[NFC] Add ClangNode::dump()

Author: beccadax

include/swift/AST/ClangNode.h

@@ -13,6 +13,7 @@
 #ifndef SWIFT_CLANGNODE_H
 #define SWIFT_CLANGNODE_H
 
+#include "swift/Basic/Debug.h"
 #include "llvm/ADT/PointerUnion.h"
 
 namespace clang {
@@ -98,6 +99,8 @@ class ClangNode {
   clang::SourceLocation getLocation() const;
   clang::SourceRange getSourceRange() const;
 
+  SWIFT_DEBUG_DUMP;
+
   void *getOpaqueValue() const { return Ptr.getOpaqueValue(); }
   static inline ClangNode getFromOpaqueValue(void *VP) {
     ClangNode N;

lib/AST/Decl.cpp

@@ -116,6 +116,17 @@ const clang::Module *ClangNode::getClangModule() const {
   return nullptr;
 }
 
+void ClangNode::dump() const {
+  if (auto D = getAsDecl())
+    D->dump();
+  else if (auto M = getAsMacro())
+    M->dump();
+  else if (auto M = getAsModule())
+    M->dump();
+  else
+    llvm::errs() << "ClangNode contains nullptr\n";
+}
+
 // Only allow allocation of Decls using the allocator in ASTContext.
 void *Decl::operator new(size_t Bytes, const ASTContext &C,
                          unsigned Alignment) {