1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Simple backtrace functionality (to print on failure)
13 #![allow(non_camel_case_types)]
16 use collections::Collection;
17 use from_str::from_str;
18 use io::{IoResult, Writer};
20 use option::{Some, None};
22 use result::{Ok, Err};
26 pub use self::imp::write;
28 // For now logging is turned off by default, and this function checks to see
29 // whether the magical environment variable is present to see if it's turned on.
30 pub fn log_enabled() -> bool {
31 static mut ENABLED: atomics::AtomicInt = atomics::INIT_ATOMIC_INT;
33 match ENABLED.load(atomics::SeqCst) {
40 let val = match os::getenv("RUST_BACKTRACE") {
44 unsafe { ENABLED.store(val, atomics::SeqCst); }
48 #[cfg(target_word_size = "64")] static HEX_WIDTH: uint = 18;
49 #[cfg(target_word_size = "32")] static HEX_WIDTH: uint = 10;
51 // All rust symbols are in theory lists of "::"-separated identifiers. Some
52 // assemblers, however, can't handle these characters in symbol names. To get
53 // around this, we use C++-style mangling. The mangling method is:
55 // 1. Prefix the symbol with "_ZN"
56 // 2. For each element of the path, emit the length plus the element
57 // 3. End the path with "E"
59 // For example, "_ZN4testE" => "test" and "_ZN3foo3bar" => "foo::bar".
61 // We're the ones printing our backtraces, so we can't rely on anything else to
62 // demangle our symbols. It's *much* nicer to look at demangled symbols, so
63 // this function is implemented to give us nice pretty output.
65 // Note that this demangler isn't quite as fancy as it could be. We have lots
66 // of other information in our symbols like hashes, version, type information,
67 // etc. Additionally, this doesn't handle glue symbols at all.
68 fn demangle(writer: &mut Writer, s: &str) -> IoResult<()> {
69 // First validate the symbol. If it doesn't look like anything we're
70 // expecting, we just print it literally. Note that we must handle non-rust
71 // symbols because we could have any function in the backtrace.
73 if s.len() > 4 && s.starts_with("_ZN") && s.ends_with("E") {
74 let mut chars = s.slice(3, s.len() - 1).chars();
79 i = i * 10 + c as uint - '0' as uint;
85 valid = chars.next().is_none();
87 } else if chars.by_ref().take(i - 1).count() != i - 1 {
95 // Alright, let's do this.
97 try!(writer.write_str(s));
99 let mut s = s.slice_from(3);
100 let mut first = true;
103 try!(writer.write_str("::"));
108 while rest.char_at(0).is_digit() {
109 rest = rest.slice_from(1);
111 let i: uint = from_str(s.slice_to(s.len() - rest.len())).unwrap();
112 s = rest.slice_from(i);
113 rest = rest.slice_to(i);
114 while rest.len() > 0 {
115 if rest.starts_with("$") {
116 macro_rules! demangle(
117 ($($pat:expr => $demangled:expr),*) => ({
118 $(if rest.starts_with($pat) {
119 try!(writer.write_str($demangled));
120 rest = rest.slice_from($pat.len());
123 try!(writer.write_str(rest));
129 // see src/librustc/back/link.rs for these mappings
141 // in theory we can demangle any unicode code point, but
142 // for simplicity we just catch the common ones.
149 let idx = match rest.find('$') {
153 try!(writer.write_str(rest.slice_to(idx)));
154 rest = rest.slice_from(idx);
163 /// Backtrace support built on libgcc with some extra OS-specific support
165 /// Some methods of getting a backtrace:
167 /// * The backtrace() functions on unix. It turns out this doesn't work very
168 /// well for green threads on OSX, and the address to symbol portion of it
169 /// suffers problems that are described below.
171 /// * Using libunwind. This is more difficult than it sounds because libunwind
172 /// isn't installed everywhere by default. It's also a bit of a hefty library,
173 /// so possibly not the best option. When testing, libunwind was excellent at
174 /// getting both accurate backtraces and accurate symbols across platforms.
175 /// This route was not chosen in favor of the next option, however.
177 /// * We're already using libgcc_s for exceptions in rust (triggering task
178 /// unwinding and running destructors on the stack), and it turns out that it
179 /// conveniently comes with a function that also gives us a backtrace. All of
180 /// these functions look like _Unwind_*, but it's not quite the full
181 /// repertoire of the libunwind API. Due to it already being in use, this was
182 /// the chosen route of getting a backtrace.
184 /// After choosing libgcc_s for backtraces, the sad part is that it will only
185 /// give us a stack trace of instruction pointers. Thankfully these instruction
186 /// pointers are accurate (they work for green and native threads), but it's
187 /// then up to us again to figure out how to translate these addresses to
188 /// symbols. As with before, we have a few options. Before, that, a little bit
189 /// of an interlude about symbols. This is my very limited knowledge about
190 /// symbol tables, and this information is likely slightly wrong, but the
191 /// general idea should be correct.
193 /// When talking about symbols, it's helpful to know a few things about where
194 /// symbols are located. Some symbols are located in the dynamic symbol table
195 /// of the executable which in theory means that they're available for dynamic
196 /// linking and lookup. Other symbols end up only in the local symbol table of
197 /// the file. This loosely corresponds to pub and priv functions in Rust.
199 /// Armed with this knowledge, we know that our solution for address to symbol
200 /// translation will need to consult both the local and dynamic symbol tables.
201 /// With that in mind, here's our options of translating an address to
204 /// * Use dladdr(). The original backtrace()-based idea actually uses dladdr()
205 /// behind the scenes to translate, and this is why backtrace() was not used.
206 /// Conveniently, this method works fantastically on OSX. It appears dladdr()
207 /// uses magic to consult the local symbol table, or we're putting everything
208 /// in the dynamic symbol table anyway. Regardless, for OSX, this is the
209 /// method used for translation. It's provided by the system and easy to do.o
211 /// Sadly, all other systems have a dladdr() implementation that does not
212 /// consult the local symbol table. This means that most functions are blank
213 /// because they don't have symbols. This means that we need another solution.
215 /// * Use unw_get_proc_name(). This is part of the libunwind api (not the
216 /// libgcc_s version of the libunwind api), but involves taking a dependency
217 /// to libunwind. We may pursue this route in the future if we bundle
218 /// libunwind, but libunwind was unwieldy enough that it was not chosen at
219 /// this time to provide this functionality.
221 /// * Shell out to a utility like `readelf`. Crazy though it may sound, it's a
222 /// semi-reasonable solution. The stdlib already knows how to spawn processes,
223 /// so in theory it could invoke readelf, parse the output, and consult the
224 /// local/dynamic symbol tables from there. This ended up not getting chosen
225 /// due to the craziness of the idea plus the advent of the next option.
227 /// * Use `libbacktrace`. It turns out that this is a small library bundled in
228 /// the gcc repository which provides backtrace and symbol translation
229 /// functionality. All we really need from it is the backtrace functionality,
230 /// and we only really need this on everything that's not OSX, so this is the
231 /// chosen route for now.
233 /// In summary, the current situation uses libgcc_s to get a trace of stack
234 /// pointers, and we use dladdr() or libbacktrace to translate these addresses
235 /// to symbols. This is a bit of a hokey implementation as-is, but it works for
236 /// all unix platforms we support right now, so it at least gets the job done.
240 use io::{IoResult, Writer};
243 use option::{Some, None, Option};
244 use result::{Ok, Err};
245 use rt::mutex::{StaticNativeMutex, NATIVE_MUTEX_INIT};
247 /// As always - iOS on arm uses SjLj exceptions and
248 /// _Unwind_Backtrace is even not available there. Still,
249 /// backtraces could be extracted using a backtrace function,
250 /// which thanks god is public
252 /// As mentioned in a huge comment block above, backtrace doesn't
253 /// play well with green threads, so while it is extremely nice
254 /// and simple to use it should be used only on iOS devices as the
255 /// only viable option.
256 #[cfg(target_os = "ios", target_arch = "arm")]
258 pub fn write(w: &mut Writer) -> IoResult<()> {
259 use iter::{Iterator, range};
261 use slice::{MutableVector};
264 fn backtrace(buf: *mut *libc::c_void, sz: libc::c_int) -> libc::c_int;
267 // while it doesn't requires lock for work as everything is
268 // local, it still displays much nicier backtraces when a
269 // couple of tasks fail simultaneously
270 static mut LOCK: StaticNativeMutex = NATIVE_MUTEX_INIT;
271 let _g = unsafe { LOCK.lock() };
273 try!(writeln!(w, "stack backtrace:"));
274 // 100 lines should be enough
275 static SIZE: libc::c_int = 100;
276 let mut buf: [*libc::c_void, ..SIZE] = unsafe {mem::zeroed()};
277 let cnt = unsafe { backtrace(buf.as_mut_ptr(), SIZE) as uint};
279 // skipping the first one as it is write itself
280 result::fold_(range(1, cnt).map(|i| {
281 print(w, i as int, buf[i])
285 #[cfg(not(target_os = "ios", target_arch = "arm"))]
286 #[inline(never)] // if we know this is a function call, we can skip it when
288 pub fn write(w: &mut Writer) -> IoResult<()> {
293 writer: &'a mut Writer,
294 last_error: Option<IoError>,
297 // When using libbacktrace, we use some necessary global state, so we
298 // need to prevent more than one thread from entering this block. This
299 // is semi-reasonable in terms of printing anyway, and we know that all
300 // I/O done here is blocking I/O, not green I/O, so we don't have to
301 // worry about this being a native vs green mutex.
302 static mut LOCK: StaticNativeMutex = NATIVE_MUTEX_INIT;
303 let _g = unsafe { LOCK.lock() };
305 try!(writeln!(w, "stack backtrace:"));
307 let mut cx = Context { writer: w, last_error: None, idx: 0 };
308 return match unsafe {
309 uw::_Unwind_Backtrace(trace_fn,
310 &mut cx as *mut Context as *libc::c_void)
312 uw::_URC_NO_REASON => {
313 match cx.last_error {
314 Some(err) => Err(err),
321 extern fn trace_fn(ctx: *uw::_Unwind_Context,
322 arg: *libc::c_void) -> uw::_Unwind_Reason_Code {
323 let cx: &mut Context = unsafe { mem::transmute(arg) };
324 let ip = unsafe { uw::_Unwind_GetIP(ctx) as *libc::c_void };
325 // dladdr() on osx gets whiny when we use FindEnclosingFunction, and
326 // it appears to work fine without it, so we only use
327 // FindEnclosingFunction on non-osx platforms. In doing so, we get a
328 // slightly more accurate stack trace in the process.
330 // This is often because failure involves the last instruction of a
331 // function being "call std::rt::begin_unwind", with no ret
332 // instructions after it. This means that the return instruction
333 // pointer points *outside* of the calling function, and by
334 // unwinding it we go back to the original function.
335 let ip = if cfg!(target_os = "macos") || cfg!(target_os = "ios") {
338 unsafe { uw::_Unwind_FindEnclosingFunction(ip) }
341 // Don't print out the first few frames (they're not user frames)
343 if cx.idx <= 0 { return uw::_URC_NO_REASON }
344 // Don't print ginormous backtraces
346 match write!(cx.writer, " ... <frames omitted>\n") {
348 Err(e) => { cx.last_error = Some(e); }
350 return uw::_URC_FAILURE
353 // Once we hit an error, stop trying to print more frames
354 if cx.last_error.is_some() { return uw::_URC_FAILURE }
356 match print(cx.writer, cx.idx, ip) {
358 Err(e) => { cx.last_error = Some(e); }
362 return uw::_URC_NO_REASON
366 #[cfg(target_os = "macos")]
367 #[cfg(target_os = "ios")]
368 fn print(w: &mut Writer, idx: int, addr: *libc::c_void) -> IoResult<()> {
372 dli_fname: *libc::c_char,
373 dli_fbase: *libc::c_void,
374 dli_sname: *libc::c_char,
375 dli_saddr: *libc::c_void,
378 fn dladdr(addr: *libc::c_void,
379 info: *mut Dl_info) -> libc::c_int;
382 let mut info: Dl_info = unsafe { intrinsics::init() };
383 if unsafe { dladdr(addr, &mut info) == 0 } {
384 output(w, idx,addr, None)
386 output(w, idx, addr, Some(unsafe {
387 CString::new(info.dli_sname, false)
392 #[cfg(not(target_os = "macos"), not(target_os = "ios"))]
393 fn print(w: &mut Writer, idx: int, addr: *libc::c_void) -> IoResult<()> {
394 use collections::Collection;
397 use path::GenericPath;
400 use slice::{ImmutableVector, MutableVector};
402 ////////////////////////////////////////////////////////////////////////
403 // libbacktrace.h API
404 ////////////////////////////////////////////////////////////////////////
405 type backtrace_syminfo_callback =
406 extern "C" fn(data: *mut libc::c_void,
408 symname: *libc::c_char,
409 symval: libc::uintptr_t,
410 symsize: libc::uintptr_t);
411 type backtrace_error_callback =
412 extern "C" fn(data: *mut libc::c_void,
414 errnum: libc::c_int);
415 enum backtrace_state {}
416 #[link(name = "backtrace", kind = "static")]
418 fn backtrace_create_state(filename: *libc::c_char,
419 threaded: libc::c_int,
420 error: backtrace_error_callback,
421 data: *mut libc::c_void)
422 -> *mut backtrace_state;
423 fn backtrace_syminfo(state: *mut backtrace_state,
424 addr: libc::uintptr_t,
425 cb: backtrace_syminfo_callback,
426 error: backtrace_error_callback,
427 data: *mut libc::c_void) -> libc::c_int;
430 ////////////////////////////////////////////////////////////////////////
432 ////////////////////////////////////////////////////////////////////////
434 extern fn error_cb(_data: *mut libc::c_void, _msg: *libc::c_char,
435 _errnum: libc::c_int) {
436 // do nothing for now
438 extern fn syminfo_cb(data: *mut libc::c_void,
439 _pc: libc::uintptr_t,
440 symname: *libc::c_char,
441 _symval: libc::uintptr_t,
442 _symsize: libc::uintptr_t) {
443 let slot = data as *mut *libc::c_char;
444 unsafe { *slot = symname; }
447 // The libbacktrace API supports creating a state, but it does not
448 // support destroying a state. I personally take this to mean that a
449 // state is meant to be created and then live forever.
451 // I would love to register an at_exit() handler which cleans up this
452 // state, but libbacktrace provides no way to do so.
454 // With these constraints, this function has a statically cached state
455 // that is calculated the first time this is requested. Remember that
456 // backtracing all happens serially (one global lock).
458 // An additionally oddity in this function is that we initialize the
459 // filename via self_exe_name() to pass to libbacktrace. It turns out
460 // that on linux libbacktrace seamlessly gets the filename of the
461 // current executable, but this fails on freebsd. by always providing
462 // it, we make sure that libbacktrace never has a reason to not look up
463 // the symbols. The libbacktrace API also states that the filename must
464 // be in "permanent memory", so we copy it to a static and then use the
465 // static as the pointer.
466 unsafe fn init_state() -> *mut backtrace_state {
467 static mut STATE: *mut backtrace_state = 0 as *mut backtrace_state;
468 static mut LAST_FILENAME: [libc::c_char, ..256] = [0, ..256];
469 if !STATE.is_null() { return STATE }
470 let selfname = if cfg!(target_os = "freebsd") {
475 let filename = match selfname {
477 let bytes = path.as_vec();
478 if bytes.len() < LAST_FILENAME.len() {
479 let i = bytes.iter();
480 for (slot, val) in LAST_FILENAME.mut_iter().zip(i) {
481 *slot = *val as libc::c_char;
483 LAST_FILENAME.as_ptr()
490 STATE = backtrace_create_state(filename, 0, error_cb,
495 ////////////////////////////////////////////////////////////////////////
497 ////////////////////////////////////////////////////////////////////////
499 // backtrace errors are currently swept under the rug, only I/O
500 // errors are reported
501 let state = unsafe { init_state() };
503 return output(w, idx, addr, None)
505 let mut data = 0 as *libc::c_char;
506 let data_addr = &mut data as *mut *libc::c_char;
508 backtrace_syminfo(state, addr as libc::uintptr_t,
509 syminfo_cb, error_cb,
510 data_addr as *mut libc::c_void)
512 if ret == 0 || data.is_null() {
513 output(w, idx, addr, None)
515 output(w, idx, addr, Some(unsafe { CString::new(data, false) }))
519 // Finally, after all that work above, we can emit a symbol.
520 fn output(w: &mut Writer, idx: int, addr: *libc::c_void,
521 s: Option<CString>) -> IoResult<()> {
522 try!(write!(w, " {:2}: {:2$} - ", idx, addr, super::HEX_WIDTH));
523 match s.as_ref().and_then(|c| c.as_str()) {
524 Some(string) => try!(super::demangle(w, string)),
525 None => try!(write!(w, "<unknown>")),
527 w.write(['\n' as u8])
530 /// Unwind library interface used for backtraces
532 /// Note that the native libraries come from librustrt, not this
534 /// Note that dead code is allowed as here are just bindings
535 /// iOS doesn't use all of them it but adding more
536 /// platform-specific configs pollutes the code too much
537 #[allow(non_camel_case_types)]
538 #[allow(non_snake_case_functions)]
544 pub enum _Unwind_Reason_Code {
546 _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
547 _URC_FATAL_PHASE2_ERROR = 2,
548 _URC_FATAL_PHASE1_ERROR = 3,
549 _URC_NORMAL_STOP = 4,
550 _URC_END_OF_STACK = 5,
551 _URC_HANDLER_FOUND = 6,
552 _URC_INSTALL_CONTEXT = 7,
553 _URC_CONTINUE_UNWIND = 8,
554 _URC_FAILURE = 9, // used only by ARM EABI
557 pub enum _Unwind_Context {}
559 pub type _Unwind_Trace_Fn =
560 extern fn(ctx: *_Unwind_Context,
561 arg: *libc::c_void) -> _Unwind_Reason_Code;
564 // No native _Unwind_Backtrace on iOS
565 #[cfg(not(target_os = "ios", target_arch = "arm"))]
566 pub fn _Unwind_Backtrace(trace: _Unwind_Trace_Fn,
567 trace_argument: *libc::c_void)
568 -> _Unwind_Reason_Code;
570 #[cfg(not(target_os = "android"),
571 not(target_os = "linux", target_arch = "arm"))]
572 pub fn _Unwind_GetIP(ctx: *_Unwind_Context) -> libc::uintptr_t;
573 #[cfg(not(target_os = "android"),
574 not(target_os = "linux", target_arch = "arm"))]
575 pub fn _Unwind_FindEnclosingFunction(pc: *libc::c_void)
579 // On android, the function _Unwind_GetIP is a macro, and this is the
580 // expansion of the macro. This is all copy/pasted directly from the
581 // header file with the definition of _Unwind_GetIP.
582 #[cfg(target_os = "android")]
583 #[cfg(target_os = "linux", target_arch = "arm")]
584 pub unsafe fn _Unwind_GetIP(ctx: *_Unwind_Context) -> libc::uintptr_t {
586 enum _Unwind_VRS_Result {
588 _UVRSR_NOT_IMPLEMENTED = 1,
592 enum _Unwind_VRS_RegClass {
600 enum _Unwind_VRS_DataRepresentation {
609 type _Unwind_Word = libc::c_uint;
611 fn _Unwind_VRS_Get(ctx: *_Unwind_Context,
612 klass: _Unwind_VRS_RegClass,
614 repr: _Unwind_VRS_DataRepresentation,
615 data: *mut libc::c_void)
616 -> _Unwind_VRS_Result;
619 let mut val: _Unwind_Word = 0;
620 let ptr = &mut val as *mut _Unwind_Word;
621 let _ = _Unwind_VRS_Get(ctx, _UVRSC_CORE, 15, _UVRSD_UINT32,
622 ptr as *mut libc::c_void);
623 (val & !1) as libc::uintptr_t
626 // This function also doesn't exist on android or arm/linux, so make it
628 #[cfg(target_os = "android")]
629 #[cfg(target_os = "linux", target_arch = "arm")]
630 pub unsafe fn _Unwind_FindEnclosingFunction(pc: *libc::c_void)
638 /// As always, windows has something very different than unix, we mainly want
639 /// to avoid having to depend too much on libunwind for windows.
641 /// If you google around, you'll find a fair bit of references to built-in
642 /// functions to get backtraces on windows. It turns out that most of these are
643 /// in an external library called dbghelp. I was unable to find this library
644 /// via `-ldbghelp`, but it is apparently normal to do the `dlopen` equivalent
647 /// You'll also find that there's a function called CaptureStackBackTrace
648 /// mentioned frequently (which is also easy to use), but sadly I didn't have a
649 /// copy of that function in my mingw install (maybe it was broken?). Instead,
650 /// this takes the route of using StackWalk64 in order to walk the stack.
652 #[allow(dead_code, uppercase_variables)]
655 use core_collections::Collection;
657 use io::{IoResult, Writer};
661 use option::{Some, None};
663 use result::{Ok, Err};
664 use rt::mutex::{StaticNativeMutex, NATIVE_MUTEX_INIT};
665 use slice::ImmutableVector;
667 use dynamic_lib::DynamicLibrary;
669 #[allow(non_snake_case_functions)]
671 fn GetCurrentProcess() -> libc::HANDLE;
672 fn GetCurrentThread() -> libc::HANDLE;
673 fn RtlCaptureContext(ctx: *mut arch::CONTEXT);
677 extern "system" fn(libc::HANDLE, u64, *mut u64,
678 *mut SYMBOL_INFO) -> libc::BOOL;
679 type SymInitializeFn =
680 extern "system" fn(libc::HANDLE, *libc::c_void,
681 libc::BOOL) -> libc::BOOL;
683 extern "system" fn(libc::HANDLE) -> libc::BOOL;
686 extern "system" fn(libc::DWORD, libc::HANDLE, libc::HANDLE,
687 *mut STACKFRAME64, *mut arch::CONTEXT,
688 *libc::c_void, *libc::c_void,
689 *libc::c_void, *libc::c_void) -> libc::BOOL;
691 static MAX_SYM_NAME: uint = 2000;
692 static IMAGE_FILE_MACHINE_I386: libc::DWORD = 0x014c;
693 static IMAGE_FILE_MACHINE_IA64: libc::DWORD = 0x0200;
694 static IMAGE_FILE_MACHINE_AMD64: libc::DWORD = 0x8664;
698 SizeOfStruct: libc::c_ulong,
699 TypeIndex: libc::c_ulong,
700 Reserved: [u64, ..2],
701 Index: libc::c_ulong,
704 Flags: libc::c_ulong,
707 Register: libc::c_ulong,
708 Scope: libc::c_ulong,
710 NameLen: libc::c_ulong,
711 MaxNameLen: libc::c_ulong,
712 // note that windows has this as 1, but it basically just means that
713 // the name is inline at the end of the struct. For us, we just bump
714 // the struct size up to MAX_SYM_NAME.
715 Name: [libc::c_char, ..MAX_SYM_NAME],
732 struct STACKFRAME64 {
734 AddrReturn: ADDRESS64,
735 AddrFrame: ADDRESS64,
736 AddrStack: ADDRESS64,
737 AddrBStore: ADDRESS64,
738 FuncTableEntry: *libc::c_void,
742 Reserved: [u64, ..3],
748 ThCallbackStack: libc::DWORD,
749 ThCallbackBStore: libc::DWORD,
750 NextCallback: libc::DWORD,
751 FramePointer: libc::DWORD,
753 KeUserCallbackDispatcher: u64,
754 SystemRangeStart: u64,
755 KiUserExceptionDispatcher: u64,
758 Reserved: [u64, ..5],
761 #[cfg(target_arch = "x86")]
765 static MAXIMUM_SUPPORTED_EXTENSION: uint = 512;
768 ContextFlags: libc::DWORD,
775 FloatSave: FLOATING_SAVE_AREA,
792 ExtendedRegisters: [u8, ..MAXIMUM_SUPPORTED_EXTENSION],
795 pub struct FLOATING_SAVE_AREA {
796 ControlWord: libc::DWORD,
797 StatusWord: libc::DWORD,
798 TagWord: libc::DWORD,
799 ErrorOffset: libc::DWORD,
800 ErrorSelector: libc::DWORD,
801 DataOffset: libc::DWORD,
802 DataSelector: libc::DWORD,
803 RegisterArea: [u8, ..80],
804 Cr0NpxState: libc::DWORD,
807 pub fn init_frame(frame: &mut super::STACKFRAME64,
808 ctx: &CONTEXT) -> libc::DWORD {
809 frame.AddrPC.Offset = ctx.Eip as u64;
810 frame.AddrPC.Mode = super::AddrModeFlat;
811 frame.AddrStack.Offset = ctx.Esp as u64;
812 frame.AddrStack.Mode = super::AddrModeFlat;
813 frame.AddrFrame.Offset = ctx.Ebp as u64;
814 frame.AddrFrame.Mode = super::AddrModeFlat;
815 super::IMAGE_FILE_MACHINE_I386
819 #[cfg(target_arch = "x86_64")]
821 use libc::{c_longlong, c_ulonglong};
822 use libc::types::os::arch::extra::{WORD, DWORD, DWORDLONG};
869 FltSave: FLOATING_SAVE_AREA,
871 VectorRegister: [M128A, .. 26],
872 VectorControl: DWORDLONG,
874 DebugControl: DWORDLONG,
875 LastBranchToRip: DWORDLONG,
876 LastBranchFromRip: DWORDLONG,
877 LastExceptionToRip: DWORDLONG,
878 LastExceptionFromRip: DWORDLONG,
886 pub struct FLOATING_SAVE_AREA {
887 _Dummy: [u8, ..512] // FIXME: Fill this out
890 pub fn init_frame(frame: &mut super::STACKFRAME64,
891 ctx: &CONTEXT) -> DWORD {
892 frame.AddrPC.Offset = ctx.Rip as u64;
893 frame.AddrPC.Mode = super::AddrModeFlat;
894 frame.AddrStack.Offset = ctx.Rsp as u64;
895 frame.AddrStack.Mode = super::AddrModeFlat;
896 frame.AddrFrame.Offset = ctx.Rbp as u64;
897 frame.AddrFrame.Mode = super::AddrModeFlat;
898 super::IMAGE_FILE_MACHINE_AMD64
903 handle: libc::HANDLE,
904 SymCleanup: SymCleanupFn,
907 impl Drop for Cleanup {
908 fn drop(&mut self) { (self.SymCleanup)(self.handle); }
911 pub fn write(w: &mut Writer) -> IoResult<()> {
912 // According to windows documentation, all dbghelp functions are
914 static mut LOCK: StaticNativeMutex = NATIVE_MUTEX_INIT;
915 let _g = unsafe { LOCK.lock() };
917 // Open up dbghelp.dll, we don't link to it explicitly because it can't
918 // always be found. Additionally, it's nice having fewer dependencies.
919 let path = Path::new("dbghelp.dll");
920 let lib = match DynamicLibrary::open(Some(&path)) {
922 Err(..) => return Ok(()),
925 macro_rules! sym( ($e:expr, $t:ident) => (unsafe {
926 match lib.symbol($e) {
927 Ok(f) => mem::transmute::<*u8, $t>(f),
928 Err(..) => return Ok(())
932 // Fetch the symbols necessary from dbghelp.dll
933 let SymFromAddr = sym!("SymFromAddr", SymFromAddrFn);
934 let SymInitialize = sym!("SymInitialize", SymInitializeFn);
935 let SymCleanup = sym!("SymCleanup", SymCleanupFn);
936 let StackWalk64 = sym!("StackWalk64", StackWalk64Fn);
938 // Allocate necessary structures for doing the stack walk
939 let process = unsafe { GetCurrentProcess() };
940 let thread = unsafe { GetCurrentThread() };
941 let mut context: arch::CONTEXT = unsafe { intrinsics::init() };
942 unsafe { RtlCaptureContext(&mut context); }
943 let mut frame: STACKFRAME64 = unsafe { intrinsics::init() };
944 let image = arch::init_frame(&mut frame, &context);
946 // Initialize this process's symbols
947 let ret = SymInitialize(process, 0 as *libc::c_void, libc::TRUE);
948 if ret != libc::TRUE { return Ok(()) }
949 let _c = Cleanup { handle: process, SymCleanup: SymCleanup };
951 // And now that we're done with all the setup, do the stack walking!
953 try!(write!(w, "stack backtrace:\n"));
954 while StackWalk64(image, process, thread, &mut frame, &mut context,
955 0 as *libc::c_void, 0 as *libc::c_void,
956 0 as *libc::c_void, 0 as *libc::c_void) == libc::TRUE{
957 let addr = frame.AddrPC.Offset;
958 if addr == frame.AddrReturn.Offset || addr == 0 ||
959 frame.AddrReturn.Offset == 0 { break }
962 try!(write!(w, " {:2}: {:#2$x}", i, addr, super::HEX_WIDTH));
963 let mut info: SYMBOL_INFO = unsafe { intrinsics::init() };
964 info.MaxNameLen = MAX_SYM_NAME as libc::c_ulong;
965 info.SizeOfStruct = (mem::size_of::<SYMBOL_INFO>() -
966 info.Name.len() + 1) as libc::c_ulong;
968 let mut displacement = 0u64;
969 let ret = SymFromAddr(process, addr as u64, &mut displacement,
972 if ret == libc::TRUE {
973 try!(write!(w, " - "));
974 let cstr = unsafe { CString::new(info.Name.as_ptr(), false) };
975 let bytes = cstr.as_bytes();
976 match cstr.as_str() {
977 Some(s) => try!(super::demangle(w, s)),
978 None => try!(w.write(bytes.slice_to(bytes.len() - 1))),
981 try!(w.write(['\n' as u8]));
994 macro_rules! t( ($a:expr, $b:expr) => ({
995 let mut m = MemWriter::new();
996 super::demangle(&mut m, $a).unwrap();
997 assert_eq!(str::from_utf8(m.unwrap().as_slice()).unwrap().to_owned(), $b.to_owned());
1003 t!("_ZN4testE", "test");
1004 t!("_ZN4test", "_ZN4test");
1005 t!("_ZN4test1a2bcE", "test::a::bc");
1009 fn demangle_dollars() {
1010 t!("_ZN4$UP$E", "Box");
1011 t!("_ZN8$UP$testE", "Boxtest");
1012 t!("_ZN8$UP$test4foobE", "Boxtest::foob");
1013 t!("_ZN8$x20test4foobE", " test::foob");
1017 fn demangle_many_dollars() {
1018 t!("_ZN12test$x20test4foobE", "test test::foob");
1019 t!("_ZN12test$UP$test4foobE", "testBoxtest::foob");