PrettyStackTrace.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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-c/Core.h"
17#include "llvm/ADT/SmallString.h"
18#include "llvm/Config/config.h"     // Get autoconf configuration settings
19#include "llvm/Support/ManagedStatic.h"
20#include "llvm/Support/Signals.h"
21#include "llvm/Support/ThreadLocal.h"
22#include "llvm/Support/Watchdog.h"
23#include "llvm/Support/raw_ostream.h"
24
25#ifdef HAVE_CRASHREPORTERCLIENT_H
26#include <CrashReporterClient.h>
27#endif
28
29using namespace llvm;
30
31static ManagedStatic<sys::ThreadLocal<const PrettyStackTraceEntry> > PrettyStackTraceHead;
32
33static unsigned PrintStack(const PrettyStackTraceEntry *Entry, raw_ostream &OS){
34  unsigned NextID = 0;
35  if (Entry->getNextEntry())
36    NextID = PrintStack(Entry->getNextEntry(), OS);
37  OS << NextID << ".\t";
38  {
39    sys::Watchdog W(5);
40    Entry->print(OS);
41  }
42
43  return NextID+1;
44}
45
46/// PrintCurStackTrace - Print the current stack trace to the specified stream.
47static void PrintCurStackTrace(raw_ostream &OS) {
48  // Don't print an empty trace.
49  if (!PrettyStackTraceHead->get()) return;
50
51  // If there are pretty stack frames registered, walk and emit them.
52  OS << "Stack dump:\n";
53
54  PrintStack(PrettyStackTraceHead->get(), OS);
55  OS.flush();
56}
57
58// Integrate with crash reporter libraries.
59#if defined (__APPLE__) && HAVE_CRASHREPORTERCLIENT_H
60//  If any clients of llvm try to link to libCrashReporterClient.a themselves,
61//  only one crash info struct will be used.
62extern "C" {
63CRASH_REPORTER_CLIENT_HIDDEN
64struct crashreporter_annotations_t gCRAnnotations
65        __attribute__((section("__DATA," CRASHREPORTER_ANNOTATIONS_SECTION)))
66        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0 };
67}
68#elif defined (__APPLE__) && HAVE_CRASHREPORTER_INFO
69static const char *__crashreporter_info__ = 0;
70asm(".desc ___crashreporter_info__, 0x10");
71#endif
72
73
74/// CrashHandler - This callback is run if a fatal signal is delivered to the
75/// process, it prints the pretty stack trace.
76static void CrashHandler(void *) {
77#ifndef __APPLE__
78  // On non-apple systems, just emit the crash stack trace to stderr.
79  PrintCurStackTrace(errs());
80#else
81  // Otherwise, emit to a smallvector of chars, send *that* to stderr, but also
82  // put it into __crashreporter_info__.
83  SmallString<2048> TmpStr;
84  {
85    raw_svector_ostream Stream(TmpStr);
86    PrintCurStackTrace(Stream);
87  }
88
89  if (!TmpStr.empty()) {
90#ifdef HAVE_CRASHREPORTERCLIENT_H
91    // Cast to void to avoid warning.
92    (void)CRSetCrashLogMessage(std::string(TmpStr.str()).c_str());
93#elif HAVE_CRASHREPORTER_INFO
94    __crashreporter_info__ = strdup(std::string(TmpStr.str()).c_str());
95#endif
96    errs() << TmpStr.str();
97  }
98
99#endif
100}
101
102PrettyStackTraceEntry::PrettyStackTraceEntry() {
103  // Link ourselves.
104  NextEntry = PrettyStackTraceHead->get();
105  PrettyStackTraceHead->set(this);
106}
107
108PrettyStackTraceEntry::~PrettyStackTraceEntry() {
109  // Do nothing if PrettyStackTraceHead is uninitialized. This can only happen
110  // if a shutdown occurred after we created the PrettyStackTraceEntry. That
111  // does occur in the following idiom:
112  //
113  // PrettyStackTraceProgram X(...);
114  // llvm_shutdown_obj Y;
115  //
116  // Without this check, we may end up removing ourselves from the stack trace
117  // after PrettyStackTraceHead has already been destroyed.
118  if (!PrettyStackTraceHead.isConstructed())
119    return;
120
121  assert(PrettyStackTraceHead->get() == this &&
122         "Pretty stack trace entry destruction is out of order");
123  PrettyStackTraceHead->set(getNextEntry());
124}
125
126void PrettyStackTraceString::print(raw_ostream &OS) const {
127  OS << Str << "\n";
128}
129
130void PrettyStackTraceProgram::print(raw_ostream &OS) const {
131  OS << "Program arguments: ";
132  // Print the argument list.
133  for (unsigned i = 0, e = ArgC; i != e; ++i)
134    OS << ArgV[i] << ' ';
135  OS << '\n';
136}
137
138static bool RegisterCrashPrinter() {
139  sys::AddSignalHandler(CrashHandler, nullptr);
140  return false;
141}
142
143void llvm::EnablePrettyStackTrace() {
144  // The first time this is called, we register the crash printer.
145  static bool HandlerRegistered = RegisterCrashPrinter();
146  (void)HandlerRegistered;
147}
148
149void LLVMEnablePrettyStackTrace() {
150  EnablePrettyStackTrace();
151}
152