Restart nSIM and GDB each time for GCC tests

There seem to be issues with scenarios where GDB uses `file` command to load
new application - for some reason debug symbols loaded seem to be off the
previous application, thus breakpoint at `exit()` is installed improperly.
To workaround that issues this patch modifued "gdb-comm.exp" board to quit
GDB and nSIM each time where possible.

Signed-off-by: Anton Kolesov <[email protected]>

Author: anthony-kolesov

dejagnu/baseboards/arc-nsim.exp

@@ -69,7 +69,7 @@ set_board_info ldscript ""
 # Call to nsim_open will set the netport (used by gdb-comm) as well as setting
 # up nSim specific data.
 set port [exec [file dirname $env(DEJAGNU)]/get-random-port.sh]
-nsim_open $port
+set_board_info nsim_port $port
 
 # GDB protocol to be used
 set_board_info gdb_protocol "remote"

dejagnu/nsim-extra.exp

@@ -111,41 +111,31 @@ proc arc-nsim_reboot { connhost args } {
     return 1
 }
 
-# By default between tests GDB will do `target exec`, then will reconnect to
-# target with `target remote`. As a result target will be left at the state of
-# end of previous test, likely in `exit()`. When GDB will reconnect with new
-# application, it will automatically try to unwind trace using old register
-# values, that will happen immediately after `target remote` before `load` that
-# will overwrite PC register. Consequently old-register values will be used and
-# in some unfortunate cases that might cause a failed assert in GDB. To avoid
-# possible issues this board should redefine gdb_comm_go_idle, so before
-# disconnecting from target GDB will reset crucial registers to 0.
-rename gdb_comm_go_idle arc_saved_gdb_comm_go_idle
-
-proc gdb_comm_go_idle {} {
-    global gdb_prompt
-
-    # Original gdb_comm_go_idle does the same, so it is save to not call it.
-    if {![board_info host exists fileid]} {
-	return -1
-    }
-
-    remote_send host "set \$pc=0\n"
-    remote_expect host 10 {
-	-re ".*$gdb_prompt $" {}
-    }
+# There are problems with GDB loading new application with `file` command, at
+# least when new file has same filename as the old one. That problem is
+# not-deterministic and I wasn't able to trace down the source, however I see
+# that this happened between 7.5 and 7.6. To avoid troubles - restart GDB
+# completely. Restarting nSIM is not really required if it's registers are
+# reset, however for a good measure it is better to restart it, at the price of
+# performance penalty for restarting, of course.
+rename gdb_comm_start arc_saved_gdb_comm_start
+
+proc gdb_comm_leave { } {
+    verbose "ARC specific gdb_comm_leave"
+    nsim_close
+    quit_gdb
+}
 
-    remote_send host "set \$blink=0\n"
-    remote_expect host 10 {
-	-re ".*$gdb_prompt $" {}
-    }
+proc gdb_comm_start { dest } {
+    global board board_info
 
-    remote_send host "set \$lp_count=0\n"
-    remote_expect host 10 {
-	-re ".*$gdb_prompt $" {}
+    if { ![info exists board] } {
+	set board $dest
     }
 
-    arc_saved_gdb_comm_go_idle
+    verbose "ARC specific gdb_comm_start"
+    nsim_open [target_info nsim_port]
+    arc_saved_gdb_comm_start $dest
 }
 
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