systemc: Implement sc_export.

This change ignores the rule that sc_exports all have to be bound
exactly once and only by the end of elaboration. If it's bound more
than once, then the earlier binding will be overwritten, and if it's
not bound at all then it will act like a null pointer. To accomodate
doing those checks in the future, the sc_export_base constructor and
destructor are in the .cc file even though they do very little so that
they can be extended to track a list of all exports which exist.

Change-Id: Ie9a3416b8fa87bca55bc9f87f3238c4de3c2e729
Reviewed-on: https://gem5-review.googlesource.com/12079
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

2 files changed, 24 insertions, 39 deletions

diff --git a/src/systemc/core/sc_export.cc b/src/systemc/core/sc_export.cc
index 387b8a7fd..8340cf9c6 100644
--- a/src/systemc/core/sc_export.cc
+++ b/src/systemc/core/sc_export.cc
@@ -33,10 +33,7 @@
 namespace sc_core
 {
 
-void
-sc_export_base::warn_unimpl(const char *func) const
-{
-    warn("%s not implemented.\n", func);
-}
+sc_export_base::sc_export_base(const char *n) : sc_object(n) {}
+sc_export_base::~sc_export_base() {}
 
 } // namespace sc_core
diff --git a/src/systemc/ext/core/sc_export.hh b/src/systemc/ext/core/sc_export.hh
index 421e063c0..f3cf81619 100644
--- a/src/systemc/ext/core/sc_export.hh
+++ b/src/systemc/ext/core/sc_export.hh
@@ -30,6 +30,7 @@
 #ifndef __SYSTEMC_EXT_CORE_SC_EXPORT_HH__
 #define __SYSTEMC_EXT_CORE_SC_EXPORT_HH__
 
+#include "sc_module.hh" // for sc_gen_unique_name
 #include "sc_object.hh"
 
 namespace sc_core
@@ -40,7 +41,8 @@ class sc_interface;
 class sc_export_base : public sc_object
 {
   public:
-    void warn_unimpl(const char *func) const;
+    sc_export_base(const char *n);
+    ~sc_export_base();
 
     virtual sc_interface *get_iterface() = 0;
     virtual const sc_interface *get_interface() const = 0;
@@ -50,42 +52,26 @@ template <class IF>
 class sc_export : public sc_export_base
 {
   public:
-    sc_export() { warn_unimpl(__PRETTY_FUNCTION__); }
-    explicit sc_export(const char *) { warn_unimpl(__PRETTY_FUNCTION__); }
-    virtual ~sc_export() { warn_unimpl(__PRETTY_FUNCTION__); };
+    sc_export() :
+        sc_export_base(sc_gen_unique_name("export")), interface(nullptr)
+    {}
+    explicit sc_export(const char *n) :
+        sc_export_base(n), interface(nullptr)
+    {}
+    virtual ~sc_export() {}
 
     virtual const char *kind() const { return "sc_export"; }
 
-    void operator () (IF &) { warn_unimpl(__PRETTY_FUNCTION__); };
-    virtual void bind(IF &) { warn_unimpl(__PRETTY_FUNCTION__); };
-    operator IF & () { warn_unimpl(__PRETTY_FUNCTION__); };
-    operator const IF & () const { warn_unimpl(__PRETTY_FUNCTION__); };
-
-    IF *
-    operator -> ()
-    {
-        warn_unimpl(__PRETTY_FUNCTION__);
-        return nullptr;
-    }
-    const IF *
-    operator -> () const
-    {
-        warn_unimpl(__PRETTY_FUNCTION__);
-        return nullptr;
-    }
-
-    sc_interface *
-    get_iterface() override
-    {
-        warn_unimpl(__PRETTY_FUNCTION__);
-        return nullptr;
-    }
-    const sc_interface *
-    get_interface() const override
-    {
-        warn_unimpl(__PRETTY_FUNCTION__);
-        return nullptr;
-    }
+    void operator () (IF &i) { bind(i); }
+    virtual void bind(IF &i) { interface = &i; }
+    operator IF & () { return *interface; }
+    operator const IF & () const { return *interface; }
+
+    IF *operator -> () { return interface; }
+    const IF *operator -> () const { return interface; }
+
+    sc_interface *get_iterface() override { return interface; }
+    const sc_interface *get_interface() const override { return interface; }
 
   protected:
     virtual void before_end_of_elaboration() {}
@@ -94,6 +80,8 @@ class sc_export : public sc_export_base
     virtual void end_of_simulation() {}
 
   private:
+    IF *interface;
+
     // Disabled
     sc_export(const sc_export<IF> &);
     sc_export<IF> &operator = (const sc_export<IF> &);