Implement dumpFunctionDeclParameters in NodeDumper

[aaron.ballman]

LGTM!

[steveire]

Abandoning this because it's not really the right approach as it appears in the interface between the generic traverser and the generic node dumper, which it really shouldn't.

include/clang/AST/TextNodeDumper.h

public:
   void dumpLocation(SourceLocation Loc);
   void dumpSourceRange(SourceRange R);
   void dumpBareType(QualType T, bool Desugar = true);
   void dumpType(QualType T);
   void dumpBareDeclRef(const Decl *D);
   void dumpName(const NamedDecl *ND);
   void dumpAccessSpecifier(AccessSpecifier AS);
   void dumpCXXTemporary(const CXXTemporary *Temporary);
+  void dumpFunctionDeclParameters(const FunctionDecl *D);
 
   void dumpDeclRef(const Decl *D, const char *Label = nullptr);
 
   void visitTextComment(const comments::TextComment *C,
                         const comments::FullComment *);
   void visitInlineCommandComment(const comments::InlineCommandComment *C,
                                  const comments::FullComment *);
   void visitHTMLStartTagComment(const comments::HTMLStartTagComment *C,

lib/AST/ASTDumper.cpp

public:
     // Utilities
     void dumpType(QualType T) { NodeDumper.dumpType(T); }
     void dumpTypeAsChild(QualType T);
     void dumpTypeAsChild(const Type *T);
     void dumpBareDeclRef(const Decl *Node) { NodeDumper.dumpBareDeclRef(Node); }
     void dumpDeclContext(const DeclContext *DC);
     void dumpLookups(const DeclContext *DC, bool DumpDecls);
     void dumpAttr(const Attr *A);
+    void dumpFunctionDeclParameters(const FunctionDecl *D) {
+      NodeDumper.dumpFunctionDeclParameters(D);
+      if (D->param_begin() || !D->getNumParams())
+        for (const ParmVarDecl *Parameter : D->parameters())
+          dumpDecl(Parameter);
+    }
 
     // C++ Utilities
     void dumpCXXCtorInitializer(const CXXCtorInitializer *Init);
     void dumpTemplateParameters(const TemplateParameterList *TPL);
     void dumpTemplateArgumentListInfo(const TemplateArgumentListInfo &TALI);
     void dumpTemplateArgumentLoc(const TemplateArgumentLoc &A,
                                  const Decl *From = nullptr,
                                  const char *label = nullptr);
case EST_Uninstantiated:
       break;
     }
   }
 
   if (const FunctionTemplateSpecializationInfo *FTSI =
           D->getTemplateSpecializationInfo())
     dumpTemplateArgumentList(*FTSI->TemplateArguments);
 
-  if (!D->param_begin() && D->getNumParams())
-    dumpChild([=] { OS << "<<NULL params x " << D->getNumParams() << ">>"; });
-  else
-    for (const ParmVarDecl *Parameter : D->parameters())
-      dumpDecl(Parameter);
+  dumpFunctionDeclParameters(D);
 
   if (const CXXConstructorDecl *C = dyn_cast<CXXConstructorDecl>(D))
     for (CXXConstructorDecl::init_const_iterator I = C->init_begin(),
                                                  E = C->init_end();
          I != E; ++I)
       dumpCXXCtorInitializer(*I);
 
   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {

lib/AST/TextNodeDumper.cpp

 }
 
 void TextNodeDumper::dumpCXXTemporary(const CXXTemporary *Temporary) {
   OS << "(CXXTemporary";
   dumpPointer(Temporary);
   OS << ")";
 }
 
+void TextNodeDumper::dumpFunctionDeclParameters(const FunctionDecl *D) {
+  if (!D->param_begin() && D->getNumParams())
+    TreeStructure.addChild(
+        [=] { OS << "<<NULL params x " << D->getNumParams() << ">>"; });
+}
+
 void TextNodeDumper::dumpDeclRef(const Decl *D, const char *Label) {
   if (!D)
     return;
 
   TreeStructure.addChild([=] {
     if (Label)
       OS << Label << ' ';
     dumpBareDeclRef(D);