[PATCH 3/3] [gdb/testsuite] Fix gdb.base/quit-live.exp for remote host

[Tom de Vries <tdevries@suse.de>]

I ran into trouble running test-case gdb.base/quit-live.exp using a remote
host configuration:
- host board local-remote-host
- target board remote-gdbserver-on-localhost.

The test-case uses kill to send a signal to gdb_spawn_id, but with remote host
the gdb_spawn_id points to an ssh session, not gdb.

Detect this more clearly by factoring out a proc kill_gdb (and
remote_kill_spawn_id and remote_kill_spawn_id_p), and erroring out for remote
host/target.

Then fix this by skipping the relevant tests using remote_kill_spawn_id_p.
---
 gdb/testsuite/gdb.base/quit-live.exp | 13 ++++++++++---
 gdb/testsuite/lib/gdb.exp            | 29 ++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/gdb/testsuite/gdb.base/quit-live.exp b/gdb/testsuite/gdb.base/quit-live.exp
index 8dae4fe2aca..8e1b4a428c7 100644
--- a/gdb/testsuite/gdb.base/quit-live.exp
+++ b/gdb/testsuite/gdb.base/quit-live.exp
@@ -43,8 +43,7 @@ if {[build_executable "failed to build" $testfile $srcfile debug]} {
 # Send signal SIG to GDB, and expect GDB to exit.
 
 proc test_quit_with_sig {sig} {
-    set gdb_pid [exp_pid -i [board_info host fileid]]
-    remote_exec host "kill -$sig ${gdb_pid}"
+    kill_gdb $sig
 
     set test "quit with SIG$sig"
     # If GDB mishandles the signal and doesn't exit, this should FAIL
@@ -176,7 +175,15 @@ foreach_with_prefix appear_how {"run" "attach" "attach-nofile"} {
     }
 
     foreach_with_prefix extra_inferior {0 1} {
-	foreach_with_prefix quit_how {"quit" "sigterm" "sighup"} {
+	set qhs {}
+	lappend qhs "quit"
+	foreach sig {"sigterm" "sighup"} {
+	    if {[remote_kill_spawn_id_p host $sig]} {
+		lappend qhs $sig
+	    }
+	}
+
+	foreach_with_prefix quit_how $qhs {
 	    quit_with_live_inferior $appear_how $extra_inferior $quit_how
 	}
     }
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 7bdc5dad0a7..b249425528d 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -12473,6 +12473,35 @@ proc unprintable_to_octal { input_string } {
 # Ignore args and don't do anything.  Can be used with proc with_override.
 proc nop {args} {}
 
+# Return 1 if SIG can be delivered to a spawn_id on board.
+proc remote_kill_spawn_id_p { board sig } {
+    if {$board == "host" || $board == "target"} {
+	if {[isremote $board]} {
+	    # For remote host/target, the spawn_id holds the pid of the ssh
+	    # session, so we'd end up sending signals to ssh instead.
+	    return 0
+	}
+    }
+
+    return 1
+}
+
+# Send SIG to PID on BOARD.
+proc remote_kill_spawn_id { board spawn_id sig } {
+    set pid [exp_pid -i $spawn_id]
+
+    if {![remote_kill_spawn_id_p $board $sig]} {
+	error "Can't send signal $sig to $pid on remote $board"
+    }
+
+    return [remote_exec $board "kill -$sig $pid"]
+}
+
+# Send SIG to GDB.
+proc kill_gdb { sig } {
+    return [remote_kill_spawn_id host $::gdb_spawn_id $sig]
+}
+
 require {tcl_version_at_least 8 6 2}
 
 # Always load compatibility stuff.
-- 
2.51.0