Example usage for org.objectweb.asm Label Label

List of usage examples for org.objectweb.asm Label Label

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Introduction

In this page you can find the example usage for org.objectweb.asm Label Label.

Prototype

public Label()

Source Link

Document

Constructs a new label.

Usage

From source file:com.google.template.soy.jbcsrc.MsgCompiler.java

License:Apache License

/**
 * Returns a statement that adds the content rendered by the call to the map.
 *
 * @param mapExpression The map to put the new entry in
 * @param mapKey The map key/*from  ww  w .j  a v a 2s.  com*/
 * @param printNode The node
 */
private Statement addPrintNodeToPlaceholderMap(Expression mapExpression, String mapKey, PrintNode printNode) {
    // This is much like the escaping path of visitPrintNode but somewhat simpler because our
    // ultimate target is a string rather than putting bytes on the output stream.
    Label reattachPoint = new Label();
    Expression compileToString = soyNodeCompiler.compileToString(printNode, reattachPoint);
    return putToMap(mapExpression, mapKey, compileToString).labelStart(reattachPoint);
}

From source file:com.google.template.soy.jbcsrc.PluginFunctionCompiler.java

License:Apache License

/**
 * @see com.google.template.soy.basicfunctions.IsNonnullFunction
 *//*from   ww  w  .  j  av  a2 s  .com*/
private SoyExpression invokeIsNonnullFunction(final SoyExpression soyExpression) {
    if (BytecodeUtils.isPrimitive(soyExpression.resultType())) {
        return SoyExpression.TRUE;
    }
    return SoyExpression.forBool(new Expression(Type.BOOLEAN_TYPE, soyExpression.features()) {
        @Override
        void doGen(CodeBuilder adapter) {
            soyExpression.gen(adapter);
            Label isNull = new Label();
            adapter.ifNull(isNull);
            // non-null
            adapter.pushBoolean(true);
            Label end = new Label();
            adapter.goTo(end);
            adapter.mark(isNull);
            adapter.pushBoolean(false);
            adapter.mark(end);
        }
    });
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeProducer.java

License:Apache License

/** Writes the bytecode to the adapter. */
public final void gen(CodeBuilder adapter) {
    boolean shouldClearIsGeneratingBit = false;
    if (Flags.DEBUG && !isGenerating.get()) {
        isGenerating.set(true);// ww  w.  j  av  a 2s  .c o  m
        shouldClearIsGeneratingBit = true;
    }
    try {
        if (location.isKnown()) {
            // These add entries to the line number tables that are associated with the current method.
            // The line number table is just a mapping of bytecode offset (aka 'pc') to line number,
            // http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.7.12
            // It is used by the JVM to add source data to stack traces and by debuggers to highlight
            // source files.
            Label start = new Label();
            adapter.mark(start);
            adapter.visitLineNumber(location.getBeginLine(), start);
        }

        doGen(adapter);

        if (location.isKnown()) {
            Label end = new Label();
            adapter.mark(end);
            adapter.visitLineNumber(location.getEndLine(), end);
        }
    } finally {
        if (shouldClearIsGeneratingBit) {
            isGenerating.set(false);
        }
    }
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

/**
 * Returns an expression that evaluates to {@code left} if left is non null, and evaluates to
 * {@code right} otherwise./*from  w  w w  .  jav a2 s .  com*/
 */
public static Expression firstNonNull(final Expression left, final Expression right) {
    checkArgument(left.resultType().getSort() == Type.OBJECT);
    checkArgument(right.resultType().getSort() == Type.OBJECT);
    Features features = Features.of();
    if (Expression.areAllCheap(left, right)) {
        features = features.plus(Feature.CHEAP);
    }
    if (right.isNonNullable()) {
        features = features.plus(Feature.NON_NULLABLE);
    }
    return new Expression(left.resultType(), features) {
        @Override
        protected void doGen(CodeBuilder cb) {
            Label leftIsNonNull = new Label();
            left.gen(cb); // Stack: L
            cb.dup(); // Stack: L, L
            cb.ifNonNull(leftIsNonNull); // Stack: L
            // pop the extra copy of left
            cb.pop(); // Stack:
            right.gen(cb); // Stack: R
            cb.mark(leftIsNonNull); // At this point the stack has an instance of L or R
        }
    };
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

/**
 * Returns an expression that evaluates equivalently to a java ternary expression: {@code
 * condition ? left : right}//from w  w  w  . j  ava  2  s  .  c  o m
 */
public static Expression ternary(final Expression condition, final Expression trueBranch,
        final Expression falseBranch) {
    checkArgument(condition.resultType().equals(Type.BOOLEAN_TYPE));
    checkArgument(trueBranch.resultType().getSort() == falseBranch.resultType().getSort());
    Features features = Features.of();
    if (Expression.areAllCheap(condition, trueBranch, falseBranch)) {
        features = features.plus(Feature.CHEAP);
    }
    if (trueBranch.isNonNullable() && falseBranch.isNonNullable()) {
        features = features.plus(Feature.NON_NULLABLE);
    }
    return new Expression(trueBranch.resultType(), features) {
        @Override
        protected void doGen(CodeBuilder mv) {
            condition.gen(mv);
            Label ifFalse = new Label();
            Label end = new Label();
            mv.visitJumpInsn(Opcodes.IFEQ, ifFalse); // if 0 goto ifFalse
            trueBranch.gen(mv); // eval true branch
            mv.visitJumpInsn(Opcodes.GOTO, end); // jump to the end
            mv.visitLabel(ifFalse);
            falseBranch.gen(mv); // eval false branch
            mv.visitLabel(end);
        }
    };
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

private static Expression doShortCircuitingLogicalOperator(
        final ImmutableList<? extends Expression> expressions, final boolean isOrOperator) {
    checkArgument(!expressions.isEmpty());
    for (Expression expr : expressions) {
        expr.checkAssignableTo(Type.BOOLEAN_TYPE);
    }/*from   w w w . ja v a 2 s.c o m*/
    if (expressions.size() == 1) {
        return expressions.get(0);
    }

    return new Expression(Type.BOOLEAN_TYPE,
            Expression.areAllCheap(expressions) ? Features.of(Feature.CHEAP) : Features.of()) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            Label end = new Label();
            Label shortCircuit = new Label();
            for (int i = 0; i < expressions.size(); i++) {
                Expression expr = expressions.get(i);
                expr.gen(adapter);
                if (i == expressions.size() - 1) {
                    // if we are the last one, just goto end. Whatever the result of the last expression is
                    // determines the result of the whole expression (when all prior tests fail).
                    adapter.goTo(end);
                } else {
                    adapter.ifZCmp(isOrOperator ? Opcodes.IFNE : Opcodes.IFEQ, shortCircuit);
                }
            }
            adapter.mark(shortCircuit);
            adapter.pushBoolean(isOrOperator); // default for || is true && is false
            adapter.mark(end);
        }
    };
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

/**
 * Outputs bytecode that will test the item at the top of the stack for null, and branch to {@code
 * nullExit} if it is {@code null}. At {@code nullSafeExit} there will be a null value at the top
 * of the stack./*  w w  w  .  ja  v  a2  s.  c om*/
 */
public static void nullCoalesce(CodeBuilder builder, Label nullExit) {
    builder.dup();
    Label nonNull = new Label();
    builder.ifNonNull(nonNull);
    // See http://mail.ow2.org/wws/arc/asm/2016-02/msg00001.html for a discussion of this pattern
    // but even though the value at the top of the stack here is null, its type isn't.  So we need
    // to pop and push.  This is the idiomatic pattern.
    builder.pop();
    builder.pushNull();
    builder.goTo(nullExit);
    builder.mark(nonNull);
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

/**
 * Returns a {@link SoyExpression} that evaluates to true if the expression evaluated to a
 * non-null value./*from   w ww. java 2  s .co m*/
 */
public static SoyExpression isNonNull(final Expression expr) {
    if (BytecodeUtils.isPrimitive(expr.resultType())) {
        return SoyExpression.TRUE;
    }
    return SoyExpression.forBool(new Expression(Type.BOOLEAN_TYPE, expr.features()) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            expr.gen(adapter);
            Label isNull = new Label();
            adapter.ifNull(isNull);
            // non-null
            adapter.pushBoolean(true);
            Label end = new Label();
            adapter.goTo(end);
            adapter.mark(isNull);
            adapter.pushBoolean(false);
            adapter.mark(end);
        }
    });
}

From source file:com.google.template.soy.jbcsrc.restricted.BytecodeUtils.java

License:Apache License

/** Returns a {@link SoyExpression} that evaluates to true if the expression evaluated to null. */
public static SoyExpression isNull(final Expression expr) {
    if (BytecodeUtils.isPrimitive(expr.resultType())) {
        return SoyExpression.FALSE;
    }// w  ww  .  ja  v  a  2 s .  c om
    // This is what javac generates for 'someObject == null'
    return SoyExpression.forBool(new Expression(Type.BOOLEAN_TYPE, expr.features()) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            expr.gen(adapter);
            Label isNull = new Label();
            adapter.ifNull(isNull);
            // non-null
            adapter.pushBoolean(false);
            Label end = new Label();
            adapter.goTo(end);
            adapter.mark(isNull);
            adapter.pushBoolean(true);
            adapter.mark(end);
        }
    });
}

From source file:com.google.template.soy.jbcsrc.restricted.SoyExpression.java

License:Apache License

/** Returns an Expression of a non-null {@link SoyValueProvider} providing this value. */
public Expression boxAsSoyValueProvider() {
    if (soyType().equals(NullType.getInstance())) {
        if (delegate == NULL || delegate == NULL_BOXED) {
            return FieldRef.NULL_PROVIDER.accessor();
        }//from  w ww  .ja  va2 s  .  c o  m
        // otherwise this expression might have side effects,  evaluate it as a statement then return
        // the NULL_PROVIDER
        return toStatement().then(FieldRef.NULL_PROVIDER.accessor());
    }
    if (delegate.isNonNullable()) {
        // Every SoyValue is-a SoyValueProvider, so if it is non-null
        return box();
    }
    if (isBoxed()) {
        return new Expression(BytecodeUtils.SOY_VALUE_PROVIDER_TYPE,
                delegate.features().plus(Feature.NON_NULLABLE)) {
            @Override
            protected void doGen(CodeBuilder adapter) {
                Label end = new Label();
                delegate.gen(adapter);
                adapter.dup();
                adapter.ifNonNull(end);
                adapter.pop();
                FieldRef.NULL_PROVIDER.accessStaticUnchecked(adapter);
                adapter.mark(end);
            }
        };
    }
    return new Expression(BytecodeUtils.SOY_VALUE_PROVIDER_TYPE,
            delegate.features().plus(Feature.NON_NULLABLE)) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            Label end = new Label();
            delegate.gen(adapter);
            adapter.dup();
            Label nonNull = new Label();
            adapter.ifNonNull(nonNull);
            adapter.pop(); // pop the null value and replace with the nullprovider
            FieldRef.NULL_PROVIDER.accessStaticUnchecked(adapter);
            adapter.goTo(end);
            adapter.mark(nonNull);
            doBox(adapter, soyRuntimeType);
            adapter.mark(end);
        }
    };
}