1 //===- Signals.cpp - Generic Unix Signals Implementation -----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines some helpful functions for dealing with the possibility of
11 // Unix signals occuring while your program is running.
13 //===----------------------------------------------------------------------===//
16 #include "llvm/ADT/STLExtras.h"
20 # include <execinfo.h> // For backtrace().
28 #if HAVE_DLFCN_H && __GNUG__
34 /// InterruptFunction - The function to call if ctrl-c is pressed.
35 static void (*InterruptFunction)() = 0;
37 static std::vector<sys::Path> *FilesToRemove = 0;
38 static std::vector<std::pair<void(*)(void*), void*> > *CallBacksToRun = 0;
40 // IntSigs - Signals that may interrupt the program at any time.
41 static const int IntSigs[] = {
42 SIGHUP, SIGINT, SIGQUIT, SIGPIPE, SIGTERM, SIGUSR1, SIGUSR2
44 static const int *const IntSigsEnd =
45 IntSigs + sizeof(IntSigs) / sizeof(IntSigs[0]);
47 // KillSigs - Signals that are synchronous with the program that will cause it
49 static const int KillSigs[] = {
50 SIGILL, SIGTRAP, SIGABRT, SIGFPE, SIGBUS, SIGSEGV, SIGSYS, SIGXCPU, SIGXFSZ
55 static const int *const KillSigsEnd =
56 KillSigs + sizeof(KillSigs) / sizeof(KillSigs[0]);
58 static void UnregisterHandler(int Signal) {
59 signal(Signal, SIG_DFL);
63 // SignalHandler - The signal handler that runs.
64 static RETSIGTYPE SignalHandler(int Sig) {
65 // Restore the signal behavior to default, so that the program actually
66 // crashes when we return and the signal reissues. This also ensures that if
67 // we crash in our signal handler that the program will terminate immediately
68 // instead of recursing in the signal handler.
69 std::for_each(KillSigs, KillSigsEnd, UnregisterHandler);
71 // Unmask all potentially blocked kill signals.
74 sigprocmask(SIG_UNBLOCK, &SigMask, 0);
76 if (FilesToRemove != 0)
77 while (!FilesToRemove->empty()) {
78 FilesToRemove->back().eraseFromDisk(true);
79 FilesToRemove->pop_back();
82 if (std::find(IntSigs, IntSigsEnd, Sig) != IntSigsEnd) {
83 if (InterruptFunction) {
84 void (*IF)() = InterruptFunction;
85 InterruptFunction = 0;
86 IF(); // run the interrupt function.
89 exit(1); // If this is an interrupt signal, exit the program
92 // Otherwise if it is a fault (like SEGV) run any handler.
94 for (unsigned i = 0, e = CallBacksToRun->size(); i != e; ++i)
95 (*CallBacksToRun)[i].first((*CallBacksToRun)[i].second);
99 static void RegisterHandler(int Signal) {
100 signal(Signal, SignalHandler);
104 void llvm::sys::SetInterruptFunction(void (*IF)()) {
105 InterruptFunction = IF;
106 RegisterHandler(SIGINT);
109 // RemoveFileOnSignal - The public API
110 bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
111 std::string* ErrMsg) {
112 if (FilesToRemove == 0)
113 FilesToRemove = new std::vector<sys::Path>();
115 FilesToRemove->push_back(Filename);
117 std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
118 std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
122 /// AddSignalHandler - Add a function to be called when a signal is delivered
123 /// to the process. The handler can have a cookie passed to it to identify
124 /// what instance of the handler it is.
125 void llvm::sys::AddSignalHandler(void (*FnPtr)(void *), void *Cookie) {
126 if (CallBacksToRun == 0)
127 CallBacksToRun = new std::vector<std::pair<void(*)(void*), void*> >();
128 CallBacksToRun->push_back(std::make_pair(FnPtr, Cookie));
129 std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
133 // PrintStackTrace - In the case of a program crash or fault, print out a stack
134 // trace so that the user has an indication of why and where we died.
136 // On glibc systems we have the 'backtrace' function, which works nicely, but
137 // doesn't demangle symbols.
138 static void PrintStackTrace(void *) {
139 #ifdef HAVE_BACKTRACE
140 static void* StackTrace[256];
141 // Use backtrace() to output a backtrace on Linux systems with glibc.
142 int depth = backtrace(StackTrace,
143 static_cast<int>(array_lengthof(StackTrace)));
144 #if HAVE_DLFCN_H && __GNUG__
146 for (int i = 0; i < depth; ++i) {
148 dladdr(StackTrace[i], &dlinfo);
149 const char* name = strrchr(dlinfo.dli_fname, '/');
152 if (name == NULL) nwidth = strlen(dlinfo.dli_fname);
153 else nwidth = strlen(name) - 1;
155 if (nwidth > width) width = nwidth;
158 for (int i = 0; i < depth; ++i) {
160 dladdr(StackTrace[i], &dlinfo);
162 fprintf(stderr, "%-3d", i);
164 const char* name = strrchr(dlinfo.dli_fname, '/');
165 if (name == NULL) fprintf(stderr, " %-*s", width, dlinfo.dli_fname);
166 else fprintf(stderr, " %-*s", width, name+1);
168 fprintf(stderr, " %#0*lx",
169 (int)(sizeof(void*) * 2) + 2, (unsigned long)StackTrace[i]);
171 if (dlinfo.dli_sname != NULL) {
174 char* d = abi::__cxa_demangle(dlinfo.dli_sname, NULL, NULL, &res);
175 if (d == NULL) fputs(dlinfo.dli_sname, stderr);
176 else fputs(d, stderr);
179 fprintf(stderr, " + %tu",(char*)StackTrace[i]-(char*)dlinfo.dli_saddr);
184 backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
189 /// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
190 /// SIGSEGV) is delivered to the process, print a stack trace and then exit.
191 void llvm::sys::PrintStackTraceOnErrorSignal() {
192 AddSignalHandler(PrintStackTrace, 0);