CodeHTML.java
/*
* 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.IOException;
import java.io.PrintWriter;
import java.nio.charset.Charset;
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.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.classfile.Utility;
/**
* Convert code into HTML file.
*/
final class CodeHTML {
private static boolean wide;
private final String className; // name of current class
// private Method[] methods; // Methods to print
private final PrintWriter printWriter; // file to write to
private BitSet gotoSet;
private final ConstantPool constantPool;
private final ConstantHTML constantHtml;
CodeHTML(final String dir, final String className, final Method[] methods, final ConstantPool constantPool, final ConstantHTML constantHtml,
final Charset charset) throws IOException {
this.className = className;
// this.methods = methods;
this.constantPool = constantPool;
this.constantHtml = constantHtml;
try (PrintWriter newPrintWriter = new PrintWriter(dir + className + "_code.html", charset.name())) {
printWriter = newPrintWriter;
printWriter.print("<HTML><head><meta charset=\"");
printWriter.print(charset.name());
printWriter.println("\"></head>");
printWriter.println("<BODY BGCOLOR=\"#C0C0C0\">");
for (int i = 0; i < methods.length; i++) {
writeMethod(methods[i], i);
}
printWriter.println("</BODY></HTML>");
}
}
/**
* 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 methodNumber) throws IOException {
final short opcode = (short) bytes.readUnsignedByte();
String name;
String signature;
int defaultOffset = 0;
int low;
int high;
int index;
int classIndex;
int vindex;
int constant;
int[] jumpTable;
int noPadBytes = 0;
int offset;
final StringBuilder buf = new StringBuilder(256); // CHECKSTYLE IGNORE MagicNumber
buf.append("<TT>").append(Const.getOpcodeName(opcode)).append("</TT></TD><TD>");
/*
* 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;
noPadBytes = remainder == 0 ? 0 : 4 - remainder;
for (int i = 0; i < noPadBytes; i++) {
bytes.readByte();
}
// Both cases have a field default_offset in common
defaultOffset = bytes.readInt();
}
switch (opcode) {
case Const.TABLESWITCH:
low = bytes.readInt();
high = bytes.readInt();
offset = bytes.getIndex() - 12 - noPadBytes - 1;
defaultOffset += offset;
buf.append("<TABLE BORDER=1><TR>");
// Print switch indices in first row (and default)
jumpTable = new int[high - low + 1];
for (int i = 0; i < jumpTable.length; i++) {
jumpTable[i] = offset + bytes.readInt();
buf.append("<TH>").append(low + i).append("</TH>");
}
buf.append("<TH>default</TH></TR>\n<TR>");
// Print target and default indices in second row
for (final int element : jumpTable) {
buf.append("<TD><A HREF=\"#code").append(methodNumber).append("@").append(element).append("\">").append(element).append("</A></TD>");
}
buf.append("<TD><A HREF=\"#code").append(methodNumber).append("@").append(defaultOffset).append("\">").append(defaultOffset)
.append("</A></TD></TR>\n</TABLE>\n");
break;
/*
* Lookup switch has variable length arguments.
*/
case Const.LOOKUPSWITCH:
final int npairs = bytes.readInt();
offset = bytes.getIndex() - 8 - noPadBytes - 1;
jumpTable = new int[npairs];
defaultOffset += offset;
buf.append("<TABLE BORDER=1><TR>");
// Print switch indices in first row (and default)
for (int i = 0; i < npairs; i++) {
final int match = bytes.readInt();
jumpTable[i] = offset + bytes.readInt();
buf.append("<TH>").append(match).append("</TH>");
}
buf.append("<TH>default</TH></TR>\n<TR>");
// Print target and default indices in second row
for (int i = 0; i < npairs; i++) {
buf.append("<TD><A HREF=\"#code").append(methodNumber).append("@").append(jumpTable[i]).append("\">").append(jumpTable[i])
.append("</A></TD>");
}
buf.append("<TD><A HREF=\"#code").append(methodNumber).append("@").append(defaultOffset).append("\">").append(defaultOffset)
.append("</A></TD></TR>\n</TABLE>\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("<A HREF=\"#code").append(methodNumber).append("@").append(index).append("\">").append(index).append("</A>");
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("<A HREF=\"#code").append(methodNumber).append("@").append(windex).append("\">").append(windex).append("</A>");
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("<FONT COLOR=\"#00FF00\">").append(Const.getTypeName(bytes.readByte())).append("</FONT>");
break;
/*
* Access object/class fields.
*/
case Const.GETFIELD:
case Const.GETSTATIC:
case Const.PUTFIELD:
case Const.PUTSTATIC:
index = bytes.readShort();
final ConstantFieldref c1 = constantPool.getConstant(index, Const.CONSTANT_Fieldref, ConstantFieldref.class);
classIndex = c1.getClassIndex();
name = constantPool.getConstantString(classIndex, Const.CONSTANT_Class);
name = Utility.compactClassName(name, false);
index = c1.getNameAndTypeIndex();
final String fieldName = constantPool.constantToString(index, Const.CONSTANT_NameAndType);
if (name.equals(className)) { // Local field
buf.append("<A HREF=\"").append(className).append("_methods.html#field").append(fieldName).append("\" TARGET=Methods>").append(fieldName)
.append("</A>\n");
} else {
buf.append(constantHtml.referenceConstant(classIndex)).append(".").append(fieldName);
}
break;
/*
* Operands are references to classes in constant pool
*/
case Const.CHECKCAST:
case Const.INSTANCEOF:
case Const.NEW:
index = bytes.readShort();
buf.append(constantHtml.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 mIndex = 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 = constantPool.getConstant(mIndex, Const.CONSTANT_InterfaceMethodref, ConstantInterfaceMethodref.class);
classIndex = c.getClassIndex();
index = c.getNameAndTypeIndex();
name = Class2HTML.referenceClass(classIndex);
} else if (opcode == Const.INVOKEDYNAMIC) { // Special treatment needed
bytes.readUnsignedByte(); // Reserved
bytes.readUnsignedByte(); // Reserved
final ConstantInvokeDynamic c = constantPool.getConstant(mIndex, Const.CONSTANT_InvokeDynamic, ConstantInvokeDynamic.class);
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 = constantPool.getConstant(mIndex, Const.CONSTANT_Methodref, ConstantMethodref.class);
classIndex = c.getClassIndex();
index = c.getNameAndTypeIndex();
name = Class2HTML.referenceClass(classIndex);
}
str = Class2HTML.toHTML(constantPool.constantToString(constantPool.getConstant(index, Const.CONSTANT_NameAndType)));
// Get signature, i.e., types
final ConstantNameAndType c2 = constantPool.getConstant(index, Const.CONSTANT_NameAndType, ConstantNameAndType.class);
signature = constantPool.constantToString(c2.getSignatureIndex(), Const.CONSTANT_Utf8);
final String[] args = Utility.methodSignatureArgumentTypes(signature, false);
final String type = Utility.methodSignatureReturnType(signature, false);
buf.append(name).append(".<A HREF=\"").append(className).append("_cp.html#cp").append(mIndex).append("\" TARGET=ConstantPool>").append(str)
.append("</A>").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("<A HREF=\"").append(className).append("_cp.html#cp").append(index).append("\" TARGET=\"ConstantPool\">")
.append(Class2HTML.toHTML(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))).append("</a>");
break;
case Const.LDC:
index = bytes.readUnsignedByte();
buf.append("<A HREF=\"").append(className).append("_cp.html#cp").append(index).append("\" TARGET=\"ConstantPool\">")
.append(Class2HTML.toHTML(constantPool.constantToString(index, constantPool.getConstant(index).getTag()))).append("</a>");
break;
/*
* Array of references.
*/
case Const.ANEWARRAY:
index = bytes.readShort();
buf.append(constantHtml.referenceConstant(index));
break;
/*
* Multidimensional array of references.
*/
case Const.MULTIANEWARRAY:
index = bytes.readShort();
final int dimensions = bytes.readByte();
buf.append(constantHtml.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("</TD>");
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;
gotoSet = 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) {
gotoSet.set(cex.getStartPC());
gotoSet.set(cex.getEndPC());
gotoSet.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) {
((LocalVariableTable) attribute).forEach(var -> {
final int start = var.getStartPC();
gotoSet.set(start);
gotoSet.set(start + var.getLength());
});
break;
}
}
}
// Get target addresses from GOTO, JSR, TABLESWITCH, etc.
while (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 noPadBytes = remainder == 0 ? 0 : 4 - remainder;
int defaultOffset;
int offset;
for (int j = 0; j < noPadBytes; j++) {
bytes.readByte();
}
// Both cases have a field default_offset in common
defaultOffset = bytes.readInt();
if (opcode == Const.TABLESWITCH) {
final int low = bytes.readInt();
final int high = bytes.readInt();
offset = bytes.getIndex() - 12 - noPadBytes - 1;
defaultOffset += offset;
gotoSet.set(defaultOffset);
for (int j = 0; j < high - low + 1; j++) {
index = offset + bytes.readInt();
gotoSet.set(index);
}
} else { // LOOKUPSWITCH
final int npairs = bytes.readInt();
offset = bytes.getIndex() - 8 - noPadBytes - 1;
defaultOffset += offset;
gotoSet.set(defaultOffset);
for (int j = 0; j < npairs; j++) {
// int match = bytes.readInt();
bytes.readInt();
index = offset + bytes.readInt();
gotoSet.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;
gotoSet.set(index);
break;
case Const.GOTO_W:
case Const.JSR_W:
// bytes.readByte(); // Skip already read byte
index = bytes.getIndex() + bytes.readInt() - 1;
gotoSet.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 methodNumber) 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 htmlName = 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();
printWriter.print("<P><B><FONT COLOR=\"#FF0000\">" + access + "</FONT> " + "<A NAME=method" + methodNumber + ">" + Class2HTML.referenceType(type)
+ "</A> <A HREF=\"" + className + "_methods.html#method" + methodNumber + "\" TARGET=Methods>" + htmlName + "</A>(");
for (int i = 0; i < args.length; i++) {
printWriter.print(Class2HTML.referenceType(args[i]));
if (i < args.length - 1) {
printWriter.print(", ");
}
}
printWriter.println(")</B></P>");
Code c = null;
byte[] code = null;
if (attributes.length > 0) {
printWriter.print("<H4>Attributes</H4><UL>\n");
for (int i = 0; i < attributes.length; i++) {
byte tag = attributes[i].getTag();
if (tag != Const.ATTR_UNKNOWN) {
printWriter.print("<LI><A HREF=\"" + className + "_attributes.html#method" + methodNumber + "@" + i + "\" TARGET=Attributes>"
+ Const.getAttributeName(tag) + "</A></LI>\n");
} else {
printWriter.print("<LI>" + attributes[i] + "</LI>");
}
if (tag == Const.ATTR_CODE) {
c = (Code) attributes[i];
final Attribute[] attributes2 = c.getAttributes();
code = c.getCode();
printWriter.print("<UL>");
for (int j = 0; j < attributes2.length; j++) {
tag = attributes2[j].getTag();
printWriter.print("<LI><A HREF=\"" + className + "_attributes.html#" + "method" + methodNumber + "@" + i + "@" + j
+ "\" TARGET=Attributes>" + Const.getAttributeName(tag) + "</A></LI>\n");
}
printWriter.print("</UL>");
}
}
printWriter.println("</UL>");
}
if (code != null) { // No code, an abstract method, e.g.
// System.out.println(name + "\n" + Utility.codeToString(code, constantPool, 0, -1));
// Print the byte code
try (ByteSequence stream = new ByteSequence(code)) {
stream.mark(stream.available());
findGotos(stream, c);
stream.reset();
printWriter.println("<TABLE BORDER=0><TR><TH ALIGN=LEFT>Byte<BR>offset</TH>" + "<TH ALIGN=LEFT>Instruction</TH><TH ALIGN=LEFT>Argument</TH>");
while (stream.available() > 0) {
final int offset = stream.getIndex();
final String str = codeToHTML(stream, methodNumber);
String anchor = "";
/*
* Sets an anchor mark if this line is targetted by a goto, jsr, etc. Defining an anchor for every line is very
* inefficient!
*/
if (gotoSet.get(offset)) {
anchor = "<A NAME=code" + methodNumber + "@" + offset + "></A>";
}
String anchor2;
if (stream.getIndex() == code.length) {
anchor2 = "<A NAME=code" + methodNumber + "@" + code.length + ">" + offset + "</A>";
} else {
anchor2 = "" + offset;
}
printWriter.println("<TR VALIGN=TOP><TD>" + anchor2 + "</TD><TD>" + anchor + str + "</TR>");
}
}
// Mark last line, may be targetted from Attributes window
printWriter.println("<TR><TD> </A></TD></TR>");
printWriter.println("</TABLE>");
}
}
}