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 occurring while your program is running.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Support/PrettyStackTrace.h"
16#include "llvm/ADT/SmallString.h"
17#include "llvm/Config/config.h"     // Get autoconf configuration settings
18#include "llvm/Support/Signals.h"
19#include "llvm/Support/ThreadLocal.h"
20#include "llvm/Support/Watchdog.h"
21#include "llvm/Support/raw_ostream.h"
22
23#ifdef HAVE_CRASHREPORTERCLIENT_H
24#include <CrashReporterClient.h>
25#endif
26
27using namespace llvm;
28
29namespace llvm {
30  bool DisablePrettyStackTrace = false;
31}
32
33// FIXME: This should be thread local when llvm supports threads.
34static sys::ThreadLocal<const PrettyStackTraceEntry> PrettyStackTraceHead;
35
36static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
37  unsigned NextID = 0;
38  if (Entry->getNextEntry())
39    NextID = PrintStack(Entry->getNextEntry(), OS);
40  OS << NextID << ".\t";
41  {
42    sys::Watchdog W(5);
43    Entry->print(OS);
44  }
45
46  return NextID+1;
47}
48
49/// PrintCurStackTrace - Print the current stack trace to the specified stream.
50static void PrintCurStackTrace(raw_ostream &OS) {
51  // Don't print an empty trace.
52  if (PrettyStackTraceHead.get() == 0) return;
53
54  // If there are pretty stack frames registered, walk and emit them.
55  OS << "Stack dump:\n";
56
57  PrintStack(PrettyStackTraceHead.get(), OS);
58  OS.flush();
59}
60
61// Integrate with crash reporter libraries.
62#if defined (__APPLE__) && HAVE_CRASHREPORTERCLIENT_H
63//  If any clients of llvm try to link to libCrashReporterClient.a themselves,
64//  only one crash info struct will be used.
65extern "C" {
66CRASH_REPORTER_CLIENT_HIDDEN
67struct crashreporter_annotations_t gCRAnnotations
68        __attribute__((section("__DATA," CRASHREPORTER_ANNOTATIONS_SECTION)))
69        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0 };
70}
71#elif defined (__APPLE__) && HAVE_CRASHREPORTER_INFO
72static const char *__crashreporter_info__ = 0;
73asm(".desc ___crashreporter_info__, 0x10");
74#endif
75
76
77/// CrashHandler - This callback is run if a fatal signal is delivered to the
78/// process, it prints the pretty stack trace.
79static void CrashHandler(void *) {
80#ifndef __APPLE__
81  // On non-apple systems, just emit the crash stack trace to stderr.
82  PrintCurStackTrace(errs());
83#else
84  // Otherwise, emit to a smallvector of chars, send *that* to stderr, but also
85  // put it into __crashreporter_info__.
86  SmallString<2048> TmpStr;
87  {
88    raw_svector_ostream Stream(TmpStr);
89    PrintCurStackTrace(Stream);
90  }
91
92  if (!TmpStr.empty()) {
93#ifdef HAVE_CRASHREPORTERCLIENT_H
94    // Cast to void to avoid warning.
95    (void)CRSetCrashLogMessage(std::string(TmpStr.str()).c_str());
96#elif HAVE_CRASHREPORTER_INFO
97    __crashreporter_info__ = strdup(std::string(TmpStr.str()).c_str());
98#endif
99    errs() << TmpStr.str();
100  }
101
102#endif
103}
104
105static bool RegisterCrashPrinter() {
106  if (!DisablePrettyStackTrace)
107    sys::AddSignalHandler(CrashHandler, 0);
108  return false;
109}
110
111PrettyStackTraceEntry::PrettyStackTraceEntry() {
112  // The first time this is called, we register the crash printer.
113  static bool HandlerRegistered = RegisterCrashPrinter();
114  (void)HandlerRegistered;
115
116  // Link ourselves.
117  NextEntry = PrettyStackTraceHead.get();
118  PrettyStackTraceHead.set(this);
119}
120
121PrettyStackTraceEntry::~PrettyStackTraceEntry() {
122  assert(PrettyStackTraceHead.get() == this &&
123         "Pretty stack trace entry destruction is out of order");
124  PrettyStackTraceHead.set(getNextEntry());
125}
126
127void PrettyStackTraceString::print(raw_ostream &OS) const {
128  OS << Str << "\n";
129}
130
131void PrettyStackTraceProgram::print(raw_ostream &OS) const {
132  OS << "Program arguments: ";
133  // Print the argument list.
134  for (unsigned i = 0, e = ArgC; i != e; ++i)
135    OS << ArgV[i] << ' ';
136  OS << '\n';
137}
138