gdb: sim: automatically pass down sysroot

Since gdb sets up a nice sysroot path for us by default, automatically
pass it down to the sim target so it too gets a good default.  This does
not override anything the user explicitly specifies of course.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2011-06-01  Mike Frysinger  <vapier@gentoo.org>
+
+	* remote-sim.c (gdbsim_open): Add the strlen of " --sysroot=" and
+	gdb_sysroot to the "len" variable.  Append both to "arg_buf".
+
 2011-06-01  Yao Qi  <yao@codesourcery.com>
 
 	* objfiles.h (obj_section_addr): Update reference to objfile from

gdb/remote-sim.c

@@ -684,6 +684,7 @@ gdbsim_open (char *args, int from_tty)
   len = (7 + 1			/* gdbsim */
 	 + strlen (" -E little")
 	 + strlen (" --architecture=xxxxxxxxxx")
+	 + strlen (" --sysroot=") + strlen (gdb_sysroot) +
 	 + (args ? strlen (args) : 0)
 	 + 50) /* slack */ ;
   arg_buf = (char *) alloca (len);
@@ -708,6 +709,9 @@ gdbsim_open (char *args, int from_tty)
       strcat (arg_buf, " --architecture=");
       strcat (arg_buf, selected_architecture_name ());
     }
+  /* Pass along gdb's concept of the sysroot.  */
+  strcat (arg_buf, " --sysroot=");
+  strcat (arg_buf, gdb_sysroot);
   /* finally, any explicit args */
   if (args)
     {