dev/core/src/com/google/gwt/dev/jjs/impl/SourceGenerationVisitor.java

/*
 * Copyright 2007 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.gwt.dev.jjs.impl;

import com.google.gwt.dev.jjs.ast.Context;
import com.google.gwt.dev.jjs.ast.JClassType;
import com.google.gwt.dev.jjs.ast.JDeclaredType;
import com.google.gwt.dev.jjs.ast.JField;
import com.google.gwt.dev.jjs.ast.JInterfaceType;
import com.google.gwt.dev.jjs.ast.JMethod;
import com.google.gwt.dev.jjs.ast.JMethodBody;
import com.google.gwt.dev.jjs.ast.JProgram;
import com.google.gwt.dev.util.TextOutput;

/**
 * Generates Java source from our AST. ToStringGenerationVisitor is for
 * relatively short toString() results, for easy viewing in a debugger. This
 * subclass delves into the bodies of classes, interfaces, and methods to
 * produce the whole source tree.
 *
 * The goal is not to generate the input source tree. Rather, the goal is to
 * produce a set of classes that can be pasted into an enclosing class and
 * compiled with a standard Java compiler. In practice, there are cases that
 * require hand-editing to actually get a full compilation, due to Java's
 * built-in reliance on particular built-in types.
 *
 * Known to be broken: Our generated String, Class, and Throwable are not
 * compatible with the real ones, which breaks string literals, class literals,
 * try/catch/throw, and overrides of Object methods.
 */
public class SourceGenerationVisitor extends ToStringGenerationVisitor {

  public SourceGenerationVisitor(TextOutput textOutput) {
    super(textOutput);
  }

  @Override
  public boolean visit(JClassType x, Context ctx) {
    printAbstractFlag(x);
    printFinalFlag(x);
    print(CHARS_CLASS);
    space();
    if (x.getSuperClass() != null) {
      print(CHARS_EXTENDS);
      printTypeName(x.getSuperClass());
      space();
    }

    if (x.getImplements().size() > 0) {
      print(CHARS_IMPLEMENTS);
      for (int i = 0, c = x.getImplements().size(); i < c; ++i) {
        if (i > 0) {
          print(CHARS_COMMA);
        }
        printTypeName(x.getImplements().get(i));
      }
      space();
    }
    openBlock();

    for (JField field : x.getFields()) {
      accept(field);
      newline();
      newline();
    }
    for (JMethod method : x.getMethods()) {
      if (JProgram.isClinit(method)) {
        // Suppress empty clinit.
        JMethodBody body = (JMethodBody) method.getBody();
        if (body.getBlock().getStatements().isEmpty()) {
          continue;
        }
      }
      accept(method);
      newline();
      newline();
    }

    closeBlock();
    return false;
  }

  @Override
  public boolean visit(JInterfaceType x, Context ctx) {
    print(CHARS_INTERFACE);
    printTypeName(x);
    space();

    if (x.getImplements().size() > 0) {
      print(CHARS_EXTENDS);
      for (int i = 0, c = x.getImplements().size(); i < c; ++i) {
        if (i > 0) {
          print(CHARS_COMMA);
        }
        printTypeName(x.getImplements().get(i));
      }
      space();
    }

    openBlock();

    for (JField field : x.getFields()) {
      accept(field);
      newline();
      newline();
    }
    for (JMethod method : x.getMethods()) {
      if (JProgram.isClinit(method)) {
        // Suppress empty clinit.
        JMethodBody body = (JMethodBody) method.getBody();
        if (body.getBlock().getStatements().isEmpty()) {
          continue;
        }
      }
      accept(method);
      newline();
      newline();
    }

    closeBlock();
    return false;
  }

  @Override
  public boolean visit(JProgram x, Context ctx) {
    for (int i = 0; i < x.getDeclaredTypes().size(); ++i) {
      JDeclaredType type = x.getDeclaredTypes().get(i);
      accept(type);
      newline();
      newline();
    }
    return false;
  }

  @Override
  protected boolean shouldPrintMethodBody() {
    return true;
  }

}