examples/Mini/ASTIdent.java

/* Generated By:JJTree: Do not edit this line. ASTIdent.java */
/* JJT: 0.3pre1 */

package Mini;
import org.apache.bcel.classfile.*;
import org.apache.bcel.generic.*;

/**
 *
 * @version $Id$
 * @author  <A HREF="http://www.berlin.de/~markus.dahm/">M. Dahm</A>
 */
public class ASTIdent extends ASTExpr implements org.apache.bcel.Constants {
  private String   name;
  private Variable reference; // Reference in environment to decl of this ident

  // Generated methods
  ASTIdent(int id) {
    super(id);
  }

  ASTIdent(MiniParser p, int id) {
    super(p, id);
  }

  public static Node jjtCreate(MiniParser p, int id) {
    return new ASTIdent(p, id);
  }

  public ASTIdent(String name, int type, int line, int column) {
    super(line, column, JJTIDENT);

    this.name  = name;
    this.type  = type;
  }

  // closeNode, dump inherited

  /**
   * @return identifier and line/column number of appearance
   */
  public String toString() {
    return super.toString() + " = " + name;
  }

  /**
   * Overrides ASTExpr.traverse()
   */
  public ASTExpr traverse(Environment env) {
    EnvEntry entry = env.get(name);

    if(entry == null)
      MiniC.addError(line, column, "Undeclared identifier " + name);
    else if(entry instanceof Function)
      MiniC.addError(line, column,
		     "Function " + name + " used as an identifier.");
    else
      reference = (Variable)entry;

    return this; // Nothing to reduce/traverse further here
  }

  /**
   * Overrides AstExpr.eval()
   */
  public int eval(int expected) {
    ASTIdent ident = reference.getName();
    int      t     = ident.getType();

    is_simple = true; // (Very) simple expression, always true

    if((t == T_UNKNOWN) && (expected == T_UNKNOWN))
      type = T_UNKNOWN;
    else if((t == T_UNKNOWN) && (expected != T_UNKNOWN)) {
      ident.setType(expected);
      type = expected;
    }
    else if((t != T_UNKNOWN) && (expected == T_UNKNOWN)) {
      ident.setType(t);
      type = t;
    }
    else // (t != T_UNKNOWN) && (expected != T_UNKNOWN) 
      type = t; // Caller has to check for an error, i.e. t != expected

    return type;
  }

  /**
   * Fourth pass, produce Java code.
   */
  public void code(StringBuffer buf) {
    if(name.equals("TRUE"))
      ASTFunDecl.push(buf, "1");
    else if(name.equals("FALSE"))
      ASTFunDecl.push(buf, "0");
    else
      ASTFunDecl.push(buf, name);
  }

  /**
   * Fifth pass, produce Java byte code.
   */
  public void byte_code(InstructionList il, MethodGen method, ConstantPoolGen cp) {
    if(name.equals("TRUE"))
      il.append(new PUSH(cp, 1));
    else if(name.equals("FALSE"))
      il.append(new PUSH(cp, 0));
    else {
      LocalVariableGen local_var = reference.getLocalVariable();
      il.append(new ILOAD(local_var.getIndex()));
    }
    ASTFunDecl.push();
  }


  public void   setName(String name) { this.name = name; }
  public String getName()            { return name; }
}