From 1ef11ac752d985df1d30ea7848afd09d5a623914 Mon Sep 17 00:00:00 2001
From: Vas Crabb <vas@vastheman.com>
Date: Wed, 10 Jan 2018 06:51:01 +1100
Subject: [PATCH] detect attached debugger on OSX before generating
 trace/breakpoint trap

---
 src/osd/modules/lib/osdlib_macosx.cpp | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/osd/modules/lib/osdlib_macosx.cpp b/src/osd/modules/lib/osdlib_macosx.cpp
index ba105007d52..1f6dec46c76 100644
--- a/src/osd/modules/lib/osdlib_macosx.cpp
+++ b/src/osd/modules/lib/osdlib_macosx.cpp
@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <sys/sysctl.h>
 #include <sys/types.h>
 #include <signal.h>
 #include <dlfcn.h>
@@ -92,13 +93,22 @@ void osd_free_executable(void *ptr, size_t size)
 
 void osd_break_into_debugger(const char *message)
 {
-	#ifdef MAME_DEBUG
-	printf("MAME exception: %s\n", message);
-	printf("Attempting to fall into debugger\n");
-	kill(getpid(), SIGTRAP);
-	#else
-	printf("Ignoring MAME exception: %s\n", message);
-	#endif
+	pid_t const mypid = getpid();
+	int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, int(mypid) };
+	struct kinfo_proc info;
+	info.kp_proc.p_flag = 0;
+	std::size_t infosz = sizeof(info);
+	sysctl(mib, ARRAY_LENGTH(mib), &info, &infosz, nullptr, 0);
+	if (info.kp_proc.p_flag & P_TRACED)
+	{
+		printf("MAME exception: %s\n", message);
+		printf("Attempting to fall into debugger\n");
+		kill(mypid, SIGTRAP);
+	}
+	else
+	{
+		printf("Ignoring MAME exception: %s\n", message);
+	}
 }