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Cosmos/source/Cosmos.IL2CPU/ILReader.cs

432 lines
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C#
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using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Reflection.Emit;
namespace Cosmos.IL2CPU {
public class ILReader {
// We split this into two arrays since we have to read
// a byte at a time anways. In the future if we need to
// back to a unifed array, instead of 64k entries
// we can change it to a signed int, and then add x0200 to the value.
// This will reduce array size down to 768 entries.
protected OpCode[] mOpCodesLo = new OpCode[256];
protected OpCode[] mOpCodesHi = new OpCode[256];
public ILReader() {
LoadOpCodes();
}
protected void LoadOpCodes() {
foreach (var xField in typeof(OpCodes).GetFields(BindingFlags.DeclaredOnly | BindingFlags.Static | BindingFlags.Public)) {
var xOpCode = (OpCode)xField.GetValue(null);
var xValue = (ushort)xOpCode.Value;
if (xValue <= 0xFF) {
mOpCodesLo[xValue] = xOpCode;
} else {
mOpCodesHi[xValue & 0xFF] = xOpCode;
}
}
}
protected void CheckBranch(int aTarget, int aMethodSize) {
// this method is a safety-measure. Should never occur
if (aTarget < 0 || aTarget >= aMethodSize) {
throw new Exception("Branch jumps outside method.");
}
}
public List<ILOpCode> ProcessMethod(MethodBase aMethod) {
var xResult = new List<ILOpCode>();
var xBody = aMethod.GetMethodBody();
// Cache for use in field and method resolution
Type[] xTypeGenArgs = null;
Type[] xMethodGenArgs = null;
if (aMethod.DeclaringType.IsGenericType) {
xTypeGenArgs = aMethod.DeclaringType.GetGenericArguments();
}
if (aMethod.IsGenericMethod) {
xMethodGenArgs = aMethod.GetGenericArguments();
}
// Some methods return no body. Not sure why.. have to investigate
// They arent abstracts or icalls...
if (xBody == null) {
return null;
}
var xIL = xBody.GetILAsByteArray();
int xPos = 0;
while (xPos < xIL.Length) {
ExceptionHandlingClause xCurrentHandler = null;
#region Determine current handler
// todo: add support for nested handlers using a stack or so..
foreach (ExceptionHandlingClause xHandler in xBody.ExceptionHandlingClauses)
{
if (xHandler.TryOffset > 0)
{
if (xHandler.TryOffset <= xPos && (xHandler.TryLength + xHandler.TryOffset ) > xPos)
{
if (xCurrentHandler == null)
{
xCurrentHandler = xHandler;
continue;
}
else if (xHandler.TryOffset > xCurrentHandler.TryOffset && (xHandler.TryLength + xHandler.TryOffset) < (xCurrentHandler.TryLength + xCurrentHandler.TryOffset))
{
// only replace if the current found handler is narrower
xCurrentHandler = xHandler;
continue;
}
}
}
if (xHandler.HandlerOffset > 0)
{
if (xHandler.HandlerOffset <= xPos && (xHandler.HandlerOffset + xHandler.HandlerLength) > xPos)
{
if (xCurrentHandler == null)
{
xCurrentHandler = xHandler;
continue;
}
else if (xHandler.HandlerOffset > xCurrentHandler.HandlerOffset && (xHandler.HandlerOffset + xHandler.HandlerLength) < (xCurrentHandler.HandlerOffset + xCurrentHandler.HandlerLength))
{
// only replace if the current found handler is narrower
xCurrentHandler = xHandler;
continue;
}
}
}
if ((xHandler.Flags & ExceptionHandlingClauseOptions.Filter) > 0)
{
if (xHandler.FilterOffset > 0)
{
if (xHandler.FilterOffset <= xPos)
{
if (xCurrentHandler == null)
{
xCurrentHandler = xHandler;
continue;
}
else if (xHandler.FilterOffset > xCurrentHandler.FilterOffset)
{
// only replace if the current found handler is narrower
xCurrentHandler = xHandler;
continue;
}
}
}
}
}
#endregion
ILOpCode.Code xOpCodeVal;
OpCode xOpCode;
int xOpPos = xPos;
if (xIL[xPos] == 0xFE) {
xOpCodeVal = (ILOpCode.Code)(0xFE00 | xIL[xPos + 1]);
xOpCode = mOpCodesHi[xIL[xPos + 1]];
xPos = xPos + 2;
} else {
xOpCodeVal = (ILOpCode.Code)xIL[xPos];
xOpCode = mOpCodesLo[xIL[xPos]];
xPos++;
}
ILOpCode xILOpCode = null;
switch (xOpCode.OperandType) {
// No operand.
case OperandType.InlineNone:
{
#region Inline none options
// These shortcut translation regions expand shortcut ops into full ops
// This elminates the amount of code required in the assemblers
// by allowing them to ignore the shortcuts
switch (xOpCodeVal) {
case ILOpCode.Code.Ldarg_0:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarg, xOpPos, xPos, 0, xCurrentHandler);
break;
case ILOpCode.Code.Ldarg_1:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarg, xOpPos, xPos, 1, xCurrentHandler);
break;
case ILOpCode.Code.Ldarg_2:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarg, xOpPos, xPos, 2, xCurrentHandler);
break;
case ILOpCode.Code.Ldarg_3:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarg, xOpPos, xPos, 3, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_0:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 0, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_1:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 1, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_2:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 2, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_3:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 3, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_4:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 4, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_5:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 5, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_6:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 6, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_7:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 7, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_8:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, 8, xCurrentHandler);
break;
case ILOpCode.Code.Ldc_I4_M1:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos, -1, xCurrentHandler);
break;
case ILOpCode.Code.Ldloc_0:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloc, xOpPos, xPos, 0, xCurrentHandler);
break;
case ILOpCode.Code.Ldloc_1:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloc, xOpPos, xPos, 1, xCurrentHandler);
break;
case ILOpCode.Code.Ldloc_2:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloc, xOpPos, xPos, 2, xCurrentHandler);
break;
case ILOpCode.Code.Ldloc_3:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloc, xOpPos, xPos, 3, xCurrentHandler);
break;
case ILOpCode.Code.Stloc_0:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Stloc, xOpPos, xPos, 0, xCurrentHandler);
break;
case ILOpCode.Code.Stloc_1:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Stloc, xOpPos, xPos, 1, xCurrentHandler);
break;
case ILOpCode.Code.Stloc_2:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Stloc, xOpPos, xPos, 2, xCurrentHandler);
break;
case ILOpCode.Code.Stloc_3:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Stloc, xOpPos, xPos, 3, xCurrentHandler);
break;
default:
xILOpCode = new ILOpCodes.OpNone(xOpCodeVal, xOpPos, xPos, xCurrentHandler);
break;
}
#endregion
break;
}
case OperandType.ShortInlineBrTarget:
{
#region Inline branch
// By calculating target, we assume all branches are within a method
// So far at least wtih csc, its true. We check it with CheckBranch
// just in case.
int xTarget = xPos + 1 + (sbyte)xIL[xPos];
CheckBranch(xTarget, xIL.Length);
switch (xOpCodeVal)
{
case ILOpCode.Code.Beq_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Beq, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Bge_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Bge, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Bge_Un_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Bge_Un, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Bgt_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Bgt, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Bgt_Un_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Bgt_Un, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Ble_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Ble, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Ble_Un_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Ble_Un, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Blt_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Blt, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Blt_Un_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Blt_Un, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Bne_Un_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Bne_Un, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Br_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Br, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Brfalse_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Brfalse, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Brtrue_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Brtrue, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
case ILOpCode.Code.Leave_S:
xILOpCode = new ILOpCodes.OpBranch(ILOpCode.Code.Leave, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
default:
xILOpCode = new ILOpCodes.OpBranch(xOpCodeVal, xOpPos, xPos + 1, xTarget, xCurrentHandler);
break;
}
xPos = xPos + 1;
break;
#endregion
}
case OperandType.InlineBrTarget: {
int xTarget = xPos + 4 + ReadInt32(xIL, xPos);
CheckBranch(xTarget, xIL.Length);
xILOpCode = new ILOpCodes.OpBranch(xOpCodeVal, xOpPos, xPos + 4, xTarget, xCurrentHandler);
xPos = xPos + 4;
break;
}
case OperandType.ShortInlineI:
switch (xOpCodeVal) {
case ILOpCode.Code.Ldc_I4_S:
xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos + 1, ((sbyte)xIL[xPos]), xCurrentHandler);
break;
default:
xILOpCode = new ILOpCodes.OpInt(xOpCodeVal, xOpPos, xPos + 1, ((sbyte)xIL[xPos]), xCurrentHandler);
break;
}
xPos = xPos + 1;
break;
case OperandType.InlineI:
xILOpCode = new ILOpCodes.OpInt(xOpCodeVal, xOpPos, xPos + 4, ReadInt32(xIL, xPos), xCurrentHandler);
xPos = xPos + 4;
break;
case OperandType.InlineI8:
xILOpCode = new ILOpCodes.OpInt64(xOpCodeVal, xOpPos, xPos + 8, ReadUInt64(xIL, xPos), xCurrentHandler);
xPos = xPos + 8;
break;
case OperandType.ShortInlineR:
xILOpCode = new ILOpCodes.OpSingle(xOpCodeVal, xOpPos, xPos + 4, BitConverter.ToSingle(xIL, xPos), xCurrentHandler);
xPos = xPos + 4;
break;
case OperandType.InlineR:
xILOpCode = new ILOpCodes.OpDouble(xOpCodeVal, xOpPos, xPos + 8, BitConverter.ToDouble(xIL, xPos), xCurrentHandler);
xPos = xPos + 8;
break;
// The operand is a 32-bit metadata token.
case OperandType.InlineField: {
var xValue = aMethod.Module.ResolveField(ReadInt32(xIL, xPos), xTypeGenArgs, xMethodGenArgs);
xILOpCode = new ILOpCodes.OpField(xOpCodeVal, xOpPos, xPos + 4, xValue, xCurrentHandler);
xPos = xPos + 4;
break;
}
// The operand is a 32-bit metadata token.
case OperandType.InlineMethod: {
var xValue = aMethod.Module.ResolveMethod(ReadInt32(xIL, xPos), xTypeGenArgs, xMethodGenArgs);
xILOpCode = new ILOpCodes.OpMethod(xOpCodeVal, xOpPos, xPos + 4, xValue, xCurrentHandler);
xPos = xPos + 4;
break;
}
// 32-bit metadata signature token.
case OperandType.InlineSig:
xILOpCode = new ILOpCodes.OpSig(xOpCodeVal, xOpPos, xPos + 4, ReadInt32(xIL, xPos), xCurrentHandler);
xPos = xPos + 4;
break;
case OperandType.InlineString:
xILOpCode = new ILOpCodes.OpString(xOpCodeVal, xOpPos, xPos + 4, aMethod.Module.ResolveString(ReadInt32(xIL, xPos)), xCurrentHandler);
xPos = xPos + 4;
break;
case OperandType.InlineSwitch: {
int xCount = ReadInt32(xIL, xPos);
xPos = xPos + 4;
int xNextOpPos = xPos + xCount * 4;
var xBranchLocations = new int[xCount];
for (int i = 0; i < xCount; i++) {
xBranchLocations[i] = xNextOpPos + ReadInt32(xIL, xPos + i * 4);
CheckBranch(xBranchLocations[i], xIL.Length);
}
xILOpCode = new ILOpCodes.OpSwitch(xOpCodeVal, xOpPos, xNextOpPos, xBranchLocations, xCurrentHandler);
xPos = xNextOpPos;
break;
}
// The operand is a FieldRef, MethodRef, or TypeRef token.
case OperandType.InlineTok:
xILOpCode = new ILOpCodes.OpToken(xOpCodeVal, xOpPos, xPos + 4, ReadInt32(xIL, xPos), aMethod.Module, xTypeGenArgs, xMethodGenArgs, xCurrentHandler);
xPos = xPos + 4;
break;
// 32-bit metadata token.
case OperandType.InlineType: {
var xValue = aMethod.Module.ResolveType(ReadInt32(xIL, xPos), xTypeGenArgs, xMethodGenArgs);
xILOpCode = new ILOpCodes.OpType(xOpCodeVal, xOpPos, xPos + 4, xValue, xCurrentHandler);
xPos = xPos + 4;
break;
}
case OperandType.ShortInlineVar:
switch (xOpCodeVal) {
case ILOpCode.Code.Ldloc_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloc, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
case ILOpCode.Code.Ldloca_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldloca, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
case ILOpCode.Code.Ldarg_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarg, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
case ILOpCode.Code.Ldarga_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Ldarga, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
case ILOpCode.Code.Starg_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Starg, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
case ILOpCode.Code.Stloc_S:
xILOpCode = new ILOpCodes.OpVar(ILOpCode.Code.Stloc, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
default:
xILOpCode = new ILOpCodes.OpVar(xOpCodeVal, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
break;
}
xPos = xPos + 1;
break;
case OperandType.InlineVar:
xILOpCode = new ILOpCodes.OpVar(xOpCodeVal, xOpPos, xPos + 2, ReadUInt16(xIL, xPos), xCurrentHandler);
xPos = xPos + 2;
break;
default:
throw new Exception("Unknown OperandType");
}
xILOpCode.InitStackAnalysis(aMethod);
xResult.Add(xILOpCode);
}
return xResult;
}
// We could use BitConvertor, unfortuantely they "hardcoded" endianness. Its fine for reading IL now...
// but they essentially do the same as we do, just a bit slower.
private UInt16 ReadUInt16(byte[] aBytes, int aPos) {
return (UInt16)(aBytes[aPos + 1] << 8 | aBytes[aPos]);
}
private Int32 ReadInt32(byte[] aBytes, int aPos) {
return aBytes[aPos + 3] << 24 | aBytes[aPos + 2] << 16 | aBytes[aPos + 1] << 8 | aBytes[aPos];
}
private UInt64 ReadUInt64(byte[] aBytes, int aPos) {
//return (UInt64)(
// aBytes[aPos + 7] << 56 | aBytes[aPos + 6] << 48 | aBytes[aPos + 5] << 40 | aBytes[aPos + 4] << 32
// | aBytes[aPos + 3] << 24 | aBytes[aPos + 2] << 16 | aBytes[aPos + 1] << 8 | aBytes[aPos]);
return BitConverter.ToUInt64(aBytes, aPos);
}
}
}
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