icu/tools/srcgen/src/main/java/com/android/icu4j/srcgen/checker/RecordPublicApiRules.java

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * 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.android.icu4j.srcgen.checker;

import com.google.common.collect.Lists;
import com.google.currysrc.api.Rules;
import com.google.currysrc.api.input.InputFileGenerator;
import com.google.currysrc.api.output.NullOutputSourceFileGenerator;
import com.google.currysrc.api.output.OutputSourceFileGenerator;
import com.google.currysrc.api.process.Context;
import com.google.currysrc.api.process.Processor;
import com.google.currysrc.api.process.Rule;
import com.google.currysrc.api.process.ast.BodyDeclarationLocators;
import com.google.currysrc.api.process.ast.TypeLocator;

import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTVisitor;
import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
import org.eclipse.jdt.core.dom.AnnotationTypeDeclaration;
import org.eclipse.jdt.core.dom.AnnotationTypeMemberDeclaration;
import org.eclipse.jdt.core.dom.BodyDeclaration;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.EnumConstantDeclaration;
import org.eclipse.jdt.core.dom.EnumDeclaration;
import org.eclipse.jdt.core.dom.FieldDeclaration;
import org.eclipse.jdt.core.dom.Javadoc;
import org.eclipse.jdt.core.dom.MethodDeclaration;
import org.eclipse.jdt.core.dom.Modifier;
import org.eclipse.jdt.core.dom.TagElement;
import org.eclipse.jdt.core.dom.TypeDeclaration;

import java.io.File;
import java.util.Collections;
import java.util.List;

import static com.android.icu4j.srcgen.Icu4jTransformRules.createOptionalRule;

/**
 * Rules that operate over a set of files and record the public API (according to Android's rules
 * for @hide).
 */
class RecordPublicApiRules implements Rules {

  private final InputFileGenerator inputFileGenerator;

  private final RecordPublicApi recordPublicApi;

  public RecordPublicApiRules(InputFileGenerator inputFileGenerator) {
    this.inputFileGenerator = inputFileGenerator;
    recordPublicApi = new RecordPublicApi();
  }

  @Override public InputFileGenerator getInputFileGenerator() {
    return inputFileGenerator;
  }

  @Override public List<Rule> getRuleList(File file) {
    return Collections.<Rule>singletonList(createOptionalRule(recordPublicApi));
  }

  @Override public OutputSourceFileGenerator getOutputSourceFileGenerator() {
    return NullOutputSourceFileGenerator.INSTANCE;
  }

  public List<String> publicMembers() {
    return recordPublicApi.publicMembers();
  }

  private static class RecordPublicApi implements Processor {
    private final List<String> publicMembers = Lists.newArrayList();

    @Override public void process(Context context, CompilationUnit cu) {
      cu.accept(new ASTVisitor() {
        @Override public boolean visit(AnnotationTypeDeclaration node) {
          throw new AssertionError("Not supported");
        }

        @Override public boolean visit(AnnotationTypeMemberDeclaration node) {
          throw new AssertionError("Not supported");
        }

        @Override public boolean visit(EnumConstantDeclaration node) {
          return handleMemberDeclarationNode(node);
        }

        @Override public boolean visit(EnumDeclaration node) {
          return handleTypeDeclarationNode(node);
        }

        @Override public boolean visit(FieldDeclaration node) {
          return handleMemberDeclarationNode(node);
        }

        @Override public boolean visit(MethodDeclaration node) {
          return handleMemberDeclarationNode(node);
        }

        @Override public boolean visit(TypeDeclaration node) {
          return handleTypeDeclarationNode(node);
        }
      });
    }

    @Override
    public String toString() {
      return "RecordPublicApi{}";
    }

    private boolean handleTypeDeclarationNode(AbstractTypeDeclaration node) {
      handleDeclarationNode(node);
      // Continue processing for nested types / methods.
      return true;
    }

    private boolean handleMemberDeclarationNode(BodyDeclaration node) {
      handleDeclarationNode(node);
      // Leaf declaration (i.e. a method, fields, enum constant).
      return false;
    }

    private void handleDeclarationNode(BodyDeclaration node) {
      if (isExplicitlyHidden(node)) {
        return;
      }

      AbstractTypeDeclaration typeDeclaration = TypeLocator.findTypeDeclarationNode(node);
      if (typeDeclaration == null) {
        // Not unusual: methods / fields defined on anonymous types are like this. The parent
        // is a constructor expression, not a declaration.
        return;
      }

      boolean isNonTypeDeclaration = typeDeclaration != node;
      if (isNonTypeDeclaration) {
        if (isExplicitlyHidden(node) || !isMemberPublicApiEligible(typeDeclaration, node)) {
          return;
        }
      }
      while (typeDeclaration != null) {
        if (isExplicitlyHidden(typeDeclaration) || !isTypePublicApiEligible(typeDeclaration)) {
          return;
        }
        typeDeclaration = TypeLocator.findEnclosingTypeDeclaration(typeDeclaration);
      }
      // The node is appropriately public and is not hidden.
      publicMembers.addAll(BodyDeclarationLocators.toLocatorStringForms(node));
    }

    private boolean isTypePublicApiEligible(AbstractTypeDeclaration typeDeclaration) {
      int typeModifiers = typeDeclaration.getModifiers();
      return ((typeModifiers & Modifier.PUBLIC) != 0);
    }

    public boolean isMemberPublicApiEligible(AbstractTypeDeclaration type, BodyDeclaration node) {
      if (node.getNodeType() == ASTNode.ENUM_DECLARATION
          || node.getNodeType() == ASTNode.TYPE_DECLARATION) {
        throw new AssertionError("Unsupported node type: " + node);
      }

      if (type instanceof TypeDeclaration) {
        TypeDeclaration typeDeclaration = (TypeDeclaration) type;
        // All methods are public on interfaces. Not sure if true on Java 8.
        if (typeDeclaration.isInterface()) {
          return true;
        }
      }
      int memberModifiers = node.getModifiers();
      return ((memberModifiers & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0);
    }

    private boolean isExplicitlyHidden(BodyDeclaration node) {
      Javadoc javadoc = node.getJavadoc();
      if (javadoc == null) {
        return false;
      }
      final Boolean[] isHidden = new Boolean[] { false };
      javadoc.accept(new ASTVisitor(true /* visitDocNodes */) {
        @Override public boolean visit(TagElement node) {
          String tagName = node.getTagName();
          if (tagName == null) {
            return true;
          }
          if (tagName.equals("@hide")) {
            isHidden[0] = true;
            return false;
          }
          return true;
        }
      });
      return isHidden[0];
    }

    public List<String> publicMembers() {
      return publicMembers;
    }
  }
}