From 820df28ad910fa12f84740c157e35a4c32cba69d Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sat, 1 Feb 2020 19:11:19 -0500
Subject: [PATCH] Internals: V3CUse state refactoring. No functional change
 intended.

---
 src/V3CUse.cpp    | 59 ++++++++++++++++++++++++++++++-----------------
 src/Verilator.cpp |  6 ++---
 2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/src/V3CUse.cpp b/src/V3CUse.cpp
index a79525efe..e19a77d24 100644
--- a/src/V3CUse.cpp
+++ b/src/V3CUse.cpp
@@ -19,8 +19,9 @@
 //*************************************************************************
 // V3Class's Transformations:
 //
-// Each class:
-//      Create string access functions
+// Each module:
+//   Each cell:
+//      Create CUse for cell forward declaration
 //
 //*************************************************************************
 
@@ -36,7 +37,7 @@
 
 //######################################################################
 
-class CUseVisitor : public AstNVisitor {
+class CUseState {
 private:
     // MEMBERS
     AstNodeModule* m_modInsertp;  // Current module to insert AstCUse under
@@ -45,12 +46,13 @@ private:
 
     // NODE STATE
     // Entire netlist:
-    //  AstClass::user()     -> bool.  True if class needs to_string dumper
+    //  AstClass::user1()     -> bool.  True if class needs to_string dumper
     AstUser1InUse m_inuser1;
 
     // METHODS
     VL_DEBUG_FUNC;  // Declare debug()
 
+public:
     AstCUse* newUse(AstNode* nodep, VUseType useType, const string& name) {
         UseString key(useType, name);
         if (m_didUse.find(key) == m_didUse.end()) {
@@ -61,39 +63,48 @@ private:
         }
         return m_didUse[key];
     }
+
+    // CONSTRUCTORS
+    explicit CUseState(AstNodeModule* nodep)
+        : m_modInsertp(nodep) {}
+    virtual ~CUseState() {}
+    VL_UNCOPYABLE(CUseState);
+};
+
+class CUseVisitor : public AstNVisitor {
+    // MEMBERS
+    CUseState m_state;  // Inserter state
+
+    // METHODS
+    VL_DEBUG_FUNC;  // Declare debug()
+
+    // Module use builders
     void makeUseCells(AstNodeModule* nodep) {
         for (AstNode* itemp = nodep->stmtsp(); itemp; itemp = itemp->nextp()) {
             if (AstCell* cellp = VN_CAST(itemp, Cell)) {
                 // Currently no include because we include __Syms which has them all
-                AstCUse* usep = newUse(nodep, VUseType::INT_FWD_CLASS, cellp->modp()->name());
+                AstCUse* usep
+                    = m_state.newUse(nodep, VUseType::INT_FWD_CLASS, cellp->modp()->name());
             }
         }
     }
 
+    // VISITORS
     virtual void visit(AstNodeModule* nodep) VL_OVERRIDE {
         if (v3Global.opt.trace()) {
-            AstCUse* usep = newUse(nodep, VUseType::INT_FWD_CLASS, v3Global.opt.traceClassBase());
+            AstCUse* usep
+                = m_state.newUse(nodep, VUseType::INT_FWD_CLASS, v3Global.opt.traceClassBase());
             usep->protect(false);
         }
         makeUseCells(nodep);
     }
-    virtual void visit(AstNodeMath* nodep) VL_OVERRIDE {}  // Short circuit
-    virtual void visit(AstNodeStmt* nodep) VL_OVERRIDE {}  // Short circuit
-    virtual void visit(AstNode* nodep) VL_OVERRIDE { iterateChildren(nodep); }
+    virtual void visit(AstNode* nodep) VL_OVERRIDE {}  // All in AstNodeModule
 
 public:
     // CONSTRUCTORS
-    explicit CUseVisitor(AstNetlist* nodep)
-        : m_modInsertp(NULL) {
-        for (AstNodeModule* nodep = v3Global.rootp()->modulesp(); nodep;
-             nodep = VN_CAST(nodep->nextp(), NodeModule)) {
-            // Insert under this module; someday we should e.g. make Ast
-            // for each output file and put under that
-            m_modInsertp = nodep;
-            m_didUse.clear();
-            iterate(nodep);
-            m_modInsertp = NULL;
-        }
+    explicit CUseVisitor(AstNodeModule* nodep)
+        : m_state(nodep) {
+        iterate(nodep);
     }
     virtual ~CUseVisitor() {}
     VL_UNCOPYABLE(CUseVisitor);
@@ -104,6 +115,12 @@ public:
 
 void V3CUse::cUseAll(AstNetlist* nodep) {
     UINFO(2, __FUNCTION__ << ": " << endl);
-    { CUseVisitor visitor(nodep); }  // Destruct before checking
+    // Call visitor separately for each module, so visitor state is cleared
+    for (AstNodeModule* nodep = v3Global.rootp()->modulesp(); nodep;
+         nodep = VN_CAST(nodep->nextp(), NodeModule)) {
+        // Insert under this module; someday we should e.g. make Ast
+        // for each output file and put under that
+        CUseVisitor visitor(nodep);
+    }
     V3Global::dumpCheckGlobalTree("cuse", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
diff --git a/src/Verilator.cpp b/src/Verilator.cpp
index 65b6a1218..0a89f2f0e 100644
--- a/src/Verilator.cpp
+++ b/src/Verilator.cpp
@@ -374,9 +374,6 @@ static void process() {
     //--MODULE OPTIMIZATIONS--------------
 
     if (!v3Global.opt.xmlOnly()) {
-        // Create AstCUse to determine what class forward declarations/#includes needed in C
-        V3CUse::cUseAll(v3Global.rootp());
-
         // Split deep blocks to appease MSVC++.  Must be before Localize.
         if (!v3Global.opt.lintOnly() && v3Global.opt.compLimitBlocks()) {
             V3DepthBlock::depthBlockAll(v3Global.rootp());
@@ -468,6 +465,9 @@ static void process() {
     if (!v3Global.opt.lintOnly()
         && !v3Global.opt.xmlOnly()
         && !v3Global.opt.dpiHdrOnly()) {
+        // Create AstCUse to determine what class forward declarations/#includes needed in C
+        V3CUse::cUseAll(v3Global.rootp());
+
         // emitcInlines is first, as it may set needHInlines which other emitters read
         V3EmitC::emitcInlines();
         V3EmitC::emitcSyms();