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com.tangosol.dev.compiler.java.ArrayAccessExpression Maven / Gradle / Ivy
/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.dev.compiler.java;
import com.tangosol.dev.assembler.CodeAttribute;
import com.tangosol.dev.assembler.Op;
import com.tangosol.dev.assembler.Baload;
import com.tangosol.dev.assembler.Caload;
import com.tangosol.dev.assembler.Saload;
import com.tangosol.dev.assembler.Iaload;
import com.tangosol.dev.assembler.Laload;
import com.tangosol.dev.assembler.Faload;
import com.tangosol.dev.assembler.Daload;
import com.tangosol.dev.assembler.Aaload;
import com.tangosol.dev.compiler.CompilerException;
import com.tangosol.dev.compiler.Context;
import com.tangosol.dev.component.DataType;
import com.tangosol.util.ErrorList;
import java.util.Set;
import java.util.Map;
/**
* The array access ([]) expression.
*
* @version 1.00, 10/05/98
* @author Cameron Purdy
*/
public class ArrayAccessExpression extends UnaryExpression
{
// ----- construction ---------------------------------------------------
/**
* Construct a ArrayAccessExpression.
*
* @param operator the operator token
* @param expr the array expression
* @param index the array element index expression
*/
public ArrayAccessExpression(Token operator, Expression expr, Expression index, Token tokLast)
{
super(operator, expr);
setStartToken(expr.getStartToken());
setEndToken(tokLast);
this.index = index;
}
// ----- code generation ------------------------------------------------
/**
* Perform semantic checks, parse tree re-organization, name binding,
* and optimizations.
*
* @param ctx the compiler context
* @param setUVars the set of potentially unassigned variables
* @param setFVars the set of potentially assigned final variables
* @param mapThrown the set of potentially thrown checked exceptions
* @param errlist the error list
*
* @return the resulting language element (typically this)
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected Element precompile(Context ctx, DualSet setUVars, DualSet setFVars, Map mapThrown, ErrorList errlist)
throws CompilerException
{
Expression exprArray = getArray();
Expression exprIndex = getIndex();
exprArray = (Expression) exprArray.precompile(ctx, setUVars, setFVars, mapThrown, errlist);
exprIndex = (Expression) exprIndex.precompile(ctx, setUVars, setFVars, mapThrown, errlist);
// type of sub-expression must be array
// index must be int (or promotable to int)
if (exprArray.checkArray(errlist) && exprIndex.checkAssignable(ctx, INT, errlist))
{
exprIndex = exprIndex.promoteNumeric();
setType(exprArray.getType().getElementType());
}
setArray(exprArray);
setIndex(exprIndex);
return this;
}
/**
* Perform final optimizations and code generation.
*
* @param ctx the compiler context
* @param code the assembler code attribute to compile to
* @param fReached true if this language element is reached (JLS 14.19)
* @param errlist the error list to log errors to
*
* @return true if the element can complete normally (JLS 14.1)
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected boolean compile(Context ctx, CodeAttribute code, boolean fReached, ErrorList errlist)
throws CompilerException
{
// this is the compilation for array access, not storing into an
// array; that is handled by AssignExpression
if (!ctx.isDebug() && isConstant() && !(getValue() instanceof Object[]))
{
// Expression has compiler implementation for constant values
return super.compile(ctx, code, fReached, errlist);
}
// compilation for "[]":
//
// [expr]
// [index]
// ?aload
getArray().compile(ctx, code, fReached, errlist);
getIndex().compile(ctx, code, fReached, errlist);
Op opLoad = null;
switch (getType().getTypeString().charAt(0))
{
case 'Z':
case 'B':
opLoad = new Baload();
break;
case 'C':
opLoad = new Caload();
break;
case 'S':
opLoad = new Saload();
break;
case 'I':
opLoad = new Iaload();
break;
case 'J':
opLoad = new Laload();
break;
case 'F':
opLoad = new Faload();
break;
case 'D':
opLoad = new Daload();
break;
case '[':
case 'N':
case 'L':
case 'R':
opLoad = new Aaload();
break;
default:
throw new IllegalStateException();
}
code.add(opLoad);
return fReached;
}
// ----- accessors ------------------------------------------------------
/**
* Get the array reference expression.
*
* @return the array reference expression
*/
public Expression getArray()
{
return getExpression();
}
/**
* Set the array reference expression.
*
* @param expr the array reference expression
*/
protected void setArray(Expression expr)
{
setExpression(expr);
}
/**
* Get the array index expression.
*
* @return the array index expression
*/
public Expression getIndex()
{
return index;
}
/**
* Set the array index expression.
*
* @param expr the array index expression
*/
protected void setIndex(Expression expr)
{
index = expr;
}
// ----- Expression methods ---------------------------------------------
/**
* Determine if the expression has a constant value.
*
* @return true if the expression results in a constant value
*/
public boolean isConstant()
{
if (getArray().isConstant() && getIndex().isConstant())
{
Object[] a = (Object[]) getArray().getValue();
int i = ((Number) getIndex().getValue()).intValue();
return a != null && i >= 0 && i < a.length;
}
return false;
}
/**
* Determine the constant value of the expression.
*
* @return the constant value of the expression
*/
public Object getValue()
{
Object[] a = (Object[]) getArray().getValue();
int i = ((Number) getIndex().getValue()).intValue();
return a[i];
}
/**
* Check that the expression is assignable (a "variable"). This call
* may occur before pre-compilation.
*
* @param errlist the error list to log errors to
*
* @return true if the expression is a variable
*
* @exception CompilerException thrown if an error occurs that should
* stop the compilation process
*/
protected boolean checkAssignable(ErrorList errlist)
throws CompilerException
{
return true;
}
// ----- Element methods ------------------------------------------------
/**
* Print the element information.
*
* @param sIndent
*/
public void print(String sIndent)
{
super.print(sIndent);
out(sIndent + " Index:");
index.print(sIndent + " ");
}
// ----- data members ---------------------------------------------------
/**
* The class name.
*/
private static final String CLASS = "ArrayAccessExpression";
/**
* Int data type.
*/
private static final DataType INT = DataType.INT;
/**
* The array index expression.
*/
private Expression index;
}
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