systemc: If no sc_module_name was used, throw an error.

This is tested by the regression tests. Also make sure the handshake
which sets up instances of sc_module is cleaned up if we bail partway
through for some reason, for instance if an intermediate class throws
an exception as part of its constructor.

Change-Id: I89afe5f76832cc132aa2bb8f19916dea64546784
Reviewed-on: https://gem5-review.googlesource.com/12251
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/core/module.cc

@@ -32,6 +32,7 @@
 #include <cassert>
 
 #include "base/logging.hh"
+#include "systemc/ext/utils/sc_report_handler.hh"
 
 namespace sc_gem5
 {
@@ -52,7 +53,14 @@ Module::Module(const char *name) : _name(name), _sc_mod(nullptr), _obj(nullptr)
     _new_module = this;
 }
 
-Module::~Module() { allModules.remove(this); }
+Module::~Module()
+{
+    if (_new_module == this) {
+        // Aborted module construction?
+        _new_module = nullptr;
+    }
+    allModules.remove(this);
+}
 
 void
 Module::finish(Object *this_obj)
@@ -85,6 +93,17 @@ currentModule()
     return _modules.back();
 }
 
+Module *
+newModuleChecked()
+{
+    if (!_new_module) {
+        SC_REPORT_ERROR("(E533) module name stack is empty: "
+                "did you forget to add a sc_module_name parameter to "
+                "your module constructor?", nullptr);
+    }
+    return _new_module;
+}
+
 Module *
 newModule()
 {

src/systemc/core/module.hh

@@ -116,6 +116,7 @@ class Module
 };
 
 Module *currentModule();
+Module *newModuleChecked();
 Module *newModule();
 
 void callbackModule(Module *m);

src/systemc/core/sc_module.cc

@@ -168,7 +168,7 @@ sc_module::get_child_events() const
 }
 
 sc_module::sc_module() :
-    sc_object(sc_gem5::newModule()->name()),
+    sc_object(sc_gem5::newModuleChecked()->name()),
     _gem5_module(sc_gem5::currentModule())
 {}