Fixed a build issue on an older Xcode.
git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@143679 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Host/common/Host.cpp b/source/Host/common/Host.cpp
index 280f197..451a575 100644
--- a/source/Host/common/Host.cpp
+++ b/source/Host/common/Host.cpp
@@ -438,7 +438,7 @@
case SIGILL: return "SIGILL"; // 4 illegal instruction (not reset when caught)
case SIGTRAP: return "SIGTRAP"; // 5 trace trap (not reset when caught)
case SIGABRT: return "SIGABRT"; // 6 abort()
-#if defined(_POSIX_C_SOURCE)
+#if (defined(_POSIX_C_SOURCE) && !defined(_DARWIN_C_SOURCE))
case SIGPOLL: return "SIGPOLL"; // 7 pollable event ([XSR] generated, not supported)
#else // !_POSIX_C_SOURCE
case SIGEMT: return "SIGEMT"; // 7 EMT instruction