From d6e8b0263c43d2681ecbbbfc18cb8769d8333df9 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Tue, 3 Sep 2013 21:40:43 -0400
Subject: [PATCH] Fix crash on 32-bit Ubuntu, bug670.

---
 Changes             | 2 ++
 src/V3Ast.cpp       | 8 ++++++++
 src/V3Ast.h         | 2 ++
 src/V3LinkLevel.cpp | 1 +
 4 files changed, 13 insertions(+)

diff --git a/Changes b/Changes
index 84efbc4ec..9b61e995c 100644
--- a/Changes
+++ b/Changes
@@ -9,6 +9,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 ****  Fix --output-split-cfunc to count internal functions. [Chris Randall]
 
+****  Fix crash on 32-bit Ubuntu, bug670. [Mark Jackson Pulver]
+
 
 
 * Verilator 3.851 2013-08-15
diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index d0f1a3110..0f5f73946 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -965,6 +965,14 @@ void AstNode::dumpTreeFileGdb(const char* filenamep) {  // For GDB only
     v3Global.rootp()->dumpTreeFile(filename);
 }
 
+void AstNode::checkIter() const {
+    if (m_iterpp) {
+	dumpPtrs(cout);
+	// Perhaps something forgot to clear m_iterpp?
+	this->v3fatalSrc("Iteration link should be NULL");
+    }
+}
+
 void AstNode::dumpPtrs(ostream& os) const {
     os<<"This="<<typeName()<<" "<<(void*)this;
     os<<" back="<<(void*)backp();
diff --git a/src/V3Ast.h b/src/V3Ast.h
index 0413cc191..24e9d0a7f 100644
--- a/src/V3Ast.h
+++ b/src/V3Ast.h
@@ -1153,6 +1153,8 @@ public:
     bool	sameTree(AstNode* node2p);	// Does tree of this == node2p?
     void	deleteTree();	// Always deletes the next link
     void	checkTree();  // User Interface version
+    void	checkIter() const;
+    void	clearIter() { m_iterpp=NULL; }
     void	dumpPtrs(ostream& str=cout) const;
     void	dumpTree(ostream& str=cout, const string& indent="    ", int maxDepth=0);
     void	dumpTree(const string& indent, int maxDepth=0) { dumpTree(cout,indent,maxDepth); }
diff --git a/src/V3LinkLevel.cpp b/src/V3LinkLevel.cpp
index 5f3e739d3..235820f20 100644
--- a/src/V3LinkLevel.cpp
+++ b/src/V3LinkLevel.cpp
@@ -71,6 +71,7 @@ void V3LinkLevel::modSortByLevel() {
     UINFO(9,"modSortByLevel() sorted\n");  // Comment required for gcc4.6.3 / bug666
     for (ModVec::iterator it = vec.begin(); it != vec.end(); ++it) {
 	AstNodeModule* nodep = *it;
+	nodep->clearIter();  // Because we didn't iterate to find the node pointers, may have a stale m_iterp() needing cleanup
 	nodep->unlinkFrBack();
     }
     if (v3Global.rootp()->modulesp()) v3Global.rootp()->v3fatalSrc("Unlink didn't work");