import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
/**
 * Checks a given class.
 *
 * @param cr
 *            a <code>ClassReader</code> that contains bytecode for the
 *            analysis.
 * @param loader
 *            a <code>ClassLoader</code> which will be used to load
 *            referenced classes. This is useful if you are verifiying
 *            multiple interdependent classes.
 * @param dump
 *            true if bytecode should be printed out not only when errors
 *            are found.
 * @param pw
 *            write where results going to be printed
 */
public static void verify(final ClassReader cr, final ClassLoader loader,
        final boolean dump, final PrintWriter pw) {
    ClassNode cn = new ClassNode();
    cr.accept(new CheckClassAdapter(cn, false), ClassReader.SKIP_DEBUG);

    Type syperType = cn.superName == null ? null : Type
            .getObjectType(cn.superName);
    List<MethodNode> methods = cn.methods;

    List<Type> interfaces = new ArrayList<Type>();
    for (Iterator<String> i = cn.interfaces.iterator(); i.hasNext();) {
        interfaces.add(Type.getObjectType(i.next()));
    }

    for (int i = 0; i < methods.size(); ++i) {
        MethodNode method = methods.get(i);
        SimpleVerifier verifier = new SimpleVerifier(
                Type.getObjectType(cn.name), syperType, interfaces,
                (cn.access & Opcodes.ACC_INTERFACE) != 0);
        Analyzer<BasicValue> a = new Analyzer<BasicValue>(verifier);
        if (loader != null) {
            verifier.setClassLoader(loader);
        }
        try {
            a.analyze(cn.name, method);
            if (!dump) {
                continue;
            }
        } catch (Exception e) {
            e.printStackTrace(pw);
        }
        printAnalyzerResult(method, a, pw);
    }
    pw.flush();
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
static void printAnalyzerResult(MethodNode method, Analyzer<BasicValue> a,
        final PrintWriter pw) {
    Frame<BasicValue>[] frames = a.getFrames();
    Textifier t = new Textifier();
    TraceMethodVisitor mv = new TraceMethodVisitor(t);

    pw.println(method.name + method.desc);
    for (int j = 0; j < method.instructions.size(); ++j) {
        method.instructions.get(j).accept(mv);

        StringBuilder sb = new StringBuilder();
        Frame<BasicValue> f = frames[j];
        if (f == null) {
            sb.append('?');
        } else {
            for (int k = 0; k < f.getLocals(); ++k) {
                sb.append(getShortName(f.getLocal(k).toString()))
                        .append(' ');
            }
            sb.append(" : ");
            for (int k = 0; k < f.getStackSize(); ++k) {
                sb.append(getShortName(f.getStack(k).toString()))
                        .append(' ');
            }
        }
        while (sb.length() < method.maxStack + method.maxLocals + 1) {
            sb.append(' ');
        }
        pw.print(Integer.toString(j + 100000).substring(1));
        pw.print(" " + sb + " : " + t.text.get(t.text.size() - 1));
    }
    for (int j = 0; j < method.tryCatchBlocks.size(); ++j) {
        method.tryCatchBlocks.get(j).accept(mv);
        pw.print(" " + t.text.get(t.text.size() - 1));
    }
    pw.println();
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
/**
 * Constructs a new {@link CheckMethodAdapter} object. This method adapter
 * will perform basic data flow checks. For instance in a method whose
 * signature is <tt>void m ()</tt>, the invalid instruction IRETURN, or the
 * invalid sequence IADD L2I will be detected.
 *
 * @param access
 *            the method's access flags.
 * @param name
 *            the method's name.
 * @param desc
 *            the method's descriptor (see {@link Type Type}).
 * @param cmv
 *            the method visitor to which this adapter must delegate calls.
 * @param labels
 *            a map of already visited labels (in other methods).
 */
public CheckMethodAdapter(final int access, final String name,
        final String desc, final MethodVisitor cmv,
        final Map<Label, Integer> labels) {
    this(new MethodNode(Opcodes.ASM5, access, name, desc, null, null) {
        @Override
        public void visitEnd() {
            Analyzer<BasicValue> a = new Analyzer<BasicValue>(
                    new BasicVerifier());
            try {
                a.analyze("dummy", this);
            } catch (Exception e) {
                if (e instanceof IndexOutOfBoundsException
                        && maxLocals == 0 && maxStack == 0) {
                    throw new RuntimeException(
                            "Data flow checking option requires valid, non zero maxLocals and maxStack values.");
                }
                e.printStackTrace();
                StringWriter sw = new StringWriter();
                PrintWriter pw = new PrintWriter(sw, true);
                CheckClassAdapter.printAnalyzerResult(this, a, pw);
                pw.close();
                throw new RuntimeException(e.getMessage() + ' '
                        + sw.toString());
            }
            accept(cmv);
        }
    }, labels);
    this.access = access;
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
private void analyze() throws AnalyzerException {
    Analyzer<BasicValue> analyzer = new Analyzer<BasicValue>(new BasicInterpreter()) {

        @Override
        protected boolean newControlFlowExceptionEdge(int insn,
                int successor) {
            List<Integer> lst = handlers.get(successor);
            if (lst == null) {
                lst = new ArrayList<>();
                handlers.put(successor, lst);
            }
            lst.add(insn);
            return true;
        }

        @Override
        protected void newControlFlowEdge(int from,
                int to) {
            if (root == null) {
                root = new InstructionNode(from, method.instructions.get(from));
                instructions.put(from, root);
            }
            InstructionNode fromNode = instructions.get(from);
            if (fromNode == null) {
                fromNode = new InstructionNode(from, method.instructions.get(from));
                instructions.put(from, fromNode);
            }
            InstructionNode toNode = instructions.get(to);
            if (toNode == null) {
                toNode = new InstructionNode(to, method.instructions.get(to));
                instructions.put(to, toNode);
            }
            if (!fromNode.next.contains(toNode)) {
                fromNode.next.add(toNode);
            }

        }
    };
    analyzer.analyze(owner, method);
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
static void printAnalyzerResult(MethodNode method, Analyzer<BasicValue> a,
        final PrintWriter pw) {
    Frame<BasicValue>[] frames = a.getFrames();
    Textifier t = new Textifier();
    TraceMethodVisitor mv = new TraceMethodVisitor(t);

    pw.println(method.name + method.desc);
    for (int j = 0; j < method.instructions.size(); ++j) {
        method.instructions.get(j).accept(mv);

        StringBuffer s = new StringBuffer();
        Frame<BasicValue> f = frames[j];
        if (f == null) {
            s.append('?');
        } else {
            for (int k = 0; k < f.getLocals(); ++k) {
                s.append(getShortName(f.getLocal(k).toString()))
                        .append(' ');
            }
            s.append(" : ");
            for (int k = 0; k < f.getStackSize(); ++k) {
                s.append(getShortName(f.getStack(k).toString()))
                        .append(' ');
            }
        }
        while (s.length() < method.maxStack + method.maxLocals + 1) {
            s.append(' ');
        }
        pw.print(Integer.toString(j + 100000).substring(1));
        pw.print(" " + s + " : " + t.text.get(t.text.size() - 1));
    }
    for (int j = 0; j < method.tryCatchBlocks.size(); ++j) {
        method.tryCatchBlocks.get(j).accept(mv);
        pw.print(" " + t.text.get(t.text.size() - 1));
    }
    pw.println();
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
static void printAnalyzerResult(
    MethodNode method,
    Analyzer<BasicValue> a,
    final PrintWriter pw)
{
    Frame<BasicValue>[] frames = a.getFrames();
    Textifier t = new Textifier();
    TraceMethodVisitor mv = new TraceMethodVisitor(t);

    pw.println(method.name + method.desc);
    for (int j = 0; j < method.instructions.size(); ++j) {
        method.instructions.get(j).accept(mv);

        StringBuffer s = new StringBuffer();
        Frame<BasicValue> f = frames[j];
        if (f == null) {
            s.append('?');
        } else {
            for (int k = 0; k < f.getLocals(); ++k) {
                s.append(getShortName(f.getLocal(k).toString()))
                        .append(' ');
            }
            s.append(" : ");
            for (int k = 0; k < f.getStackSize(); ++k) {
                s.append(getShortName(f.getStack(k).toString()))
                        .append(' ');
            }
        }
        while (s.length() < method.maxStack + method.maxLocals + 1) {
            s.append(' ');
        }
        pw.print(Integer.toString(j + 100000).substring(1));
        pw.print(" " + s + " : " + t.text.get(t.text.size() - 1));
    }
    for (int j = 0; j < method.tryCatchBlocks.size(); ++j) {
        method.tryCatchBlocks.get(j).accept(mv);
        pw.print(" " + t.text.get(t.text.size() - 1));
    }
    pw.println();
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
/**
 * Constructs a new {@link CheckMethodAdapter} object. This method adapter
 * will perform basic data flow checks. For instance in a method whose
 * signature is <tt>void m ()</tt>, the invalid instruction IRETURN, or the
 * invalid sequence IADD L2I will be detected.
 *
 * @param access the method's access flags.
 * @param name the method's name.
 * @param desc the method's descriptor (see {@link Type Type}).
 * @param cmv the method visitor to which this adapter must delegate calls.
 * @param labels a map of already visited labels (in other methods).
 */
public CheckMethodAdapter(
    final int access,
    final String name,
    final String desc,
    final MethodVisitor cmv,
    final Map<Label, Integer> labels)
{
    this(new MethodNode(access, name, desc, null, null) {
        @Override
        public void visitEnd() {
            Analyzer<BasicValue> a = new Analyzer<BasicValue>(new BasicVerifier());
            try {
                a.analyze("dummy", this);
            } catch (Exception e) {
                if (e instanceof IndexOutOfBoundsException
                        && maxLocals == 0 && maxStack == 0)
                {
                    throw new RuntimeException("Data flow checking option requires valid, non zero maxLocals and maxStack values.");
                }
                e.printStackTrace();
                StringWriter sw = new StringWriter();
                PrintWriter pw = new PrintWriter(sw, true);
                CheckClassAdapter.printAnalyzerResult(this, a, pw);
                pw.close();
                throw new RuntimeException(e.getMessage() + ' '
                        + sw.toString());
            }
            accept(cmv);
        }
    },
            labels);
}
 

import jdk.internal.org.objectweb.asm.tree.analysis.BasicValue; //导入依赖的package包/类
/**
 * Checks a given class.
 *
 * @param cr a <code>ClassReader</code> that contains bytecode for the
 *        analysis.
 * @param loader a <code>ClassLoader</code> which will be used to load
 *        referenced classes. This is useful if you are verifiying multiple
 *        interdependent classes.
 * @param dump true if bytecode should be printed out not only when errors
 *        are found.
 * @param pw write where results going to be printed
 */
public static void verify(
    final ClassReader cr,
    final ClassLoader loader,
    final boolean dump,
    final PrintWriter pw)
{
    ClassNode cn = new ClassNode();
    cr.accept(new CheckClassAdapter(cn, false), ClassReader.SKIP_DEBUG);

    Type syperType = cn.superName == null
            ? null
            : Type.getObjectType(cn.superName);
    List<MethodNode> methods = cn.methods;

    List<Type> interfaces = new ArrayList<Type>();
    for (Iterator<String> i = cn.interfaces.iterator(); i.hasNext();) {
        interfaces.add(Type.getObjectType(i.next().toString()));
    }

    for (int i = 0; i < methods.size(); ++i) {
        MethodNode method = methods.get(i);
        SimpleVerifier verifier = new SimpleVerifier(Type.getObjectType(cn.name),
                syperType,
                interfaces,
                (cn.access & Opcodes.ACC_INTERFACE) != 0);
        Analyzer<BasicValue> a = new Analyzer<BasicValue>(verifier);
        if (loader != null) {
            verifier.setClassLoader(loader);
        }
        try {
            a.analyze(cn.name, method);
            if (!dump) {
                continue;
            }
        } catch (Exception e) {
            e.printStackTrace(pw);
        }
        printAnalyzerResult(method, a, pw);
    }
    pw.flush();
}