Fix virtual methods (#4616)

src/V3AstNodeExpr.h

@@ -183,6 +183,7 @@ class AstNodeCCall VL_NOT_FINAL : public AstNodeExpr {
     // @astgen op2 := argsp : List[AstNodeExpr] // Note: op1 used by some sub-types only
     AstCFunc* m_funcp;
     string m_argTypes;
+    bool m_superReference = false;  // Called with super reference
 
 protected:
     AstNodeCCall(VNType t, FileLine* fl, AstCFunc* funcp, AstNodeExpr* argsp = nullptr)
@@ -213,6 +214,8 @@ public:
     string emitVerilog() final override { V3ERROR_NA_RETURN(""); }
     string emitC() final override { V3ERROR_NA_RETURN(""); }
     bool cleanOut() const final override { return true; }
+    bool superReference() const { return m_superReference; }
+    void superReference(bool flag) { m_superReference = flag; }
 };
 class AstNodeFTaskRef VL_NOT_FINAL : public AstNodeExpr {
     // A reference to a task (or function)
@@ -4198,12 +4201,15 @@ public:
 // === AstNodeFTaskRef ===
 class AstFuncRef final : public AstNodeFTaskRef {
     // A reference to a function
+    bool m_superReference = false;  // Called with super reference
 public:
     AstFuncRef(FileLine* fl, AstParseRef* namep, AstNodeExpr* pinsp)
         : ASTGEN_SUPER_FuncRef(fl, (AstNode*)namep, pinsp) {}
     AstFuncRef(FileLine* fl, const string& name, AstNodeExpr* pinsp)
         : ASTGEN_SUPER_FuncRef(fl, name, pinsp) {}
     ASTGEN_MEMBERS_AstFuncRef;
+    bool superReference() const { return m_superReference; }
+    void superReference(bool flag) { m_superReference = flag; }
 };
 class AstMethodCall final : public AstNodeFTaskRef {
     // A reference to a member task (or function)
@@ -4240,6 +4246,7 @@ public:
 };
 class AstTaskRef final : public AstNodeFTaskRef {
     // A reference to a task
+    bool m_superReference = false;  // Called with super reference
 public:
     AstTaskRef(FileLine* fl, AstParseRef* namep, AstNodeExpr* pinsp)
         : ASTGEN_SUPER_TaskRef(fl, (AstNode*)namep, pinsp) {
@@ -4250,6 +4257,8 @@ public:
         dtypeSetVoid();
     }
     ASTGEN_MEMBERS_AstTaskRef;
+    bool superReference() const { return m_superReference; }
+    void superReference(bool flag) { m_superReference = flag; }
 };
 
 // === AstNodePreSel ===

src/V3EmitCFunc.h

@@ -486,7 +486,7 @@ public:
             // Call static method via the containing class
             puts(prefixNameProtect(funcModp) + "::");
             puts(funcp->nameProtect());
-        } else if (VN_IS(funcModp, Class) && funcModp != m_modp) {
+        } else if (nodep->superReference()) {
             // Calling superclass method
             puts(prefixNameProtect(funcModp) + "::");
             puts(funcp->nameProtect());

src/V3LinkDot.cpp

@@ -2039,6 +2039,7 @@ private:
         DotPosition m_dotPos;  // Scope part of dotted resolution
         VSymEnt* m_dotSymp;  // SymEnt for dotted AstParse lookup
         const AstDot* m_dotp;  // Current dot
+        bool m_super;  // Starts with super reference
         bool m_unresolvedCell;  // Unresolved cell, needs help from V3Param
         bool m_unresolvedClass;  // Unresolved class reference, needs help from V3Param
         AstNode* m_unlinkedScopep;  // Unresolved scope, needs corresponding VarXRef
@@ -2050,6 +2051,7 @@ private:
             m_dotPos = DP_NONE;
             m_dotSymp = curSymp;
             m_dotp = nullptr;
+            m_super = false;
             m_dotErr = false;
             m_dotText = "";
             m_unresolvedCell = false;
@@ -2061,6 +2063,7 @@ private:
             std::ostringstream sstr;
             sstr << "ds=" << names[m_dotPos];
             sstr << "  dse" << cvtToHex(m_dotSymp);
+            sstr << "  sup=" << m_super;
             sstr << "  txt=" << m_dotText;
             sstr << "  unrCell=" << m_unresolvedCell;
             sstr << "  unrClass=" << m_unresolvedClass;
@@ -2462,6 +2465,7 @@ private:
                             const auto baseClassp = cextp->classp();
                             UASSERT_OBJ(baseClassp, nodep, "Bad superclass");
                             m_ds.m_dotSymp = m_statep->getNodeSym(baseClassp);
+                            m_ds.m_super = true;
                             UINFO(8, "     super. " << m_ds.ascii() << endl);
                         }
                     }
@@ -2538,7 +2542,6 @@ private:
         // Generally resolved during Primay, but might be at param time under AstUnlinkedRef
         UASSERT_OBJ(m_statep->forPrimary() || m_statep->forPrearray(), nodep,
                     "ParseRefs should no longer exist");
-        if (nodep->name() == "super") nodep->v3warn(E_UNSUPPORTED, "Unsupported: super");
         const DotStates lastStates = m_ds;
         const bool start = (m_ds.m_dotPos == DP_NONE);  // Save, as m_dotp will be changed
         if (start) {
@@ -3079,6 +3082,14 @@ private:
             iterateChildren(nodep);
         }
 
+        if (m_ds.m_super) {
+            if (AstFuncRef* const funcRefp = VN_CAST(nodep, FuncRef)) {
+                funcRefp->superReference(true);
+            } else if (AstTaskRef* const taskRefp = VN_CAST(nodep, TaskRef)) {
+                taskRefp->superReference(true);
+            }
+        }
+
         bool staticAccess = false;
         if (m_ds.m_unresolvedClass) {
             // Unable to link before V3Param

src/V3Randomize.cpp

@@ -310,6 +310,7 @@ private:
                 baseRandCallp->taskp(baseRandomizep);
                 baseRandCallp->dtypeFrom(baseRandomizep->dtypep());
                 baseRandCallp->classOrPackagep(nodep->extendsp()->classp());
+                baseRandCallp->superReference(true);
                 beginValp = baseRandCallp;
             }
         }

src/V3Task.cpp

@@ -638,6 +638,12 @@ private:
             beginp->addNext(ccallp->makeStmt());
         }
 
+        if (const AstFuncRef* const funcRefp = VN_CAST(refp, FuncRef)) {
+            ccallp->superReference(funcRefp->superReference());
+        } else if (const AstTaskRef* const taskRefp = VN_CAST(refp, TaskRef)) {
+            ccallp->superReference(taskRefp->superReference());
+        }
+
         // Convert complicated outputs to temp signals
         {
             const V3TaskConnects tconnects = V3Task::taskConnects(refp, refp->taskp()->stmtsp());

test_regress/t/t_class_virtual.v

@@ -22,12 +22,48 @@ class VB extends VBase;
    endfunction
 endclass
 
+virtual class uvm_phase;
+   virtual function int exec_func;
+      return 0;
+   endfunction
+endclass
+
+class uvm_topdown_phase extends uvm_phase;
+   function int get1;
+      return exec_func();
+   endfunction
+endclass
+
+class uvm_build_phase extends uvm_topdown_phase;
+   virtual function int exec_func;
+      return 1;
+   endfunction
+endclass
+
+virtual class Cls;
+   uvm_phase ph;
+endclass
+
+class ExtendsCls extends Cls;
+   function new;
+      uvm_build_phase bp = new;
+      ph = bp;
+   endfunction
+
+   function int get1;
+      return super.ph.exec_func();
+   endfunction
+endclass
+
 module t;
    initial begin
       VA va = new;
       VB vb = new;
       VBase b;
 
+      uvm_build_phase ph;
+      ExtendsCls ec;
+
       if (va.hello() != 2) $stop;
       if (vb.hello() != 3) $stop;
 
@@ -35,6 +71,13 @@ module t;
       if (b.hello() != 2) $stop;
       b = vb;
       if (b.hello() != 3) $stop;
+
+      ph = new;
+      if (ph.get1() != 1) $stop;
+
+      ec = new;
+      if (ec.get1() != 1) $stop;
+
       $write("*-* All Finished *-*\n");
       $finish;
    end