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package com.sun.org.apache.bcel.internal.util;


import com.sun.org.apache.bcel.internal.classfile.*;
import java.io.*;
import java.util.BitSet;

Convert code into HTML file.
Author: M. Dahm
/** * Convert code into HTML file. * * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> * */
final class CodeHTML implements com.sun.org.apache.bcel.internal.Constants { private String class_name; // name of current class private Method[] methods; // Methods to print private PrintWriter file; // file to write to private BitSet goto_set; private ConstantPool constant_pool; private ConstantHTML constant_html; private static boolean wide=false; CodeHTML(String dir, String class_name, Method[] methods, ConstantPool constant_pool, 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("<HTML><BODY BGCOLOR=\"#C0C0C0\">"); for(int i=0; i < methods.length; i++) writeMethod(methods[i], i); file.println("</BODY></HTML>"); file.close(); }
Disassemble a stream of byte codes and return the string representation.
Params:
  • stream – data input stream
Returns:String representation of byte code
/** * Disassemble a stream of byte codes and return the * string representation. * * @param stream data input stream * @return String representation of byte code */
private final String codeToHTML(ByteSequence bytes, int method_number) throws IOException { short opcode = (short)bytes.readUnsignedByte(); StringBuffer buf; String name, signature; int default_offset=0, low, high; int index, class_index, vindex, constant; int[] jump_table; int no_pad_bytes=0, offset; buf = new StringBuffer("<TT>" + OPCODE_NAMES[opcode] + "</TT></TD><TD>"); /* Special case: Skip (0-3) padding bytes, i.e., the * following bytes are 4-byte-aligned */ if((opcode == TABLESWITCH) || (opcode == LOOKUPSWITCH)) { 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 TABLESWITCH: low = bytes.readInt(); high = bytes.readInt(); offset = bytes.getIndex() - 12 - no_pad_bytes - 1; default_offset += offset; buf.append("<TABLE BORDER=1><TR>"); // 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("<TH>" + (low + i) + "</TH>"); } buf.append("<TH>default</TH></TR>\n<TR>"); // Print target and default indices in second row for(int i=0; i < jump_table.length; i++) buf.append("<TD><A HREF=\"#code" + method_number + "@" + jump_table[i] + "\">" + jump_table[i] + "</A></TD>"); buf.append("<TD><A HREF=\"#code" + method_number + "@" + default_offset + "\">" + default_offset + "</A></TD></TR>\n</TABLE>\n"); break; /* Lookup switch has variable length arguments. */ case LOOKUPSWITCH: int npairs = bytes.readInt(); offset = bytes.getIndex() - 8 - no_pad_bytes - 1; jump_table = new int[npairs]; default_offset += offset; buf.append("<TABLE BORDER=1><TR>"); // Print switch indices in first row (and default) for(int i=0; i < npairs; i++) { int match = bytes.readInt(); jump_table[i] = offset + bytes.readInt(); buf.append("<TH>" + match + "</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" + method_number + "@" + jump_table[i] + "\">" + jump_table[i] + "</A></TD>"); buf.append("<TD><A HREF=\"#code" + method_number + "@" + default_offset + "\">" + default_offset + "</A></TD></TR>\n</TABLE>\n"); break; /* Two address bytes + offset from start of byte stream form the * jump target. */ case GOTO: case IFEQ: case IFGE: case IFGT: case IFLE: case IFLT: case IFNE: case IFNONNULL: case IFNULL: case IF_ACMPEQ: case IF_ACMPNE: case IF_ICMPEQ: case IF_ICMPGE: case IF_ICMPGT: case IF_ICMPLE: case IF_ICMPLT: case IF_ICMPNE: case JSR: index = (int)(bytes.getIndex() + bytes.readShort() - 1); buf.append("<A HREF=\"#code" + method_number + "@" + index + "\">" + index + "</A>"); break; /* Same for 32-bit wide jumps */ case GOTO_W: case JSR_W: int windex = bytes.getIndex() + bytes.readInt() - 1; buf.append("<A HREF=\"#code" + method_number + "@" + windex + "\">" + windex + "</A>"); break; /* Index byte references local variable (register) */ case ALOAD: case ASTORE: case DLOAD: case DSTORE: case FLOAD: case FSTORE: case ILOAD: case ISTORE: case LLOAD: case LSTORE: case RET: if(wide) { vindex = bytes.readShort(); wide=false; // Clear flag } else vindex = bytes.readUnsignedByte(); buf.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 WIDE: wide = true; buf.append("(wide)"); break; /* Array of basic type. */ case NEWARRAY: buf.append("<FONT COLOR=\"#00FF00\">" + TYPE_NAMES[bytes.readByte()] + "</FONT>"); break; /* Access object/class fields. */ case GETFIELD: case GETSTATIC: case PUTFIELD: case PUTSTATIC: index = bytes.readShort(); ConstantFieldref c1 = (ConstantFieldref)constant_pool.getConstant(index, CONSTANT_Fieldref); class_index = c1.getClassIndex(); name = constant_pool.getConstantString(class_index, CONSTANT_Class); name = Utility.compactClassName(name, false); index = c1.getNameAndTypeIndex(); String field_name = constant_pool.constantToString(index, CONSTANT_NameAndType); if(name.equals(class_name)) { // Local field buf.append("<A HREF=\"" + class_name + "_methods.html#field" + field_name + "\" TARGET=Methods>" + field_name + "</A>\n"); } else buf.append(constant_html.referenceConstant(class_index) + "." + field_name); break; /* Operands are references to classes in constant pool */ case CHECKCAST: case INSTANCEOF: case NEW: index = bytes.readShort(); buf.append(constant_html.referenceConstant(index)); break; /* Operands are references to methods in constant pool */ case INVOKESPECIAL: case INVOKESTATIC: case INVOKEVIRTUAL: case INVOKEINTERFACE: int m_index = bytes.readShort(); String str; if(opcode == INVOKEINTERFACE) { // Special treatment needed int nargs = bytes.readUnsignedByte(); // Redundant int reserved = bytes.readUnsignedByte(); // Reserved ConstantInterfaceMethodref c=(ConstantInterfaceMethodref)constant_pool.getConstant(m_index, CONSTANT_InterfaceMethodref); class_index = c.getClassIndex(); str = constant_pool.constantToString(c); index = c.getNameAndTypeIndex(); } else { ConstantMethodref c = (ConstantMethodref)constant_pool.getConstant(m_index, CONSTANT_Methodref); class_index = c.getClassIndex(); str = constant_pool.constantToString(c); index = c.getNameAndTypeIndex(); } name = Class2HTML.referenceClass(class_index); str = Class2HTML.toHTML(constant_pool.constantToString(constant_pool.getConstant(index, CONSTANT_NameAndType))); // Get signature, i.e., types ConstantNameAndType c2 = (ConstantNameAndType)constant_pool. getConstant(index, CONSTANT_NameAndType); signature = constant_pool.constantToString(c2.getSignatureIndex(), CONSTANT_Utf8); String[] args = Utility.methodSignatureArgumentTypes(signature, false); String type = Utility.methodSignatureReturnType(signature, false); buf.append(name + ".<A HREF=\"" + class_name + "_cp.html#cp" + m_index + "\" TARGET=ConstantPool>" + str + "</A>" + "("); // 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("):" + Class2HTML.referenceType(type)); break; /* Operands are references to items in constant pool */ case LDC_W: case LDC2_W: index = bytes.readShort(); buf.append("<A HREF=\"" + class_name + "_cp.html#cp" + index + "\" TARGET=\"ConstantPool\">" + Class2HTML.toHTML(constant_pool.constantToString(index, constant_pool. getConstant(index).getTag()))+ "</a>"); break; case LDC: index = bytes.readUnsignedByte(); buf.append("<A HREF=\"" + class_name + "_cp.html#cp" + index + "\" TARGET=\"ConstantPool\">" + Class2HTML.toHTML(constant_pool.constantToString(index, constant_pool. getConstant(index).getTag()))+ "</a>"); break; /* Array of references. */ case ANEWARRAY: index = bytes.readShort(); buf.append(constant_html.referenceConstant(index)); break; /* Multidimensional array of references. */ case MULTIANEWARRAY: index = bytes.readShort(); int dimensions = bytes.readByte(); buf.append(constant_html.referenceConstant(index) + ":" + dimensions + "-dimensional"); break; /* Increment local variable. */ case IINC: if(wide) { vindex = bytes.readShort(); constant = bytes.readShort(); wide = false; } else { vindex = bytes.readUnsignedByte(); constant = bytes.readByte(); } buf.append("%" + vindex + " " + constant); break; default: if(NO_OF_OPERANDS[opcode] > 0) { for(int i=0; i < TYPE_OF_OPERANDS[opcode].length; i++) { switch(TYPE_OF_OPERANDS[opcode][i]) { case T_BYTE: buf.append(bytes.readUnsignedByte()); break; case T_SHORT: // Either branch or index buf.append(bytes.readShort()); break; case T_INT: buf.append(bytes.readInt()); break; default: // Never reached System.err.println("Unreachable default case reached!"); System.exit(-1); } buf.append("&nbsp;"); } } } 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.
/** * Find all target addresses in code, so that they can be marked * with &lt;A NAME = ...&gt;. Target addresses are kept in an BitSet object. */
private final void findGotos(ByteSequence bytes, Method method, 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) { CodeException[] ce = code.getExceptionTable(); int len = ce.length; for(int i=0; i < len; i++) { goto_set.set(ce[i].getStartPC()); goto_set.set(ce[i].getEndPC()); goto_set.set(ce[i].getHandlerPC()); } // Look for local variables and their range Attribute[] attributes = code.getAttributes(); for(int i=0; i < attributes.length; i++) { if(attributes[i].getTag() == ATTR_LOCAL_VARIABLE_TABLE) { LocalVariable[] vars = ((LocalVariableTable)attributes[i]).getLocalVariableTable(); for(int j=0; j < vars.length; j++) { int start = vars[j].getStartPC(); int end = (int)(start + vars[j].getLength()); goto_set.set(start); goto_set.set(end); } break; } } } // Get target addresses from GOTO, JSR, TABLESWITCH, etc. for(int i=0; bytes.available() > 0; i++) { opcode = bytes.readUnsignedByte(); //System.out.println(OPCODE_NAMES[opcode]); switch(opcode) { case TABLESWITCH: case LOOKUPSWITCH: //bytes.readByte(); // Skip already read byte int remainder = bytes.getIndex() % 4; int no_pad_bytes = (remainder == 0)? 0 : 4 - remainder; int default_offset, 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 == TABLESWITCH) { int low = bytes.readInt(); 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 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(); index = offset + bytes.readInt(); goto_set.set(index); } } break; case GOTO: case IFEQ: case IFGE: case IFGT: case IFLE: case IFLT: case IFNE: case IFNONNULL: case IFNULL: case IF_ACMPEQ: case IF_ACMPNE: case IF_ICMPEQ: case IF_ICMPGE: case IF_ICMPGT: case IF_ICMPLE: case IF_ICMPLT: case IF_ICMPNE: case JSR: //bytes.readByte(); // Skip already read byte index = bytes.getIndex() + bytes.readShort() - 1; goto_set.set(index); break; case GOTO_W: case 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.
/** * Write a single method with the byte code associated with it. */
private void writeMethod(Method method, int method_number) throws IOException { // Get raw signature String signature = method.getSignature(); // Get array of strings containing the argument types String[] args = Utility.methodSignatureArgumentTypes(signature, false); // Get return type string String type = Utility.methodSignatureReturnType(signature, false); // Get method name String name = method.getName(); String html_name = Class2HTML.toHTML(name); // Get method's access flags String access = Utility.accessToString(method.getAccessFlags()); access = Utility.replace(access, " ", "&nbsp;"); // Get the method's attributes, the Code Attribute in particular Attribute[] attributes= method.getAttributes(); file.print("<P><B><FONT COLOR=\"#FF0000\">" + access + "</FONT>&nbsp;" + "<A NAME=method" + method_number + ">" + Class2HTML.referenceType(type) + "</A>&nbsp<A HREF=\"" + class_name + "_methods.html#method" + method_number + "\" TARGET=Methods>" + html_name + "</A>("); for(int i=0; i < args.length; i++) { file.print(Class2HTML.referenceType(args[i])); if(i < args.length - 1) file.print(",&nbsp;"); } file.println(")</B></P>"); Code c=null; byte[] code=null; if(attributes.length > 0) { file.print("<H4>Attributes</H4><UL>\n"); for(int i=0; i < attributes.length; i++) { byte tag = attributes[i].getTag(); if(tag != ATTR_UNKNOWN) file.print("<LI><A HREF=\"" + class_name + "_attributes.html#method" + method_number + "@" + i + "\" TARGET=Attributes>" + ATTRIBUTE_NAMES[tag] + "</A></LI>\n"); else file.print("<LI>" + attributes[i] + "</LI>"); if(tag == ATTR_CODE) { c = (Code)attributes[i]; Attribute[] attributes2 = c.getAttributes(); code = c.getCode(); file.print("<UL>"); for(int j=0; j < attributes2.length; j++) { tag = attributes2[j].getTag(); file.print("<LI><A HREF=\"" + class_name + "_attributes.html#" + "method" + method_number + "@" + i + "@" + j + "\" TARGET=Attributes>" + ATTRIBUTE_NAMES[tag] + "</A></LI>\n"); } file.print("</UL>"); } } file.println("</UL>"); } 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 ByteSequence stream = new ByteSequence(code); stream.mark(stream.available()); findGotos(stream, method, c); stream.reset(); file.println("<TABLE BORDER=0><TR><TH ALIGN=LEFT>Byte<BR>offset</TH>" + "<TH ALIGN=LEFT>Instruction</TH><TH ALIGN=LEFT>Argument</TH>"); for(int i=0; stream.available() > 0; i++) { int offset = stream.getIndex(); 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 = "<A NAME=code" + method_number + "@" + offset + "></A>"; String anchor2; if(stream.getIndex() == code.length) // last loop anchor2 = "<A NAME=code" + method_number + "@" + code.length + ">" + offset + "</A>"; else anchor2 = "" + offset; file.println("<TR VALIGN=TOP><TD>" + anchor2 + "</TD><TD>" + anchor + str + "</TR>"); } // Mark last line, may be targetted from Attributes window file.println("<TR><TD> </A></TD></TR>"); file.println("</TABLE>"); } } }