systemc: Hook up gem5_getPort to the gem5 getPort mechanism.

Change-Id: I771607c4436f4c1ca9d355d1da52924308cfc3b3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17229
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
diff --git a/src/systemc/core/SystemC.py b/src/systemc/core/SystemC.py
index 649d6d3..74b7cec 100644
--- a/src/systemc/core/SystemC.py
+++ b/src/systemc/core/SystemC.py
@@ -25,7 +25,7 @@
 #
 # Authors: Gabe Black
 
-from m5.SimObject import SimObject
+from m5.SimObject import SimObject, cxxMethod
 
 # This class represents the systemc kernel. There should be exactly one in the
 # simulation. It receives gem5 SimObject lifecycle callbacks (init, regStats,
@@ -62,6 +62,10 @@
     cxx_class = 'sc_core::sc_module'
     cxx_header = 'systemc/ext/core/sc_module.hh'
 
+    @cxxMethod(return_value_policy="reference", cxx_name="gem5_getPort")
+    def getPort(self, if_name, iex):
+        return None
+
 try:
     import _m5
 except:
diff --git a/src/systemc/core/sc_module.cc b/src/systemc/core/sc_module.cc
index fc98aa3..ba9c76a 100644
--- a/src/systemc/core/sc_module.cc
+++ b/src/systemc/core/sc_module.cc
@@ -31,6 +31,7 @@
 #include <string>
 #include <vector>
 
+#include "base/logging.hh"
 #include "systemc/core/event.hh"
 #include "systemc/core/kernel.hh"
 #include "systemc/core/module.hh"
@@ -114,6 +115,12 @@
 
 const sc_bind_proxy SC_BIND_PROXY_NIL;
 
+::Port &
+sc_module::gem5_getPort(const std::string &if_name, int idx)
+{
+    fatal("%s does not have any port named %s\n", name(), if_name);
+}
+
 sc_module::~sc_module() { delete _gem5_module; }
 
 void
diff --git a/src/systemc/ext/core/sc_module.hh b/src/systemc/ext/core/sc_module.hh
index 0c8bd9f..24a1aea 100644
--- a/src/systemc/ext/core/sc_module.hh
+++ b/src/systemc/ext/core/sc_module.hh
@@ -30,6 +30,7 @@
 #ifndef __SYSTEMC_CORE_EXT_SC_MODULE_HH__
 #define __SYSTEMC_CORE_EXT_SC_MODULE_HH__
 
+#include <string>
 #include <vector>
 
 #include "sc_object.hh"
@@ -58,6 +59,9 @@
 
 } // namespace sc_gem5
 
+// Gem5 prototype
+class Port;
+
 namespace sc_core
 {
 
@@ -95,6 +99,10 @@
 class sc_module : public sc_object
 {
   public:
+    // Gem5 specific extensions
+    virtual ::Port &gem5_getPort(const std::string &if_name, int idx=-1);
+
+  public:
     friend class ::sc_gem5::Kernel;
     friend class ::sc_gem5::Module;