diff options
Diffstat (limited to 'vendor/backtrace/src/symbolize/mod.rs')
-rw-r--r-- | vendor/backtrace/src/symbolize/mod.rs | 485 |
1 files changed, 0 insertions, 485 deletions
diff --git a/vendor/backtrace/src/symbolize/mod.rs b/vendor/backtrace/src/symbolize/mod.rs deleted file mode 100644 index a7c1995..0000000 --- a/vendor/backtrace/src/symbolize/mod.rs +++ /dev/null @@ -1,485 +0,0 @@ -use core::{fmt, str}; - -cfg_if::cfg_if! { - if #[cfg(feature = "std")] { - use std::path::Path; - use std::prelude::v1::*; - } -} - -use super::backtrace::Frame; -use super::types::BytesOrWideString; -use core::ffi::c_void; -use rustc_demangle::{try_demangle, Demangle}; - -/// Resolve an address to a symbol, passing the symbol to the specified -/// closure. -/// -/// This function will look up the given address in areas such as the local -/// symbol table, dynamic symbol table, or DWARF debug info (depending on the -/// activated implementation) to find symbols to yield. -/// -/// The closure may not be called if resolution could not be performed, and it -/// also may be called more than once in the case of inlined functions. -/// -/// Symbols yielded represent the execution at the specified `addr`, returning -/// file/line pairs for that address (if available). -/// -/// Note that if you have a `Frame` then it's recommended to use the -/// `resolve_frame` function instead of this one. -/// -/// # Required features -/// -/// This function requires the `std` feature of the `backtrace` crate to be -/// enabled, and the `std` feature is enabled by default. -/// -/// # Panics -/// -/// This function strives to never panic, but if the `cb` provided panics then -/// some platforms will force a double panic to abort the process. Some -/// platforms use a C library which internally uses callbacks which cannot be -/// unwound through, so panicking from `cb` may trigger a process abort. -/// -/// # Example -/// -/// ``` -/// extern crate backtrace; -/// -/// fn main() { -/// backtrace::trace(|frame| { -/// let ip = frame.ip(); -/// -/// backtrace::resolve(ip, |symbol| { -/// // ... -/// }); -/// -/// false // only look at the top frame -/// }); -/// } -/// ``` -#[cfg(feature = "std")] -pub fn resolve<F: FnMut(&Symbol)>(addr: *mut c_void, cb: F) { - let _guard = crate::lock::lock(); - unsafe { resolve_unsynchronized(addr, cb) } -} - -/// Resolve a previously capture frame to a symbol, passing the symbol to the -/// specified closure. -/// -/// This function performs the same function as `resolve` except that it takes a -/// `Frame` as an argument instead of an address. This can allow some platform -/// implementations of backtracing to provide more accurate symbol information -/// or information about inline frames for example. It's recommended to use this -/// if you can. -/// -/// # Required features -/// -/// This function requires the `std` feature of the `backtrace` crate to be -/// enabled, and the `std` feature is enabled by default. -/// -/// # Panics -/// -/// This function strives to never panic, but if the `cb` provided panics then -/// some platforms will force a double panic to abort the process. Some -/// platforms use a C library which internally uses callbacks which cannot be -/// unwound through, so panicking from `cb` may trigger a process abort. -/// -/// # Example -/// -/// ``` -/// extern crate backtrace; -/// -/// fn main() { -/// backtrace::trace(|frame| { -/// backtrace::resolve_frame(frame, |symbol| { -/// // ... -/// }); -/// -/// false // only look at the top frame -/// }); -/// } -/// ``` -#[cfg(feature = "std")] -pub fn resolve_frame<F: FnMut(&Symbol)>(frame: &Frame, cb: F) { - let _guard = crate::lock::lock(); - unsafe { resolve_frame_unsynchronized(frame, cb) } -} - -pub enum ResolveWhat<'a> { - Address(*mut c_void), - Frame(&'a Frame), -} - -impl<'a> ResolveWhat<'a> { - #[allow(dead_code)] - fn address_or_ip(&self) -> *mut c_void { - match self { - ResolveWhat::Address(a) => adjust_ip(*a), - ResolveWhat::Frame(f) => adjust_ip(f.ip()), - } - } -} - -// IP values from stack frames are typically (always?) the instruction -// *after* the call that's the actual stack trace. Symbolizing this on -// causes the filename/line number to be one ahead and perhaps into -// the void if it's near the end of the function. -// -// This appears to basically always be the case on all platforms, so we always -// subtract one from a resolved ip to resolve it to the previous call -// instruction instead of the instruction being returned to. -// -// Ideally we would not do this. Ideally we would require callers of the -// `resolve` APIs here to manually do the -1 and account that they want location -// information for the *previous* instruction, not the current. Ideally we'd -// also expose on `Frame` if we are indeed the address of the next instruction -// or the current. -// -// For now though this is a pretty niche concern so we just internally always -// subtract one. Consumers should keep working and getting pretty good results, -// so we should be good enough. -fn adjust_ip(a: *mut c_void) -> *mut c_void { - if a.is_null() { - a - } else { - (a as usize - 1) as *mut c_void - } -} - -/// Same as `resolve`, only unsafe as it's unsynchronized. -/// -/// This function does not have synchronization guarantees but is available when -/// the `std` feature of this crate isn't compiled in. See the `resolve` -/// function for more documentation and examples. -/// -/// # Panics -/// -/// See information on `resolve` for caveats on `cb` panicking. -pub unsafe fn resolve_unsynchronized<F>(addr: *mut c_void, mut cb: F) -where - F: FnMut(&Symbol), -{ - imp::resolve(ResolveWhat::Address(addr), &mut cb) -} - -/// Same as `resolve_frame`, only unsafe as it's unsynchronized. -/// -/// This function does not have synchronization guarantees but is available -/// when the `std` feature of this crate isn't compiled in. See the -/// `resolve_frame` function for more documentation and examples. -/// -/// # Panics -/// -/// See information on `resolve_frame` for caveats on `cb` panicking. -pub unsafe fn resolve_frame_unsynchronized<F>(frame: &Frame, mut cb: F) -where - F: FnMut(&Symbol), -{ - imp::resolve(ResolveWhat::Frame(frame), &mut cb) -} - -/// A trait representing the resolution of a symbol in a file. -/// -/// This trait is yielded as a trait object to the closure given to the -/// `backtrace::resolve` function, and it is virtually dispatched as it's -/// unknown which implementation is behind it. -/// -/// A symbol can give contextual information about a function, for example the -/// name, filename, line number, precise address, etc. Not all information is -/// always available in a symbol, however, so all methods return an `Option`. -pub struct Symbol { - // TODO: this lifetime bound needs to be persisted eventually to `Symbol`, - // but that's currently a breaking change. For now this is safe since - // `Symbol` is only ever handed out by reference and can't be cloned. - inner: imp::Symbol<'static>, -} - -impl Symbol { - /// Returns the name of this function. - /// - /// The returned structure can be used to query various properties about the - /// symbol name: - /// - /// * The `Display` implementation will print out the demangled symbol. - /// * The raw `str` value of the symbol can be accessed (if it's valid - /// utf-8). - /// * The raw bytes for the symbol name can be accessed. - pub fn name(&self) -> Option<SymbolName<'_>> { - self.inner.name() - } - - /// Returns the starting address of this function. - pub fn addr(&self) -> Option<*mut c_void> { - self.inner.addr().map(|p| p as *mut _) - } - - /// Returns the raw filename as a slice. This is mainly useful for `no_std` - /// environments. - pub fn filename_raw(&self) -> Option<BytesOrWideString<'_>> { - self.inner.filename_raw() - } - - /// Returns the column number for where this symbol is currently executing. - /// - /// Only gimli currently provides a value here and even then only if `filename` - /// returns `Some`, and so it is then consequently subject to similar caveats. - pub fn colno(&self) -> Option<u32> { - self.inner.colno() - } - - /// Returns the line number for where this symbol is currently executing. - /// - /// This return value is typically `Some` if `filename` returns `Some`, and - /// is consequently subject to similar caveats. - pub fn lineno(&self) -> Option<u32> { - self.inner.lineno() - } - - /// Returns the file name where this function was defined. - /// - /// This is currently only available when libbacktrace or gimli is being - /// used (e.g. unix platforms other) and when a binary is compiled with - /// debuginfo. If neither of these conditions is met then this will likely - /// return `None`. - /// - /// # Required features - /// - /// This function requires the `std` feature of the `backtrace` crate to be - /// enabled, and the `std` feature is enabled by default. - #[cfg(feature = "std")] - #[allow(unreachable_code)] - pub fn filename(&self) -> Option<&Path> { - self.inner.filename() - } -} - -impl fmt::Debug for Symbol { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - let mut d = f.debug_struct("Symbol"); - if let Some(name) = self.name() { - d.field("name", &name); - } - if let Some(addr) = self.addr() { - d.field("addr", &addr); - } - - #[cfg(feature = "std")] - { - if let Some(filename) = self.filename() { - d.field("filename", &filename); - } - } - - if let Some(lineno) = self.lineno() { - d.field("lineno", &lineno); - } - d.finish() - } -} - -cfg_if::cfg_if! { - if #[cfg(feature = "cpp_demangle")] { - // Maybe a parsed C++ symbol, if parsing the mangled symbol as Rust - // failed. - struct OptionCppSymbol<'a>(Option<::cpp_demangle::BorrowedSymbol<'a>>); - - impl<'a> OptionCppSymbol<'a> { - fn parse(input: &'a [u8]) -> OptionCppSymbol<'a> { - OptionCppSymbol(::cpp_demangle::BorrowedSymbol::new(input).ok()) - } - - fn none() -> OptionCppSymbol<'a> { - OptionCppSymbol(None) - } - } - } else { - use core::marker::PhantomData; - - // Make sure to keep this zero-sized, so that the `cpp_demangle` feature - // has no cost when disabled. - struct OptionCppSymbol<'a>(PhantomData<&'a ()>); - - impl<'a> OptionCppSymbol<'a> { - fn parse(_: &'a [u8]) -> OptionCppSymbol<'a> { - OptionCppSymbol(PhantomData) - } - - fn none() -> OptionCppSymbol<'a> { - OptionCppSymbol(PhantomData) - } - } - } -} - -/// A wrapper around a symbol name to provide ergonomic accessors to the -/// demangled name, the raw bytes, the raw string, etc. -// Allow dead code for when the `cpp_demangle` feature is not enabled. -#[allow(dead_code)] -pub struct SymbolName<'a> { - bytes: &'a [u8], - demangled: Option<Demangle<'a>>, - cpp_demangled: OptionCppSymbol<'a>, -} - -impl<'a> SymbolName<'a> { - /// Creates a new symbol name from the raw underlying bytes. - pub fn new(bytes: &'a [u8]) -> SymbolName<'a> { - let str_bytes = str::from_utf8(bytes).ok(); - let demangled = str_bytes.and_then(|s| try_demangle(s).ok()); - - let cpp = if demangled.is_none() { - OptionCppSymbol::parse(bytes) - } else { - OptionCppSymbol::none() - }; - - SymbolName { - bytes: bytes, - demangled: demangled, - cpp_demangled: cpp, - } - } - - /// Returns the raw (mangled) symbol name as a `str` if the symbol is valid utf-8. - /// - /// Use the `Display` implementation if you want the demangled version. - pub fn as_str(&self) -> Option<&'a str> { - self.demangled - .as_ref() - .map(|s| s.as_str()) - .or_else(|| str::from_utf8(self.bytes).ok()) - } - - /// Returns the raw symbol name as a list of bytes - pub fn as_bytes(&self) -> &'a [u8] { - self.bytes - } -} - -fn format_symbol_name( - fmt: fn(&str, &mut fmt::Formatter<'_>) -> fmt::Result, - mut bytes: &[u8], - f: &mut fmt::Formatter<'_>, -) -> fmt::Result { - while bytes.len() > 0 { - match str::from_utf8(bytes) { - Ok(name) => { - fmt(name, f)?; - break; - } - Err(err) => { - fmt("\u{FFFD}", f)?; - - match err.error_len() { - Some(len) => bytes = &bytes[err.valid_up_to() + len..], - None => break, - } - } - } - } - Ok(()) -} - -cfg_if::cfg_if! { - if #[cfg(feature = "cpp_demangle")] { - impl<'a> fmt::Display for SymbolName<'a> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - if let Some(ref s) = self.demangled { - s.fmt(f) - } else if let Some(ref cpp) = self.cpp_demangled.0 { - cpp.fmt(f) - } else { - format_symbol_name(fmt::Display::fmt, self.bytes, f) - } - } - } - } else { - impl<'a> fmt::Display for SymbolName<'a> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - if let Some(ref s) = self.demangled { - s.fmt(f) - } else { - format_symbol_name(fmt::Display::fmt, self.bytes, f) - } - } - } - } -} - -cfg_if::cfg_if! { - if #[cfg(all(feature = "std", feature = "cpp_demangle"))] { - impl<'a> fmt::Debug for SymbolName<'a> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - use std::fmt::Write; - - if let Some(ref s) = self.demangled { - return s.fmt(f) - } - - // This may to print if the demangled symbol isn't actually - // valid, so handle the error here gracefully by not propagating - // it outwards. - if let Some(ref cpp) = self.cpp_demangled.0 { - let mut s = String::new(); - if write!(s, "{}", cpp).is_ok() { - return s.fmt(f) - } - } - - format_symbol_name(fmt::Debug::fmt, self.bytes, f) - } - } - } else { - impl<'a> fmt::Debug for SymbolName<'a> { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - if let Some(ref s) = self.demangled { - s.fmt(f) - } else { - format_symbol_name(fmt::Debug::fmt, self.bytes, f) - } - } - } - } -} - -/// Attempt to reclaim that cached memory used to symbolicate addresses. -/// -/// This method will attempt to release any global data structures that have -/// otherwise been cached globally or in the thread which typically represent -/// parsed DWARF information or similar. -/// -/// # Caveats -/// -/// While this function is always available it doesn't actually do anything on -/// most implementations. Libraries like dbghelp or libbacktrace do not provide -/// facilities to deallocate state and manage the allocated memory. For now the -/// `gimli-symbolize` feature of this crate is the only feature where this -/// function has any effect. -#[cfg(feature = "std")] -pub fn clear_symbol_cache() { - let _guard = crate::lock::lock(); - unsafe { - imp::clear_symbol_cache(); - } -} - -cfg_if::cfg_if! { - if #[cfg(miri)] { - mod miri; - use miri as imp; - } else if #[cfg(all(windows, target_env = "msvc", not(target_vendor = "uwp")))] { - mod dbghelp; - use dbghelp as imp; - } else if #[cfg(all( - any(unix, all(windows, target_env = "gnu")), - not(target_vendor = "uwp"), - not(target_os = "emscripten"), - any(not(backtrace_in_libstd), feature = "backtrace"), - ))] { - mod gimli; - use gimli as imp; - } else { - mod noop; - use noop as imp; - } -} |