Internal debug: avoid segflt with gdb "pnt"

src/.gdbinit

@@ -7,21 +7,21 @@
 # SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
 
 define pn
-  call $arg0->dumpGdb()
+  call AstNode::dumpGdb($arg0)
 end
 document pn
   Verilator: Print single AstNode NODEP
 end
 
 define pnt
-  call $arg0->dumpTreeGdb()
+  call AstNode::dumpTreeGdb($arg0)
 end
 document pnt
   Verilator: Print AstNode NODEP's tree
 end
 
 define dtf
-  call AstNode::dumpTreeFileGdb(0)
+  call AstNode::dumpTreeFileGdb($arg0, 0)
 end
 document dtf
   Verilator: Dump AstNode tree to file

src/V3Ast.cpp

@@ -1029,28 +1029,40 @@ void AstNode::checkTree() {
 }
 
 // cppcheck-suppress unusedFunction  // Debug only
-void AstNode::dumpGdb() {  // For GDB only  // LCOV_EXCL_LINE
+void AstNode::dumpGdb(const AstNode* nodep) {  // For GDB only  // LCOV_EXCL_LINE
-    dumpGdbHeader();  // LCOV_EXCL_LINE
+    if (!nodep) {
+        cout << "<nullptr>" << endl;
+        return;
+    }
+    nodep->dumpGdbHeader();
     cout << "  ";
-    dump(cout);
+    nodep->dump(cout);
-    cout << endl;  // LCOV_EXCL_LINE
+    cout << endl;
-}
+}  // LCOV_EXCL_STOP
 // cppcheck-suppress unusedFunction  // Debug only
-void AstNode::dumpGdbHeader() const {  // For GDB only  // LCOV_EXCL_LINE
+void AstNode::dumpGdbHeader() const {  // For GDB only  // LCOV_EXCL_START
-    dumpPtrs(cout);  // LCOV_EXCL_LINE
+    dumpPtrs(cout);
-    cout << "  Fileline = " << fileline() << endl;  // LCOV_EXCL_LINE
+    cout << "  Fileline = " << fileline() << endl;
-}
+}  // LCOV_EXCL_STOP
 // cppcheck-suppress unusedFunction  // Debug only
-void AstNode::dumpTreeGdb() {  // For GDB only  // LCOV_EXCL_LINE
+void AstNode::dumpTreeGdb(const AstNode* nodep) {  // For GDB only  // LCOV_EXCL_START
-    dumpGdbHeader();  // LCOV_EXCL_LINE
+    if (!nodep) {
-    dumpTree(cout);  // LCOV_EXCL_LINE
+        cout << "<nullptr>" << endl;
-}
+        return;
+    }
+    nodep->dumpGdbHeader();
+    nodep->dumpTree(cout);
+}  // LCOV_EXCL_STOP
 // cppcheck-suppress unusedFunction  // Debug only
-void AstNode::dumpTreeFileGdb(const char* filenamep) {  // For GDB only  // LCOV_EXCL_LINE
+void AstNode::dumpTreeFileGdb(const AstNode* nodep,  // LCOV_EXCL_START
-    string filename
+                              const char* filenamep) {  // For GDB only
-        = filenamep ? filenamep : v3Global.debugFilename("debug.tree", 98);  // LCOV_EXCL_LINE
+    if (!nodep) {
-    v3Global.rootp()->dumpTreeFile(filename);  // LCOV_EXCL_LINE
+        cout << "<nullptr>" << endl;
-}
+        return;
+    }
+    string filename = filenamep ? filenamep : v3Global.debugFilename("debug.tree", 98);
+    v3Global.rootp()->dumpTreeFile(filename);
+}  // LCOV_EXCL_STOP
 
 // cppcheck-suppress unusedFunction  // Debug only
 void AstNode::checkIter() const {

src/V3Ast.h

@@ -1761,7 +1761,7 @@ public:
     string warnOther() const { return fileline()->warnOther(); }
 
     virtual void dump(std::ostream& str = std::cout) const;
-    void dumpGdb();  // For GDB only
+    static void dumpGdb(const AstNode* nodep);  // For GDB only
     void dumpGdbHeader() const;
 
     // METHODS - Tree modifications
@@ -1811,12 +1811,12 @@ public:
     void dumpTree(const string& indent, int maxDepth = 0) const {
         dumpTree(cout, indent, maxDepth);
     }
-    void dumpTreeGdb();  // For GDB only
+    static void dumpTreeGdb(const AstNode* nodep);  // For GDB only
     void dumpTreeAndNext(std::ostream& os = std::cout, const string& indent = "    ",
                          int maxDepth = 0) const;
     void dumpTreeFile(const string& filename, bool append = false, bool doDump = true,
                       bool doCheck = true);
-    static void dumpTreeFileGdb(const char* filenamep = nullptr);
+    static void dumpTreeFileGdb(const AstNode* nodep, const char* filenamep = nullptr);
 
     // METHODS - queries
     // Changes control flow, disable some optimizations