#include "Unix.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/System/Mutex.h"
#include <vector>
#include <algorithm>
#if HAVE_EXECINFO_H
#endif
using namespace llvm;
-namespace {
+static RETSIGTYPE SignalHandler(int Sig); // defined below.
-static bool StackTraceRequested = false;
+static SmartMutex<true> SignalsMutex;
/// InterruptFunction - The function to call if ctrl-c is pressed.
static void (*InterruptFunction)() = 0;
-static std::vector<sys::Path> *FilesToRemove = 0 ;
-static std::vector<sys::Path> *DirectoriesToRemove = 0;
+static std::vector<sys::Path> FilesToRemove;
+static std::vector<std::pair<void(*)(void*), void*> > CallBacksToRun;
// IntSigs - Signals that may interrupt the program at any time.
static const int IntSigs[] = {
// KillSigs - Signals that are synchronous with the program that will cause it
// to die.
static const int KillSigs[] = {
- SIGILL, SIGTRAP, SIGABRT, SIGFPE, SIGBUS, SIGSEGV, SIGSYS, SIGXCPU, SIGXFSZ
+ SIGILL, SIGTRAP, SIGABRT, SIGFPE, SIGBUS, SIGSEGV
+#ifdef SIGSYS
+ , SIGSYS
+#endif
+#ifdef SIGXCPU
+ , SIGXCPU
+#endif
+#ifdef SIGXFSZ
+ , SIGXFSZ
+#endif
#ifdef SIGEMT
, SIGEMT
#endif
static const int *const KillSigsEnd =
KillSigs + sizeof(KillSigs) / sizeof(KillSigs[0]);
-#ifdef HAVE_BACKTRACE
-static void* StackTrace[256];
-#endif
+static unsigned NumRegisteredSignals = 0;
+static struct {
+ struct sigaction SA;
+ int SigNo;
+} RegisteredSignalInfo[(sizeof(IntSigs)+sizeof(KillSigs))/sizeof(KillSigs[0])];
+
+
+static void RegisterHandler(int Signal) {
+ assert(NumRegisteredSignals <
+ sizeof(RegisteredSignalInfo)/sizeof(RegisteredSignalInfo[0]) &&
+ "Out of space for signal handlers!");
+
+ struct sigaction NewHandler;
+
+ NewHandler.sa_handler = SignalHandler;
+ NewHandler.sa_flags = SA_NODEFER|SA_RESETHAND;
+ sigemptyset(&NewHandler.sa_mask);
+
+ // Install the new handler, save the old one in RegisteredSignalInfo.
+ sigaction(Signal, &NewHandler,
+ &RegisteredSignalInfo[NumRegisteredSignals].SA);
+ RegisteredSignalInfo[NumRegisteredSignals].SigNo = Signal;
+ ++NumRegisteredSignals;
+}
+
+static void RegisterHandlers() {
+ // If the handlers are already registered, we're done.
+ if (NumRegisteredSignals != 0) return;
+
+ std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
+ std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
+}
+
+static void UnregisterHandlers() {
+ // Restore all of the signal handlers to how they were before we showed up.
+ for (unsigned i = 0, e = NumRegisteredSignals; i != e; ++i)
+ sigaction(RegisteredSignalInfo[i].SigNo,
+ &RegisteredSignalInfo[i].SA, 0);
+ NumRegisteredSignals = 0;
+}
+
+
+
+// SignalHandler - The signal handler that runs.
+static RETSIGTYPE SignalHandler(int Sig) {
+ // Restore the signal behavior to default, so that the program actually
+ // crashes when we return and the signal reissues. This also ensures that if
+ // we crash in our signal handler that the program will terminate immediately
+ // instead of recursing in the signal handler.
+ UnregisterHandlers();
+
+ // Unmask all potentially blocked kill signals.
+ sigset_t SigMask;
+ sigfillset(&SigMask);
+ sigprocmask(SIG_UNBLOCK, &SigMask, 0);
+
+ SignalsMutex.acquire();
+ while (!FilesToRemove.empty()) {
+ FilesToRemove.back().eraseFromDisk(true);
+ FilesToRemove.pop_back();
+ }
+
+ if (std::find(IntSigs, IntSigsEnd, Sig) != IntSigsEnd) {
+ if (InterruptFunction) {
+ void (*IF)() = InterruptFunction;
+ SignalsMutex.release();
+ InterruptFunction = 0;
+ IF(); // run the interrupt function.
+ return;
+ }
+
+ SignalsMutex.release();
+ raise(Sig); // Execute the default handler.
+ return;
+ }
+
+ SignalsMutex.release();
+
+ // Otherwise if it is a fault (like SEGV) run any handler.
+ for (unsigned i = 0, e = CallBacksToRun.size(); i != e; ++i)
+ CallBacksToRun[i].first(CallBacksToRun[i].second);
+}
+
+
+
+void llvm::sys::SetInterruptFunction(void (*IF)()) {
+ SignalsMutex.acquire();
+ InterruptFunction = IF;
+ SignalsMutex.release();
+ RegisterHandlers();
+}
+
+// RemoveFileOnSignal - The public API
+bool llvm::sys::RemoveFileOnSignal(const sys::Path &Filename,
+ std::string* ErrMsg) {
+ SignalsMutex.acquire();
+ FilesToRemove.push_back(Filename);
+
+ SignalsMutex.release();
+
+ RegisterHandlers();
+ return false;
+}
+
+/// AddSignalHandler - Add a function to be called when a signal is delivered
+/// to the process. The handler can have a cookie passed to it to identify
+/// what instance of the handler it is.
+void llvm::sys::AddSignalHandler(void (*FnPtr)(void *), void *Cookie) {
+ CallBacksToRun.push_back(std::make_pair(FnPtr, Cookie));
+ RegisterHandlers();
+}
+
// PrintStackTrace - In the case of a program crash or fault, print out a stack
// trace so that the user has an indication of why and where we died.
//
// On glibc systems we have the 'backtrace' function, which works nicely, but
// doesn't demangle symbols.
-static void PrintStackTrace() {
+static void PrintStackTrace(void *) {
#ifdef HAVE_BACKTRACE
+ static void* StackTrace[256];
// Use backtrace() to output a backtrace on Linux systems with glibc.
int depth = backtrace(StackTrace,
static_cast<int>(array_lengthof(StackTrace)));
Dl_info dlinfo;
dladdr(StackTrace[i], &dlinfo);
- fprintf(stderr, "%-3d", i);
+ fprintf(stderr, "%-2d", i);
const char* name = strrchr(dlinfo.dli_fname, '/');
if (name == NULL) fprintf(stderr, " %-*s", width, dlinfo.dli_fname);
#endif
}
-// SignalHandler - The signal handler that runs...
-static RETSIGTYPE SignalHandler(int Sig) {
- if (FilesToRemove != 0)
- while (!FilesToRemove->empty()) {
- FilesToRemove->back().eraseFromDisk(true);
- FilesToRemove->pop_back();
- }
-
- if (DirectoriesToRemove != 0)
- while (!DirectoriesToRemove->empty()) {
- DirectoriesToRemove->back().eraseFromDisk(true);
- DirectoriesToRemove->pop_back();
- }
-
- if (std::find(IntSigs, IntSigsEnd, Sig) != IntSigsEnd) {
- if (InterruptFunction) {
- void (*IF)() = InterruptFunction;
- InterruptFunction = 0;
- IF(); // run the interrupt function.
- return;
- } else {
- exit(1); // If this is an interrupt signal, exit the program
- }
- }
-
- // Otherwise if it is a fault (like SEGV) output the stacktrace to
- // STDERR (if we can) and reissue the signal to die...
- if (StackTraceRequested)
- PrintStackTrace();
- signal(Sig, SIG_DFL);
-}
-
-// Just call signal
-static void RegisterHandler(int Signal) {
- signal(Signal, SignalHandler);
-}
-
-}
-
-
-void sys::SetInterruptFunction(void (*IF)()) {
- InterruptFunction = IF;
- RegisterHandler(SIGINT);
-}
-
-// RemoveFileOnSignal - The public API
-bool sys::RemoveFileOnSignal(const sys::Path &Filename, std::string* ErrMsg) {
- if (FilesToRemove == 0)
- FilesToRemove = new std::vector<sys::Path>;
-
- FilesToRemove->push_back(Filename);
-
- std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
- std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
- return false;
-}
-
-// RemoveDirectoryOnSignal - The public API
-bool sys::RemoveDirectoryOnSignal(const sys::Path& path, std::string* ErrMsg) {
- // Not a directory?
- struct stat buf;
- if (0 != stat(path.c_str(), &buf)) {
- MakeErrMsg(ErrMsg, path.toString() + ": can't get status of file");
- return true;
- }
-
- if (!S_ISDIR(buf.st_mode)) {
- if (ErrMsg)
- *ErrMsg = path.toString() + " is not a directory";
- return true;
- }
-
- if (DirectoriesToRemove == 0)
- DirectoriesToRemove = new std::vector<sys::Path>;
-
- DirectoriesToRemove->push_back(path);
-
- std::for_each(IntSigs, IntSigsEnd, RegisterHandler);
- std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
- return false;
-}
-
/// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
/// SIGSEGV) is delivered to the process, print a stack trace and then exit.
-void sys::PrintStackTraceOnErrorSignal() {
- StackTraceRequested = true;
- std::for_each(KillSigs, KillSigsEnd, RegisterHandler);
+void llvm::sys::PrintStackTraceOnErrorSignal() {
+ AddSignalHandler(PrintStackTrace, 0);
}
+