systemc: Add facilities to add extra SystemC message handlers

Some clients (e.g. fastmodel integration) would like to catch specific
warning messages from SystemC. Adding facilities to chain extra report
handler (instead of just replacing the default one), that are run
after the default/set handler.

Change-Id: I8ef140fc897ae5eee0fc78c70caf081f625efbfd
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/67234
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/systemc/utils/report.cc

@@ -68,6 +68,31 @@ sc_core::sc_actions reportCatchActions = sc_core::SC_DISPLAY;
 sc_core::sc_report_handler_proc reportHandlerProc =
     &sc_core::sc_report_handler::default_handler;
 
+namespace
+{
+
+std::list<sc_core::sc_report_handler_proc> extraReportHandlerProcs;
+
+} // anonymous namespace
+
+const std::list<sc_core::sc_report_handler_proc> &
+getExtraSystemCReportHandlers()
+{
+    return extraReportHandlerProcs;
+}
+
+void
+addExtraSystemCReportHandler(sc_core::sc_report_handler_proc proc)
+{
+    extraReportHandlerProcs.push_back(proc);
+}
+
+void
+removeExtraSystemCReportHandler(sc_core::sc_report_handler_proc proc)
+{
+    extraReportHandlerProcs.remove(proc);
+}
+
 std::unique_ptr<sc_core::sc_report> globalReportCache;
 
 bool reportWarningsAsErrors = false;

src/systemc/utils/report.hh

@@ -29,6 +29,7 @@
 #define __SYSTEMC_UTILS_REPORT_HH__
 
 #include <initializer_list>
+#include <list>
 #include <map>
 #include <memory>
 #include <string>
@@ -103,6 +104,13 @@ extern sc_core::sc_actions reportCatchActions;
 
 extern sc_core::sc_report_handler_proc reportHandlerProc;
 
+// gem5-specific support for extra SystemC report handlers. Called _after_
+// the default/set handler.
+const std::list<sc_core::sc_report_handler_proc>
+    &getExtraSystemCReportHandlers();
+void addExtraSystemCReportHandler(sc_core::sc_report_handler_proc proc);
+void removeExtraSystemCReportHandler(sc_core::sc_report_handler_proc proc);
+
 extern std::unique_ptr<sc_core::sc_report> globalReportCache;
 
 extern bool reportWarningsAsErrors;

src/systemc/utils/sc_report_handler.cc

@@ -103,6 +103,10 @@ sc_report_handler::report(sc_severity severity, const char *msg_type,
     }
 
     sc_gem5::reportHandlerProc(report, actions);
+
+    for (auto& handler : sc_gem5::getExtraSystemCReportHandlers()) {
+        handler(report, actions);
+    }
 }
 
 void