[RFA 3/5] Darwin: set startup-with-shell to off on Sierra and later.

[Xavier Roirand <roirand at adacore dot com>]

On Mac OS X Sierra and later, the shell is not allowed to be
debug so add a check and disable startup with shell in that
case.

gdb/ChangeLog:
    * darwin-nat.c (disable_startup_with_shell): New function.
    (_initialize_darwin_inferior): Add call.

Change-Id: Ia3cbeaa89b2b44a173b93ee22cce0d3884a16924
---
 gdb/darwin-nat.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index be80163..96f70cf 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -2362,6 +2362,26 @@ darwin_nat_target::supports_multi_process ()
   return true;
 }
 
+/* Read kernel version, and set startup-with-shell to false on Sierra or
+   later.  */
+
+void
+disable_startup_with_shell ()
+{
+  char str[16];
+    size_t sz = sizeof (str);
+    int ret;
+    unsigned long ver;
+
+    ret = sysctlbyname ("kern.osrelease", str, &sz, NULL, 0);
+    if (ret == 0 && sz < sizeof (str))
+      {
+       ver = strtoul (str, NULL, 10);
+       if (ver >= 16)
+         startup_with_shell = 0;
+      }
+}
+
 void
 _initialize_darwin_nat ()
 {
@@ -2396,4 +2416,6 @@ When this mode is on, all low level exceptions are reported before being\n\
 reported by the kernel."),
 			   &set_enable_mach_exceptions, NULL,
 			   &setlist, &showlist);
+
+  disable_startup_with_shell ();
 }
-- 
2.7.4