Disable all LLVM signal handlers.

third_party/LLVM/lib/Support/CrashRecoveryContext.cpp

@@ -268,6 +268,7 @@ void CrashRecoveryContext::Enable() {
 
   gCrashRecoveryEnabled = true;
 
+#ifdef ENABLE_SIGNAL_OVERRIDES
   // Setup the signal handler.
   struct sigaction Handler;
   Handler.sa_handler = CrashRecoverySignalHandler;
@@ -277,6 +278,7 @@ void CrashRecoveryContext::Enable() {
   for (unsigned i = 0; i != NumSignals; ++i) {
     sigaction(Signals[i], &Handler, &PrevActions[i]);
   }
+#endif
 }
 
 void CrashRecoveryContext::Disable() {
@@ -287,9 +289,11 @@ void CrashRecoveryContext::Disable() {
 
   gCrashRecoveryEnabled = false;
 
+#ifdef ENABLE_SIGNAL_OVERRIDES
   // Restore the previous signal handlers.
   for (unsigned i = 0; i != NumSignals; ++i)
     sigaction(Signals[i], &PrevActions[i], 0);
+#endif
 }
 
 #endif

third_party/LLVM/lib/Support/Unix/Program.inc

@@ -308,6 +308,7 @@ Program::Wait(const sys::Path &path,
     return -1;
   }
 
+#ifdef ENABLE_SIGNAL_OVERRIDES
   // Install a timeout handler.  The handler itself does nothing, but the simple
   // fact of having a handler at all causes the wait below to return with EINTR,
   // unlike if we used SIG_IGN.
@@ -318,12 +319,14 @@ Program::Wait(const sys::Path &path,
     sigaction(SIGALRM, &Act, &Old);
     alarm(secondsToWait);
   }
+#endif
 
   // Parent process: Wait for the child process to terminate.
   int status;
   uint64_t pid = reinterpret_cast<uint64_t>(Data_);
   pid_t child = static_cast<pid_t>(pid);
-  while (waitpid(pid, &status, 0) != child)
+  while (waitpid(pid, &status, 0) != child) {
+#ifdef ENABLE_SIGNAL_OVERRIDES
     if (secondsToWait && errno == EINTR) {
       // Kill the child.
       kill(child, SIGKILL);
@@ -339,16 +342,21 @@ Program::Wait(const sys::Path &path,
         MakeErrMsg(ErrMsg, "Child timed out", 0);
 
       return -2;   // Timeout detected
-    } else if (errno != EINTR) {
+    } else
+#endif
+    if (errno != EINTR) {
       MakeErrMsg(ErrMsg, "Error waiting for child process");
       return -1;
     }
+  }
 
+#ifdef ENABLE_SIGNAL_OVERRIDES
   // We exited normally without timeout, so turn off the timer.
   if (secondsToWait) {
     alarm(0);
     sigaction(SIGALRM, &Old, 0);
   }
+#endif
 
   // Return the proper exit status. Detect error conditions
   // so we can return -1 for them and set ErrMsg informatively.

third_party/LLVM/lib/Support/Unix/Signals.inc

@@ -57,7 +57,7 @@ static const int KillSigs[] = {
   , SIGSYS
 #endif
 #ifdef SIGXCPU
-  //, SIGXCPU
+  , SIGXCPU
 #endif
 #ifdef SIGXFSZ
   , SIGXFSZ
@@ -95,11 +95,13 @@ static void RegisterHandler(int Signal) {
 }
 
 static void RegisterHandlers() {
+#ifdef ENABLE_SIGNAL_OVERRIDES
   // 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);
+#endif
 }
 
 static void UnregisterHandlers() {