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package sun.tools.tree;

import sun.tools.java.*;
import sun.tools.asm.Assembler;
import java.io.PrintStream;
import java.util.Hashtable;

WARNING: The contents of this source file are not part of any supported API. Code that depends on them does so at its own risk: they are subject to change or removal without notice.
/** * WARNING: The contents of this source file are not part of any * supported API. Code that depends on them does so at its own risk: * they are subject to change or removal without notice. */
public class AssignExpression extends BinaryAssignExpression { private FieldUpdater updater = null;
Constructor
/** * Constructor */
public AssignExpression(long where, Expression left, Expression right) { super(ASSIGN, where, left, right); }
Check an assignment expression
/** * Check an assignment expression */
public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable<Object, Object> exp) { if (left instanceof IdentifierExpression) { // we don't want to mark an identifier as having a value // until having evaluated the right-hand side vset = right.checkValue(env, ctx, vset, exp); vset = left.checkLHS(env, ctx, vset, exp); } else { // normally left to right evaluation. vset = left.checkLHS(env, ctx, vset, exp); vset = right.checkValue(env, ctx, vset, exp); } type = left.type; right = convert(env, ctx, type, right); // Get field updater (access method) if needed, else null. updater = left.getAssigner(env, ctx); return vset; }
Inline
/** * Inline */
public Expression inlineValue(Environment env, Context ctx) { if (implementation != null) return implementation.inlineValue(env, ctx); // Must be 'inlineLHS' here. But compare with similar case in // 'AssignOpExpression' and 'IncDecExpression', which needs 'inlineValue'. left = left.inlineLHS(env, ctx); right = right.inlineValue(env, ctx); if (updater != null) { updater = updater.inline(env, ctx); } return this; }
Create a copy of the expression for method inlining
/** * Create a copy of the expression for method inlining */
public Expression copyInline(Context ctx) { if (implementation != null) return implementation.copyInline(ctx); AssignExpression e = (AssignExpression)clone(); e.left = left.copyInline(ctx); e.right = right.copyInline(ctx); if (updater != null) { e.updater = updater.copyInline(ctx); } return e; }
The cost of inlining this expression
/** * The cost of inlining this expression */
public int costInline(int thresh, Environment env, Context ctx) { /*----------* return 2 + super.costInline(thresh, env, ctx); *----------*/ return (updater != null) // Cost of rhs expression + cost of access method call. // Access method call cost includes lhs cost. ? right.costInline(thresh, env, ctx) + updater.costInline(thresh, env, ctx, false) // Cost of rhs expression + cost of lhs expression + // cost of store instruction. : right.costInline(thresh, env, ctx) + left.costInline(thresh, env, ctx) + 2; }
Code
/** * Code */
public void codeValue(Environment env, Context ctx, Assembler asm) { if (updater == null) { // Field is directly accessible. int depth = left.codeLValue(env, ctx, asm); right.codeValue(env, ctx, asm); codeDup(env, ctx, asm, right.type.stackSize(), depth); left.codeStore(env, ctx, asm); } else { // Must use access method. // Left operand is always a 'FieldExpression', or // is rewritten as one via 'implementation'. updater.startAssign(env, ctx, asm); right.codeValue(env, ctx, asm); updater.finishAssign(env, ctx, asm, true); } } public void code(Environment env, Context ctx, Assembler asm) { if (updater == null) { // Field is directly accessible. left.codeLValue(env, ctx, asm); right.codeValue(env, ctx, asm); left.codeStore(env, ctx, asm); } else { // Must use access method. // Left operand is always a 'FieldExpression', or // is rewritten as one via 'implementation'. updater.startAssign(env, ctx, asm); right.codeValue(env, ctx, asm); updater.finishAssign(env, ctx, asm, false); } } }