Example usage for org.objectweb.asm Label Label

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

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.java.contract.core.agent.SpecificationMethodAdapter.java

License:Open Source License

/**
 * Injects calls to invariant contract methods. Invariant contract
 * methods get called with the {@code this} pointer, if any.
 */// ww w  .  j  a va 2 s.  c  o m
protected void invokeInvariants() {
    ClassContractHandle h = contracts.getClassHandle(ContractKind.INVARIANT);
    if (h == null) {
        return;
    }

    MethodNode contractMethod = injectContractMethod(h);

    Label skipInvariants = new Label();
    if (isConstructor) {
        loadThis();
        invokeVirtual(thisType, GET_CLASS_METHOD);
        loadThisClass();
        ifCmp(CLASS_TYPE, NE, skipInvariants);
    } else {
        loadLocal(checkInvariantsLocal);
        ifZCmp(EQ, skipInvariants);
    }

    if (!statik) {
        loadThis();
    }
    invokeContractMethod(contractMethod);

    mark(skipInvariants);
}

From source file:com.google.java.contract.core.agent.SpecificationMethodAdapter.java

License:Open Source License

/**
 * Marks the beginning of a busy section. A busy section is skipped
 * if the context is already busy.//w  ww. j  a v  a  2s.co  m
 */
@Requires({ "contextLocal >= 0", "checkInvariantsLocal >= 0" })
@Ensures("result != null")
protected Label enterBusySection() {
    Label skip = new Label();
    loadLocal(contextLocal);
    invokeVirtual(CONTRACT_CONTEXT_TYPE, TRY_ENTER_CONTRACT_METHOD);
    ifZCmp(EQ, skip);
    return skip;
}

From source file:com.google.java.contract.core.agent.SpecificationMethodAdapter.java

License:Open Source License

/**
 * Cancels busy state of the current object.
 *//*  w w  w.j ava  2s.c  o  m*/
@Requires("contextLocal >= 0")
protected void leaveContractedMethod() {
    Label skip = new Label();
    loadLocal(checkInvariantsLocal);
    ifZCmp(EQ, skip);

    loadLocal(contextLocal);
    if (statik) {
        loadThisClass();
    } else {
        loadThis();
    }
    invokeVirtual(CONTRACT_CONTEXT_TYPE, LEAVE_METHOD);

    mark(skip);
}

From source file:com.google.monitoring.runtime.instrumentation.adapters.AllocationMethodAdapter.java

License:Apache License

private void pushProductOfIntArrayOnStack() {
    final Label beginScopeLabel = new Label();
    final Label endScopeLabel = new Label();

    final int dimsArrayIndex = newLocal("[I", beginScopeLabel, endScopeLabel);
    final int counterIndex = newLocal("I", beginScopeLabel, endScopeLabel);
    final int productIndex = newLocal("I", beginScopeLabel, endScopeLabel);
    final Label loopLabel = new Label();
    final Label endLabel = new Label();

    super.visitLabel(beginScopeLabel);

    // stack: ... intArray
    super.visitVarInsn(Opcodes.ASTORE, dimsArrayIndex);
    // -> stack: ...

    // counter = 0
    super.visitInsn(Opcodes.ICONST_0);
    super.visitVarInsn(Opcodes.ISTORE, counterIndex);
    // product = 1
    super.visitInsn(Opcodes.ICONST_1);
    super.visitVarInsn(Opcodes.ISTORE, productIndex);
    // loop:/*from  ww  w.  java  2s  . c  o  m*/
    super.visitLabel(loopLabel);
    // if index >= arraylength goto end:
    super.visitVarInsn(Opcodes.ILOAD, counterIndex);
    super.visitVarInsn(Opcodes.ALOAD, dimsArrayIndex);
    super.visitInsn(Opcodes.ARRAYLENGTH);
    super.visitJumpInsn(Opcodes.IF_ICMPGE, endLabel);
    // product = product * max(array[counter],1)
    super.visitVarInsn(Opcodes.ALOAD, dimsArrayIndex);
    super.visitVarInsn(Opcodes.ILOAD, counterIndex);
    super.visitInsn(Opcodes.IALOAD);
    super.visitInsn(Opcodes.DUP);
    final Label nonZeroDimension = new Label();
    super.visitJumpInsn(Opcodes.IFNE, nonZeroDimension);
    super.visitInsn(Opcodes.POP);
    super.visitInsn(Opcodes.ICONST_1);
    super.visitLabel(nonZeroDimension);
    super.visitVarInsn(Opcodes.ILOAD, productIndex);
    super.visitInsn(Opcodes.IMUL); // if overflow happens it happens.
    super.visitVarInsn(Opcodes.ISTORE, productIndex);
    // iinc counter 1
    super.visitIincInsn(counterIndex, 1);
    // goto loop
    super.visitJumpInsn(Opcodes.GOTO, loopLabel);
    // end:
    super.visitLabel(endLabel);
    // re-push dimensions array
    super.visitVarInsn(Opcodes.ALOAD, dimsArrayIndex);
    // push product
    super.visitVarInsn(Opcodes.ILOAD, productIndex);

    super.visitLabel(endScopeLabel);
}

From source file:com.google.monitoring.runtime.instrumentation.adapters.AllocationMethodAdapter.java

License:Apache License

/**
 * Reflection-based allocation (@see java.lang.reflect.Array#newInstance) is
 * triggered with a static method call (INVOKESTATIC), so we hook it here.
 * Class initialization is triggered with a constructor call (INVOKESPECIAL)
 * so we hook that here too as a proxy for the new bytecode which leaves an
 * uninitialized object on the stack that we're not allowed to touch.
 * {@link java.lang.Object#clone} is also a call to INVOKESPECIAL,
 * and is hooked here.  {@link java.lang.Class#newInstance} and
 * {@link java.lang.reflect.Constructor#newInstance} are both
 * INVOKEVIRTUAL calls, so they are hooked here, as well.
 *//*from   w w  w.j ava 2  s. c  o  m*/
@Override
public void visitMethodInsn(final int opcode, final String owner, final String name, final String signature,
        final boolean itf) {
    if (opcode == Opcodes.INVOKESTATIC &&
    // Array does its own native allocation.  Grr.
            owner.equals("java/lang/reflect/Array") && name.equals("newInstance")) {
        if (signature.equals("(Ljava/lang/Class;I)Ljava/lang/Object;")) {

            final Label beginScopeLabel = new Label();
            final Label endScopeLabel = new Label();
            super.visitLabel(beginScopeLabel);

            // stack: ... class count
            final int countIndex = newLocal("I", beginScopeLabel, endScopeLabel);
            super.visitVarInsn(Opcodes.ISTORE, countIndex);
            // -> stack: ... class
            pushClassNameOnStack();
            // -> stack: ... class className
            final int typeNameIndex = newLocal("Ljava/lang/String;", beginScopeLabel, endScopeLabel);
            super.visitVarInsn(Opcodes.ASTORE, typeNameIndex);
            // -> stack: ... class
            super.visitVarInsn(Opcodes.ILOAD, countIndex);
            // -> stack: ... class count
            super.visitMethodInsn(opcode, owner, name, signature, itf);
            // -> stack: ... newobj
            super.visitInsn(Opcodes.DUP);
            // -> stack: ... newobj newobj
            super.visitVarInsn(Opcodes.ILOAD, countIndex);
            // -> stack: ... newobj newobj count
            super.visitInsn(Opcodes.SWAP);
            // -> stack: ... newobj count newobj
            super.visitVarInsn(Opcodes.ALOAD, typeNameIndex);
            super.visitLabel(endScopeLabel);
            // -> stack: ... newobj count newobj className
            super.visitInsn(Opcodes.SWAP);
            // -> stack: ... newobj count className newobj
            super.visitMethodInsn(Opcodes.INVOKESTATIC, recorderClass, recorderMethod, RECORDER_SIGNATURE,
                    false);
            // -> stack: ... newobj
            return;
        } else if (signature.equals("(Ljava/lang/Class;[I)Ljava/lang/Object;")) {
            final Label beginScopeLabel = new Label();
            final Label endScopeLabel = new Label();
            super.visitLabel(beginScopeLabel);

            final int dimsArrayIndex = newLocal("[I", beginScopeLabel, endScopeLabel);
            // stack: ... class dimsArray
            pushProductOfIntArrayOnStack();
            // -> stack: ... class dimsArray product
            final int productIndex = newLocal("I", beginScopeLabel, endScopeLabel);
            super.visitVarInsn(Opcodes.ISTORE, productIndex);
            // -> stack: ... class dimsArray

            super.visitVarInsn(Opcodes.ASTORE, dimsArrayIndex);
            // -> stack: ... class
            pushClassNameOnStack();
            // -> stack: ... class className
            final int typeNameIndex = newLocal("Ljava/lang/String;", beginScopeLabel, endScopeLabel);
            super.visitVarInsn(Opcodes.ASTORE, typeNameIndex);
            // -> stack: ... class
            super.visitVarInsn(Opcodes.ALOAD, dimsArrayIndex);
            // -> stack: ... class dimsArray
            super.visitMethodInsn(opcode, owner, name, signature, itf);
            // -> stack: ... newobj

            super.visitInsn(Opcodes.DUP);
            // -> stack: ... newobj newobj
            super.visitVarInsn(Opcodes.ILOAD, productIndex);
            // -> stack: ... newobj newobj product
            super.visitInsn(Opcodes.SWAP);
            // -> stack: ... newobj product newobj
            super.visitVarInsn(Opcodes.ALOAD, typeNameIndex);
            super.visitLabel(endScopeLabel);
            // -> stack: ... newobj product newobj className
            super.visitInsn(Opcodes.SWAP);
            // -> stack: ... newobj product className newobj
            super.visitMethodInsn(Opcodes.INVOKESTATIC, recorderClass, recorderMethod, RECORDER_SIGNATURE,
                    false);
            // -> stack: ... newobj
            return;
        }
    }

    if (opcode == Opcodes.INVOKEVIRTUAL) {
        if ("clone".equals(name) && owner.startsWith("[")) {
            super.visitMethodInsn(opcode, owner, name, signature, itf);

            int i = 0;
            while (i < owner.length()) {
                if (owner.charAt(i) != '[') {
                    break;
                }
                i++;
            }
            if (i > 1) {
                // -> stack: ... newobj
                super.visitTypeInsn(Opcodes.CHECKCAST, owner);
                // -> stack: ... arrayref
                calculateArrayLengthAndDispatch(owner.substring(i), i);
            } else {
                // -> stack: ... newobj
                super.visitInsn(Opcodes.DUP);
                // -> stack: ... newobj newobj
                super.visitTypeInsn(Opcodes.CHECKCAST, owner);
                // -> stack: ... newobj arrayref
                super.visitInsn(Opcodes.ARRAYLENGTH);
                // -> stack: ... newobj length
                super.visitInsn(Opcodes.SWAP);
                // -> stack: ... length newobj
                invokeRecordAllocation(owner.substring(i));
            }
            return;
        } else if ("newInstance".equals(name)) {
            if ("java/lang/Class".equals(owner) && "()Ljava/lang/Object;".equals(signature)) {
                super.visitInsn(Opcodes.DUP);
                // -> stack: ... Class Class
                super.visitMethodInsn(opcode, owner, name, signature, itf);
                // -> stack: ... Class newobj
                super.visitInsn(Opcodes.DUP_X1);
                // -> stack: ... newobj Class newobj
                super.visitMethodInsn(Opcodes.INVOKESTATIC, recorderClass, recorderMethod, CLASS_RECORDER_SIG,
                        false);
                // -> stack: ... newobj
                return;
            } else if ("java/lang/reflect/Constructor".equals(owner)
                    && "([Ljava/lang/Object;)Ljava/lang/Object;".equals(signature)) {
                buildRecorderFromObject(opcode, owner, name, signature, itf);
                return;
            }
        }
    }

    if (opcode == Opcodes.INVOKESPECIAL) {
        if ("clone".equals(name) && "java/lang/Object".equals(owner)) {
            buildRecorderFromObject(opcode, owner, name, signature, itf);
            return;
        } else if ("<init>".equals(name) && outstandingAllocs > 0) {
            // Tricky because superclass initializers mean there can be more calls
            // to <init> than calls to NEW; hence outstandingAllocs.
            --outstandingAllocs;

            // Most of the time (i.e. in bytecode generated by javac) it is the case
            // that following an <init> call the top of the stack has a reference ot
            // the newly-initialized object.  But nothing in the JVM Spec requires
            // this, so we need to play games with the stack to make an explicit
            // extra copy (and then discard it).

            dupStackElementBeforeSignatureArgs(signature);
            super.visitMethodInsn(opcode, owner, name, signature, itf);
            super.visitLdcInsn(-1);
            super.visitInsn(Opcodes.SWAP);
            invokeRecordAllocation(owner);
            super.visitInsn(Opcodes.POP);
            return;
        }
    }

    super.visitMethodInsn(opcode, owner, name, signature, itf);
}

From source file:com.google.monitoring.runtime.instrumentation.adapters.AllocationMethodAdapter.java

License:Apache License

private void dupStackElementBeforeSignatureArgs(final String sig) {
    final Label beginScopeLabel = new Label();
    final Label endScopeLabel = new Label();
    super.visitLabel(beginScopeLabel);

    final Type[] argTypes = Type.getArgumentTypes(sig);
    final int[] args = new int[argTypes.length];

    for (int i = argTypes.length - 1; i >= 0; --i) {
        args[i] = newLocal(argTypes[i], beginScopeLabel, endScopeLabel);
        super.visitVarInsn(argTypes[i].getOpcode(Opcodes.ISTORE), args[i]);
    }//from   w w w  . ja  v  a2  s .co  m
    super.visitInsn(Opcodes.DUP);
    for (int i = 0; i < argTypes.length; ++i) {
        final int op = argTypes[i].getOpcode(Opcodes.ILOAD);
        super.visitVarInsn(op, args[i]);
        if (op == Opcodes.ALOAD) {
            super.visitInsn(Opcodes.ACONST_NULL);
            super.visitVarInsn(Opcodes.ASTORE, args[i]);
        }
    }
    super.visitLabel(endScopeLabel);
}

From source file:com.google.monitoring.runtime.instrumentation.adapters.AllocationMethodAdapter.java

License:Apache License

void calculateArrayLengthAndDispatch(final String typeName, final int dimCount) {
    // Since the dimensions of the array are not known at instrumentation
    // time, we take the created multi-dimensional array and peel off nesting
    // levels from the left.  For each nesting layer we probe the array length
    // and accumulate a partial product which we can then feed the recording
    // function./*from  w  w w . j a  v  a 2s  .  c o  m*/

    // below we note the partial product of dimensions 1 to X-1 as productToX
    // (so productTo1 == 1 == no dimensions yet).  We denote by aref0 the
    // array reference at the current nesting level (the containing aref's [0]
    // element).  If we hit a level whose arraylength is 0 there's no point
    // continuing so we shortcut out.
    final Label zeroDimension = new Label();
    super.visitInsn(Opcodes.DUP); // -> stack: ... origaref aref0
    super.visitLdcInsn(1); // -> stack: ... origaref aref0 productTo1
    for (int i = 0; i < dimCount; ++i) {
        // pre: stack: ... origaref aref0 productToI
        super.visitInsn(Opcodes.SWAP); // -> stack: ... origaref productToI aref
        super.visitInsn(Opcodes.DUP_X1);
        // -> stack: ... origaref aref0 productToI aref
        super.visitInsn(Opcodes.ARRAYLENGTH);
        // -> stack: ... origaref aref0 productToI dimI

        final Label nonZeroDimension = new Label();
        super.visitInsn(Opcodes.DUP);
        // -> stack: ... origaref aref0 productToI dimI dimI
        super.visitJumpInsn(Opcodes.IFNE, nonZeroDimension);
        // -> stack: ... origaref aref0 productToI dimI
        super.visitInsn(Opcodes.POP);
        // -> stack: ... origaref aref0 productToI
        super.visitJumpInsn(Opcodes.GOTO, zeroDimension);
        super.visitLabel(nonZeroDimension);
        // -> stack: ... origaref aref0 productToI max(dimI,1)

        super.visitInsn(Opcodes.IMUL);
        // -> stack: ... origaref aref0 productTo{I+1}
        if (i < dimCount - 1) {
            super.visitInsn(Opcodes.SWAP);
            // -> stack: ... origaref productTo{I+1} aref0
            super.visitInsn(Opcodes.ICONST_0);
            // -> stack: ... origaref productTo{I+1} aref0 0
            super.visitInsn(Opcodes.AALOAD);
            // -> stack: ... origaref productTo{I+1} aref0'
            super.visitInsn(Opcodes.SWAP);
        }
        // post: stack: ... origaref aref0 productTo{I+1}
    }
    super.visitLabel(zeroDimension);

    super.visitInsn(Opcodes.SWAP); // -> stack: ... origaref product aref0
    super.visitInsn(Opcodes.POP); // -> stack: ... origaref product
    super.visitInsn(Opcodes.SWAP); // -> stack: ... product origaref
    invokeRecordAllocation(typeName);
}

From source file:com.google.template.soy.basicfunctions.IsNonnullFunction.java

License:Apache License

@Override
public SoyExpression computeForJbcSrc(JbcSrcPluginContext context, List<SoyExpression> args) {
    final SoyExpression arg = args.get(0);
    if (BytecodeUtils.isPrimitive(arg.resultType())) {
        return SoyExpression.TRUE;
    }/*from w  ww  .j  a  v a2  s . c  o  m*/
    // This is what javac generates for 'someObject != null'
    return SoyExpression.forBool(new Expression(Type.BOOLEAN_TYPE, arg.features()) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            arg.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.basicfunctions.IsNullFunction.java

License:Apache License

@Override
public SoyExpression computeForJbcSrc(JbcSrcPluginContext context, List<SoyExpression> args) {
    final SoyExpression arg = args.get(0);
    if (BytecodeUtils.isPrimitive(arg.resultType())) {
        return SoyExpression.FALSE;
    }/*from   www  . j a  v a  2 s  .c o m*/
    // This is what javac generates for 'someObject == null'
    return SoyExpression.forBool(new Expression(Type.BOOLEAN_TYPE, arg.features()) {
        @Override
        protected void doGen(CodeBuilder adapter) {
            arg.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.BytecodeProducer.java

License:Apache License

/** Writes the bytecode to the adapter. */
final void gen(CodeBuilder adapter) {
    boolean shouldClearIsGeneratingBit = false;
    if (Flags.DEBUG && !isGenerating.get()) {
        isGenerating.set(true);//from w  w w.  ja  va2s . com
        shouldClearIsGeneratingBit = true;
    }
    try {
        if (location.isPresent()) {
            // These add entries to the line number tables that are associated with the current method.
            // The line number table is just a mapping of 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.get().getLineNumber(), start);
        }

        doGen(adapter);

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