From 60a1d25a96dfa5990c04e7728ee0578bbc60ba16 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Thu, 26 Nov 2020 08:55:32 -0500
Subject: [PATCH] Fix extern function member references.

---
 src/V3LinkDot.cpp               |  5 +++--
 test_regress/t/t_class_extern.v | 10 ++++++----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/V3LinkDot.cpp b/src/V3LinkDot.cpp
index a0cb84763..45c949149 100644
--- a/src/V3LinkDot.cpp
+++ b/src/V3LinkDot.cpp
@@ -985,7 +985,7 @@ class LinkDotFindVisitor final : public AstNVisitor {
         // Remember the existing symbol table scope
         VL_RESTORER(m_classOrPackagep);
         VL_RESTORER(m_curSymp);
-        VSymEnt* const oldCurSymp = m_curSymp;
+        VSymEnt* upSymp = m_curSymp;
         {
             // Change to appropriate package if extern declaration (vs definition)
             if (nodep->classOrPackagep()) {
@@ -1000,6 +1000,7 @@ class LinkDotFindVisitor final : public AstNVisitor {
                         nodep->v3error("Extern declaration's scope is not a defined class");
                     } else {
                         m_curSymp = m_statep->getNodeSym(classp);
+                        upSymp = m_curSymp;
                         if (!nodep->isExternDef()) {
                             // Move it to proper spot under the target class
                             nodep->unlinkFrBack();
@@ -1017,7 +1018,7 @@ class LinkDotFindVisitor final : public AstNVisitor {
             // Create symbol table for the task's vars
             string name = string{nodep->isExternProto() ? "extern " : ""} + nodep->name();
             m_curSymp = m_statep->insertBlock(m_curSymp, name, nodep, m_classOrPackagep);
-            m_curSymp->fallbackp(oldCurSymp);
+            m_curSymp->fallbackp(upSymp);
             // Convert the func's range to the output variable
             // This should probably be done in the Parser instead, as then we could
             // just attach normal signal attributes to it.
diff --git a/test_regress/t/t_class_extern.v b/test_regress/t/t_class_extern.v
index ba96dc70e..94a71825f 100644
--- a/test_regress/t/t_class_extern.v
+++ b/test_regress/t/t_class_extern.v
@@ -5,6 +5,7 @@
 // SPDX-License-Identifier: CC0-1.0
 
 class Cls;
+   int value;
    extern function int ext_f_np;
    extern function int ext_f_p();
    extern function int ext_f_i(int in);
@@ -18,7 +19,7 @@ function int Cls::ext_f_np;
 endfunction
 
 function int Cls::ext_f_p();
-   return 2;
+   return value;
 endfunction
 
 function int Cls::ext_f_i(int in);
@@ -33,16 +34,17 @@ task Cls::ext_t_p();
 endtask
 task Cls::ext_t_i(int in);
    if (in != 2) $stop;
+   value = in;
 endtask
 
 module t (/*AUTOARG*/);
    initial begin
       Cls c = new;
-      if (c.ext_f_np() != 1) $stop;
-      if (c.ext_f_p() != 2) $stop;
-      if (c.ext_f_i(10) != 11) $stop;
       c.ext_t_i(2);
       c.ext_t_np();
       c.ext_t_p();
+      if (c.ext_f_np() != 1) $stop;
+      if (c.ext_f_p() != 2) $stop;
+      if (c.ext_f_i(10) != 11) $stop;
    end
 endmodule