Add debugger detector for macOS

src/slic3r/GUI/GUI_UtilsMac.mm

@@ -1,4 +1,5 @@
-
+#include <unistd.h>
+#include <sys/sysctl.h>
 #import <wx/osx/cocoa/dataview.h>
 #import "GUI_Utils.hpp"
 
@@ -14,6 +15,40 @@ void dataview_remove_insets(wxDataViewCtrl* dv) {
     }
 }
 
+bool is_debugger_present()
+// Returns true if the current process is being debugged (either
+// running under the debugger or has a debugger attached post facto).
+// https://stackoverflow.com/a/2200786/3289421
+{
+    int                 junk;
+    int                 mib[4];
+    struct kinfo_proc   info;
+    size_t              size;
+
+    // Initialize the flags so that, if sysctl fails for some bizarre
+    // reason, we get a predictable result.
+
+    info.kp_proc.p_flag = 0;
+
+    // Initialize mib, which tells sysctl the info we want, in this case
+    // we're looking for information about a specific process ID.
+
+    mib[0] = CTL_KERN;
+    mib[1] = KERN_PROC;
+    mib[2] = KERN_PROC_PID;
+    mib[3] = getpid();
+
+    // Call sysctl.
+
+    size = sizeof(info);
+    junk = sysctl(mib, sizeof(mib) / sizeof(*mib), &info, &size, NULL, 0);
+    assert(junk == 0);
+
+    // We're being debugged if the P_TRACED flag is set.
+
+    return ( (info.kp_proc.p_flag & P_TRACED) != 0 );
+}
+
 }
 }