[Darwin] Make a final check on PIC options.

Final check on PCI options; for Darwin these are not dependent on the PIE
ones, although PIE does require PIC to support it.  Specifically, for Darwin,
"fPIC fno-PIE" should result in the same as "-fno-PIE -fPIC".

2019-07-07  Iain Sandoe  <iain@sandoe.co.uk>

	* config/darwin.c (darwin_override_options): Make a final check on PIC
	options.

From-SVN: r273181

gcc/ChangeLog

 2019-07-07  Iain Sandoe  <iain@sandoe.co.uk>
 
+	* config/darwin.c (darwin_override_options): Make a final check on PIC
+	options.
+
+2019-07-07  Iain Sandoe  <iain@sandoe.co.uk>
+
 	* config/darwin.c (darwin_override_options): Don't jam symbol stubs
 	on for kernel code.
 

gcc/config/darwin.c

@@ -3241,6 +3241,8 @@ darwin_override_options (void)
       && write_symbols == DWARF2_DEBUG)
     flag_var_tracking_uninit = flag_var_tracking;
 
+  /* Final check on PCI options; for Darwin these are not dependent on the PIE
+     ones, although PIE does require PIC to support it.  */
   if (MACHO_DYNAMIC_NO_PIC_P)
     {
       if (flag_pic)
@@ -3249,9 +3251,11 @@ darwin_override_options (void)
 		 " %<-fpie%> or %<-fPIE%>");
       flag_pic = 0;
     }
-  else if (flag_pic == 1)
+  else if (flag_pic == 1
+	   || (flag_pic == 0 && !(flag_mkernel || flag_apple_kext)))
     {
-      /* Darwin's -fpic is -fPIC.  */
+      /* Darwin's -fpic is -fPIC.
+	 We only support "static" code in the kernel and kernel exts.  */
       flag_pic = 2;
     }