src/prettyprinter.h

// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
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//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef V8_PRETTYPRINTER_H_
#define V8_PRETTYPRINTER_H_

#include "ast.h"

namespace v8 {
namespace internal {

#ifdef DEBUG

class PrettyPrinter: public AstVisitor {
 public:
  PrettyPrinter();
  virtual ~PrettyPrinter();

  // The following routines print a node into a string.
  // The result string is alive as long as the PrettyPrinter is alive.
  const char* Print(AstNode* node);
  const char* PrintExpression(FunctionLiteral* program);
  const char* PrintProgram(FunctionLiteral* program);

  void Print(const char* format, ...);

  // Print a node to stdout.
  static void PrintOut(AstNode* node);

  virtual void VisitSlot(Slot* node);
  // Individual nodes
#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
  AST_NODE_LIST(DECLARE_VISIT)
#undef DECLARE_VISIT

 private:
  char* output_;  // output string buffer
  int size_;  // output_ size
  int pos_;  // current printing position

 protected:
  void Init();
  const char* Output() const { return output_; }

  virtual void PrintStatements(ZoneList<Statement*>* statements);
  void PrintLabels(ZoneStringList* labels);
  virtual void PrintArguments(ZoneList<Expression*>* arguments);
  void PrintLiteral(Handle<Object> value, bool quote);
  void PrintParameters(Scope* scope);
  void PrintDeclarations(ZoneList<Declaration*>* declarations);
  void PrintFunctionLiteral(FunctionLiteral* function);
  void PrintCaseClause(CaseClause* clause);
};


// Prints the AST structure
class AstPrinter: public PrettyPrinter {
 public:
  AstPrinter();
  virtual ~AstPrinter();

  const char* PrintProgram(FunctionLiteral* program);

  // Individual nodes
  virtual void VisitSlot(Slot* node);
#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
  AST_NODE_LIST(DECLARE_VISIT)
#undef DECLARE_VISIT

 private:
  friend class IndentedScope;
  void PrintIndented(const char* txt);
  void PrintIndentedVisit(const char* s, AstNode* node);

  void PrintStatements(ZoneList<Statement*>* statements);
  void PrintDeclarations(ZoneList<Declaration*>* declarations);
  void PrintParameters(Scope* scope);
  void PrintArguments(ZoneList<Expression*>* arguments);
  void PrintCaseClause(CaseClause* clause);
  void PrintLiteralIndented(const char* info, Handle<Object> value, bool quote);
  void PrintLiteralWithModeIndented(const char* info,
                                    Variable* var,
                                    Handle<Object> value);
  void PrintLabelsIndented(const char* info, ZoneStringList* labels);

  void inc_indent() { indent_++; }
  void dec_indent() { indent_--; }

  int indent_;
};


// Forward declaration of helper classes.
class TagScope;
class AttributesScope;

// Build a C string containing a JSON representation of a function's
// AST. The representation is based on JsonML (www.jsonml.org).
class JsonAstBuilder: public PrettyPrinter {
 public:
  JsonAstBuilder()
      : indent_(0), top_tag_scope_(NULL), attributes_scope_(NULL) {
  }
  virtual ~JsonAstBuilder() {}

  // Controls the indentation of subsequent lines of a tag body after
  // the first line.
  static const int kTagIndentSize = 2;

  // Controls the indentation of subsequent lines of an attributes
  // blocks's body after the first line.
  static const int kAttributesIndentSize = 1;

  // Construct a JSON representation of a function literal.
  const char* BuildProgram(FunctionLiteral* program);

  // Print text indented by the current indentation level.
  void PrintIndented(const char* text) { Print("%*s%s", indent_, "", text); }

  // Change the indentation level.
  void increase_indent(int amount) { indent_ += amount; }
  void decrease_indent(int amount) { indent_ -= amount; }

  // The builder maintains a stack of opened AST node constructors.
  // Each node constructor corresponds to a JsonML tag.
  TagScope* tag() { return top_tag_scope_; }
  void set_tag(TagScope* scope) { top_tag_scope_ = scope; }

  // The builder maintains a pointer to the currently opened attributes
  // of current AST node or NULL if the attributes are not opened.
  AttributesScope* attributes() { return attributes_scope_; }
  void set_attributes(AttributesScope* scope) { attributes_scope_ = scope; }

  // Add an attribute to the currently opened attributes.
  void AddAttribute(const char* name, Handle<String> value);
  void AddAttribute(const char* name, const char* value);
  void AddAttribute(const char* name, int value);
  void AddAttribute(const char* name, bool value);

  // AST node visit functions.
  virtual void VisitSlot(Slot* node);
#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
  AST_NODE_LIST(DECLARE_VISIT)
#undef DECLARE_VISIT

 private:
  int indent_;
  TagScope* top_tag_scope_;
  AttributesScope* attributes_scope_;

  // Utility function used by AddAttribute implementations.
  void AddAttributePrefix(const char* name);
};


// The JSON AST builder keeps a stack of open element tags (AST node
// constructors from the current iteration point to the root of the
// AST).  TagScope is a helper class to manage the opening and closing
// of tags, the indentation of their bodies, and comma separating their
// contents.
class TagScope BASE_EMBEDDED {
 public:
  TagScope(JsonAstBuilder* builder, const char* name);
  ~TagScope();

  void use() { has_body_ = true; }

 private:
  JsonAstBuilder* builder_;
  TagScope* next_;
  bool has_body_;
};


// AttributesScope is a helper class to manage the opening and closing
// of attribute blocks, the indentation of their bodies, and comma
// separating their contents. JsonAstBuilder::AddAttribute adds an
// attribute to the currently open AttributesScope. They cannot be
// nested so the builder keeps an optional single scope rather than a
// stack.
class AttributesScope BASE_EMBEDDED {
 public:
  explicit AttributesScope(JsonAstBuilder* builder);
  ~AttributesScope();

  bool is_used() { return attribute_count_ > 0; }
  void use() { ++attribute_count_; }

 private:
  JsonAstBuilder* builder_;
  int attribute_count_;
};

#endif  // DEBUG

} }  // namespace v8::internal

#endif  // V8_PRETTYPRINTER_H_