ()> { |
| // 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.starts_with("_ZN") { |
| &s[3..] |
| } else if s.starts_with("ZN") { |
| // On Windows, dbghelp strips leading underscores, so we accept "ZN...E" |
| // form too. |
| &s[2..] |
| } else if s.starts_with("__ZN") { |
| // On OSX, symbols are prefixed with an extra _ |
| &s[4..] |
| } 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(); |
| let mut c = chars.next().ok_or(())?; |
| while c != 'E' { |
| // Decode an identifier element's length. |
| if !c.is_digit(10) { |
| return Err(()); |
| } |
| let mut len = 0usize; |
| while let Some(d) = c.to_digit(10) { |
| len = len |
| .checked_mul(10) |
| .and_then(|len| len.checked_add(d as usize)) |
| .ok_or(())?; |
| c = chars.next().ok_or(())?; |
| } |
| |
| // `c` already contains the first character of this identifier, skip it and |
| // all the other characters of this identifier, to reach the next element. |
| for _ in 0..len { |
| c = chars.next().ok_or(())?; |
| } |
| |
| elements += 1; |
| } |
| |
| Ok((Demangle { inner, elements }, chars.as_str())) |
| } |
| |
| // 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 { |
| f.write_str("::")?; |
| } |
| if rest.starts_with("_$") { |
| rest = &rest[1..]; |
| } |
| loop { |
| if rest.starts_with('.') { |
| if let Some('.') = rest[1..].chars().next() { |
| f.write_str("::")?; |
| rest = &rest[2..]; |
| } else { |
| f.write_str(".")?; |
| rest = &rest[1..]; |
| } |
| } else if rest.starts_with('$') { |
| let (escape, after_escape) = if let Some(end) = rest[1..].find('$') { |
| (&rest[1..=end], &rest[end + 2..]) |
| } else { |
| break; |
| }; |
| |
| // see src/librustc_codegen_utils/symbol_names/legacy.rs for these mappings |
| let unescaped = match escape { |
| "SP" => "@", |
| "BP" => "*", |
| "RF" => "&", |
| "LT" => "<", |
| "GT" => ">", |
| "LP" => "(", |
| "RP" => ")", |
| "C" => ",", |
| |
| _ => { |
| if escape.starts_with('u') { |
| let digits = &escape[1..]; |
| let all_lower_hex = digits.chars().all(|c| match c { |
| '0'..='9' | 'a'..='f' => true, |
| _ => false, |
| }); |
| let c = u32::from_str_radix(digits, 16) |
| .ok() |
| .and_then(char::from_u32); |
| if let (true, Some(c)) = (all_lower_hex, c) { |
| // FIXME(eddyb) do we need to filter out control codepoints? |
| if !c.is_control() { |
| c.fmt(f)?; |
| rest = after_escape; |
| continue; |
| } |
| } |
| } |
| break; |
| } |
| }; |
| f.write_str(unescaped)?; |
| rest = after_escape; |
| } else if let Some(i) = rest.find(|c| c == '$' || c == '.') { |
| f.write_str(&rest[..i])?; |
| rest = &rest[i..]; |
| } else { |
| break; |
| } |
| } |
| f.write_str(rest)?; |
| } |
| |
| 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$$u20$as$u20$std..process..Termination$GT$6report17hfc41d0da4a40b3e8E", |
| "<core::result::Result<!, E> as std::process::Termination>::report::hfc41d0da4a40b3e8" |
| ); |
| } |
| |
| #[test] |
| fn demangle_utf8_idents() { |
| t_nohash!( |
| "_ZN11utf8_idents157_$u10e1$$u10d0$$u10ed$$u10db$$u10d4$$u10da$$u10d0$$u10d3$_$u10d2$$u10d4$$u10db$$u10e0$$u10d8$$u10d4$$u10da$$u10d8$_$u10e1$$u10d0$$u10d3$$u10d8$$u10da$$u10d8$17h21634fd5714000aaE", |
| "utf8_idents::საჭმელად_გემრიელი_სადილი" |
| ); |
| } |
| |
| #[test] |
| fn demangle_issue_60925() { |
| t_nohash!( |
| "_ZN11issue_609253foo37Foo$LT$issue_60925..llv$u6d$..Foo$GT$3foo17h059a991a004536adE", |
| "issue_60925::foo::Foo<issue_60925::llvm::Foo>::foo" |
| ); |
| } |
| } |
