/** Boolean operator code generation Optimized operations are: || */ public void generateOptimizedBoolean( BlockScope currentScope, CodeStream codeStream, BranchLabel trueLabel, BranchLabel falseLabel, boolean valueRequired) { if (this.constant != Constant.NotAConstant) { super.generateOptimizedBoolean( currentScope, codeStream, trueLabel, falseLabel, valueRequired); return; } // <expr> || false --> <expr> Constant cst = this.right.constant; if (cst != Constant.NotAConstant && cst.booleanValue() == false) { int pc = codeStream.position; this.left.generateOptimizedBoolean( currentScope, codeStream, trueLabel, falseLabel, valueRequired); if (this.mergedInitStateIndex != -1) { codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex); } codeStream.recordPositionsFrom(pc, this.sourceStart); return; } cst = this.left.optimizedBooleanConstant(); boolean leftIsConst = cst != Constant.NotAConstant; boolean leftIsTrue = leftIsConst && cst.booleanValue() == true; cst = this.right.optimizedBooleanConstant(); boolean rightIsConst = cst != Constant.NotAConstant; boolean rightIsTrue = rightIsConst && cst.booleanValue() == true; // default case generateOperands: { if (falseLabel == null) { if (trueLabel != null) { // implicit falling through the FALSE case this.left.generateOptimizedBoolean( currentScope, codeStream, trueLabel, null, !leftIsConst); // need value, e.g. if (a == 1 || ((b = 2) > 0)) {} -> shouldn't initialize 'b' if a==1 if (leftIsTrue) { if (valueRequired) codeStream.goto_(trueLabel); codeStream.recordPositionsFrom(codeStream.position, this.left.sourceEnd); break generateOperands; // no need to generate right operand } if (this.rightInitStateIndex != -1) { codeStream.addDefinitelyAssignedVariables(currentScope, this.rightInitStateIndex); } this.right.generateOptimizedBoolean( currentScope, codeStream, trueLabel, null, valueRequired && !rightIsConst); if (valueRequired && rightIsTrue) { codeStream.goto_(trueLabel); codeStream.recordPositionsFrom(codeStream.position, this.sourceEnd); } } } else { // implicit falling through the TRUE case if (trueLabel == null) { BranchLabel internalTrueLabel = new BranchLabel(codeStream); this.left.generateOptimizedBoolean( currentScope, codeStream, internalTrueLabel, null, !leftIsConst); // need value, e.g. if (a == 1 || ((b = 2) > 0)) {} -> shouldn't initialize 'b' if a==1 if (leftIsTrue) { internalTrueLabel.place(); break generateOperands; // no need to generate right operand } if (this.rightInitStateIndex != -1) { codeStream.addDefinitelyAssignedVariables(currentScope, this.rightInitStateIndex); } this.right.generateOptimizedBoolean( currentScope, codeStream, null, falseLabel, valueRequired && !rightIsConst); int pc = codeStream.position; if (valueRequired && rightIsConst && !rightIsTrue) { codeStream.goto_(falseLabel); codeStream.recordPositionsFrom(pc, this.sourceEnd); } internalTrueLabel.place(); } else { // no implicit fall through TRUE/FALSE --> should never occur } } } if (this.mergedInitStateIndex != -1) { codeStream.removeNotDefinitelyAssignedVariables(currentScope, this.mergedInitStateIndex); } }