codeattr.java

这是一个Linux下的集成开发环境

    pushType(type);
  }

  public void emitInstanceof (Type type)
  {
    emitCheckcast(type, 193);
    pushType(Type.boolean_type);
  }

  public final void emitThrow ()
  {
    popType();
    reserve(1);
    put1 (191);  // athrow
    unreachable_here = true;
  }

  /**
   * Compile a method return.
   */
  public final void emitReturn ()
  {
    if (getMethod().getReturnType() == Type.void_type)
      {
	reserve(1);
	put1(177); // return
      }
    else
      emitTypedOp (172, popType().promote());
  }

  /** Add an exception handler. */
  public void addHandler (int start_pc, int end_pc,
			  int handler_pc, int catch_type)
  {
    int index = 4 * exception_table_length;
    if (exception_table == null)
      {
	exception_table = new short[20];
      }
    else if (exception_table.length <= index)
      {
	short[] new_table = new short[2 * exception_table.length];
	System.arraycopy(exception_table, 0, new_table, 0, index);
	exception_table = new_table;
      }
    exception_table[index++] = (short) start_pc;
    exception_table[index++] = (short) end_pc;
    exception_table[index++] = (short) handler_pc;
    exception_table[index++] = (short) catch_type;
    exception_table_length++;
  }

  /** Add an exception handler. */
  public void addHandler (int start_pc, int end_pc, int handler_pc,
			  ClassType catch_type, ConstantPool constants)
  {
    int catch_type_index;
    if (catch_type == null)
      catch_type_index = 0;
    else
      catch_type_index = constants.addClass(catch_type).index;
    addHandler(start_pc, end_pc, handler_pc, catch_type_index);
  }


  public void emitTryStart(boolean has_finally, Type result_type)
  {
    TryState try_state = new TryState(this);
    boolean must_save_result = has_finally && result_type != null;
    if (must_save_result || SP > 0)
      {
	pushScope();
	if (must_save_result)
	  try_state.saved_result = addLocal(result_type);
      }
    if (SP > 0)
      {
	try_state.savedStack = new Variable[SP];
	int i = 0;
	while (SP > 0)
	  {
	    Variable var = addLocal(topType());
	    emitStore(var);
	    try_state.savedStack[i++] = var;
	  }
      }
    if (has_finally)
      try_state.finally_subr = new Label(this);
  }

  public void emitTryEnd()
  {
    if (try_stack.end_label == null)
      {
	if (try_stack.saved_result != null)
	  emitStore(try_stack.saved_result);
	try_stack.end_label = new Label(this);
	if (try_stack.finally_subr != null)
	  emitGoto(try_stack.finally_subr, 168);  // jsr
	if (reachableHere())
	  emitGoto(try_stack.end_label);
	readPC = PC;
	try_stack.end_pc = PC;
      }
  }

  public void emitCatchStart(Variable var)
  {
    emitTryEnd();
    if (try_stack.try_type != null)
      {
	emitCatchEnd();
      }
    ClassType type = var == null ? null : (ClassType) var.getType();
    try_stack.try_type = type;
    readPC = PC;
    addHandler(try_stack.start_pc, try_stack.end_pc,
	       PC, type, getConstants());
    if (var != null)
      {
	pushType(type);
	emitStore(var);
      }
  }

  public void emitCatchEnd()
  {
    if (reachableHere())
      {
	if (try_stack.saved_result != null)
	  emitStore(try_stack.saved_result);
	if (try_stack.finally_subr != null)
	  emitGoto(try_stack.finally_subr, 168); // jsr
	emitGoto(try_stack.end_label);
      }
    popScope();
    try_stack.try_type = null;
  }

  public void emitFinallyStart()
  {
    emitTryEnd();
    if (try_stack.try_type != null)
      {
	emitCatchEnd();
      }
    readPC = PC;
    try_stack.end_pc = PC;

    pushScope();
    Type except_type = Type.pointer_type;
    Variable except = addLocal(except_type);
    emitCatchStart(null);
    pushType(except_type);
    emitStore(except);
    emitGoto(try_stack.finally_subr, 168); // jsr
    emitLoad(except);
    emitThrow();
    
    //emitCatchEnd();
    
    //if (try_stack.finally_subr == null)
    // error();
    try_stack.finally_subr.define(this);
    Type ret_addr_type = Type.pointer_type;
    try_stack.finally_ret_addr = addLocal(ret_addr_type);
    pushType(ret_addr_type);
    emitStore(try_stack.finally_ret_addr);
  }

  public void emitFinallyEnd()
  {
    emitRet(try_stack.finally_ret_addr);
    unreachable_here = true;
    popScope();
    try_stack.finally_subr = null;
  }

  public void emitTryCatchEnd()
  {
    if (try_stack.finally_subr != null)
      emitFinallyEnd();
    try_stack.end_label.define(this);
    Variable[] vars = try_stack.savedStack;
    if (vars != null)
      {
	for (int i = vars.length;  --i >= 0; )
	  {
	    Variable v = vars[i];
	    if (v != null) {
	      emitLoad(v);
	    }
	  }
      }
    if (try_stack.saved_result != null)
	emitLoad(try_stack.saved_result);
    if (try_stack.saved_result != null || vars != null)
	popScope();
    try_stack = try_stack.previous;
  }

  /* Make sure the label with oldest fixup is first in labels. */
  void reorder_fixups ()
  {
    Label prev = null;
    Label cur;
    Label oldest = null;
    Label oldest_prev = null;
    int oldest_fixup = PC+100;
    for (cur = labels;  cur != null;  cur = cur.next)
      {
	if (cur.fixups != null && cur.fixups[0] < oldest_fixup)
	  {
	    oldest = cur;
	    oldest_prev = prev;
	    oldest_fixup = cur.fixups[0];
	  }
	prev = cur;
      }
    if (oldest != labels)
      {
	oldest_prev.next = oldest.next;
	oldest.next = labels;
	labels = oldest;
      }
  }

  public void finalize_labels ()
  {
    while (labels != null && labels.fixups != null)
      labels.emit_spring (this);
    for (Label label = labels;  label != null;  label = label.next)
      {
	if (!label.defined ())
	  throw new Error ("undefined label");
	if (label.fixups != null)
	  throw new Error ("internal error: finalize_labels");
    }
  }

  public void assignConstants (ClassType cl)
  {
    super.assignConstants(cl);
    Attribute.assignConstants(this, cl);
  }

  public final int getLength()
  {
    return 12 + getCodeLength() + 8 * exception_table_length
      + Attribute.getLengthAll(this);
  }

  public void write (DataOutputStream dstr) throws java.io.IOException
  {
    dstr.writeShort (max_stack);
    dstr.writeShort (max_locals);
    dstr.writeInt (PC);
    dstr.write (code, 0, PC);

    dstr.writeShort (exception_table_length);
    int count = exception_table_length;
    for (int i = 0;  --count >= 0;  i += 4)
      {
	dstr.writeShort(exception_table[i]);
	dstr.writeShort(exception_table[i+1]);
	dstr.writeShort(exception_table[i+2]);
	dstr.writeShort(exception_table[i+3]);
      }

    Attribute.writeAll(this, dstr);
  }

  public void print (ClassTypeWriter dst) 
  {
    dst.print("Attribute \"");
    dst.print(getName());
    dst.print("\", length:");
    dst.print(getLength());
    dst.print(", max_stack:");
    dst.print(max_stack);
    dst.print(", max_locals:");
    dst.print(max_locals);
    dst.print(", code_length:");
    int length = getCodeLength();
    dst.println(length);
    disAssemble(dst, 0, length);
    if (exception_table_length > 0)
      {
	dst.print("Exceptions (count: ");
	dst.print(exception_table_length);
	dst.println("):");
	int count = exception_table_length;
	for (int i = 0;  --count >= 0;  i += 4)
	  {
	    dst.print("  start: ");
	    dst.print(exception_table[i] & 0xffff);
	    dst.print(", end: ");
	    dst.print(exception_table[i+1] & 0xffff);
	    dst.print(", handler: ");
	    dst.print(exception_table[i+2] & 0xffff);
	    dst.print(", type: ");
	    int catch_type_index = exception_table[i+3] & 0xffff;
	    if (catch_type_index == 0)
	      dst.print("0 /* finally */");
	    else
	      {
		dst.printOptionalIndex(catch_type_index);
		dst.printConstantTersely(catch_type_index, ConstantPool.CLASS);
	      }
	    dst.println();
	  }
      }
    dst.printAttributes(this);
  }

  public void disAssemble (ClassTypeWriter dst, int offset, int length)
  {
    boolean wide = false;
    for (int i = offset;  i < length; )
      {
	int oldpc = i++;
	int op = code[oldpc] & 0xff;
	String str = Integer.toString(oldpc);
	int printConstant = 0;
	int j = str.length();
	while (++j <= 3) dst.print(' ');
	dst.print(str);
	dst.print(": ");
	if (op < 120)
	  {
	    if (op < 87)
	      {
		if (op < 3)  print("nop;aconst_null;iconst_m1;", op, dst);
		else if (op < 9) { dst.print("iconst_");  dst.print(op-3); }
		else if (op < 16) // op >= 9 [lconst_0] && op <= 15 [dconst_1]
		  {
		    char typ;
		    if (op < 11) { typ = 'l';  op -= 9; }
		    else if (op < 14) { typ = 'f';  op -= 11; }
		    else { typ = 'd';  op -= 14; }
		    dst.print(typ);  dst.print("const_");  dst.print(op);
		  }
		else if (op < 21)
		  {
		    if (op < 18)  // op >= 16 [bipush] && op <= 17 [sipush]
		      {
			print("bipush ;sipush ;", op-16, dst);
			int constant;
			if (op == 16)  constant = code[i++];
			else { constant = (short) readUnsignedShort(i);  i+=2;}
			dst.print(constant);
		      }
		    else // op >= 18 [ldc] && op <= 20 [ldc2_w]
		      {
			printConstant = op == 18 ? 1 : 2;
			print("ldc;ldc_w;ldc2_w;", op-18, dst);
		      }
		  }
		else // op >= 21 && op < 87
		  {
		    String load_or_store;
		    if (op < 54) { load_or_store = "load"; }
		    else { load_or_store = "store"; op -=(54-21); }
		    int index;  // -2 if array op;  -1 if index follows
		    if (op < 26) { index = -1; op -= 21; }
		    else if (op < 46) { op -= 26;  index = op % 4;  op >>= 2; }
		    else { index = -2; op -= 46; }
		    dst.print("ilfdabcs".charAt(op));
		    if (index == -2) dst.write('a');
		    dst.print(load_or_store);
		    if (index >= 0) { dst.write('_');  dst.print(index); }
		    else if (index == -1)
		      {
			if (wide) { index = readUnsignedShort(i); index += 2; }
			else { index = code[i] & 0xff; i++; }
			wide = false;
			dst.print(' ');
			dst.print(index);
		      }
		  }
	      }
	    else // op >= 87 && op < 120
	      {
		if (op < 96)
		  print("pop;pop2;dup;dup_x1;dup_x2;dup2;dup2_x1;dup2_x2;swap;"
			, op-87, dst);
		else // op >= 96 [iadd] && op <= 119 [dneg]
		  {
		    dst.print("ilfda".charAt((op-96) % 4));
		    print("add;sub;mul;div;rem;neg;", (op-96)>>2, dst);
		  }
	      }
	  }
	else // op >= 120
	  {
	    if (op < 170)
	      {
		if (op < 132) // op >= 120 [ishl] && op <= 131 [lxor]
		  {
		    dst.print((op & 1) == 0 ? 'i' : 'l');
		    print("shl;shr;ushr;and;or;xor;", (op-120)>>1, dst);
		  }
		else if (op == 132) // iinc
		  {
		    int var_index;
		    int constant;
		    dst.print("iinc");
		    if (! wide)
		      {
			var_index = 0xff & code[i++];
			constant = code[i++];
		      }
		    else
		      {
			var_index = readUnsignedShort(i);
			i += 2;
			constant = (short) readUnsignedShort(i);
			i += 2;
			wide = false;
		      }
		    dst.print(' ');  dst.print(var_index);
		    dst.print(' ');  dst.print(constant);
		  }
		else if (op < 148) // op >= 133 [i2l] && op <= 147 [i2s]
		  {
		    dst.print("ilfdi".charAt((op-133) / 3));
		    dst.print('2');
		    dst.print("lfdifdildilfbcs".charAt(op-133));
		  }
		else if (op < 153) // op >= 148 [lcmp] && op <= 152 [dcmpg]
		  print("lcmp;fcmpl;fcmpg;dcmpl;dcmpg;", op-148, dst);
		else
		  {
		    if (op < 159)
		      {
			dst.print("if");
			print("eq;ne;lt;ge;gt;le;", op-153, dst);
		      }
		    else if (op < 167)
		      {
			if (op < 165) { dst.print("if_icmp"); }
			else { dst.print("if_acmp"); op -= 165-159; }
			print("eq;ne;lt;ge;gt;le;", op-159, dst);
		      }
		    else
		      print("goto;jsr;ret;", op-167, dst);
		    int delta = (short) readUnsignedShort(i);
		    i += 2;
		    dst.print(' ');  dst.print(oldpc+delta);
		  }
	      }
	    else
	      {
		if (op < 172) //  [tableswitch] or [lookupswitch]
		  {
		    i = (i + 3) & ~3; // skip 0-3 byte padding.
		    int code_offset = readInt(i);  i += 4;
		    if (op == 170)
		      {
			dst.print("tableswitch");
			int low = readInt(i);  i += 4;
			int high = readInt(i+4);  i += 4;
			dst.print(" low: "); dst.print(low);
			dst.print(" high: "); dst.print(high);
			dst.print(" default: "); dst.print(code_offset);
			for (;  low <= high;  low++)
			  {
			    code_offset = readInt(i);  i += 4;
			    dst.println();
			    dst.print("  ");  dst.print(low);
			    dst.print(": ");  dst.print(oldpc + code_offset); 
			  }
		      }
		    else
		      {
			dst.print("lookupswitch");
			int npairs = readInt(i);  i += 4;
			dst.print(" npairs: "); dst.print(npairs);
			dst.print(" default: "); dst.print(code_offset);
			while (--npairs >= 0)
			  {
			    int match = readInt(i);  i += 4;
			    code_offset = readInt(i);  i += 4;
			    dst.println();
			    dst.print("  ");  dst.print(match);
			    dst.print(": ");  dst.print(oldpc + code_offset); 
			  }
		      }
		  }
		else if (op < 178) // op >= 172 [ireturn] && op <= 177 [return]
		  {
		    if (op < 177) dst.print("ilfda".charAt(op-172));
		    dst.print("return");
		  }
		else if (op < 182) // op >= 178 [getstatic] && op <= 181 [putfield]
		  {
		    print("getstatic;putstatic;getfield;putfield;", op-178, dst);
		    printConstant = 2;
		  }
		else if (op < 186) // op >= 182 && op <= 185 [invoke*]
		  {
		    dst.print("invoke");
		    print("virtual;special;static;interface;", op-182, dst);
		    printConstant = 2;
		    if (op == 185) // invokeinterface
		      i += 2;
		  }
		else if (op < 196)
		  {
		    print("186;new;newarray;anewarray;arraylength;athrow;checkcast;instanceof;moniorenter;monitorexit;", op-186, dst);
		    if (op == 187 || op == 189 || op == 192 || op == 193)
		      printConstant = 2;
		    else if (op == 188)  // newarray
		      {
			int type = code[i++];
			dst.print(' ');
			if (type >= 4 && type <= 11)
			  print("boolean;char;float;double;byte;short;int;long;",
				type-4, dst);
			else
			  dst.print(type);
		      }
			
		  }
		else if (op == 196) // wide
		  {
		    dst.print("wide");
		    wide = true;
		  }
		else if (op == 197)
		  {
		    dst.print("multianewarray");
		    int index = readUnsignedShort(i);
		    i += 2;
		    dst.printConstantOperand(index);
		    int dims = 0xff & code[i++];
		    dst.print(' ');
		    dst.print(dims);
		  }
		else if (op < 200)
		  {
		    print("ifnull;ifnonnull;", op-198, dst);
		    int delta = (short) readUnsignedShort(i);
		    i += 2;
		    dst.print(' ');  dst.print(oldpc+delta);
		  }
		else if (op < 202)
		  {
		    print("goto_w;jsr_w;", op-200, dst);
		    int delta = readInt(i);
		    i += 4;
		    dst.print(' ');  dst.print(oldpc+delta);
		  }
		else
		  dst.print(op);
	      }
	  }
	if (printConstant > 0)
	  {
	    int index;
	    if (printConstant == 1) index = 0xff & code[i++];
	    else { index = readUnsignedShort(i);  i += 2; }
	    dst.printConstantOperand(index);
	  }
	dst.println();
      }
  }

  private int readUnsignedShort(int offset)
  {
    return ((0xff & code[offset]) << 8) | (0xff & code[offset+1]);
  }

  private int readInt(int offset)
  {
    return (readUnsignedShort(offset) << 16) | readUnsignedShort(offset+2);
  }

  /* Print the i'th ';'-delimited substring of str on dst. */
  private void print (String str, int i, PrintWriter dst)
  {
    int last = 0;
    int pos = -1;
    for (; i >= 0; i--)
      {
	last = ++pos;
	pos = str.indexOf(';', last);
      }
    dst.write(str, last, pos-last);
  }
}