Internals: Restore AstNode naming property. #2133.

The intention was that all subclasses of AstNode which are
intermediate must be abstract as well and called AstNode*. This was
violated recently by 28b9db1903. This
patch restores that property by:
- Renaming AstFile to AstNodeFile
- Introducing AstNodeSimpleText as the common base of AstText and
  AstTextBlock, rather than AstTextBlock deriving from AstText.

docs/CONTRIBUTORS

@@ -11,6 +11,7 @@ Chris Randall
 Driss Hafdi
 Eric Rippey
 Garrett Smith
+Geza Lore
 Gianfranco Costamagna
 Howard Su
 Iztok Jeras

docs/internals.adoc

@@ -70,7 +70,10 @@ The AST is represented at the top level by the class `AstNode`. This
 abstract class has derived classes for the individual components
 (e.g. `AstGenerate` for a generate block) or groups of components
 (e.g. `AstNodeFTask` for functions and tasks, which in turn has `AstFunc`
-and `AstTask` as derived classes).
+and `AstTask` as derived classes). An important property of the `AstNode`
+type hierarchy is that all non-final subclasses of `AstNode` (i.e.: those
+which themselves have subclasses) must be abstract as well, and be named
+with the prefix `AstNode*`. The `astgen` (see below) script relies on this.
 
 Each `AstNode` has pointers to up to four children, accessed by the `op1p`
 through `op4p` methods.  These methods are then abstracted in a specific
@@ -959,7 +962,8 @@ src/VParseGrammar.y, as this grammar supports the full SystemVerilog
 language and has a lot of back-and-forth with Verilator's grammar.  Copy
 the appropriate rules to src/verilog.y and modify the productions.
 
-. If a new Ast type is needed, add it to V3AstNodes.h.
+. If a new Ast type is needed, add it to V3AstNodes.h. Follow the convention
+described above about the AstNode type hierarchy.
 
 . Now you can run "test_regress/t/t_{new testcase}.pl --debug" and it'll
 probably fail but you'll see a test_regress/obj_dir/t_{newtestcase}/*.tree

src/V3AstNodes.h

@@ -6355,24 +6355,31 @@ public:
 //======================================================================
 // Text based nodes
 
-class AstText : public AstNodeText {
+class AstNodeSimpleText : public AstNodeText {
 private:
     bool m_tracking;  // When emit, it's ok to parse the string to do indentation
 public:
-    AstText(FileLine* fl, const string& textp, bool tracking=false)
+    AstNodeSimpleText(FileLine* fl, const string& textp, bool tracking=false)
         : AstNodeText(fl, textp), m_tracking(tracking) {}
-    ASTNODE_NODE_FUNCS(Text)
+    ASTNODE_BASE_FUNCS(NodeSimpleText)
     void tracking(bool flag) { m_tracking = flag; }
     bool tracking() const { return m_tracking; }
 };
 
-class AstTextBlock : public AstText {
+class AstText : public AstNodeSimpleText {
+public:
+    AstText(FileLine* fl, const string& textp, bool tracking=false)
+        : AstNodeSimpleText(fl, textp, tracking) {}
+    ASTNODE_NODE_FUNCS(Text)
+};
+
+class AstTextBlock : public AstNodeSimpleText {
 private:
     bool m_commas;  // Comma separate emitted children
 public:
     AstTextBlock(FileLine* fl, const string& textp="", bool tracking=false,
                  bool commas=false)
-        : AstText(fl, textp, tracking), m_commas(commas) {}
+        : AstNodeSimpleText(fl, textp, tracking), m_commas(commas) {}
     ASTNODE_NODE_FUNCS(TextBlock)
     void commas(bool flag) { m_commas = flag; }
     bool commas() const { return m_commas; }
@@ -6457,18 +6464,18 @@ public:
 //======================================================================
 // Emitted file nodes
 
-class AstFile : public AstNode {
+class AstNodeFile : public AstNode {
     // Emitted Otput file
     // Parents:  NETLIST
     // Children: AstTextBlock
 private:
     string      m_name;         ///< Filename
 public:
-    AstFile(FileLine* fl, const string& name)
+    AstNodeFile(FileLine* fl, const string& name)
         : AstNode(fl) {
         m_name = name;
     }
-    ASTNODE_BASE_FUNCS(File)
+    ASTNODE_BASE_FUNCS(NodeFile)
     virtual string name() const { return m_name; }
     virtual V3Hash sameHash() const { return V3Hash(); }
     virtual bool same(const AstNode* samep) const { return true; }
@@ -6479,12 +6486,12 @@ public:
 //======================================================================
 // Emit V nodes
 
-class AstVFile : public AstFile {
+class AstVFile : public AstNodeFile {
     // Verilog output file
     // Parents:  NETLIST
 public:
     AstVFile(FileLine* fl, const string& name)
-        : AstFile(fl, name) { }
+        : AstNodeFile(fl, name) { }
     ASTNODE_NODE_FUNCS(VFile)
     virtual void dump(std::ostream& str=std::cout) const;
 };
@@ -6492,7 +6499,7 @@ public:
 //======================================================================
 // Emit C nodes
 
-class AstCFile : public AstFile {
+class AstCFile : public AstNodeFile {
     // C++ output file
     // Parents:  NETLIST
 private:
@@ -6501,7 +6508,7 @@ private:
     bool        m_support:1;    ///< Support file (non systemc)
 public:
     AstCFile(FileLine* fl, const string& name)
-        : AstFile(fl, name) {
+        : AstNodeFile(fl, name) {
         m_slow = false;
         m_source = false;
         m_support = false;
@@ -6877,8 +6884,8 @@ public:
     AstNodeModule* topModulep() const {  // * = Top module in hierarchy (first one added, for now)
         return VN_CAST(op1p(), NodeModule); }
     void addModulep(AstNodeModule* modulep) { addOp1p(modulep); }
-    AstFile* filesp() const { return VN_CAST(op2p(), File);}  // op2 = List of files
+    AstNodeFile* filesp() const { return VN_CAST(op2p(), NodeFile); }  // op2 = List of files
-    void addFilesp(AstFile* filep) { addOp2p(filep); }
+    void addFilesp(AstNodeFile* filep) { addOp2p(filep); }
     AstNode* miscsp() const { return op3p(); }  // op3 = List of dtypes etc
     void addMiscsp(AstNode* nodep) { addOp3p(nodep); }
     AstTypeTable* typeTablep() { return m_typeTablep; }

src/V3EmitC.cpp

@@ -642,7 +642,7 @@ public:
         puts(cvtToStr(nodep->fileline()->lineno()));
         puts(", \"\");\n");
     }
-    virtual void visit(AstText* nodep) VL_OVERRIDE {
+    virtual void visit(AstNodeSimpleText* nodep) VL_OVERRIDE {
         if (nodep->tracking() || m_trackText) {
             puts(nodep->text());
         } else {
@@ -650,7 +650,7 @@ public:
         }
     }
     virtual void visit(AstTextBlock* nodep) VL_OVERRIDE {
-        visit(VN_CAST(nodep, Text));
+        visit(VN_CAST(nodep, NodeSimpleText));
         for (AstNode* childp = nodep->nodesp(); childp; childp = childp->nextp()) {
             iterate(childp);
             if (nodep->commas() && childp->nextp()) puts(", ");
@@ -3301,8 +3301,8 @@ void V3EmitC::emitcTrace() {
 
 void V3EmitC::emitcFiles() {
     UINFO(2,__FUNCTION__<<": "<<endl);
-    for (AstFile* filep = v3Global.rootp()->filesp(); filep;
+    for (AstNodeFile* filep = v3Global.rootp()->filesp(); filep;
-         filep = VN_CAST(filep->nextp(), File)) {
+         filep = VN_CAST(filep->nextp(), NodeFile)) {
         AstCFile* cfilep = VN_CAST(filep, CFile);
         if (cfilep && cfilep->tblockp()) {
             V3OutCFile of(cfilep->name());

src/V3EmitCMake.cpp

@@ -125,8 +125,8 @@ class CMakeEmitter {
 
         *of << "\n### Sources...\n";
         std::vector<string> classes_fast, classes_slow, support_fast, support_slow, global;
-        for (AstFile* nodep = v3Global.rootp()->filesp(); nodep;
+        for (AstNodeFile* nodep = v3Global.rootp()->filesp(); nodep;
-             nodep = VN_CAST(nodep->nextp(), File)) {
+             nodep = VN_CAST(nodep->nextp(), NodeFile)) {
             AstCFile* cfilep = VN_CAST(nodep, CFile);
             if (cfilep && cfilep->source()) {
                 if (cfilep->support()) {

src/V3EmitMk.cpp

@@ -101,8 +101,8 @@ public:
                 else if (support==2 && slow) {
                 }
                 else {
-                    for (AstFile* nodep = v3Global.rootp()->filesp();
+                    for (AstNodeFile* nodep = v3Global.rootp()->filesp();
-                         nodep; nodep = VN_CAST(nodep->nextp(), File)) {
+                         nodep; nodep = VN_CAST(nodep->nextp(), NodeFile)) {
                         AstCFile* cfilep = VN_CAST(nodep, CFile);
                         if (cfilep && cfilep->source()
                             && cfilep->slow()==(slow!=0)

src/V3EmitV.cpp

@@ -355,7 +355,7 @@ class EmitVBaseVisitor : public EmitCBaseVisitor {
     virtual void visit(AstFinish* nodep) VL_OVERRIDE {
         putfs(nodep, "$finish;\n");
     }
-    virtual void visit(AstText* nodep) VL_OVERRIDE {
+    virtual void visit(AstNodeSimpleText* nodep) VL_OVERRIDE {
         if (nodep->tracking() || m_trackText) {
             puts(nodep->text());
         } else {
@@ -363,7 +363,7 @@ class EmitVBaseVisitor : public EmitCBaseVisitor {
         }
     }
     virtual void visit(AstTextBlock* nodep) VL_OVERRIDE {
-        visit(VN_CAST(nodep, Text));
+        visit(VN_CAST(nodep, NodeSimpleText));
         for (AstNode* childp = nodep->nodesp(); childp; childp = childp->nextp()) {
             iterate(childp);
             if (nodep->commas() && childp->nextp()) puts(", ");
@@ -779,8 +779,8 @@ void V3EmitV::verilogPrefixedTree(AstNode* nodep, std::ostream& os,
 
 void V3EmitV::emitvFiles() {
     UINFO(2,__FUNCTION__<<": "<<endl);
-    for (AstFile* filep = v3Global.rootp()->filesp(); filep;
+    for (AstNodeFile* filep = v3Global.rootp()->filesp(); filep;
-         filep = VN_CAST(filep->nextp(), File)) {
+         filep = VN_CAST(filep->nextp(), NodeFile)) {
         AstVFile* vfilep = VN_CAST(filep, VFile);
         if (vfilep && vfilep->tblockp()) {
             V3OutVFile of(vfilep->name());

src/astgen

@@ -30,6 +30,15 @@ if (! GetOptions(
 
 read_types("$Opt_I[0]/V3Ast.h");
 read_types("$Opt_I[0]/V3AstNodes.h");
+foreach my $type (sort (keys %Classes)) {
+    # Chekc all leafs are not AstNode* and non-leave are AstNode*
+    my @children = children_of($type);
+    if ($type =~ /^Node/) {
+        @children  || die "Error: Final AstNode subclasses must not be named AstNode*: Ast$type"
+    } else {
+        !@children || die "Error: Non-final AstNode subclasses must be named AstNode*: Ast$type"
+    }
+}
 read_stages("$Opt_I[0]/Verilator.cpp");
 read_refs(glob("$Opt_I[0]/*.y"), glob("$Opt_I[0]/*.h"), glob("$Opt_I[0]/*.cpp"));
 if ($opt_report) {