PrettyStackTrace.cpp revision dddfd34e32ff081409e5a1c95b991a898d63dff2 
1//===- PrettyStackTrace.cpp - Pretty Crash Handling -----------------------===//
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 defines some helpful functions for dealing with the possibility of
11// Unix signals occuring while your program is running.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Support/PrettyStackTrace.h"
16#include "llvm/Support/raw_ostream.h"
17#include "llvm/System/Signals.h"
18#include "llvm/System/ThreadLocal.h"
19#include "llvm/ADT/SmallString.h"
20using namespace llvm;
21
22namespace llvm {
23  bool DisablePrettyStackTrace = false;
24}
25
26// FIXME: This should be thread local when llvm supports threads.
27static sys::ThreadLocal<const PrettyStackTraceEntry> PrettyStackTraceHead;
28
29static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
30  unsigned NextID = 0;
31  if (Entry->getNextEntry())
32    NextID = PrintStack(Entry->getNextEntry(), OS);
33  OS << NextID << ".\t";
34  Entry->print(OS);
35
36  return NextID+1;
37}
38
39/// PrintCurStackTrace - Print the current stack trace to the specified stream.
40static void PrintCurStackTrace(raw_ostream &OS) {
41  // Don't print an empty trace.
42  if (PrettyStackTraceHead.get() == 0) return;
43
44  // If there are pretty stack frames registered, walk and emit them.
45  OS << "Stack dump:\n";
46
47  PrintStack(PrettyStackTraceHead.get(), OS);
48  OS.flush();
49}
50
51// Integrate with crash reporter.
52#ifdef __APPLE__
53extern "C" const char *__crashreporter_info__;
54const char *__crashreporter_info__ = 0;
55#endif
56
57
58/// CrashHandler - This callback is run if a fatal signal is delivered to the
59/// process, it prints the pretty stack trace.
60static void CrashHandler(void *Cookie) {
61#ifndef __APPLE__
62  // On non-apple systems, just emit the crash stack trace to stderr.
63  PrintCurStackTrace(errs());
64#else
65  // Otherwise, emit to a smallvector of chars, send *that* to stderr, but also
66  // put it into __crashreporter_info__.
67  SmallString<2048> TmpStr;
68  {
69    raw_svector_ostream Stream(TmpStr);
70    PrintCurStackTrace(Stream);
71  }
72
73  if (!TmpStr.empty()) {
74    __crashreporter_info__ = strdup(std::string(TmpStr.str()).c_str());
75    errs() << TmpStr.str();
76  }
77
78#endif
79}
80
81static bool RegisterCrashPrinter() {
82  if (!DisablePrettyStackTrace)
83    sys::AddSignalHandler(CrashHandler, 0);
84  return false;
85}
86
87PrettyStackTraceEntry::PrettyStackTraceEntry() {
88  // The first time this is called, we register the crash printer.
89  static bool HandlerRegistered = RegisterCrashPrinter();
90  HandlerRegistered = HandlerRegistered;
91
92  // Link ourselves.
93  NextEntry = PrettyStackTraceHead.get();
94  PrettyStackTraceHead.set(this);
95}
96
97PrettyStackTraceEntry::~PrettyStackTraceEntry() {
98  assert(PrettyStackTraceHead.get() == this &&
99         "Pretty stack trace entry destruction is out of order");
100  PrettyStackTraceHead.set(getNextEntry());
101}
102
103void PrettyStackTraceString::print(raw_ostream &OS) const {
104  OS << Str << "\n";
105}
106
107void PrettyStackTraceProgram::print(raw_ostream &OS) const {
108  OS << "Program arguments: ";
109  // Print the argument list.
110  for (unsigned i = 0, e = ArgC; i != e; ++i)
111    OS << ArgV[i] << ' ';
112  OS << '\n';
113}
114
115