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Commit | Line | Data |
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3dfed10e | 1 | use crate::backtrace_rs::{self, BacktraceFmt, BytesOrWideString, PrintFmt}; |
dfeec247 | 2 | use crate::borrow::Cow; |
8bb4bdeb XL |
3 | /// Common code for printing the backtrace in the same way across the different |
4 | /// supported platforms. | |
532ac7d7 | 5 | use crate::env; |
e1599b0c | 6 | use crate::fmt; |
532ac7d7 | 7 | use crate::io; |
dc9dc135 | 8 | use crate::io::prelude::*; |
e1599b0c | 9 | use crate::path::{self, Path, PathBuf}; |
29967ef6 | 10 | use crate::sys_common::mutex::StaticMutex; |
532ac7d7 | 11 | |
8bb4bdeb XL |
12 | /// Max number of frames to print. |
13 | const MAX_NB_FRAMES: usize = 100; | |
14 | ||
29967ef6 XL |
15 | // SAFETY: Don't attempt to lock this reentrantly. |
16 | pub unsafe fn lock() -> impl Drop { | |
17 | static LOCK: StaticMutex = StaticMutex::new(); | |
18 | LOCK.lock() | |
e1599b0c XL |
19 | } |
20 | ||
21 | /// Prints the current backtrace. | |
22 | pub fn print(w: &mut dyn Write, format: PrintFmt) -> io::Result<()> { | |
0731742a XL |
23 | // There are issues currently linking libbacktrace into tests, and in |
24 | // general during libstd's own unit tests we're not testing this path. In | |
25 | // test mode immediately return here to optimize away any references to the | |
26 | // libbacktrace symbols | |
27 | if cfg!(test) { | |
dc9dc135 | 28 | return Ok(()); |
0731742a XL |
29 | } |
30 | ||
8bb4bdeb XL |
31 | // Use a lock to prevent mixed output in multithreading context. |
32 | // Some platforms also requires it, like `SymFromAddr` on Windows. | |
33 | unsafe { | |
e1599b0c XL |
34 | let _lock = lock(); |
35 | _print(w, format) | |
36 | } | |
37 | } | |
38 | ||
39 | unsafe fn _print(w: &mut dyn Write, format: PrintFmt) -> io::Result<()> { | |
40 | struct DisplayBacktrace { | |
41 | format: PrintFmt, | |
8bb4bdeb | 42 | } |
e1599b0c XL |
43 | impl fmt::Display for DisplayBacktrace { |
44 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { | |
dfeec247 | 45 | unsafe { _print_fmt(fmt, self.format) } |
e1599b0c XL |
46 | } |
47 | } | |
48 | write!(w, "{}", DisplayBacktrace { format }) | |
8bb4bdeb XL |
49 | } |
50 | ||
e1599b0c | 51 | unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::Result { |
60c5eb7d XL |
52 | // Always 'fail' to get the cwd when running under Miri - |
53 | // this allows Miri to display backtraces in isolation mode | |
dfeec247 | 54 | let cwd = if !cfg!(miri) { env::current_dir().ok() } else { None }; |
60c5eb7d | 55 | |
e1599b0c XL |
56 | let mut print_path = move |fmt: &mut fmt::Formatter<'_>, bows: BytesOrWideString<'_>| { |
57 | output_filename(fmt, bows, print_fmt, cwd.as_ref()) | |
58 | }; | |
ba9703b0 | 59 | writeln!(fmt, "stack backtrace:")?; |
e1599b0c XL |
60 | let mut bt_fmt = BacktraceFmt::new(fmt, print_fmt, &mut print_path); |
61 | bt_fmt.add_context()?; | |
62 | let mut idx = 0; | |
63 | let mut res = Ok(()); | |
3dfed10e XL |
64 | // Start immediately if we're not using a short backtrace. |
65 | let mut start = print_fmt != PrintFmt::Short; | |
e1599b0c XL |
66 | backtrace_rs::trace_unsynchronized(|frame| { |
67 | if print_fmt == PrintFmt::Short && idx > MAX_NB_FRAMES { | |
68 | return false; | |
69 | } | |
8bb4bdeb | 70 | |
e1599b0c XL |
71 | let mut hit = false; |
72 | let mut stop = false; | |
73 | backtrace_rs::resolve_frame_unsynchronized(frame, |symbol| { | |
74 | hit = true; | |
75 | if print_fmt == PrintFmt::Short { | |
76 | if let Some(sym) = symbol.name().and_then(|s| s.as_str()) { | |
94222f64 | 77 | if start && sym.contains("__rust_begin_short_backtrace") { |
e1599b0c XL |
78 | stop = true; |
79 | return; | |
80 | } | |
3dfed10e XL |
81 | if sym.contains("__rust_end_short_backtrace") { |
82 | start = true; | |
83 | return; | |
84 | } | |
e1599b0c | 85 | } |
7cac9316 | 86 | } |
e1599b0c | 87 | |
3dfed10e XL |
88 | if start { |
89 | res = bt_fmt.frame().symbol(frame, symbol); | |
90 | } | |
dc9dc135 | 91 | }); |
e1599b0c XL |
92 | if stop { |
93 | return false; | |
94 | } | |
c295e0f8 XL |
95 | if !hit && start { |
96 | res = bt_fmt.frame().print_raw(frame.ip(), None, None, None); | |
e1599b0c XL |
97 | } |
98 | ||
99 | idx += 1; | |
100 | res.is_ok() | |
101 | }); | |
102 | res?; | |
103 | bt_fmt.finish()?; | |
104 | if print_fmt == PrintFmt::Short { | |
dc9dc135 | 105 | writeln!( |
e1599b0c | 106 | fmt, |
dc9dc135 XL |
107 | "note: Some details are omitted, \ |
108 | run with `RUST_BACKTRACE=full` for a verbose backtrace." | |
109 | )?; | |
110 | } | |
111 | Ok(()) | |
7cac9316 XL |
112 | } |
113 | ||
e74abb32 XL |
114 | /// Fixed frame used to clean the backtrace with `RUST_BACKTRACE=1`. Note that |
115 | /// this is only inline(never) when backtraces in libstd are enabled, otherwise | |
116 | /// it's fine to optimize away. | |
117 | #[cfg_attr(feature = "backtrace", inline(never))] | |
7cac9316 | 118 | pub fn __rust_begin_short_backtrace<F, T>(f: F) -> T |
dc9dc135 XL |
119 | where |
120 | F: FnOnce() -> T, | |
7cac9316 | 121 | { |
3dfed10e XL |
122 | let result = f(); |
123 | ||
124 | // prevent this frame from being tail-call optimised away | |
125 | crate::hint::black_box(()); | |
126 | ||
127 | result | |
128 | } | |
129 | ||
130 | /// Fixed frame used to clean the backtrace with `RUST_BACKTRACE=1`. Note that | |
131 | /// this is only inline(never) when backtraces in libstd are enabled, otherwise | |
132 | /// it's fine to optimize away. | |
133 | #[cfg_attr(feature = "backtrace", inline(never))] | |
134 | pub fn __rust_end_short_backtrace<F, T>(f: F) -> T | |
135 | where | |
136 | F: FnOnce() -> T, | |
137 | { | |
138 | let result = f(); | |
139 | ||
140 | // prevent this frame from being tail-call optimised away | |
141 | crate::hint::black_box(()); | |
142 | ||
143 | result | |
8bb4bdeb XL |
144 | } |
145 | ||
e1599b0c XL |
146 | /// Prints the filename of the backtrace frame. |
147 | /// | |
148 | /// See also `output`. | |
149 | pub fn output_filename( | |
150 | fmt: &mut fmt::Formatter<'_>, | |
151 | bows: BytesOrWideString<'_>, | |
152 | print_fmt: PrintFmt, | |
153 | cwd: Option<&PathBuf>, | |
154 | ) -> fmt::Result { | |
155 | let file: Cow<'_, Path> = match bows { | |
156 | #[cfg(unix)] | |
157 | BytesOrWideString::Bytes(bytes) => { | |
158 | use crate::os::unix::prelude::*; | |
159 | Path::new(crate::ffi::OsStr::from_bytes(bytes)).into() | |
8bb4bdeb | 160 | } |
e1599b0c XL |
161 | #[cfg(not(unix))] |
162 | BytesOrWideString::Bytes(bytes) => { | |
163 | Path::new(crate::str::from_utf8(bytes).unwrap_or("<unknown>")).into() | |
dc9dc135 | 164 | } |
dc9dc135 | 165 | #[cfg(windows)] |
e1599b0c XL |
166 | BytesOrWideString::Wide(wide) => { |
167 | use crate::os::windows::prelude::*; | |
168 | Cow::Owned(crate::ffi::OsString::from_wide(wide).into()) | |
dc9dc135 | 169 | } |
e1599b0c | 170 | #[cfg(not(windows))] |
dfeec247 | 171 | BytesOrWideString::Wide(_wide) => Path::new("<unknown>").into(), |
e1599b0c XL |
172 | }; |
173 | if print_fmt == PrintFmt::Short && file.is_absolute() { | |
174 | if let Some(cwd) = cwd { | |
175 | if let Ok(stripped) = file.strip_prefix(&cwd) { | |
176 | if let Some(s) = stripped.to_str() { | |
177 | return write!(fmt, ".{}{}", path::MAIN_SEPARATOR, s); | |
dc9dc135 XL |
178 | } |
179 | } | |
180 | } | |
dc9dc135 | 181 | } |
e1599b0c | 182 | fmt::Display::fmt(&file.display(), fmt) |
e9174d1e | 183 | } |