Support vpiModule, bug1469.

Add very basic support for vpiModule. Basically it allows to traverse
the module tree to find a variable etc. It does not support more than
vpi_iterate and vpi_scan for vpiModule along basic operations like
vpi_get_str on vpiModule.

The support is added non-intrusively to non-VPI verilator runs. It
essentially:

 - Tracks the creation of cell instances and keeps them alive until
   the emit phase. They are there converted to scopes if modules.

 - Emits empty (don't add anything during construction)
   VerilatedScopes for all inlined modules, only for those inlined
   modules that are on the hierarchical path to public variables.

 - Adds VerilatedHierarchy as abstraction to structure of the
   scopes. It is only created for VPI designs. It allows to traverse
   the hierarchy from the top (NULL).

Signed-off-by: Stefan Wallentowitz <[email protected]>
Signed-off-by: Wilson Snyder <[email protected]>

include/verilated_vpi.cpp

@@ -24,17 +24,20 @@
 /// Code available from: http://www.veripool.org/verilator
 ///
 //=========================================================================
-
+
+#define _VERILATED_VPI_CPP_
 
 #if VM_SC
 # include "verilated_sc.h"
 #endif
 #include "verilated.h"
 #include "verilated_vpi.h"
+#include "verilated_imp.h"
 
 #include <list>
 #include <map>
 #include <set>
+#include <sstream>
 
 //======================================================================
 // Internal constants
@@ -307,6 +310,45 @@ public:
     }
 };
 
+class VerilatedVpioModule : public VerilatedVpio {
+    const VerilatedScope* m_modulep;
+    const char* m_name;
+    const char* m_fullname;
+public:
+    explicit VerilatedVpioModule(const VerilatedScope* modulep)
+            : m_modulep(modulep) {
+        m_fullname = m_modulep->name();
+        if (strncmp(m_fullname, "TOP.", 4) == 0) m_fullname += 4;
+        m_name = m_modulep->identifier();
+    }
+    static inline VerilatedVpioModule* castp(vpiHandle h) {
+        return dynamic_cast<VerilatedVpioModule*>((VerilatedVpio*)h); }
+    virtual vluint32_t type() const { return vpiModule; }
+    const VerilatedScope* modulep() const { return m_modulep; }
+    virtual const char* name() const { return m_name; }
+    virtual const char* fullname() const { return m_fullname; }
+};
+
+class VerilatedVpioModuleIter : public VerilatedVpio {
+    const std::vector<const VerilatedScope*> *m_vec;
+    std::vector<const VerilatedScope*>::const_iterator m_it;
+public:
+    explicit VerilatedVpioModuleIter(const std::vector<const VerilatedScope*>& vec) : m_vec(&vec) {
+        m_it = m_vec->begin();
+    }
+    virtual ~VerilatedVpioModuleIter() {}
+    static inline VerilatedVpioModuleIter* castp(vpiHandle h) {
+        return dynamic_cast<VerilatedVpioModuleIter*>((VerilatedVpio*) h); }
+    virtual vluint32_t type() const { return vpiIterator; }
+    virtual vpiHandle dovpi_scan() {
+        if (m_it == m_vec->end()) {
+            return 0;
+        }
+        const VerilatedScope* modp = *m_it++;
+        return (new VerilatedVpioModule(modp))->castVpiHandle();
+    }
+};
+
 //======================================================================
 
 struct VerilatedVpiTimedCbsCmp {
@@ -999,7 +1041,7 @@ vpiHandle vpi_handle_by_name(PLI_BYTE8* namep, vpiHandle scope) {
     if (VL_UNLIKELY(!namep)) return NULL;
     VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: vpi_handle_by_name %s %p\n", namep, scope););
     VerilatedVpioScope* voScopep = VerilatedVpioScope::castp(scope);
-    const VerilatedVar* varp;
+    const VerilatedVar* varp = NULL;
     const VerilatedScope* scopep;
     std::string scopeAndName = namep;
     if (voScopep) {
@@ -1019,9 +1061,19 @@ vpiHandle vpi_handle_by_name(PLI_BYTE8* namep, vpiHandle scope) {
             baseNamep = dotp+1;
             scopename = std::string(namep, dotp-namep);
         }
-        scopep = Verilated::scopeFind(scopename.c_str());
-        if (!scopep) return NULL;
-        varp = scopep->varFind(baseNamep);
+
+        if (scopename.find(".") == std::string::npos) {
+            // This is a toplevel, hence search in our TOP ports first.
+            scopep = Verilated::scopeFind("TOP");
+            if (scopep) {
+                varp = scopep->varFind(baseNamep);
+            }
+        }
+        if (!varp) {
+            scopep = Verilated::scopeFind(scopename.c_str());
+            if (!scopep) return NULL;
+            varp = scopep->varFind(baseNamep);
+        }
     }
     if (!varp) return NULL;
     return (new VerilatedVpioVar(varp, scopep))->castVpiHandle();
@@ -1133,6 +1185,14 @@ vpiHandle vpi_iterate(PLI_INT32 type, vpiHandle object) {
         return ((new VerilatedVpioVarIter(vop->scopep()))
                 ->castVpiHandle());
     }
+    case vpiModule: {
+        VerilatedVpioModule* vop = VerilatedVpioModule::castp(object);
+        const VerilatedHierarchyMap* map = VerilatedImp::hierarchyMap();
+        const VerilatedScope *mod = vop ? vop->modulep() : NULL;
+        VerilatedHierarchyMap::const_iterator it = map->find((VerilatedScope*) mod);
+        if (it == map->end()) return 0;
+        return  ((new VerilatedVpioModuleIter(it->second))->castVpiHandle());
+    }
     default:
         _VL_VPI_WARNING(__FILE__, __LINE__, "%s: Unsupported type %s, nothing will be returned",
                         VL_FUNC, VerilatedVpiError::strFromVpiObjType(type));