systemc: Add the nonstandard, undocumented halt function.

Used in the tests.

Change-Id: I9b4f10600a50e0def1b5d55428cb4ad49e401295
Reviewed-on: https://gem5-review.googlesource.com/11263
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/core/sc_module.cc

@@ -370,6 +370,13 @@ sc_module::wait(double, sc_time_unit, const sc_event_and_list &)
 }
 
 
+void
+sc_module::halt()
+{
+    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
+}
+
+
 void
 next_trigger()
 {
@@ -521,6 +528,12 @@ wait(double, sc_time_unit, const sc_event_and_list &)
     warn("%s not implemented.\n", __PRETTY_FUNCTION__);
 }
 
+void
+halt()
+{
+    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
+}
+
 const char *
 sc_gen_unique_name(const char *)
 {

src/systemc/ext/core/_using.hh

@@ -87,6 +87,7 @@ using sc_core::SC_BIND_PROXY_NIL;
 using sc_core::sc_module;
 using sc_core::next_trigger;
 using sc_core::wait;
+using sc_core::halt;
 using sc_core::sc_gen_unique_name;
 using sc_core::sc_behavior;
 using sc_core::sc_channel;

src/systemc/ext/core/sc_module.hh

@@ -186,6 +186,8 @@ class sc_module : public sc_object
     void wait(const sc_time &, const sc_event_and_list &);
     void wait(double, sc_time_unit, const sc_event_and_list &);
 
+    void halt();
+
     virtual void before_end_of_elaboration() {}
     virtual void end_of_elaboration() {}
     virtual void start_of_simulation() {}
@@ -236,6 +238,12 @@ void wait(double, sc_time_unit, const sc_event_and_list &);
 #define SC_THREAD(name) /* Implementation defined */
 #define SC_CTHREAD(name, clk) /* Implementation defined */
 
+// Nonstandard
+// Documentation for this is very scarce, but it looks like it's supposed to
+// stop the currently executing cthread, or if a cthread isn't running report
+// an error.
+void halt();
+
 const char *sc_gen_unique_name(const char *);
 
 typedef sc_module sc_behavior;