asmclassgenerator.java

来自「Groovy动态语言 运行在JVM中的动态语言 可以方便的处理业务逻辑变化大的业」· Java 代码 · 共 1,558 行 · 第 1/5 页

        
        compileStack.pop();
    }

    public void visitWhileLoop(WhileStatement loop) {
        onLineNumber(loop, "visitWhileLoop");
        visitStatement(loop);

        compileStack.pushLoop(loop.getStatementLabel());
        Label continueLabel = compileStack.getContinueLabel();
        Label breakLabel = compileStack.getBreakLabel();
        
        cv.visitLabel(continueLabel);
        loop.getBooleanExpression().visit(this);
        cv.visitJumpInsn(IFEQ, breakLabel);
        
        loop.getLoopBlock().visit(this);
        
        cv.visitJumpInsn(GOTO, continueLabel);
        cv.visitLabel(breakLabel);
        
        compileStack.pop();
    }

    public void visitDoWhileLoop(DoWhileStatement loop) {
        onLineNumber(loop, "visitDoWhileLoop");
        visitStatement(loop);

        compileStack.pushLoop(loop.getStatementLabel());
        Label breakLabel = compileStack.getBreakLabel();
        Label continueLabel = compileStack.getContinueLabel();
        cv.visitLabel(continueLabel);

        loop.getLoopBlock().visit(this);

        loop.getBooleanExpression().visit(this);
        cv.visitJumpInsn(IFEQ, continueLabel);
        cv.visitLabel(breakLabel);
        
        compileStack.pop();
    }

    public void visitIfElse(IfStatement ifElse) {
        onLineNumber(ifElse, "visitIfElse");
        visitStatement(ifElse);
        ifElse.getBooleanExpression().visit(this);
        
        Label l0 = new Label();
        cv.visitJumpInsn(IFEQ, l0);

        ifElse.getIfBlock().visit(this);

        Label l1 = new Label();
        cv.visitJumpInsn(GOTO, l1);
        cv.visitLabel(l0);

        ifElse.getElseBlock().visit(this);
        cv.visitLabel(l1);
    }

    public void visitTernaryExpression(TernaryExpression expression) {
        onLineNumber(expression, "visitTernaryExpression");

        expression.getBooleanExpression().visit(this);

        Label l0 = new Label();
        cv.visitJumpInsn(IFEQ, l0);
        visitAndAutoboxBoolean(expression.getTrueExpression());

        Label l1 = new Label();
        cv.visitJumpInsn(GOTO, l1);
        cv.visitLabel(l0);

        visitAndAutoboxBoolean(expression.getFalseExpression());
        cv.visitLabel(l1);
    }

    public void visitAssertStatement(AssertStatement statement) {
        onLineNumber(statement, "visitAssertStatement");
        visitStatement(statement);

        BooleanExpression booleanExpression = statement.getBooleanExpression();
        booleanExpression.visit(this);

        Label l0 = new Label();
        cv.visitJumpInsn(IFEQ, l0);

        // do nothing

        Label l1 = new Label();
        cv.visitJumpInsn(GOTO, l1);
        cv.visitLabel(l0);

        // push expression string onto stack
        String expressionText = booleanExpression.getText();
        List list = new ArrayList();
        addVariableNames(booleanExpression, list);
        if (list.isEmpty()) {
            cv.visitLdcInsn(expressionText);
        }
        else {
            boolean first = true;

            // lets create a new expression
            cv.visitTypeInsn(NEW, "java/lang/StringBuffer");
            cv.visitInsn(DUP);
            cv.visitLdcInsn(expressionText + ". Values: ");

            cv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuffer", "<init>", "(Ljava/lang/String;)V");

            int tempIndex = compileStack.defineTemporaryVariable("assert",true);

            for (Iterator iter = list.iterator(); iter.hasNext();) {
                String name = (String) iter.next();
                String text = name + " = ";
                if (first) {
                    first = false;
                }
                else {
                    text = ", " + text;
                }

                cv.visitVarInsn(ALOAD, tempIndex);
                cv.visitLdcInsn(text);
                cv.visitMethodInsn(
                    INVOKEVIRTUAL,
                    "java/lang/StringBuffer",
                    "append",
                    "(Ljava/lang/Object;)Ljava/lang/StringBuffer;");
                cv.visitInsn(POP);

                cv.visitVarInsn(ALOAD, tempIndex);
                new VariableExpression(name).visit(this);
                cv.visitMethodInsn(
                    INVOKEVIRTUAL,
                    "java/lang/StringBuffer",
                    "append",
                    "(Ljava/lang/Object;)Ljava/lang/StringBuffer;");
                cv.visitInsn(POP);

            }
            cv.visitVarInsn(ALOAD, tempIndex);
            compileStack.removeVar(tempIndex);
        }
        // now the optional exception expression
        statement.getMessageExpression().visit(this);

        assertFailedMethod.call(cv);
        cv.visitLabel(l1);
    }

    private void addVariableNames(Expression expression, List list) {
        if (expression instanceof BooleanExpression) {
            BooleanExpression boolExp = (BooleanExpression) expression;
            addVariableNames(boolExp.getExpression(), list);
        }
        else if (expression instanceof BinaryExpression) {
            BinaryExpression binExp = (BinaryExpression) expression;
            addVariableNames(binExp.getLeftExpression(), list);
            addVariableNames(binExp.getRightExpression(), list);
        }
        else if (expression instanceof VariableExpression) {
            VariableExpression varExp = (VariableExpression) expression;
            list.add(varExp.getName());
        }
    }

    public void visitTryCatchFinally(TryCatchStatement statement) {
        onLineNumber(statement, "visitTryCatchFinally");
        visitStatement(statement);
        
        CatchStatement catchStatement = statement.getCatchStatement(0);
        Statement tryStatement = statement.getTryStatement();
        final Statement finallyStatement = statement.getFinallyStatement();

        int anyExceptionIndex = compileStack.defineTemporaryVariable("exception",false);
        if (!finallyStatement.isEmpty()) {
            compileStack.pushFinallyBlock(
                new Runnable(){
                    public void run(){finallyStatement.visit(AsmClassGenerator.this);}
                }
            );
        }
        
        // start try block, label needed for exception table
        final Label tryStart = new Label();
        cv.visitLabel(tryStart);
        tryStatement.visit(this);
        // goto finally part
        final Label finallyStart = new Label();
        cv.visitJumpInsn(GOTO, finallyStart);
        // marker needed for Exception table
        final Label tryEnd = new Label();
        cv.visitLabel(tryEnd);
        
        for (Iterator it=statement.getCatchStatements().iterator(); it.hasNext();) {
            catchStatement = (CatchStatement) it.next();
            ClassNode exceptionType = catchStatement.getExceptionType();
            // start catch block, label needed for exception table
            final Label catchStart = new Label();
            cv.visitLabel(catchStart);
            // create exception variable and store the exception 
            compileStack.defineVariable(catchStatement.getVariable(),true);
            // handle catch body
            catchStatement.visit(this);
            // goto finally start
            cv.visitJumpInsn(GOTO, finallyStart);
            // add exception to table
            final String exceptionTypeInternalName = BytecodeHelper.getClassInternalName(exceptionType);
            exceptionBlocks.add(new Runnable() {
                public void run() {
                    cv.visitTryCatchBlock(tryStart, tryEnd, catchStart, exceptionTypeInternalName);
                }
            });
        }
        
        // marker needed for the exception table
        final Label endOfAllCatches = new Label();
        cv.visitLabel(endOfAllCatches);
        
        // remove the finally, don't let it visit itself
        if (!finallyStatement.isEmpty()) compileStack.popFinallyBlock();
        
        // start finally
        cv.visitLabel(finallyStart);
        finallyStatement.visit(this);
        // goto end of finally
        Label afterFinally = new Label();
        cv.visitJumpInsn(GOTO, afterFinally);
        
        // start a block catching any Exception
        final Label catchAny = new Label();
        cv.visitLabel(catchAny);
        //store exception
        cv.visitVarInsn(ASTORE, anyExceptionIndex);
        finallyStatement.visit(this);
        // load the exception and rethrow it
        cv.visitVarInsn(ALOAD, anyExceptionIndex);
        cv.visitInsn(ATHROW);
        
        // end of all catches and finally parts
        cv.visitLabel(afterFinally);
        
        // add catch any block to exception table
        exceptionBlocks.add(new Runnable() {
            public void run() {
                cv.visitTryCatchBlock(tryStart, endOfAllCatches, catchAny, null);
            }
        });
    }

    public void visitSwitch(SwitchStatement statement) {
        onLineNumber(statement, "visitSwitch");
        visitStatement(statement);

        statement.getExpression().visit(this);

        // switch does not have a continue label. use its parent's for continue
        Label breakLabel = compileStack.pushSwitch();
        
        int switchVariableIndex = compileStack.defineTemporaryVariable("switch",true);

        List caseStatements = statement.getCaseStatements();
        int caseCount = caseStatements.size();
        Label[] labels = new Label[caseCount + 1];
        for (int i = 0; i < caseCount; i++) {
            labels[i] = new Label();
        }

        int i = 0;
        for (Iterator iter = caseStatements.iterator(); iter.hasNext(); i++) {
            CaseStatement caseStatement = (CaseStatement) iter.next();
            visitCaseStatement(caseStatement, switchVariableIndex, labels[i], labels[i + 1]);
        }

        statement.getDefaultStatement().visit(this);

        cv.visitLabel(breakLabel);

        compileStack.pop();
    }

    public void visitCaseStatement(CaseStatement statement) {
    }

    public void visitCaseStatement(
        CaseStatement statement,
        int switchVariableIndex,
        Label thisLabel,
        Label nextLabel) {

        onLineNumber(statement, "visitCaseStatement");

        cv.visitVarInsn(ALOAD, switchVariableIndex);
        statement.getExpression().visit(this);

        isCaseMethod.call(cv);

        Label l0 = new Label();
        cv.visitJumpInsn(IFEQ, l0);

        cv.visitLabel(thisLabel);

        statement.getCode().visit(this);

        // now if we don't finish with a break we need to jump past
        // the next comparison
        if (nextLabel != null) {
            cv.visitJumpInsn(GOTO, nextLabel);
        }

        cv.visitLabel(l0);