trace: extend policy with log_output

Issue #3714

repos/base/include/base/trace/policy.h

@@ -32,6 +32,7 @@ namespace Genode {
 struct Genode::Trace::Policy_module
 {
 	size_t (*max_event_size)  ();
+	size_t (*log_output)      (char *, char const *, size_t);
 	size_t (*rpc_call)        (char *, char const *, Msgbuf_base const &);
 	size_t (*rpc_returned)    (char *, char const *, Msgbuf_base const &);
 	size_t (*rpc_dispatch)    (char *, char const *);

repos/os/include/trace/policy.h

@@ -22,6 +22,7 @@ namespace Genode {
 }
 
 extern "C" size_t max_event_size ();
+extern "C" size_t log_output     (char *dst, char const *log_message, size_t len);
 extern "C" size_t rpc_call       (char *dst, char const *rpc_name, Genode::Msgbuf_base const &);
 extern "C" size_t rpc_returned   (char *dst, char const *rpc_name, Genode::Msgbuf_base const &);
 extern "C" size_t rpc_dispatch   (char *dst, char const *rpc_name);

repos/os/src/lib/trace/policy/null/policy.cc

@@ -7,6 +7,11 @@ size_t max_event_size()
 	return 0;
 }
 
+size_t log_output(char *dst, char const *log_message, size_t len)
+{
+	return 0;
+}
+
 size_t rpc_call(char *dst, char const *rpc_name, Msgbuf_base const &)
 {
 	return 0;

repos/os/src/lib/trace/policy/rpc_name/policy.cc

@@ -10,6 +10,11 @@ size_t max_event_size()
 	return MAX_EVENT_SIZE;
 }
 
+size_t log_output(char *dst, char const *log_message, size_t len)
+{
+	return 0;
+}
+
 size_t rpc_call(char *dst, char const *rpc_name, Msgbuf_base const &)
 {
 	size_t len = strlen(rpc_name);

repos/os/src/lib/trace/policy/table.cc

@@ -19,6 +19,7 @@ extern "C" {
 	Genode::Trace::Policy_module policy_jump_table =
 	{
 		max_event_size,
+		log_output,
 		rpc_call,
 		rpc_returned,
 		rpc_dispatch,