From 7163c8d04838d32fe3762b683c8511d1f24e13a8 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Fri, 18 Sep 2015 20:57:27 -0400
Subject: [PATCH] Fix internal error on dotted refs into generates, bug958.

---
 Changes                          |  2 ++
 src/V3Broken.cpp                 | 13 +++++++---
 src/V3Param.cpp                  |  3 +++
 test_regress/t/t_var_xref_gen.pl | 15 +++++++++++
 test_regress/t/t_var_xref_gen.v  | 43 ++++++++++++++++++++++++++++++++
 5 files changed, 73 insertions(+), 3 deletions(-)
 create mode 100755 test_regress/t/t_var_xref_gen.pl
 create mode 100644 test_regress/t/t_var_xref_gen.v

diff --git a/Changes b/Changes
index 179e4abeb..9cd7d5638 100644
--- a/Changes
+++ b/Changes
@@ -5,6 +5,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 * Verilator 3.877 devel
 
+****  Fix internal error on dotted refs into generates, bug958. [Jie Xu]
+
 ****  Fix mis-optimizing public DPI functions, bug963. [Wei Song]
 
 
diff --git a/src/V3Broken.cpp b/src/V3Broken.cpp
index 723e840b5..abc7fee87 100644
--- a/src/V3Broken.cpp
+++ b/src/V3Broken.cpp
@@ -186,11 +186,15 @@ private:
     // NODE STATE
     //  Nothing!	// This may be called deep inside other routines
     //			// so userp and friends may not be used
-    // VISITORS
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    // METHODS
+    void processAndIterate(AstNode* nodep) {
 	BrokenTable::addInTree(nodep, nodep->maybePointedTo());
 	nodep->iterateChildrenConst(*this);
     }
+    // VISITORS
+    virtual void visit(AstNode* nodep, AstNUser*) {
+	processAndIterate(nodep);
+    }
 public:
     // CONSTUCTORS
     BrokenMarkVisitor(AstNetlist* nodep) {
@@ -210,7 +214,7 @@ private:
 	    nodep->v3fatalSrc("Width != WidthMin");
 	}
     }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    void processAndIterate(AstNode* nodep) {
 	BrokenTable::setUnder(nodep,true);
 	if (const char* whyp=nodep->broken()) {
 	    nodep->v3fatalSrc("Broken link in node (or something without maybePointedTo): "<<whyp);
@@ -232,6 +236,9 @@ private:
 	nodep->iterateChildrenConst(*this);
 	BrokenTable::setUnder(nodep,false);
     }
+    virtual void visit(AstNode* nodep, AstNUser*) {
+	processAndIterate(nodep);
+    }
 public:
     // CONSTUCTORS
     BrokenCheckVisitor(AstNetlist* nodep) {
diff --git a/src/V3Param.cpp b/src/V3Param.cpp
index 5948d3bd4..ee06aea77 100644
--- a/src/V3Param.cpp
+++ b/src/V3Param.cpp
@@ -248,6 +248,9 @@ private:
     virtual void visit(AstVarRef* nodep, AstNUser*) {
 	if (nodep->varp()) nodep->varp()->iterate(*this);
     }
+    virtual void visit(AstVarXRef* nodep, AstNUser*) {
+	nodep->varp(NULL);  // Needs relink, as may remove pointed-to var
+    }
 
     // Generate Statements
     virtual void visit(AstGenerate* nodep, AstNUser*) {
diff --git a/test_regress/t/t_var_xref_gen.pl b/test_regress/t/t_var_xref_gen.pl
new file mode 100755
index 000000000..d0b997efb
--- /dev/null
+++ b/test_regress/t/t_var_xref_gen.pl
@@ -0,0 +1,15 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+compile (
+     verilator_flags2 => ["--debug-check"],
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_var_xref_gen.v b/test_regress/t/t_var_xref_gen.v
new file mode 100644
index 000000000..ac15a246f
--- /dev/null
+++ b/test_regress/t/t_var_xref_gen.v
@@ -0,0 +1,43 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This is to test the handling of VarXRef when the referenced VAR is
+// under a generate construction.
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2015 by Jie Xu and Roland Kruse.
+
+module t (/*AUTOARG*/
+	  // Inputs
+	  clk, addr, res
+	  );
+
+   input clk;
+
+   input [31:0] addr;
+   output [15:0] res;
+
+   memory i_mem(.addr(addr),.dout(res));
+
+   assign i_mem.cxrow_inst[0].cmem_xrow[0] = 16'h0;
+
+endmodule
+
+
+
+module memory(addr, dout);
+   parameter CM_XROWSIZE = 256;
+   parameter CM_NUMXROWS = 2;
+
+   input [31:0] addr;
+   output [15:0] dout;
+
+   generate
+      genvar 	 g_cx;
+      for (g_cx = 0; g_cx < CM_NUMXROWS; g_cx++)
+        begin: cxrow_inst
+           reg [15:0] cmem_xrow[0:CM_XROWSIZE - 1];
+        end
+   endgenerate
+
+   assign dout = cxrow_inst[0].cmem_xrow[addr];
+endmodule