sgx_tstd/src/backtrace.rs - incubator-teaclave-sgx-sdk - Git at Google

 // Licensed to the Apache Software Foundation (ASF) under one
 // or more contributor license agreements.  See the NOTICE file
 // distributed with this work for additional information
 // regarding copyright ownership.  The ASF licenses this file
 // to you under the Apache License, Version 2.0 (the
 // "License"); you may not use this file except in compliance
 // with the License.  You may obtain a copy of the License at
 //
 //   http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing,
 // software distributed under the License is distributed on an
 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License..

 //! Support for capturing a stack backtrace of an OS thread
 //!
 //! This module contains the support necessary to capture a stack backtrace of a
 //! running OS thread from the OS thread itself. The `Backtrace` type supports
 //! capturing a stack trace via the `Backtrace::capture` and
 //! `Backtrace::force_capture` functions.
 //!
 //! A backtrace is typically quite handy to attach to errors (e.g. types
 //! implementing `std::error::Error`) to get a causal chain of where an error
 //! was generated.
 //!
 //! > **Note**: this module is unstable and is designed in [RFC 2504], and you
 //! > can learn more about its status in the [tracking issue].
 //!
 //! [RFC 2504]: https://github.com/rust-lang/rfcs/blob/master/text/2504-fix-error.md
 //! [tracking issue]: https://github.com/rust-lang/rust/issues/53487
 //!
 //! ## Accuracy
 //!
 //! Backtraces are attempted to be as accurate as possible, but no guarantees
 //! are provided about the exact accuracy of a backtrace. Instruction pointers,
 //! symbol names, filenames, line numbers, etc, may all be incorrect when
 //! reported. Accuracy is attempted on a best-effort basis, however, and bugs
 //! are always welcome to indicate areas of improvement!
 //!
 //! For most platforms a backtrace with a filename/line number requires that
 //! programs be compiled with debug information. Without debug information
 //! filenames/line numbers will not be reported.
 //!
 //! ## Platform support
 //!
 //! Not all platforms that libstd compiles for support capturing backtraces.
 //! Some platforms simply do nothing when capturing a backtrace. To check
 //! whether the platform supports capturing backtraces you can consult the
 //! `BacktraceStatus` enum as a result of `Backtrace::status`.
 //!
 //! Like above with accuracy platform support is done on a best effort basis.
 //! Sometimes libraries may not be available at runtime or something may go
 //! wrong which would cause a backtrace to not be captured. Please feel free to
 //! report issues with platforms where a backtrace cannot be captured though!
 //!

 pub use crate::sys_common::backtrace::__rust_begin_short_backtrace;
 pub use crate::sys_common::backtrace::PrintFormat;

 use crate::enclave;
 use crate::sys::backtrace::{self, BytesOrWideString};
 use crate::path::Path;
 use crate::io;
 use crate::sync::SgxMutex;
 use crate::sys_common::backtrace::{
     lock,
     output_filename,
     rust_backtrace_env,
     RustBacktrace,
     set_enabled,
     SymbolName,
     resolve_frame_unsynchronized,
 };
 use crate::untrusted::fs;
 use core::ffi::c_void;
 use core::fmt;
 use alloc_crate::vec::Vec;

 /// A captured OS thread stack backtrace.
 ///
 /// This type represents a stack backtrace for an OS thread captured at a
 /// previous point in time. In some instances the `Backtrace` type may
 /// internally be empty due to configuration. For more information see
 /// `Backtrace::capture`.
 pub struct Backtrace {
     inner: Inner,
 }

 /// The current status of a backtrace, indicating whether it was captured or
 /// whether it is empty for some other reason.
 #[non_exhaustive]
 #[derive(Debug, PartialEq, Eq)]
 pub enum BacktraceStatus {
     /// Capturing a backtrace is not supported.
     Unsupported,
     /// Capturing a backtrace has been disabled.
     Disabled,
     /// A backtrace has been captured and the `Backtrace` should print
     /// reasonable information when rendered.
     Captured,
 }

 enum Inner {
     Unsupported,
     Disabled,
     Captured(SgxMutex<Capture>),
 }

 struct Capture {
     actual_start: usize,
     resolved: bool,
     frames: Vec<BacktraceFrame>,
 }

 fn _assert_send_sync() {
     fn _assert<T: Send + Sync>() {}
     _assert::<Backtrace>();
 }

 struct BacktraceFrame {
     frame: RawFrame,
     symbols: Vec<BacktraceSymbol>,
 }

 enum RawFrame {
     Actual(backtrace::Frame),
     #[cfg(test)]
     Fake,
 }

 struct BacktraceSymbol {
     name: Option<Vec<u8>>,
     filename: Option<BytesOrWide>,
     lineno: Option<u32>,
 }

 enum BytesOrWide {
     Bytes(Vec<u8>),
     Wide(Vec<u16>),
 }

 impl fmt::Debug for Backtrace {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut capture = match &self.inner {
             Inner::Unsupported => return fmt.write_str("<unsupported>"),
             Inner::Disabled => return fmt.write_str("<disabled>"),
             Inner::Captured(c) => c.lock().unwrap(),
         };
         capture.resolve();

         let frames = &capture.frames[capture.actual_start..];

         write!(fmt, "Backtrace ")?;

         let mut dbg = fmt.debug_list();

         for frame in frames {
             if frame.frame.ip().is_null() {
                 continue;
             }

             dbg.entries(&frame.symbols);
         }

         dbg.finish()
     }
 }

 impl fmt::Debug for BacktraceSymbol {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(fmt, "{{ ")?;

         if let Some(fn_name) = self.name.as_ref().map(|b| SymbolName::new(b)) {
             write!(fmt, "fn: \"{:#}\"", fn_name)?;
         } else {
             write!(fmt, "fn: <unknown>")?;
         }

         if let Some(fname) = self.filename.as_ref() {
             write!(fmt, ", file: \"{:?}\"", fname)?;
         }

         if let Some(line) = self.lineno.as_ref() {
             write!(fmt, ", line: {:?}", line)?;
         }

         write!(fmt, " }}")
     }
 }

 impl fmt::Debug for BytesOrWide {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         output_filename(
             fmt,
             match self {
                 BytesOrWide::Bytes(w) => BytesOrWideString::Bytes(w),
                 BytesOrWide::Wide(w) => BytesOrWideString::Wide(w),
             },
             backtrace::PrintFmt::Short,
             None,
         )
     }
 }

 impl Backtrace {
     /// Returns whether backtrace captures are enabled.
     fn enabled() -> bool {
         match rust_backtrace_env() {
             RustBacktrace::Print(_) => true,
             _ => false,
         }
     }

     /// Capture a stack backtrace of the current thread.
     ///
     /// This function will capture a stack backtrace of the current OS thread of
     /// execution, returning a `Backtrace` type which can be later used to print
     /// the entire stack trace or render it to a string.
     ///
     #[inline(never)] // want to make sure there's a frame here to remove
     pub fn capture() -> Backtrace {
         if !Backtrace::enabled() {
             return Backtrace { inner: Inner::Disabled };
         }
         Backtrace::create(Backtrace::capture as usize)
     }

     /// Forcibly captures a full backtrace.
     ///
     #[inline(never)] // want to make sure there's a frame here to remove
     pub fn force_capture() -> Backtrace {
         if !Backtrace::enabled() {
             return Backtrace { inner: Inner::Disabled };
         }
         Backtrace::create(Backtrace::force_capture as usize)
     }

     // Capture a backtrace which start just before the function addressed by
     // `ip`
     fn create(ip: usize) -> Backtrace {
         let _lock = lock();
         let mut frames = Vec::new();
         let mut actual_start = None;
         unsafe {
             backtrace::trace_unsynchronized(|frame| {
                 frames.push(BacktraceFrame {
                     frame: RawFrame::Actual(frame.clone()),
                     symbols: Vec::new(),
                 });
                 if frame.symbol_address() as usize == ip && actual_start.is_none() {
                     actual_start = Some(frames.len());
                 }
                 true
             });
         }

         // If no frames came out assume that this is an unsupported platform
         // since `backtrace` doesn't provide a way of learning this right now,
         // and this should be a good enough approximation.
         let inner = if frames.is_empty() {
             Inner::Unsupported
         } else {
             Inner::Captured(SgxMutex::new(Capture {
                 actual_start: actual_start.unwrap_or(0),
                 frames,
                 resolved: false,
             }))
         };

         Backtrace { inner }
     }

     /// Returns the status of this backtrace, indicating whether this backtrace
     /// request was unsupported, disabled, or a stack trace was actually
     /// captured.
     pub fn status(&self) -> BacktraceStatus {
         match self.inner {
             Inner::Unsupported => BacktraceStatus::Unsupported,
             Inner::Disabled => BacktraceStatus::Disabled,
             Inner::Captured(_) => BacktraceStatus::Captured,
         }
     }
 }

 impl fmt::Display for Backtrace {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut capture = match &self.inner {
             Inner::Unsupported => return fmt.write_str("unsupported backtrace"),
             Inner::Disabled => return fmt.write_str("disabled backtrace"),
             Inner::Captured(c) => c.lock().unwrap(),
         };
         capture.resolve();

         let full = fmt.alternate();
         let (frames, style) = if full {
             (&capture.frames[..], backtrace::PrintFmt::Full)
         } else {
             (&capture.frames[capture.actual_start..], backtrace::PrintFmt::Short)
         };

         // When printing paths we try to strip the cwd if it exists, otherwise
         // we just print the path as-is. Note that we also only do this for the
         // short format, because if it's full we presumably want to print
         // everything.
         // let cwd = crate::env::current_dir();
         let mut print_path = move |fmt: &mut fmt::Formatter<'_>, path: BytesOrWideString<'_>| {
             output_filename(fmt, path, style, None)
         };

         let mut f = backtrace::BacktraceFmt::new(fmt, style, &mut print_path);
         f.add_context()?;
         for frame in frames {
             let mut f = f.frame();
             if frame.symbols.is_empty() {
                 f.print_raw(frame.frame.ip(), None, None, None)?;
             } else {
                 for symbol in frame.symbols.iter() {
                     f.print_raw(
                         frame.frame.ip(),
                         symbol.name.as_ref().map(|b| SymbolName::new(b)),
                         symbol.filename.as_ref().map(|b| match b {
                             BytesOrWide::Bytes(w) => BytesOrWideString::Bytes(w),
                             BytesOrWide::Wide(w) => BytesOrWideString::Wide(w),
                         }),
                         symbol.lineno,
                     )?;
                 }
             }
         }
         f.finish()?;
         Ok(())
     }
 }

 impl Capture {
     fn resolve(&mut self) {
         // If we're already resolved, nothing to do!
         if self.resolved {
             return;
         }
         self.resolved = true;

         // Use the global backtrace lock to synchronize this as it's a
         // requirement of the `backtrace` crate, and then actually resolve
         // everything.
         let _lock = lock();
         for frame in self.frames.iter_mut() {
             let symbols = &mut frame.symbols;
             let frame = match &frame.frame {
                 RawFrame::Actual(frame) => frame,
                 #[cfg(test)]
                 RawFrame::Fake => unimplemented!(),
             };
             unsafe {
                 resolve_frame_unsynchronized(frame, |symbol| {
                     symbols.push(BacktraceSymbol {
                         name: symbol.name().map(|m| m.as_bytes().to_vec()),
                         filename: symbol.filename_raw().map(|b| match b {
                             BytesOrWideString::Bytes(b) => BytesOrWide::Bytes(b.to_owned()),
                             BytesOrWideString::Wide(b) => BytesOrWide::Wide(b.to_owned()),
                         }),
                         lineno: symbol.lineno(),
                     });
                 });
             }
         }
     }
 }

 impl RawFrame {
     fn ip(&self) -> *mut c_void {
         match self {
             RawFrame::Actual(frame) => frame.ip(),
             #[cfg(test)]
             RawFrame::Fake => 1 as *mut c_void,
         }
     }
 }

 /// Enable backtrace for dumping call stack on crash.
 ///
 /// Enabling backtrace here makes the panic information along with call stack
 /// information. Very similar to normal `RUST_BACKTRACE=1` flag in Rust.
 ///
 /// * `path` - The path of enclave's file image. This is essential for dumping
 /// symbol information on crash point.
 /// * Always return `Ok(())`
 pub fn enable_backtrace<P: AsRef<Path>>(path: P, format: PrintFormat) -> io::Result<()> {
     let _ = fs::metadata(&path)?;
     enclave::set_enclave_path(path)?;
     set_enabled(format);
     Ok(())
 }
	// Licensed to the Apache Software Foundation (ASF) under one
	// or more contributor license agreements. See the NOTICE file
	// distributed with this work for additional information
	// regarding copyright ownership. The ASF licenses this file
	// to you under the Apache License, Version 2.0 (the
	// "License"); you may not use this file except in compliance
	// with the License. You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing,
	// software distributed under the License is distributed on an
	// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	// KIND, either express or implied. See the License for the
	// specific language governing permissions and limitations
	// under the License..

	//! Support for capturing a stack backtrace of an OS thread
	//!
	//! This module contains the support necessary to capture a stack backtrace of a
	//! running OS thread from the OS thread itself. The `Backtrace` type supports
	//! capturing a stack trace via the `Backtrace::capture` and
	//! `Backtrace::force_capture` functions.
	//!
	//! A backtrace is typically quite handy to attach to errors (e.g. types
	//! implementing `std::error::Error`) to get a causal chain of where an error
	//! was generated.
	//!
	//! > Note: this module is unstable and is designed in [RFC 2504], and you
	//! > can learn more about its status in the [tracking issue].
	//!
	//! [RFC 2504]: https://github.com/rust-lang/rfcs/blob/master/text/2504-fix-error.md
	//! [tracking issue]: https://github.com/rust-lang/rust/issues/53487
	//!
	//! ## Accuracy
	//!
	//! Backtraces are attempted to be as accurate as possible, but no guarantees
	//! are provided about the exact accuracy of a backtrace. Instruction pointers,
	//! symbol names, filenames, line numbers, etc, may all be incorrect when
	//! reported. Accuracy is attempted on a best-effort basis, however, and bugs
	//! are always welcome to indicate areas of improvement!
	//!
	//! For most platforms a backtrace with a filename/line number requires that
	//! programs be compiled with debug information. Without debug information
	//! filenames/line numbers will not be reported.
	//!
	//! ## Platform support
	//!
	//! Not all platforms that libstd compiles for support capturing backtraces.
	//! Some platforms simply do nothing when capturing a backtrace. To check
	//! whether the platform supports capturing backtraces you can consult the
	//! `BacktraceStatus` enum as a result of `Backtrace::status`.
	//!
	//! Like above with accuracy platform support is done on a best effort basis.
	//! Sometimes libraries may not be available at runtime or something may go
	//! wrong which would cause a backtrace to not be captured. Please feel free to
	//! report issues with platforms where a backtrace cannot be captured though!
	//!

	pub use crate::sys_common::backtrace::__rust_begin_short_backtrace;
	pub use crate::sys_common::backtrace::PrintFormat;

	use crate::enclave;
	use crate::sys::backtrace::{self, BytesOrWideString};
	use crate::path::Path;
	use crate::io;
	use crate::sync::SgxMutex;
	use crate::sys_common::backtrace::{
	lock,
	output_filename,
	rust_backtrace_env,
	RustBacktrace,
	set_enabled,
	SymbolName,
	resolve_frame_unsynchronized,
	};
	use crate::untrusted::fs;
	use core::ffi::c_void;
	use core::fmt;
	use alloc_crate::vec::Vec;

	/// A captured OS thread stack backtrace.
	///
	/// This type represents a stack backtrace for an OS thread captured at a
	/// previous point in time. In some instances the `Backtrace` type may
	/// internally be empty due to configuration. For more information see
	/// `Backtrace::capture`.
	pub struct Backtrace {
	inner: Inner,
	}

	/// The current status of a backtrace, indicating whether it was captured or
	/// whether it is empty for some other reason.
	#[non_exhaustive]
	#[derive(Debug, PartialEq, Eq)]
	pub enum BacktraceStatus {
	/// Capturing a backtrace is not supported.
	Unsupported,
	/// Capturing a backtrace has been disabled.
	Disabled,
	/// A backtrace has been captured and the `Backtrace` should print
	/// reasonable information when rendered.
	Captured,
	}

	enum Inner {
	Unsupported,
	Disabled,
	Captured(SgxMutex<Capture>),
	}

	struct Capture {
	actual_start: usize,
	resolved: bool,
	frames: Vec<BacktraceFrame>,
	}

	fn _assert_send_sync() {
	fn _assert<T: Send + Sync>() {}
	_assert::<Backtrace>();
	}

	struct BacktraceFrame {
	frame: RawFrame,
	symbols: Vec<BacktraceSymbol>,
	}

	enum RawFrame {
	Actual(backtrace::Frame),
	#[cfg(test)]
	Fake,
	}

	struct BacktraceSymbol {
	name: Option<Vec<u8>>,
	filename: Option<BytesOrWide>,
	lineno: Option<u32>,
	}

	enum BytesOrWide {
	Bytes(Vec<u8>),
	Wide(Vec<u16>),
	}

	impl fmt::Debug for Backtrace {
	fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
	let mut capture = match &self.inner {
	Inner::Unsupported => return fmt.write_str("<unsupported>"),
	Inner::Disabled => return fmt.write_str("<disabled>"),
	Inner::Captured(c) => c.lock().unwrap(),
	};
	capture.resolve();

	let frames = &capture.frames[capture.actual_start..];

	write!(fmt, "Backtrace ")?;

	let mut dbg = fmt.debug_list();

	for frame in frames {
	if frame.frame.ip().is_null() {
	continue;
	}

	dbg.entries(&frame.symbols);
	}

	dbg.finish()
	}
	}

	impl fmt::Debug for BacktraceSymbol {
	fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
	write!(fmt, "{{ ")?;

	if let Some(fn_name) = self.name.as_ref().map(\|b\| SymbolName::new(b)) {
	write!(fmt, "fn: \"{:#}\"", fn_name)?;
	} else {
	write!(fmt, "fn: <unknown>")?;
	}

	if let Some(fname) = self.filename.as_ref() {
	write!(fmt, ", file: \"{:?}\"", fname)?;
	}

	if let Some(line) = self.lineno.as_ref() {
	write!(fmt, ", line: {:?}", line)?;
	}

	write!(fmt, " }}")
	}
	}

	impl fmt::Debug for BytesOrWide {
	fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
	output_filename(
	fmt,
	match self {
	BytesOrWide::Bytes(w) => BytesOrWideString::Bytes(w),
	BytesOrWide::Wide(w) => BytesOrWideString::Wide(w),
	},
	backtrace::PrintFmt::Short,
	None,
	)
	}
	}

	impl Backtrace {
	/// Returns whether backtrace captures are enabled.
	fn enabled() -> bool {
	match rust_backtrace_env() {
	RustBacktrace::Print(_) => true,
	_ => false,
	}
	}

	/// Capture a stack backtrace of the current thread.
	///
	/// This function will capture a stack backtrace of the current OS thread of
	/// execution, returning a `Backtrace` type which can be later used to print
	/// the entire stack trace or render it to a string.
	///
	#[inline(never)] // want to make sure there's a frame here to remove
	pub fn capture() -> Backtrace {
	if !Backtrace::enabled() {
	return Backtrace { inner: Inner::Disabled };
	}
	Backtrace::create(Backtrace::capture as usize)
	}

	/// Forcibly captures a full backtrace.
	///
	#[inline(never)] // want to make sure there's a frame here to remove
	pub fn force_capture() -> Backtrace {
	if !Backtrace::enabled() {
	return Backtrace { inner: Inner::Disabled };
	}
	Backtrace::create(Backtrace::force_capture as usize)
	}

	// Capture a backtrace which start just before the function addressed by
	// `ip`
	fn create(ip: usize) -> Backtrace {
	let _lock = lock();
	let mut frames = Vec::new();
	let mut actual_start = None;
	unsafe {
	backtrace::trace_unsynchronized(\|frame\| {
	frames.push(BacktraceFrame {
	frame: RawFrame::Actual(frame.clone()),
	symbols: Vec::new(),
	});
	if frame.symbol_address() as usize == ip && actual_start.is_none() {
	actual_start = Some(frames.len());
	}
	true
	});
	}

	// If no frames came out assume that this is an unsupported platform
	// since `backtrace` doesn't provide a way of learning this right now,
	// and this should be a good enough approximation.
	let inner = if frames.is_empty() {
	Inner::Unsupported
	} else {
	Inner::Captured(SgxMutex::new(Capture {
	actual_start: actual_start.unwrap_or(0),
	frames,
	resolved: false,
	}))
	};

	Backtrace { inner }
	}

	/// Returns the status of this backtrace, indicating whether this backtrace
	/// request was unsupported, disabled, or a stack trace was actually
	/// captured.
	pub fn status(&self) -> BacktraceStatus {
	match self.inner {
	Inner::Unsupported => BacktraceStatus::Unsupported,
	Inner::Disabled => BacktraceStatus::Disabled,
	Inner::Captured(_) => BacktraceStatus::Captured,
	}
	}
	}

	impl fmt::Display for Backtrace {
	fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
	let mut capture = match &self.inner {
	Inner::Unsupported => return fmt.write_str("unsupported backtrace"),
	Inner::Disabled => return fmt.write_str("disabled backtrace"),
	Inner::Captured(c) => c.lock().unwrap(),
	};
	capture.resolve();

	let full = fmt.alternate();
	let (frames, style) = if full {
	(&capture.frames[..], backtrace::PrintFmt::Full)
	} else {
	(&capture.frames[capture.actual_start..], backtrace::PrintFmt::Short)
	};

	// When printing paths we try to strip the cwd if it exists, otherwise
	// we just print the path as-is. Note that we also only do this for the
	// short format, because if it's full we presumably want to print
	// everything.
	// let cwd = crate::env::current_dir();
	let mut print_path = move \|fmt: &mut fmt::Formatter<'_>, path: BytesOrWideString<'_>\| {
	output_filename(fmt, path, style, None)
	};

	let mut f = backtrace::BacktraceFmt::new(fmt, style, &mut print_path);
	f.add_context()?;
	for frame in frames {
	let mut f = f.frame();
	if frame.symbols.is_empty() {
	f.print_raw(frame.frame.ip(), None, None, None)?;
	} else {
	for symbol in frame.symbols.iter() {
	f.print_raw(
	frame.frame.ip(),
	symbol.name.as_ref().map(\|b\| SymbolName::new(b)),
	symbol.filename.as_ref().map(\|b\| match b {
	BytesOrWide::Bytes(w) => BytesOrWideString::Bytes(w),
	BytesOrWide::Wide(w) => BytesOrWideString::Wide(w),
	}),
	symbol.lineno,
	)?;
	}
	}
	}
	f.finish()?;
	Ok(())
	}
	}

	impl Capture {
	fn resolve(&mut self) {
	// If we're already resolved, nothing to do!
	if self.resolved {
	return;
	}
	self.resolved = true;

	// Use the global backtrace lock to synchronize this as it's a
	// requirement of the `backtrace` crate, and then actually resolve
	// everything.
	let _lock = lock();
	for frame in self.frames.iter_mut() {
	let symbols = &mut frame.symbols;
	let frame = match &frame.frame {
	RawFrame::Actual(frame) => frame,
	#[cfg(test)]
	RawFrame::Fake => unimplemented!(),
	};
	unsafe {
	resolve_frame_unsynchronized(frame, \|symbol\| {
	symbols.push(BacktraceSymbol {
	name: symbol.name().map(\|m\| m.as_bytes().to_vec()),
	filename: symbol.filename_raw().map(\|b\| match b {
	BytesOrWideString::Bytes(b) => BytesOrWide::Bytes(b.to_owned()),
	BytesOrWideString::Wide(b) => BytesOrWide::Wide(b.to_owned()),
	}),
	lineno: symbol.lineno(),
	});
	});
	}
	}
	}
	}

	impl RawFrame {
	fn ip(&self) -> *mut c_void {
	match self {
	RawFrame::Actual(frame) => frame.ip(),
	#[cfg(test)]
	RawFrame::Fake => 1 as *mut c_void,
	}
	}
	}

	/// Enable backtrace for dumping call stack on crash.
	///
	/// Enabling backtrace here makes the panic information along with call stack
	/// information. Very similar to normal `RUST_BACKTRACE=1` flag in Rust.
	///
	/// * `path` - The path of enclave's file image. This is essential for dumping
	/// symbol information on crash point.
	/// * Always return `Ok(())`
	pub fn enable_backtrace<P: AsRef<Path>>(path: P, format: PrintFormat) -> io::Result<()> {
	let _ = fs::metadata(&path)?;
	enclave::set_enclave_path(path)?;
	set_enabled(format);
	Ok(())
	}