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-rw-r--r--third_party/rust/rustc-demangle/src/legacy.rs392
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diff --git a/third_party/rust/rustc-demangle/src/legacy.rs b/third_party/rust/rustc-demangle/src/legacy.rs
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+++ b/third_party/rust/rustc-demangle/src/legacy.rs
@@ -0,0 +1,392 @@
+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"
+ );
+ }
+}