JVariableSymbol.java

/*
 * SonarQube Java
 * Copyright (C) SonarSource Sàrl
 * mailto:info AT sonarsource DOT com
 *
 * You can redistribute and/or modify this program under the terms of
 * the Sonar Source-Available License Version 1, as published by SonarSource Sàrl.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the Sonar Source-Available License for more details.
 *
 * You should have received a copy of the Sonar Source-Available License
 * along with this program; if not, see https://sonarsource.com/license/ssal/
 */
package org.sonar.java.model;

import java.util.Collections;
import java.util.List;
import java.util.Optional;
import javax.annotation.Nullable;
import org.eclipse.jdt.core.dom.IMethodBinding;
import org.eclipse.jdt.core.dom.ITypeBinding;
import org.eclipse.jdt.core.dom.IVariableBinding;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.semantic.SymbolMetadata;
import org.sonar.plugins.java.api.semantic.Type;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.VariableTree;

final class JVariableSymbol extends JSymbol implements Symbol.VariableSymbol {

  // cache for this.constantValue()
  private boolean constantValueComputed = false;
  private Optional<Object> constantValue;

  JVariableSymbol(JSema sema, IVariableBinding variableBinding) {
    super(sema, variableBinding);
  }

  @Nullable
  @Override
  public VariableTree declaration() {
    return (VariableTree) super.declaration();
  }

  @Override
  public boolean isEffectivelyFinal() {
    return ((IVariableBinding)binding).isEffectivelyFinal();
  }

  @Override
  public Optional<Object> constantValue() {
    if (!constantValueComputed) {
      constantValueComputed = true;
      if (!isFinal() || !isStatic()) {
        constantValue = Optional.empty();
      } else {
        Object c = ((IVariableBinding) binding).getConstantValue();
        if (c instanceof Short shortValue) {
          c = Integer.valueOf(shortValue);
        } else if (c instanceof Byte byteValue) {
          c = Integer.valueOf(byteValue);
        } else if (c instanceof Character characterValue) {
          c = Integer.valueOf(characterValue);
        }
        constantValue = Optional.ofNullable(c);
      }
    }
    return constantValue;
  }

  @Override
  public boolean isLocalVariable() {
    Symbol owner = owner();
    return owner != null && owner.isMethodSymbol();
  }

  @Override
  public boolean isParameter() {
    return ((IVariableBinding) binding).isParameter();
  }


  static class ParameterPlaceholderSymbol extends Symbols.DefaultSymbol implements Symbol.VariableSymbol {
    private final String name;
    private final Symbol owner;
    private final Type type;
    private final SymbolMetadata metadata;

    /**
     * @param typeBinding the type of the parameter at the call site, after type substitution
     * @param declaredTypeBinding the type of the parameter as declared, before type substitution. Annotations are read from it, so that
     *   annotations inferred for a type variable are not mistaken for annotations of the parameter itself.
     */
    ParameterPlaceholderSymbol(int index, JSema sema, IMethodBinding owner, ITypeBinding typeBinding, ITypeBinding declaredTypeBinding) {
      this.name = "arg" + index;
      this.owner = sema.methodSymbol(owner);
      this.type = sema.type(typeBinding);
      this.metadata = JSymbolMetadata.of(sema, this, declaredTypeBinding, owner.getParameterAnnotations(index));
    }

    @Override
    public String name() {
      return name;
    }

    @Override
    public Symbol owner() {
      return owner;
    }

    @Override
    public Type type() {
      return type;
    }

    @Override
    public boolean isUnknown() {
      return false;
    }

    @Override
    public TypeSymbol enclosingClass() {
      return owner.enclosingClass();
    }

    @Override
    public List<IdentifierTree> usages() {
      return Collections.emptyList();
    }

    @Override
    public VariableTree declaration() {
      return null;
    }

    @Override
    public boolean isEffectivelyFinal() {
      return false;
    }

    @Override
    public Optional<Object> constantValue() {
      return Optional.empty();
    }

    @Override
    public boolean isLocalVariable() {
      return false;
    }

    @Override
    public boolean isParameter() {
      return true;
    }

    @Override
    public SymbolMetadata metadata() {
      return metadata;
    }

    @Override
    public boolean isVariableSymbol() {
      return true;
    }

    @Override
    public boolean isFinal() {
      // From a caller perspective, it is not useful (and even not possible) to know if the parameter is final.
      return false;
    }

  }
}