/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.bcel.util;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.BitSet;
import org.apache.bcel.Const;
import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.ConstantFieldref;
import org.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.apache.bcel.classfile.ConstantInvokeDynamic;
import org.apache.bcel.classfile.ConstantMethodref;
import org.apache.bcel.classfile.ConstantNameAndType;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.classfile.Utility;
/**
* Convert code into HTML file.
*
* @version $Id$
*
*/
final class CodeHTML {
private final String class_name; // name of current class
// private Method[] methods; // Methods to print
private final PrintWriter file; // file to write to
private BitSet goto_set;
private final ConstantPool constant_pool;
private final ConstantHTML constant_html;
private static boolean wide = false;
CodeHTML(final String dir, final String class_name, final Method[] methods, final ConstantPool constant_pool,
final ConstantHTML constant_html) throws IOException {
this.class_name = class_name;
// this.methods = methods;
this.constant_pool = constant_pool;
this.constant_html = constant_html;
file = new PrintWriter(new FileOutputStream(dir + class_name + "_code.html"));
file.println("");
for (int i = 0; i < methods.length; i++) {
writeMethod(methods[i], i);
}
file.println("");
file.close();
}
/**
* Disassemble a stream of byte codes and return the
* string representation.
*
* @param stream data input stream
* @return String representation of byte code
*/
private String codeToHTML( final ByteSequence bytes, final int method_number ) throws IOException {
final short opcode = (short) bytes.readUnsignedByte();
String name;
String signature;
int default_offset = 0;
int low;
int high;
int index;
int class_index;
int vindex;
int constant;
int[] jump_table;
int no_pad_bytes = 0;
int offset;
final StringBuilder buf = new StringBuilder(256); // CHECKSTYLE IGNORE MagicNumber
buf.append("").append(Const.getOpcodeName(opcode)).append("");
/* Special case: Skip (0-3) padding bytes, i.e., the
* following bytes are 4-byte-aligned
*/
if ((opcode == Const.TABLESWITCH) || (opcode == Const.LOOKUPSWITCH)) {
final int remainder = bytes.getIndex() % 4;
no_pad_bytes = (remainder == 0) ? 0 : 4 - remainder;
for (int i = 0; i < no_pad_bytes; i++) {
bytes.readByte();
}
// Both cases have a field default_offset in common
default_offset = bytes.readInt();
}
switch (opcode) {
case Const.TABLESWITCH:
low = bytes.readInt();
high = bytes.readInt();
offset = bytes.getIndex() - 12 - no_pad_bytes - 1;
default_offset += offset;
buf.append("");
// Print switch indices in first row (and default)
jump_table = new int[high - low + 1];
for (int i = 0; i < jump_table.length; i++) {
jump_table[i] = offset + bytes.readInt();
buf.append("| ").append(low + i).append(" | ");
}
buf.append("default | \n");
// Print target and default indices in second row
for (final int element : jump_table) {
buf.append("| ").append(element).append(" | ");
}
buf.append("").append(default_offset).append(
" | \n
\n");
break;
/* Lookup switch has variable length arguments.
*/
case Const.LOOKUPSWITCH:
final int npairs = bytes.readInt();
offset = bytes.getIndex() - 8 - no_pad_bytes - 1;
jump_table = new int[npairs];
default_offset += offset;
buf.append("");
// Print switch indices in first row (and default)
for (int i = 0; i < npairs; i++) {
final int match = bytes.readInt();
jump_table[i] = offset + bytes.readInt();
buf.append("| ").append(match).append(" | ");
}
buf.append("default | \n");
// Print target and default indices in second row
for (int i = 0; i < npairs; i++) {
buf.append("| ").append(jump_table[i]).append(" | ");
}
buf.append("").append(default_offset).append(
" | \n
\n");
break;
/* Two address bytes + offset from start of byte stream form the
* jump target.
*/
case Const.GOTO:
case Const.IFEQ:
case Const.IFGE:
case Const.IFGT:
case Const.IFLE:
case Const.IFLT:
case Const.IFNE:
case Const.IFNONNULL:
case Const.IFNULL:
case Const.IF_ACMPEQ:
case Const.IF_ACMPNE:
case Const.IF_ICMPEQ:
case Const.IF_ICMPGE:
case Const.IF_ICMPGT:
case Const.IF_ICMPLE:
case Const.IF_ICMPLT:
case Const.IF_ICMPNE:
case Const.JSR:
index = bytes.getIndex() + bytes.readShort() - 1;
buf.append("").append(index).append("");
break;
/* Same for 32-bit wide jumps
*/
case Const.GOTO_W:
case Const.JSR_W:
final int windex = bytes.getIndex() + bytes.readInt() - 1;
buf.append("").append(windex).append("");
break;
/* Index byte references local variable (register)
*/
case Const.ALOAD:
case Const.ASTORE:
case Const.DLOAD:
case Const.DSTORE:
case Const.FLOAD:
case Const.FSTORE:
case Const.ILOAD:
case Const.ISTORE:
case Const.LLOAD:
case Const.LSTORE:
case Const.RET:
if (wide) {
vindex = bytes.readShort();
wide = false; // Clear flag
} else {
vindex = bytes.readUnsignedByte();
}
buf.append("%").append(vindex);
break;
/*
* Remember wide byte which is used to form a 16-bit address in the
* following instruction. Relies on that the method is called again with
* the following opcode.
*/
case Const.WIDE:
wide = true;
buf.append("(wide)");
break;
/* Array of basic type.
*/
case Const.NEWARRAY:
buf.append("").append(Const.getTypeName(bytes.readByte())).append(
"");
break;
/* Access object/class fields.
*/
case Const.GETFIELD:
case Const.GETSTATIC:
case Const.PUTFIELD:
case Const.PUTSTATIC:
index = bytes.readShort();
final ConstantFieldref c1 = (ConstantFieldref) constant_pool.getConstant(index,
Const.CONSTANT_Fieldref);
class_index = c1.getClassIndex();
name = constant_pool.getConstantString(class_index, Const.CONSTANT_Class);
name = Utility.compactClassName(name, false);
index = c1.getNameAndTypeIndex();
final String field_name = constant_pool.constantToString(index, Const.CONSTANT_NameAndType);
if (name.equals(class_name)) { // Local field
buf.append("").append(field_name)
.append("\n");
} else {
buf.append(constant_html.referenceConstant(class_index)).append(".").append(
field_name);
}
break;
/* Operands are references to classes in constant pool
*/
case Const.CHECKCAST:
case Const.INSTANCEOF:
case Const.NEW:
index = bytes.readShort();
buf.append(constant_html.referenceConstant(index));
break;
/* Operands are references to methods in constant pool
*/
case Const.INVOKESPECIAL:
case Const.INVOKESTATIC:
case Const.INVOKEVIRTUAL:
case Const.INVOKEINTERFACE:
case Const.INVOKEDYNAMIC:
final int m_index = bytes.readShort();
String str;
if (opcode == Const.INVOKEINTERFACE) { // Special treatment needed
bytes.readUnsignedByte(); // Redundant
bytes.readUnsignedByte(); // Reserved
// int nargs = bytes.readUnsignedByte(); // Redundant
// int reserved = bytes.readUnsignedByte(); // Reserved
final ConstantInterfaceMethodref c = (ConstantInterfaceMethodref) constant_pool
.getConstant(m_index, Const.CONSTANT_InterfaceMethodref);
class_index = c.getClassIndex();
index = c.getNameAndTypeIndex();
name = Class2HTML.referenceClass(class_index);
} else if (opcode == Const.INVOKEDYNAMIC) { // Special treatment needed
bytes.readUnsignedByte(); // Reserved
bytes.readUnsignedByte(); // Reserved
final ConstantInvokeDynamic c = (ConstantInvokeDynamic) constant_pool
.getConstant(m_index, Const.CONSTANT_InvokeDynamic);
index = c.getNameAndTypeIndex();
name = "#" + c.getBootstrapMethodAttrIndex();
} else {
// UNDONE: Java8 now allows INVOKESPECIAL and INVOKESTATIC to
// reference EITHER a Methodref OR an InterfaceMethodref.
// Not sure if that affects this code or not. (markro)
final ConstantMethodref c = (ConstantMethodref) constant_pool.getConstant(m_index,
Const.CONSTANT_Methodref);
class_index = c.getClassIndex();
index = c.getNameAndTypeIndex();
name = Class2HTML.referenceClass(class_index);
}
str = Class2HTML.toHTML(constant_pool.constantToString(constant_pool.getConstant(
index, Const.CONSTANT_NameAndType)));
// Get signature, i.e., types
final ConstantNameAndType c2 = (ConstantNameAndType) constant_pool.getConstant(index,
Const.CONSTANT_NameAndType);
signature = constant_pool.constantToString(c2.getSignatureIndex(), Const.CONSTANT_Utf8);
final String[] args = Utility.methodSignatureArgumentTypes(signature, false);
final String type = Utility.methodSignatureReturnType(signature, false);
buf.append(name).append(".").append(str).append(
"").append("(");
// List arguments
for (int i = 0; i < args.length; i++) {
buf.append(Class2HTML.referenceType(args[i]));
if (i < args.length - 1) {
buf.append(", ");
}
}
// Attach return type
buf.append("):").append(Class2HTML.referenceType(type));
break;
/* Operands are references to items in constant pool
*/
case Const.LDC_W:
case Const.LDC2_W:
index = bytes.readShort();
buf.append("").append(
Class2HTML.toHTML(constant_pool.constantToString(index,
constant_pool.getConstant(index).getTag()))).append("");
break;
case Const.LDC:
index = bytes.readUnsignedByte();
buf.append("").append(
Class2HTML.toHTML(constant_pool.constantToString(index,
constant_pool.getConstant(index).getTag()))).append("");
break;
/* Array of references.
*/
case Const.ANEWARRAY:
index = bytes.readShort();
buf.append(constant_html.referenceConstant(index));
break;
/* Multidimensional array of references.
*/
case Const.MULTIANEWARRAY:
index = bytes.readShort();
final int dimensions = bytes.readByte();
buf.append(constant_html.referenceConstant(index)).append(":").append(dimensions)
.append("-dimensional");
break;
/* Increment local variable.
*/
case Const.IINC:
if (wide) {
vindex = bytes.readShort();
constant = bytes.readShort();
wide = false;
} else {
vindex = bytes.readUnsignedByte();
constant = bytes.readByte();
}
buf.append("%").append(vindex).append(" ").append(constant);
break;
default:
if (Const.getNoOfOperands(opcode) > 0) {
for (int i = 0; i < Const.getOperandTypeCount(opcode); i++) {
switch (Const.getOperandType(opcode, i)) {
case Const.T_BYTE:
buf.append(bytes.readUnsignedByte());
break;
case Const.T_SHORT: // Either branch or index
buf.append(bytes.readShort());
break;
case Const.T_INT:
buf.append(bytes.readInt());
break;
default: // Never reached
throw new IllegalStateException("Unreachable default case reached! "+Const.getOperandType(opcode, i));
}
buf.append(" ");
}
}
}
buf.append(" | ");
return buf.toString();
}
/**
* Find all target addresses in code, so that they can be marked
* with <A NAME = ...>. Target addresses are kept in an BitSet object.
*/
private void findGotos( final ByteSequence bytes, final Code code ) throws IOException {
int index;
goto_set = new BitSet(bytes.available());
int opcode;
/* First get Code attribute from method and the exceptions handled
* (try .. catch) in this method. We only need the line number here.
*/
if (code != null) {
final CodeException[] ce = code.getExceptionTable();
for (final CodeException cex : ce) {
goto_set.set(cex.getStartPC());
goto_set.set(cex.getEndPC());
goto_set.set(cex.getHandlerPC());
}
// Look for local variables and their range
final Attribute[] attributes = code.getAttributes();
for (final Attribute attribute : attributes) {
if (attribute.getTag() == Const.ATTR_LOCAL_VARIABLE_TABLE) {
final LocalVariable[] vars = ((LocalVariableTable) attribute)
.getLocalVariableTable();
for (final LocalVariable var : vars) {
final int start = var.getStartPC();
final int end = start + var.getLength();
goto_set.set(start);
goto_set.set(end);
}
break;
}
}
}
// Get target addresses from GOTO, JSR, TABLESWITCH, etc.
for (; bytes.available() > 0;) {
opcode = bytes.readUnsignedByte();
//System.out.println(getOpcodeName(opcode));
switch (opcode) {
case Const.TABLESWITCH:
case Const.LOOKUPSWITCH:
//bytes.readByte(); // Skip already read byte
final int remainder = bytes.getIndex() % 4;
final int no_pad_bytes = (remainder == 0) ? 0 : 4 - remainder;
int default_offset;
int offset;
for (int j = 0; j < no_pad_bytes; j++) {
bytes.readByte();
}
// Both cases have a field default_offset in common
default_offset = bytes.readInt();
if (opcode == Const.TABLESWITCH) {
final int low = bytes.readInt();
final int high = bytes.readInt();
offset = bytes.getIndex() - 12 - no_pad_bytes - 1;
default_offset += offset;
goto_set.set(default_offset);
for (int j = 0; j < (high - low + 1); j++) {
index = offset + bytes.readInt();
goto_set.set(index);
}
} else { // LOOKUPSWITCH
final int npairs = bytes.readInt();
offset = bytes.getIndex() - 8 - no_pad_bytes - 1;
default_offset += offset;
goto_set.set(default_offset);
for (int j = 0; j < npairs; j++) {
// int match = bytes.readInt();
bytes.readInt();
index = offset + bytes.readInt();
goto_set.set(index);
}
}
break;
case Const.GOTO:
case Const.IFEQ:
case Const.IFGE:
case Const.IFGT:
case Const.IFLE:
case Const.IFLT:
case Const.IFNE:
case Const.IFNONNULL:
case Const.IFNULL:
case Const.IF_ACMPEQ:
case Const.IF_ACMPNE:
case Const.IF_ICMPEQ:
case Const.IF_ICMPGE:
case Const.IF_ICMPGT:
case Const.IF_ICMPLE:
case Const.IF_ICMPLT:
case Const.IF_ICMPNE:
case Const.JSR:
//bytes.readByte(); // Skip already read byte
index = bytes.getIndex() + bytes.readShort() - 1;
goto_set.set(index);
break;
case Const.GOTO_W:
case Const.JSR_W:
//bytes.readByte(); // Skip already read byte
index = bytes.getIndex() + bytes.readInt() - 1;
goto_set.set(index);
break;
default:
bytes.unreadByte();
codeToHTML(bytes, 0); // Ignore output
}
}
}
/**
* Write a single method with the byte code associated with it.
*/
private void writeMethod( final Method method, final int method_number ) throws IOException {
// Get raw signature
final String signature = method.getSignature();
// Get array of strings containing the argument types
final String[] args = Utility.methodSignatureArgumentTypes(signature, false);
// Get return type string
final String type = Utility.methodSignatureReturnType(signature, false);
// Get method name
final String name = method.getName();
final String html_name = Class2HTML.toHTML(name);
// Get method's access flags
String access = Utility.accessToString(method.getAccessFlags());
access = Utility.replace(access, " ", " ");
// Get the method's attributes, the Code Attribute in particular
final Attribute[] attributes = method.getAttributes();
file.print("" + access + " " + "" + Class2HTML.referenceType(type) + " "
+ html_name + "(");
for (int i = 0; i < args.length; i++) {
file.print(Class2HTML.referenceType(args[i]));
if (i < args.length - 1) {
file.print(", ");
}
}
file.println(")
");
Code c = null;
byte[] code = null;
if (attributes.length > 0) {
file.print("Attributes
\n");
for (int i = 0; i < attributes.length; i++) {
byte tag = attributes[i].getTag();
if (tag != Const.ATTR_UNKNOWN) {
file.print("- "
+ Const.getAttributeName(tag) + "
\n");
} else {
file.print("- " + attributes[i] + "
");
}
if (tag == Const.ATTR_CODE) {
c = (Code) attributes[i];
final Attribute[] attributes2 = c.getAttributes();
code = c.getCode();
file.print("");
}
}
file.println("
");
}
if (code != null) { // No code, an abstract method, e.g.
//System.out.println(name + "\n" + Utility.codeToString(code, constant_pool, 0, -1));
// Print the byte code
try (ByteSequence stream = new ByteSequence(code)) {
stream.mark(stream.available());
findGotos(stream, c);
stream.reset();
file.println("Byte
offset | "
+ "Instruction | Argument | ");
for (; stream.available() > 0;) {
final int offset = stream.getIndex();
final String str = codeToHTML(stream, method_number);
String anchor = "";
/*
* Set an anchor mark if this line is targetted by a goto, jsr, etc. Defining an anchor for every
* line is very inefficient!
*/
if (goto_set.get(offset)) {
anchor = "";
}
String anchor2;
if (stream.getIndex() == code.length) {
anchor2 = "" + offset + "";
} else {
anchor2 = "" + offset;
}
file.println("
|---|
| " + anchor2 + " | " + anchor + str + " |
");
}
}
// Mark last line, may be targetted from Attributes window
file.println("| |
");
file.println("
");
}
}
}