PrettyStackTrace.cpp revision 193323 
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/ADT/SmallString.h"
19using namespace llvm;
20
21// FIXME: This should be thread local when llvm supports threads.
22static const PrettyStackTraceEntry *PrettyStackTraceHead = 0;
23
24static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
25  unsigned NextID = 0;
26  if (Entry->getNextEntry())
27    NextID = PrintStack(Entry->getNextEntry(), OS);
28  OS << NextID << ".\t";
29  Entry->print(OS);
30
31  return NextID+1;
32}
33
34/// PrintCurStackTrace - Print the current stack trace to the specified stream.
35static void PrintCurStackTrace(raw_ostream &OS) {
36  // Don't print an empty trace.
37  if (PrettyStackTraceHead == 0) return;
38
39  // If there are pretty stack frames registered, walk and emit them.
40  OS << "Stack dump:\n";
41
42  PrintStack(PrettyStackTraceHead, OS);
43  OS.flush();
44}
45
46// Integrate with crash reporter.
47#ifdef __APPLE__
48extern "C" const char *__crashreporter_info__;
49const char *__crashreporter_info__ = 0;
50#endif
51
52
53/// CrashHandler - This callback is run if a fatal signal is delivered to the
54/// process, it prints the pretty stack trace.
55static void CrashHandler(void *Cookie) {
56#ifndef __APPLE__
57  // On non-apple systems, just emit the crash stack trace to stderr.
58  PrintCurStackTrace(errs());
59#else
60  // Otherwise, emit to a smallvector of chars, send *that* to stderr, but also
61  // put it into __crashreporter_info__.
62  SmallString<2048> TmpStr;
63  {
64    raw_svector_ostream Stream(TmpStr);
65    PrintCurStackTrace(Stream);
66  }
67
68  if (!TmpStr.empty()) {
69    __crashreporter_info__ = strdup(TmpStr.c_str());
70    errs() << __crashreporter_info__;
71  }
72
73#endif
74}
75
76static bool RegisterCrashPrinter() {
77  sys::AddSignalHandler(CrashHandler, 0);
78  return false;
79}
80
81PrettyStackTraceEntry::PrettyStackTraceEntry() {
82  // The first time this is called, we register the crash printer.
83  static bool HandlerRegistered = RegisterCrashPrinter();
84  HandlerRegistered = HandlerRegistered;
85
86  // Link ourselves.
87  NextEntry = PrettyStackTraceHead;
88  PrettyStackTraceHead = this;
89}
90
91PrettyStackTraceEntry::~PrettyStackTraceEntry() {
92  assert(PrettyStackTraceHead == this &&
93         "Pretty stack trace entry destruction is out of order");
94  PrettyStackTraceHead = getNextEntry();
95}
96
97void PrettyStackTraceString::print(raw_ostream &OS) const {
98  OS << Str << "\n";
99}
100
101void PrettyStackTraceProgram::print(raw_ostream &OS) const {
102  OS << "Program arguments: ";
103  // Print the argument list.
104  for (unsigned i = 0, e = ArgC; i != e; ++i)
105    OS << ArgV[i] << ' ';
106  OS << '\n';
107}
108
109