From f7c8b5931f6744f162562bbb37e73b3fa3ab1eba Mon Sep 17 00:00:00 2001
From: Alain Dargelas <alain.dargelas@gmail.com>
Date: Sat, 23 Dec 2023 03:12:43 -0800
Subject: [PATCH] Top level parameter no default value core dump fix

---
 src/DesignCompile/CompileExpression.cpp  | 4 +++-
 src/DesignCompile/NetlistElaboration.cpp | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/DesignCompile/CompileExpression.cpp b/src/DesignCompile/CompileExpression.cpp
index b777b4f431..6c3a76c55a 100644
--- a/src/DesignCompile/CompileExpression.cpp
+++ b/src/DesignCompile/CompileExpression.cpp
@@ -2574,7 +2574,9 @@ UHDM::any *CompileHelper::compileExpression(
                             param_ass->Lhs()->VpiName();
                         if (param_name == name) {
                           if ((reduce == Reduce::Yes) ||
-                              (param_ass->Rhs()->UhdmType() == uhdmconstant)) {
+                              (param_ass->Rhs() &&
+                               (param_ass->Rhs()->UhdmType() ==
+                                uhdmconstant))) {
                             if (substituteAssignedValue(param_ass->Rhs(),
                                                         compileDesign)) {
                               ElaboratorContext elaboratorContext(&s, false,
diff --git a/src/DesignCompile/NetlistElaboration.cpp b/src/DesignCompile/NetlistElaboration.cpp
index 77d2feaf19..14bcec3a06 100644
--- a/src/DesignCompile/NetlistElaboration.cpp
+++ b/src/DesignCompile/NetlistElaboration.cpp
@@ -514,7 +514,7 @@ bool NetlistElaboration::elab_parameters_(ModuleInstance* instance,
           inst_assign->VpiOverriden(true);
         }
         const any* rhs = inst_assign->Rhs();
-        if (rhs->UhdmType() == uhdmconstant) {
+        if (rhs && rhs->UhdmType() == uhdmconstant) {
           constant* c = (constant*)rhs;
           m_helper.adjustSize(tps, instance->getDefinition(), m_compileDesign,
                               instance, c);