/*

 * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.javap;

import com.sun.tools.classfile.AccessFlags;

import com.sun.tools.classfile.Code_attribute;

import com.sun.tools.classfile.ConstantPool;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.DescriptorException;

import com.sun.tools.classfile.Method;

import static com.sun.tools.classfile.OpCodes.*;

/*

 *  Write the contents of a Code attribute.

 *

 *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If

 *  you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

class CodeWriter extends BasicWriter {

    static CodeWriter instance(Context context) {

        CodeWriter instance = context.get(CodeWriter.class);

        if (instance == null)

            instance = new CodeWriter(context);

        return instance;

    }

    protected CodeWriter(Context context) {

        super(context);

        context.put(CodeWriter.class, this);

        attrWriter = AttributeWriter.instance(context);

        classWriter = ClassWriter.instance(context);

        constantWriter = ConstantWriter.instance(context);

    }

    void write(Code_attribute attr, ConstantPool constant_pool) {

        println("  Code:");

        writeVerboseHeader(attr, constant_pool);

        writeInstrs(attr);

        writeExceptionTable(attr);

        attrWriter.write(attr, attr.attributes, constant_pool);

    }

    public void writeVerboseHeader(Code_attribute attr, ConstantPool constant_pool) {

        Method method = classWriter.getMethod();

        String argCount;

        try {

            int n = method.descriptor.getParameterCount(constant_pool);

            if (!method.access_flags.is(AccessFlags.ACC_STATIC))

                ++n;  // for 'this'

            argCount = Integer.toString(n);

        } catch (ConstantPoolException e) {

            argCount = report(e);

        } catch (DescriptorException e) {

            argCount = report(e);

        }

        println("   Stack=" + attr.max_stack +

                ", Locals=" + attr.max_locals +

                ", Args_size=" + argCount);

    }

    public void writeInstrs(Code_attribute attr) {

        try {

            for (int pc = 0; pc < attr.code_length;) {

                print("   " + pc + ":\t");

                pc += writeInstr(attr, pc);

                println();

            }

        } catch (Code_attribute.InvalidIndex e) {

            println(report(e));

        }

    }

    public int writeInstr(Code_attribute attr, int pc)

            throws Code_attribute.InvalidIndex {

        String lP = "";

        int opcode = attr.getUnsignedByte(pc);

        int opcode2;

        String mnem;

        switch (opcode) {

            case opc_nonpriv:

            case opc_priv: {

                opcode2 = attr.getUnsignedByte(pc + 1);

                mnem = opcName((opcode << 8) + opcode2);

                if (mnem == null) {

                    mnem = opcName(opcode) + " " + opcode2;

                }

                print(mnem);

                return 2;

            }

            case opc_wide: {

                opcode2 = attr.getUnsignedByte(pc + 1);

                mnem = opcName((opcode << 8) + opcode2);

                if (mnem == null) {

                    print("bytecode " + opcode);

                    return 1;

                }

                print(mnem + " " + attr.getUnsignedShort(pc + 2));

                if (opcode2 == opc_iinc) {

                    print(", " + attr.getShort(pc + 4));

                    return 6;

                }

                return 4;

            }

        }

        mnem = opcName(opcode);

        if (mnem == null) {

            print("bytecode " + opcode);

            return 1;

        }

        if (opcode > opc_jsr_w) {

            print("bytecode " + opcode);

            return 1;

        }

        print(opcName(opcode));

        switch (opcode) {

            case opc_aload:

            case opc_astore:

            case opc_fload:

            case opc_fstore:

            case opc_iload:

            case opc_istore:

            case opc_lload:

            case opc_lstore:

            case opc_dload:

            case opc_dstore:

            case opc_ret:

                print("\t" + attr.getUnsignedByte(pc + 1));

                return 2;

            case opc_iinc:

                print("\t" + attr.getUnsignedByte(pc + 1) + ", " + attr.getByte(pc + 2));

                return 3;

            case opc_tableswitch:

                {

                    int tb = align(pc + 1);

                    int default_skip = attr.getInt(tb);

                    int low = attr.getInt(tb + 4);

                    int high = attr.getInt(tb + 8);

                    int count = high - low;

                    print("{ //" + low + " to " + high);

                    for (int i = 0; i <= count; i++) {

                        print("\n\t\t" + (i + low) + ": " + lP + (pc + attr.getInt(tb + 12 + 4 * i)) + ";");

                    }

                    print("\n\t\tdefault: " + lP + (default_skip + pc) + " }");

                    return tb - pc + 16 + count * 4;

                }

            case opc_lookupswitch:

                {

                    int tb = align(pc + 1);

                    int default_skip = attr.getInt(tb);

                    int npairs = attr.getInt(tb + 4);

                    print("{ //" + npairs);

                    for (int i = 1; i <= npairs; i++) {

                        print("\n\t\t" + attr.getInt(tb + i * 8) + ": " + lP + (pc + attr.getInt(tb + 4 + i * 8)) + ";");

                    }

                    print("\n\t\tdefault: " + lP + (default_skip + pc) + " }");

                    return tb - pc + (npairs + 1) * 8;

                }

            case opc_newarray:

                int type = attr.getUnsignedByte(pc + 1);

                switch (type) {

                    case T_BOOLEAN:

                        print(" boolean");

                        break;

                    case T_BYTE:

                        print(" byte");

                        break;

                    case T_CHAR:

                        print(" char");

                        break;

                    case T_SHORT:

                        print(" short");

                        break;

                    case T_INT:

                        print(" int");

                        break;

                    case T_LONG:

                        print(" long");

                        break;

                    case T_FLOAT:

                        print(" float");

                        break;

                    case T_DOUBLE:

                        print(" double");

                        break;

                    case T_CLASS:

                        print(" class");

                        break;

                    default:

                        print(" BOGUS TYPE:" + type);

                }

                return 2;

            case opc_anewarray:

                {

                    int index = attr.getUnsignedShort(pc + 1);

                    print("\t#" + index + "; //");

                    printConstant(index);

                    return 3;

                }

            case opc_sipush:

                print("\t" + attr.getShort(pc + 1));

                return 3;

            case opc_bipush:

                print("\t" + attr.getByte(pc + 1));

                return 2;

            case opc_ldc:

                {

                    int index = attr.getUnsignedByte(pc + 1);

                    print("\t#" + index + "; //");

                    printConstant(index);

                    return 2;

                }

            case opc_ldc_w:

            case opc_ldc2_w:

            case opc_instanceof:

            case opc_checkcast:

            case opc_new:

            case opc_putstatic:

            case opc_getstatic:

            case opc_putfield:

            case opc_getfield:

            case opc_invokevirtual:

            case opc_invokespecial:

            case opc_invokestatic:

                {

                    int index = attr.getUnsignedShort(pc + 1);

                    print("\t#" + index + "; //");

                    printConstant(index);

                    return 3;

                }

            case opc_invokeinterface:

                {

                    int index = attr.getUnsignedShort(pc + 1);

                    int nargs = attr.getUnsignedByte(pc + 3);

                    print("\t#" + index + ",  " + nargs + "; //");

                    printConstant(index);

                    return 5;

                }

            case opc_multianewarray:

                {

                    int index = attr.getUnsignedShort(pc + 1);

                    int dimensions = attr.getUnsignedByte(pc + 3);

                    print("\t#" + index + ",  " + dimensions + "; //");

                    printConstant(index);

                    return 4;

                }

            case opc_jsr:

            case opc_goto:

            case opc_ifeq:

            case opc_ifge:

            case opc_ifgt:

            case opc_ifle:

            case opc_iflt:

            case opc_ifne:

            case opc_if_icmpeq:

            case opc_if_icmpne:

            case opc_if_icmpge:

            case opc_if_icmpgt:

            case opc_if_icmple:

            case opc_if_icmplt:

            case opc_if_acmpeq:

            case opc_if_acmpne:

            case opc_ifnull:

            case opc_ifnonnull:

                print("\t" + lP + (pc + attr.getShort(pc + 1)));

                return 3;

            case opc_jsr_w:

            case opc_goto_w:

                print("\t" + lP + (pc + attr.getInt(pc + 1)));

                return 5;

            default:

                return 1;

        }

    }

    public void writeExceptionTable(Code_attribute attr) {

        if (attr.exception_table_langth > 0) {

            println("  Exception table:");

            println("   from   to  target type");

            for (int i = 0; i < attr.exception_table.length; i++) {

                Code_attribute.Exception_data handler = attr.exception_table[i];

                printFixedWidthInt(handler.start_pc, 6);

                printFixedWidthInt(handler.end_pc, 6);

                printFixedWidthInt(handler.handler_pc, 6);

                print("   ");

                int catch_type = handler.catch_type;

                if (catch_type == 0) {

                    println("any");

                } else {

                    print("Class ");

                    println(constantWriter.stringValue(catch_type));

                    println("");

                }

            }

        }

    }

    private void printConstant(int index) {

        constantWriter.write(index);

    }

    private void printFixedWidthInt(int n, int width) {

        String s = String.valueOf(n);

        for (int i = s.length(); i < width; i++)

            print(" ");

        print(s);

    }

    private static int align(int n) {

        return (n + 3) & ~3;

    }

    private AttributeWriter attrWriter;

    private ClassWriter classWriter;

    private ConstantWriter constantWriter;

}