1//===-- sanitizer_stacktrace_libcdep.cc -----------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is shared between AddressSanitizer and ThreadSanitizer
11// run-time libraries.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_common.h"
15#include "sanitizer_placement_new.h"
16#include "sanitizer_stacktrace.h"
17#include "sanitizer_stacktrace_printer.h"
18#include "sanitizer_symbolizer.h"
19
20namespace __sanitizer {
21
22void StackTrace::Print() const {
23  if (trace == nullptr || size == 0) {
24    Printf("    <empty stack>\n\n");
25    return;
26  }
27  InternalScopedString frame_desc(GetPageSizeCached() * 2);
28  InternalScopedString dedup_token(GetPageSizeCached());
29  int dedup_frames = common_flags()->dedup_token_length;
30  uptr frame_num = 0;
31  for (uptr i = 0; i < size && trace[i]; i++) {
32    // PCs in stack traces are actually the return addresses, that is,
33    // addresses of the next instructions after the call.
34    uptr pc = GetPreviousInstructionPc(trace[i]);
35    SymbolizedStack *frames = Symbolizer::GetOrInit()->SymbolizePC(pc);
36    CHECK(frames);
37    for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
38      frame_desc.clear();
39      RenderFrame(&frame_desc, common_flags()->stack_trace_format, frame_num++,
40                  cur->info, common_flags()->symbolize_vs_style,
41                  common_flags()->strip_path_prefix);
42      Printf("%s\n", frame_desc.data());
43      if (dedup_frames-- > 0) {
44        if (dedup_token.length())
45          dedup_token.append("--");
46        dedup_token.append(cur->info.function);
47      }
48    }
49    frames->ClearAll();
50  }
51  // Always print a trailing empty line after stack trace.
52  Printf("\n");
53  if (dedup_token.length())
54    Printf("DEDUP_TOKEN: %s\n", dedup_token.data());
55}
56
57void BufferedStackTrace::Unwind(u32 max_depth, uptr pc, uptr bp, void *context,
58                                uptr stack_top, uptr stack_bottom,
59                                bool request_fast_unwind) {
60  top_frame_bp = (max_depth > 0) ? bp : 0;
61  // Avoid doing any work for small max_depth.
62  if (max_depth == 0) {
63    size = 0;
64    return;
65  }
66  if (max_depth == 1) {
67    size = 1;
68    trace_buffer[0] = pc;
69    return;
70  }
71  if (!WillUseFastUnwind(request_fast_unwind)) {
72#if SANITIZER_CAN_SLOW_UNWIND
73    if (context)
74      SlowUnwindStackWithContext(pc, context, max_depth);
75    else
76      SlowUnwindStack(pc, max_depth);
77#else
78    UNREACHABLE("slow unwind requested but not available");
79#endif
80  } else {
81    FastUnwindStack(pc, bp, stack_top, stack_bottom, max_depth);
82  }
83}
84
85}  // namespace __sanitizer
86