Java Label类代码示例

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitTryCatchBlock(final Label start, final Label end,
        final Label handler, final String type) {
    buf.setLength(0);
    declareLabel(start);
    declareLabel(end);
    declareLabel(handler);
    buf.append(name).append(".visitTryCatchBlock(");
    appendLabel(start);
    buf.append(", ");
    appendLabel(end);
    buf.append(", ");
    appendLabel(handler);
    buf.append(", ");
    appendConstant(type);
    buf.append(");\n");
    text.add(buf.toString());
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
protected Attribute read(ClassReader cr,
                         int off,
                         int len,
                         char[] buf,
                         int codeOff,
                         Label[] labels)
{
    // package count
    int package_count = cr.readUnsignedShort(off);
    off += 2;

    // packages
    Set<String> packages = new HashSet<>();
    for (int i=0; i<package_count; i++) {
        String pkg = cr.readPackage(off, buf).replace('/', '.');
        packages.add(pkg);
        off += 2;
    }

    return new ModulePackagesAttribute(packages);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
private StringBuilder appendOpcode(final StringBuilder sb, final int opcode) {
    final Label next = getNextLabel();
    if (next instanceof NashornLabel) {
        final int bci = next.getOffset();
        if (bci != -1) {
            final String bcis = "" + bci;
            for (int i = 0; i < 5 - bcis.length(); i++) {
                sb.append(' ');
            }
            sb.append(bcis);
            sb.append(' ');
        } else {
            sb.append("       ");
        }
    }

    return sb.append(tab2).append(OPCODES[opcode].toLowerCase());
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLocalVariable(final String name, final String desc,
        final String signature, final Label start, final Label end,
        final int index) {
    buf.setLength(0);
    buf.append(this.name).append(".visitLocalVariable(");
    appendConstant(name);
    buf.append(", ");
    appendConstant(desc);
    buf.append(", ");
    appendConstant(signature);
    buf.append(", ");
    appendLabel(start);
    buf.append(", ");
    appendLabel(end);
    buf.append(", ").append(index).append(");\n");
    text.add(buf.toString());
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLocalVariable(final String name, final String desc,
        final String signature, final Label start, final Label end,
        final int index) {
    checkStartCode();
    checkEndCode();
    checkUnqualifiedName(version, name, "name");
    checkDesc(desc, false);
    checkLabel(start, true, "start label");
    checkLabel(end, true, "end label");
    checkUnsignedShort(index, "Invalid variable index");
    int s = labels.get(start).intValue();
    int e = labels.get(end).intValue();
    if (e < s) {
        throw new IllegalArgumentException(
                "Invalid start and end labels (end must be greater than start)");
    }
    super.visitLocalVariable(name, desc, signature, start, end, index);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitTableSwitchInsn(final int min, final int max,
        final Label dflt, final Label... labels) {
    checkStartCode();
    checkEndCode();
    if (max < min) {
        throw new IllegalArgumentException("Max = " + max
                + " must be greater than or equal to min = " + min);
    }
    checkLabel(dflt, false, "default label");
    checkNonDebugLabel(dflt);
    if (labels == null || labels.length != max - min + 1) {
        throw new IllegalArgumentException(
                "There must be max - min + 1 labels");
    }
    for (int i = 0; i < labels.length; ++i) {
        checkLabel(labels[i], false, "label at index " + i);
        checkNonDebugLabel(labels[i]);
    }
    super.visitTableSwitchInsn(min, max, dflt, labels);
    for (int i = 0; i < labels.length; ++i) {
        usedLabels.add(labels[i]);
    }
    ++insnCount;
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitMaxs(final int maxStack, final int maxLocals) {
    checkStartCode();
    checkEndCode();
    endCode = true;
    for (Label l : usedLabels) {
        if (labels.get(l) == null) {
            throw new IllegalStateException("Undefined label used");
        }
    }
    for (int i = 0; i < handlers.size();) {
        Integer start = labels.get(handlers.get(i++));
        Integer end = labels.get(handlers.get(i++));
        if (start == null || end == null) {
            throw new IllegalStateException(
                    "Undefined try catch block labels");
        }
        if (end.intValue() <= start.intValue()) {
            throw new IllegalStateException(
                    "Emty try catch block handler range");
        }
    }
    checkUnsignedShort(maxStack, "Invalid max stack");
    checkUnsignedShort(maxLocals, "Invalid max locals");
    super.visitMaxs(maxStack, maxLocals);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitTryCatchBlock(final Label start, final Label end,
        final Label handler, final String type) {
    checkStartCode();
    checkEndCode();
    checkLabel(start, false, "start label");
    checkLabel(end, false, "end label");
    checkLabel(handler, false, "handler label");
    checkNonDebugLabel(start);
    checkNonDebugLabel(end);
    checkNonDebugLabel(handler);
    if (labels.get(start) != null || labels.get(end) != null
            || labels.get(handler) != null) {
        throw new IllegalStateException(
                "Try catch blocks must be visited before their labels");
    }
    if (type != null) {
        checkInternalName(type, "type");
    }
    super.visitTryCatchBlock(start, end, handler, type);
    handlers.add(start);
    handlers.add(end);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
        final Label[] labels) {
    buf.setLength(0);
    for (int i = 0; i < labels.length; ++i) {
        declareLabel(labels[i]);
    }
    declareLabel(dflt);

    buf.append(name).append(".visitLookupSwitchInsn(");
    appendLabel(dflt);
    buf.append(", new int[] {");
    for (int i = 0; i < keys.length; ++i) {
        buf.append(i == 0 ? " " : ", ").append(keys[i]);
    }
    buf.append(" }, new Label[] {");
    for (int i = 0; i < labels.length; ++i) {
        buf.append(i == 0 ? " " : ", ");
        appendLabel(labels[i]);
    }
    buf.append(" });\n");
    text.add(buf.toString());
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLabel(final Label label) {
    buf.setLength(0);
    buf.append(ltab);
    appendLabel(label);
    buf.append('\n');
    text.add(buf.toString());
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public AnnotationVisitor visitLocalVariableAnnotation(int typeRef,
        TypePath typePath, Label[] start, Label[] end, int[] index,
        String desc, boolean visible) {
    AnnotationVisitor av = super.visitLocalVariableAnnotation(typeRef,
            typePath, start, end, index, remapper.mapDesc(desc), visible);
    return av == null ? av : new RemappingAnnotationAdapter(av, remapper);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLocalVariable(final String name, final String desc,
        final String signature, final Label start, final Label end,
        final int index) {
    int newIndex = remap(index, Type.getType(desc));
    mv.visitLocalVariable(name, desc, signature, start, end, newIndex);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitLabel(final Label label) {
    if (mv != null) {
        mv.visitLabel(label);
    }
    if (labels == null) {
        labels = new ArrayList<Label>(3);
    }
    labels.add(label);
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitJumpInsn(final int opcode, final Label label) {
    mv.visitJumpInsn(opcode, label);
    if (constructor) {
        switch (opcode) {
        case IFEQ:
        case IFNE:
        case IFLT:
        case IFGE:
        case IFGT:
        case IFLE:
        case IFNULL:
        case IFNONNULL:
            popValue();
            break;
        case IF_ICMPEQ:
        case IF_ICMPNE:
        case IF_ICMPLT:
        case IF_ICMPGE:
        case IF_ICMPGT:
        case IF_ICMPLE:
        case IF_ACMPEQ:
        case IF_ACMPNE:
            popValue();
            popValue();
            break;
        case JSR:
            pushValue(OTHER);
            break;
        }
        addBranch(label);
    }
}
 

import jdk.internal.org.objectweb.asm.Label; //导入依赖的package包/类
@Override
public void visitJumpInsn(final int opcode, final Label label) {
    if (mv != null) {
        mv.visitJumpInsn(opcode, label);
    }
    execute(opcode, 0, null);
    if (opcode == Opcodes.GOTO) {
        this.locals = null;
        this.stack = null;
    }
}