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 static RETSIGTYPE SignalHandler(int Sig); // defined below.
36 /// InterruptFunction - The function to call if ctrl-c is pressed.
37 static void (*InterruptFunction)() = 0;
39 static std::vector<sys::Path> *FilesToRemove = 0;
40 static std::vector<std::pair<void(*)(void*), void*> > *CallBacksToRun = 0;
42 // IntSigs - Signals that may interrupt the program at any time.
43 static const int IntSigs[] = {
44 SIGHUP, SIGINT, SIGQUIT, SIGPIPE, SIGTERM, SIGUSR1, SIGUSR2
46 static const int *const IntSigsEnd =
47 IntSigs + sizeof(IntSigs) / sizeof(IntSigs[0]);
49 // KillSigs - Signals that are synchronous with the program that will cause it
51 static const int KillSigs[] = {
52 SIGILL, SIGTRAP, SIGABRT, SIGFPE, SIGBUS, SIGSEGV, SIGSYS, SIGXCPU, SIGXFSZ
57 static const int *const KillSigsEnd =
58 KillSigs + sizeof(KillSigs) / sizeof(KillSigs[0]);
61 static void RegisterHandler(int Signal) {
62 signal(Signal, SignalHandler);
65 static void RegisterHandlers() {
66 std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
67 std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
70 static void UnregisterHandler(int Signal) {
71 signal(Signal, SIG_DFL);
74 static void UnregisterHandlers() {
75 std::for_each(KillSigs, KillSigsEnd, UnregisterHandler);
76 std::for_each(IntSigs, IntSigsEnd, UnregisterHandler);
81 // SignalHandler - The signal handler that runs.
82 static RETSIGTYPE SignalHandler(int Sig) {
83 // Restore the signal behavior to default, so that the program actually
84 // crashes when we return and the signal reissues. This also ensures that if
85 // we crash in our signal handler that the program will terminate immediately
86 // instead of recursing in the signal handler.
89 // Unmask all potentially blocked kill signals.
92 sigprocmask(SIG_UNBLOCK, &SigMask, 0);
94 if (FilesToRemove != 0)
95 while (!FilesToRemove->empty()) {
96 FilesToRemove->back().eraseFromDisk(true);
97 FilesToRemove->pop_back();
100 if (std::find(IntSigs, IntSigsEnd, Sig) != IntSigsEnd) {
101 if (InterruptFunction) {
102 void (*IF)() = InterruptFunction;
103 InterruptFunction = 0;
104 IF(); // run the interrupt function.
107 exit(1); // If this is an interrupt signal, exit the program
110 // Otherwise if it is a fault (like SEGV) run any handler.
112 for (unsigned i = 0, e = CallBacksToRun->size(); i != e; ++i)
113 (*CallBacksToRun)[i].first((*CallBacksToRun)[i].second);
118 void llvm::sys::SetInterruptFunction(void (*IF)()) {
119 InterruptFunction = IF;
123 // RemoveFileOnSignal - The public API
124 bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
125 std::string* ErrMsg) {
126 if (FilesToRemove == 0)
127 FilesToRemove = new std::vector<sys::Path>();
129 FilesToRemove->push_back(Filename);
135 /// AddSignalHandler - Add a function to be called when a signal is delivered
136 /// to the process. The handler can have a cookie passed to it to identify
137 /// what instance of the handler it is.
138 void llvm::sys::AddSignalHandler(void (*FnPtr)(void *), void *Cookie) {
139 if (CallBacksToRun == 0)
140 CallBacksToRun = new std::vector<std::pair<void(*)(void*), void*> >();
141 CallBacksToRun->push_back(std::make_pair(FnPtr, Cookie));
146 // PrintStackTrace - In the case of a program crash or fault, print out a stack
147 // trace so that the user has an indication of why and where we died.
149 // On glibc systems we have the 'backtrace' function, which works nicely, but
150 // doesn't demangle symbols.
151 static void PrintStackTrace(void *) {
152 #ifdef HAVE_BACKTRACE
153 static void* StackTrace[256];
154 // Use backtrace() to output a backtrace on Linux systems with glibc.
155 int depth = backtrace(StackTrace,
156 static_cast<int>(array_lengthof(StackTrace)));
157 #if HAVE_DLFCN_H && __GNUG__
159 for (int i = 0; i < depth; ++i) {
161 dladdr(StackTrace[i], &dlinfo);
162 const char* name = strrchr(dlinfo.dli_fname, '/');
165 if (name == NULL) nwidth = strlen(dlinfo.dli_fname);
166 else nwidth = strlen(name) - 1;
168 if (nwidth > width) width = nwidth;
171 for (int i = 0; i < depth; ++i) {
173 dladdr(StackTrace[i], &dlinfo);
175 fprintf(stderr, "%-3d", i);
177 const char* name = strrchr(dlinfo.dli_fname, '/');
178 if (name == NULL) fprintf(stderr, " %-*s", width, dlinfo.dli_fname);
179 else fprintf(stderr, " %-*s", width, name+1);
181 fprintf(stderr, " %#0*lx",
182 (int)(sizeof(void*) * 2) + 2, (unsigned long)StackTrace[i]);
184 if (dlinfo.dli_sname != NULL) {
187 char* d = abi::__cxa_demangle(dlinfo.dli_sname, NULL, NULL, &res);
188 if (d == NULL) fputs(dlinfo.dli_sname, stderr);
189 else fputs(d, stderr);
192 fprintf(stderr, " + %tu",(char*)StackTrace[i]-(char*)dlinfo.dli_saddr);
197 backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
202 /// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
203 /// SIGSEGV) is delivered to the process, print a stack trace and then exit.
204 void llvm::sys::PrintStackTraceOnErrorSignal() {
205 AddSignalHandler(PrintStackTrace, 0);