1 files changed, 355 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/Unix/Signals.inc b/contrib/llvm/lib/Support/Unix/Signals.inc
new file mode 100644
index 0000000..5195116
--- /dev/null
+++ b/contrib/llvm/lib/Support/Unix/Signals.inc
@@ -0,0 +1,355 @@
+//===- Signals.cpp - Generic Unix Signals Implementation -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines some helpful functions for dealing with the possibility of
+// Unix signals occurring while your program is running.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Unix.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Mutex.h"
+#include <string>
+#include <vector>
+#include <algorithm>
+#if HAVE_EXECINFO_H
+# include <execinfo.h>         // For backtrace().
+#endif
+#if HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_DLFCN_H && __GNUG__
+#include <dlfcn.h>
+#include <cxxabi.h>
+#endif
+#if HAVE_MACH_MACH_H
+#include <mach/mach.h>
+#endif
+
+using namespace llvm;
+
+static RETSIGTYPE SignalHandler(int Sig);  // defined below.
+
+static SmartMutex<true> SignalsMutex;
+
+/// InterruptFunction - The function to call if ctrl-c is pressed.
+static void (*InterruptFunction)() = 0;
+
+static std::vector<std::string> FilesToRemove;
+static std::vector<std::pair<void(*)(void*), void*> > CallBacksToRun;
+
+// IntSigs - Signals that may interrupt the program at any time.
+static const int IntSigs[] = {
+  SIGHUP, SIGINT, SIGQUIT, SIGPIPE, SIGTERM, SIGUSR1, SIGUSR2
+};
+static const int *const IntSigsEnd =
+  IntSigs + sizeof(IntSigs) / sizeof(IntSigs[0]);
+
+// KillSigs - Signals that are synchronous with the program that will cause it
+// to die.
+static const int KillSigs[] = {
+  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]);
+
+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;
+}
+
+
+/// RemoveFilesToRemove - Process the FilesToRemove list. This function
+/// should be called with the SignalsMutex lock held.
+/// NB: This must be an async signal safe function. It cannot allocate or free
+/// memory, even in debug builds.
+static void RemoveFilesToRemove() {
+  // Note: avoid iterators in case of debug iterators that allocate or release
+  // memory.
+  for (unsigned i = 0, e = FilesToRemove.size(); i != e; ++i) {
+    // Note that we don't want to use any external code here, and we don't care
+    // about errors. We're going to try as hard as we can as often as we need
+    // to to make these files go away. If these aren't files, too bad.
+    //
+    // We do however rely on a std::string implementation for which repeated
+    // calls to 'c_str()' don't allocate memory. We pre-call 'c_str()' on all
+    // of these strings to try to ensure this is safe.
+    unlink(FilesToRemove[i].c_str());
+  }
+}
+
+// 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();
+  RemoveFilesToRemove();
+
+  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::RunInterruptHandlers() {
+  SignalsMutex.acquire();
+  RemoveFilesToRemove();
+  SignalsMutex.release();
+}
+
+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();
+  std::string *OldPtr = FilesToRemove.empty() ? 0 : &FilesToRemove[0];
+  FilesToRemove.push_back(Filename.str());
+
+  // We want to call 'c_str()' on every std::string in this vector so that if
+  // the underlying implementation requires a re-allocation, it happens here
+  // rather than inside of the signal handler. If we see the vector grow, we
+  // have to call it on every entry. If it remains in place, we only need to
+  // call it on the latest one.
+  if (OldPtr == &FilesToRemove[0])
+    FilesToRemove.back().c_str();
+  else
+    for (unsigned i = 0, e = FilesToRemove.size(); i != e; ++i)
+      FilesToRemove[i].c_str();
+
+  SignalsMutex.release();
+
+  RegisterHandlers();
+  return false;
+}
+
+// DontRemoveFileOnSignal - The public API
+void llvm::sys::DontRemoveFileOnSignal(const sys::Path &Filename) {
+  SignalsMutex.acquire();
+  std::vector<std::string>::reverse_iterator RI =
+    std::find(FilesToRemove.rbegin(), FilesToRemove.rend(), Filename.str());
+  std::vector<std::string>::iterator I = FilesToRemove.end();
+  if (RI != FilesToRemove.rend())
+    I = FilesToRemove.erase(RI.base()-1);
+
+  // We need to call c_str() on every element which would have been moved by
+  // the erase. These elements, in a C++98 implementation where c_str()
+  // requires a reallocation on the first call may have had the call to c_str()
+  // made on insertion become invalid by being copied down an element.
+  for (std::vector<std::string>::iterator E = FilesToRemove.end(); I != E; ++I)
+    I->c_str();
+
+  SignalsMutex.release();
+}
+
+/// 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(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)));
+#if HAVE_DLFCN_H && __GNUG__
+  int width = 0;
+  for (int i = 0; i < depth; ++i) {
+    Dl_info dlinfo;
+    dladdr(StackTrace[i], &dlinfo);
+    const char* name = strrchr(dlinfo.dli_fname, '/');
+
+    int nwidth;
+    if (name == NULL) nwidth = strlen(dlinfo.dli_fname);
+    else              nwidth = strlen(name) - 1;
+
+    if (nwidth > width) width = nwidth;
+  }
+
+  for (int i = 0; i < depth; ++i) {
+    Dl_info dlinfo;
+    dladdr(StackTrace[i], &dlinfo);
+
+    fprintf(stderr, "%-2d", i);
+
+    const char* name = strrchr(dlinfo.dli_fname, '/');
+    if (name == NULL) fprintf(stderr, " %-*s", width, dlinfo.dli_fname);
+    else              fprintf(stderr, " %-*s", width, name+1);
+
+    fprintf(stderr, " %#0*lx",
+            (int)(sizeof(void*) * 2) + 2, (unsigned long)StackTrace[i]);
+
+    if (dlinfo.dli_sname != NULL) {
+      int res;
+      fputc(' ', stderr);
+      char* d = abi::__cxa_demangle(dlinfo.dli_sname, NULL, NULL, &res);
+      if (d == NULL) fputs(dlinfo.dli_sname, stderr);
+      else           fputs(d, stderr);
+      free(d);
+
+      fprintf(stderr, " + %tu",(char*)StackTrace[i]-(char*)dlinfo.dli_saddr);
+    }
+    fputc('\n', stderr);
+  }
+#else
+  backtrace_symbols_fd(StackTrace, depth, STDERR_FILENO);
+#endif
+#endif
+}
+
+/// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
+/// SIGSEGV) is delivered to the process, print a stack trace and then exit.
+void llvm::sys::PrintStackTraceOnErrorSignal() {
+  AddSignalHandler(PrintStackTrace, 0);
+
+#if defined(__APPLE__)
+  // Environment variable to disable any kind of crash dialog.
+  if (getenv("LLVM_DISABLE_CRASH_REPORT")) {
+    mach_port_t self = mach_task_self();
+
+    exception_mask_t mask = EXC_MASK_CRASH;
+
+    kern_return_t ret = task_set_exception_ports(self, 
+                             mask,
+                             MACH_PORT_NULL,
+                             EXCEPTION_STATE_IDENTITY | MACH_EXCEPTION_CODES, 
+                             THREAD_STATE_NONE);
+    (void)ret;
+  }
+#endif
+}
+
+
+/***/
+
+// On Darwin, raise sends a signal to the main thread instead of the current
+// thread. This has the unfortunate effect that assert() and abort() will end up
+// bypassing our crash recovery attempts. We work around this for anything in
+// the same linkage unit by just defining our own versions of the assert handler
+// and abort.
+
+#ifdef __APPLE__
+
+#include <signal.h>
+#include <pthread.h>
+
+int raise(int sig) {
+  return pthread_kill(pthread_self(), sig);
+}
+
+void __assert_rtn(const char *func,
+                  const char *file,
+                  int line,
+                  const char *expr) {
+  if (func)
+    fprintf(stderr, "Assertion failed: (%s), function %s, file %s, line %d.\n",
+            expr, func, file, line);
+  else
+    fprintf(stderr, "Assertion failed: (%s), file %s, line %d.\n",
+            expr, file, line);
+  abort();
+}
+
+void abort() {
+  raise(SIGABRT);
+  usleep(1000);
+  __builtin_trap();
+}
+
+#endif