/// <summary>
/// The DisasmP function is used to disassemble a p-code opcode from
/// memory, into the given buffer.
/// </summary>
/// <param name="buffer">The buffer to print the opcode into.</param>
/// <param name="segNo">The segment number the code is within</param>
/// <param name="ipcBase">The procedure base address (enter_ic).</param>
/// <param name="ipc">
/// The instruction counter (address within segment) of the
/// instruction to disassemble.
/// </param>
/// <param name="jTab">
/// The jump table (procedure attributes) of the procedure being
/// executed, or disassembled.
/// </param>
/// <param name="sp">Stack pointer (?)</param>
/// <returns></returns>
public static ushort DisasmP(StringBuilder buffer, ushort segNo, ushort ipcBase, ushort ipc, ushort jTab,
ushort sp)
{
var opCode = Memory.ReadByte(ipcBase, (short)ipc++);
var s = PTrace.instructions[opCode];
int val;
foreach (var ch in s)
{
switch (ch)
{
case 'A':
// CXP Arguments
{
int seg = Memory.ReadByte(ipcBase, (short)ipc++);
int proc = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.AppendFormat("{0},{1} ", seg, proc);
buffer.Append(PTrace.ProcName(seg, proc, sp));
}
break;
case 'B':
val = Memory.ReadByte(ipcBase, (short)ipc++);
if ((val & 0x80) != 0)
{
val = ((val & 0x7f) << 8) + Memory.ReadByte(ipcBase, (short)ipc++);
}
buffer.Append(val);
break;
case 'C':
val = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.AppendFormat("{0} ", val);
buffer.Append(PTrace.ProcName(segNo, val, sp));
break;
case 'D':
case 'U':
val = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.Append(val);
break;
case 'P':
if (sp != 0)
{
buffer.Append(PTrace.PString(PTrace.ReadStack(sp, 0)));
}
break;
case 'S':
val = Memory.ReadByte(ipcBase, (short)ipc++);
if ((val & 0x80) != 0)
{
val = -(0x100 - val);
}
buffer.Append(val);
break;
case 'T':
val = Memory.ReadByte(ipcBase, (short)ipc++);
switch (val)
{
case 2:
buffer.Append("real");
break;
case 4:
buffer.Append("string");
break;
case 6:
buffer.Append("boolean");
break;
case 8:
buffer.Append("set");
break;
case 10:
val = Memory.ReadByte(ipcBase, (short)ipc++);
if ((val & 0x80) != 0)
{
val = ((val & 0x7f) << 8) + Memory.ReadByte(ipcBase, (short)ipc++);
}
buffer.AppendFormat("byte array, {0} bytes", val);
break;
case 12:
val = Memory.ReadByte(ipcBase, (short)ipc++);
if ((val & 0x80) != 0)
{
val = ((val & 0x7f) << 8) + Memory.ReadByte(ipcBase, (short)ipc++);
}
buffer.AppendFormat("{0} words", val);
break;
default:
buffer.Append(val);
break;
}
break;
case 'W':
val = Memory.ReadByte(ipcBase, (short)ipc++);
val |= Memory.ReadByte(ipcBase, (short)ipc++) << 8;
buffer.Append(val);
break;
case 'R': // case arguments
{
ipc = (ushort)(ipc + 1 & ~1);
int min = Memory.ReadByte(ipcBase, (short)ipc++);
min |= Memory.ReadByte(ipcBase, (short)ipc++) << 8;
int max = Memory.ReadByte(ipcBase, (short)ipc++);
max |= Memory.ReadByte(ipcBase, (short)ipc++) << 8;
ipc++;
int defaultVal = Memory.ReadByte(ipcBase, (short)ipc++);
if ((defaultVal & 0x80) != 0) // less than zero?
{
defaultVal = -(0x100 - defaultVal);
defaultVal = -defaultVal;
defaultVal = Memory.ReadByte(jTab, -2) +
(Memory.ReadByte(jTab, -1) << 8) + 2 -
(Memory.ReadByte(jTab, (short)-defaultVal) +
(Memory.ReadByte(jTab, (short)(-defaultVal + 1)) << 8) + defaultVal);
}
else
{
defaultVal = ipc + defaultVal;
}
buffer.AppendFormat("{0},{1},{2} ", min, max, defaultVal);
while (min < max + 1)
{
val = Memory.ReadByte(ipcBase, (short)ipc++);
val |= Memory.ReadByte(ipcBase, (short)ipc++) << 8;
buffer.AppendFormat(",{0}", ipc - 2 - val);
min++;
}
}
break;
case 'Q':
val = Memory.ReadByte(ipcBase, (short)ipc++);
switch (val)
{
case 1:
buffer.Append("new");
break;
case 2:
buffer.Append("Moveleft");
break;
case 3:
buffer.Append("Moveright");
break;
case 4:
buffer.Append("exit");
break;
case 5:
buffer.Append("unitread");
break;
case 6:
buffer.Append("unitwrite");
break;
case 7:
buffer.Append("idsearch");
break;
case 8:
buffer.Append("treesearch");
break;
case 9:
buffer.Append("time");
break;
case 10:
buffer.Append("fillchar");
break;
case 11:
buffer.AppendFormat("scan");
break;
case 12:
buffer.Append("unitstat");
break;
case 21:
buffer.Append("load_segment");
break;
case 22:
buffer.Append("unload_segment");
break;
case 32:
buffer.Append("mark");
break;
case 33:
buffer.Append("release");
break;
case 34:
buffer.Append("ioresult");
break;
case 35:
buffer.Append("unitbusy");
break;
case 37:
buffer.Append("unitwait");
break;
case 38:
buffer.Append("unitclear");
break;
case 39:
buffer.Append("halt");
break;
case 40:
buffer.Append("memavail");
break;
default:
buffer.Append(val);
break;
}
break;
case 'J':
val = Memory.ReadByte(ipcBase, (short)ipc++);
if ((val & 0x80) != 0) /* less than zero? */
{
val = -(0x100 - val);
val = -val;
val = Memory.ReadByte(jTab, -2) +
(Memory.ReadByte(jTab, -1) << 8) + 2 -
(Memory.ReadByte(jTab, (short)-val) +
(Memory.ReadByte(jTab, (short)(-val + 1)) << 8) + val);
}
else
{
val = ipc + val;
}
buffer.Append(val);
break;
case 'V':
break;
case 'X':
val = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.Append(val);
ipc = (ushort)(ipc + 1 & ~1);
while (val-- != 0)
{
var w = Memory.ReadByte(ipcBase, (short)ipc) + (Memory.ReadByte(ipcBase,
(short)(ipc + 1)) << 8);
ipc += 2;
buffer.AppendFormat(",{0:X4}", w);
}
break;
case 'Y':
val = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.AppendFormat("{0},'", val);
while (val-- != 0)
{
buffer.Append((char)Memory.ReadByte(ipcBase, (short)ipc++));
}
buffer.Append('\'');
break;
case 'Z':
val = Memory.ReadByte(ipcBase, (short)ipc++);
buffer.Append(val);
ipc = (ushort)(ipc + 1 & ~1);
while (val-- != 0)
{
buffer.AppendFormat(",{0:X2}", Memory.ReadByte(ipcBase, (short)ipc));
ipc++;
}
break;
default:
buffer.Append(ch);
break;
}
}
return(ipc);
}
private static string ProcName(int seg, int proc, ushort sp)
{
if (seg != 0)
{
return(string.Empty);
}
StringBuilder sb = new();
switch (proc)
{
case 5:
sb.Append("Rewrite");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 2)));
sb.Append(')');
break;
case 6:
sb.Append("Close");
break;
case 7:
sb.Append("Get");
break;
case 8:
sb.Append("Put");
break;
case 10:
sb.Append("Eof");
break;
case 11:
sb.Append("Eoln");
break;
case 12:
sb.Append("ReadInteger");
break;
case 13:
sb.Append("WriteInteger");
break;
case 16:
sb.Append("ReadChar");
break;
case 17:
sb.Append("WriteChar");
break;
case 18:
sb.Append("ReadString");
break;
case 19:
sb.Append("WriteString");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 1)));
sb.Append(')');
break;
case 21:
sb.Append("ReadLn");
break;
case 22:
sb.Append("WriteLn");
break;
case 23:
sb.Append("Concat");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 2)));
sb.Append(',');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 1)));
sb.Append(')');
break;
case 24:
sb.Append("Insert");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 3)));
sb.Append(',');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 2)));
sb.AppendFormat(", {0})", PTrace.ReadStack(sp, 0));
break;
case 25:
sb.Append("Copy");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 3)));
sb.AppendFormat(", {0}, {1})", PTrace.ReadStack(sp, 1), PTrace.ReadStack(sp, 0));
break;
case 26:
sb.Append("Delete");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 2)));
sb.AppendFormat(", {0}, {1})", PTrace.ReadStack(sp, 1), PTrace.ReadStack(sp, 0));
break;
case 27:
sb.Append("Pos");
if (sp == 0)
{
break;
}
sb.Append('(');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 3)));
sb.Append(',');
sb.Append(PTrace.PString(PTrace.ReadStack(sp, 2)));
sb.Append(')');
break;
case 28:
sb.Append("BlockRead/BlockWrite");
break;
case 29:
sb.Append("GotoXY");
if (sp != 0)
{
sb.AppendFormat("( {0}, {1})", PTrace.ReadStack(sp, 1), PTrace.ReadStack(sp, 0));
}
break;
}
return(sb.ToString());
}