private static MethodBodyBlock CreateBody(MethodEx methodEx)
{
if(!methodEx.IsVerified)
return null;
MethodBodyBlock body;
body = Converter.Convert(methodEx);
return(body);
}
private static void ProcessLeave(int iNum,MethodEx method,StackTypes stack)
{
CheckCanLeave(method.EHClauses, iNum, (int)method[iNum].Param);
ProcessLeave(stack);
ProcessBranch(iNum,(int)method[iNum].Param,method,stack);
}
private static void ProcessSwitch(int iNum,MethodEx method,StackTypes stack)
{
int[] INums = (int[])method[iNum].Param;
for(int i = 0;i<INums.Length;i++)
{
CheckSameBlock(method.EHClauses, iNum, INums[i]);
ProcessBranch(iNum,INums[i],method,stack);
}
}
private static void ProcessBr(int iNum,MethodEx method,StackTypes stack)
{
CheckSameBlock(method.EHClauses, iNum, (int)method[iNum].Param);
ProcessBranch(iNum, (int)method[iNum].Param, method, stack);
}
private static void ProcessBranch(int iNum,int INum,MethodEx method,StackTypes stack)
{
Instruction I = method[INum];
if(INum > iNum)
I.SetStack(MergeStacks(I.Stack,stack));
else
CheckStacks(I.Stack,stack);
}
internal static bool Check(MethodEx methodRepr)
{
//Attention: the `null` value on stack means a null reference that is of any object type
//As `typeof(object)` is the most general Type, so `null` is the most exact object type
FreeStacks(methodRepr);
try
{
Instruction lastI = methodRepr[methodRepr.Count-1];
if( lastI.Code != InstructionCode.RET
&& lastI.Code != InstructionCode.BR
&& lastI.Code != InstructionCode.THROW
&& lastI.Code != InstructionCode.RETHROW
&& lastI.Code != InstructionCode.LEAVE
&& lastI.Code != InstructionCode.ENDFINALLY
&& lastI.Code != InstructionCode.ENDFILTER )
throw new VerifierException();
MethodInfoExtention method = new MethodInfoExtention(methodRepr.Method);
StackTypes stack = new StackTypes(); //initially the stack is empty
int nextHandler = FindNextHandler(-1,methodRepr.EHClauses);
CheckBlockExits(methodRepr);
for (int iNum = 0; iNum < methodRepr.Count ; iNum ++)
{
Instruction i = methodRepr[iNum];
i.SetStack(MergeStacks(i.Stack,stack));
if(nextHandler == iNum)
{
PushExceptionOnStack(iNum,i.Stack,methodRepr.EHClauses);
nextHandler = FindNextHandler(iNum,methodRepr.EHClauses);
}
stack = i.Stack.Clone() as StackTypes;
switch(i.Code)
{
case InstructionCode.DUP :
{
stack.Push(stack.Peek());
} break;
case InstructionCode.LDARG :
{
stack.Push(method.GetArgType((Int32)i.Param));
} break;
case InstructionCode.LDARGA :
{
TypeEx t = method.GetArgType((Int32)i.Param).BuildRefType();
stack.Push(t);
} break;
case InstructionCode.LDLOCA :
{
TypeEx t = new TypeEx(TypeEx.BuildRefType(methodRepr.Locals[(Int32)i.Param]));
stack.Push(t);
} break;
case InstructionCode.LDLOC :
{
stack.Push(new TypeEx(methodRepr.Locals[(Int32)i.Param]));
} break;
case InstructionCode.LDIND :
{
ProcessLdInd(i.TypeBySuffixOrParam(), stack);
} break;
case InstructionCode.LDC:
{
stack.Push(new TypeEx(i.TypeBySuffixOrParam()));
} break;
case InstructionCode.LDNULL:
{
stack.Push(new TypeEx(null));//see `Attention` at the top of the method.
} break;
case InstructionCode.LDFLD:
{
ProcessLdFld(stack, i.Param as FieldInfo,false);
} break;
case InstructionCode.LDFLDA:
{
ProcessLdFld(stack, i.Param as FieldInfo,true);
} break;
case InstructionCode.LDSFLD:
{
stack.Push(new TypeEx((i.Param as FieldInfo).FieldType));
} break;
case InstructionCode.LDSFLDA:
{
stack.Push(TypeEx.BuildRefType((i.Param as FieldInfo).FieldType));
} break;
case InstructionCode.LDELEM:
{
ProcessLdElem(stack, new TypeEx(i.TypeBySuffixOrParam()), false);
} break;
case InstructionCode.LDELEMA:
{
ProcessLdElem(stack, new TypeEx(i.TypeBySuffixOrParam()), true);
} break;
case InstructionCode.LDLEN :
{
ProcessLdLen(stack);
} break;
case InstructionCode.LDOBJ :
{
ProcessLdObj(stack, i.Param as Type);
} break;
case InstructionCode.LDSTR:
{
if(!(i.Param is string))
throw new VerifierException();
stack.Push(typeof(string));
} break;
case InstructionCode.LDFTN:
{
stack.Push(new TypeEx(typeof(IntPtr)));
} break;
case InstructionCode.LDVIRTFTN:
{
TypeEx obj = stack.Pop();
MethodInfo methodInfo = i.Param as MethodInfo;
if(!methodInfo.IsVirtual)
throw new VerifierException();
TypeChecker.CheckAssignment(new TypeEx(methodInfo.DeclaringType , true), obj);
stack.Push(typeof(IntPtr));
} break;
case InstructionCode.LDTOKEN:
{
if(i.Param is Type)
stack.Push(typeof(System.RuntimeTypeHandle));
else if(i.Param is MethodBase)
stack.Push(typeof(System.RuntimeMethodHandle));
else if(i.Param is FieldInfo)
stack.Push(typeof(System.RuntimeFieldHandle));
else
throw new VerifierException();
} break;
case InstructionCode.SIZEOF :
{
ProcessSizeOf(stack,i.Param as Type);
} break;
case InstructionCode.CLT:
case InstructionCode.CGT:
case InstructionCode.CEQ:
{
ProcessBinOp(OpType.Compare,stack);
} break;
case InstructionCode.BLE:
case InstructionCode.BLT:
case InstructionCode.BGE:
case InstructionCode.BGT:
case InstructionCode.BEQ:
case InstructionCode.BNE:
{
TypeEx t1 = stack.Pop();
TypeEx t2 = stack.Pop();
Arithmetics.CheckTypes(t1,t2);
ProcessBr(iNum,methodRepr,stack);
stack = stack.Clone() as StackTypes;
//Andrew: mb wrong, we may let equal stacks to be the same object
} break;
case InstructionCode.BRTRUE:
case InstructionCode.BRFALSE:
{
ProcessBrTrueFalse(stack);
ProcessBr(iNum,methodRepr,stack);
stack = stack.Clone() as StackTypes;
//Andrew: mb wrong, we may let equal stacks to be the same object
} break;
case InstructionCode.BR :
{
ProcessBr(iNum,methodRepr,stack);
stack = null;
} break;
case InstructionCode.SWITCH:
{
ProcessSwitch(stack);
ProcessSwitch(iNum,methodRepr,stack);
stack = stack.Clone() as StackTypes;
} break;
case InstructionCode.THROW :
{
ProcessThrow(stack);
stack = null;
}break;
case InstructionCode.RETHROW :
{
if(GetNearestBlock(methodRepr.EHClauses,iNum).type != BlockType.Catch)
throw new VerifierException();
stack = null;
}break;
case InstructionCode.LEAVE :
{
BlockType blockType = GetNearestBlock(methodRepr.EHClauses,iNum).type;
if(blockType != BlockType.Catch && blockType != BlockType.Try)
throw new VerifierException();
ProcessLeave(iNum,methodRepr,stack);
stack = null;
} break;
case InstructionCode.ENDFINALLY :
{
if(GetNearestBlock(methodRepr.EHClauses,iNum).type != BlockType.Finally)
throw new VerifierException();
ProcessLeave(stack);
stack = null;
} break;
case InstructionCode.ENDFILTER :
{
if(GetNearestBlock(methodRepr.EHClauses,iNum).type != BlockType.Filter)
throw new VerifierException();
ProcessEndFilter(stack);
stack = null;
} break;
case InstructionCode.NOT:
{
ProcessNot(stack);
} break;
case InstructionCode.NEG:
{
ProcessNeg(stack);
} break;
case InstructionCode.CKFINITE :
{
ProcessCkFinite(stack);
} break;
case InstructionCode.CONV:
{
ProcessConv(i.TypeBySuffixOrParam(), stack);
} break;
case InstructionCode.SUB:
case InstructionCode.ADD:
case InstructionCode.MUL:
case InstructionCode.DIV:
case InstructionCode.REM:
case InstructionCode.XOR:
case InstructionCode.OR:
case InstructionCode.AND:
{
ProcessBinOp(IsFloatOperation(i) ? OpType.FloatOrInt : OpType.Int , stack);
} break;
case InstructionCode.SHL:
case InstructionCode.SHR:
{
ProcessBinOp(OpType.Shift , stack);
} break;
case InstructionCode.CPOBJ :
{
ProcessCpObj(stack, i.Param as Type);
} break;
case InstructionCode.STARG :
{
ProcessSt(method.GetArgType((Int32)i.Param) , stack);
} break;
case InstructionCode.STLOC :
{
ProcessSt(new TypeEx(methodRepr.Locals[(Int32)i.Param]) , stack);
} break;
case InstructionCode.STIND :
{
ProcessStInd(i.TypeBySuffixOrParam() , stack);
} break;
case InstructionCode.STFLD:
{
ProcessStFld(stack, i.Param as FieldInfo);
} break;
case InstructionCode.STSFLD:
{
ProcessStSFld(stack, i.Param as FieldInfo);
} break;
case InstructionCode.STELEM:
{
ProcessStElem(stack, new TypeEx(i.TypeBySuffixOrParam()));
} break;
case InstructionCode.STOBJ :
{
ProcessStObj(stack, i.Param as Type);
} break;
case InstructionCode.RET :
{
if(GetNearestBlock(methodRepr.EHClauses,iNum).type != BlockType.Global)
throw new VerifierException();
ProcessRet(method.GetReturnType(), stack);
stack = null;
} break;
case InstructionCode.CALL :
case InstructionCode.CALLVIRT :
case InstructionCode.NEWOBJ :
{
//constructor may be invoked using either CALL or NEWOBJ instructions
MethodBase callee = i.Param as MethodBase;
if(i.Code == InstructionCode.NEWOBJ && callee.IsConstructor && IsDelegate(callee.DeclaringType))
ProcessDelegateConstruction(methodRepr,iNum,stack);
else
ProcessCallOrNewobj(new MethodInfoExtention(callee,i.Code == InstructionCode.CALLVIRT), stack, i.Code == InstructionCode.NEWOBJ);
if(i.HasTail && methodRepr[iNum+1].Code != InstructionCode.RET)
throw new VerifierException();
} break;
case InstructionCode.INITOBJ :
{
ProcessInitObj(stack, i.Param as Type);
} break;
case InstructionCode.NEWARR :
{
ProcessNewArr(stack, i.Param as Type);
} break;
case InstructionCode.ISINST :
case InstructionCode.CASTCLASS :
{
ProcessCastClass(stack, new TypeEx(i.Param as Type , true));
} break;
case InstructionCode.BOX :
{
ProcessBox(stack, i.Param as Type);
} break;
case InstructionCode.UNBOX :
{
ProcessUnBox(stack, i.Param as Type);
} break;
case InstructionCode.POP :
{
stack.Pop();
} break;
case InstructionCode.NOP :
case InstructionCode.BREAK :
break;
default:
{
throw new VerifierException();
//Instruction is not supported yet...
}
}
}
return(true);
}
catch(VerifierException )
{
FreeStacks(methodRepr);
return(false);
}
//catch(NullReferenceException ) //Andrew: ZaLyaPa :( waiting for Sergey to patch NEWOBJ (delegate construction)
//{
// FreeStacks(methodRepr);
// return(false);
//}
}
static private void ProcessDelegateConstruction(MethodEx method,int iNum,StackTypes stack)
{
if(!(IsInstanceDispatch(method,iNum) || IsVirtualDispatch(method,iNum)))
throw new VerifierException();
TypeEx intPtr = stack.Pop();
MethodInfo ftn = method[iNum-1].Param as MethodInfo;
ConstructorInfo ctor = method[iNum].Param as ConstructorInfo;
ProcessDelegateConstruction(stack,ftn,ctor);
}
static public bool IsVirtualDispatch(MethodEx body,int iNum)
{
Instruction i0 = body[iNum-2];
Instruction i1 = body[iNum-1];
Instruction i2 = body[iNum];
if(i2.Code != InstructionCode.NEWOBJ)
return(false);
if(i1.Code != InstructionCode.LDVIRTFTN)
return(false);
if(i0.Code != InstructionCode.DUP)
return(false);
return(true);
}
static public bool IsInstanceDispatch(MethodEx body,int iNum)
{
Instruction i1 = body[iNum-1];
Instruction i2 = body[iNum];
if(i2.Code != InstructionCode.NEWOBJ)
return(false);
if(i1.Code != InstructionCode.LDFTN)
return(false);
return(true);
}
private static void CheckBlockExits(MethodEx methodRepr)
{
foreach(EHClause c in methodRepr.EHClauses)
{
int handlerEnd = c.HandlerStart + c.HandlerLength - 1;
int tryEnd = c.TryStart + c.TryLength - 1;
if(!IsTryExit(methodRepr[tryEnd].Code))
throw new VerifierException();
if(c.Kind == EHClauseKind.FinallyHandler ? !IsFinallyExit(methodRepr[handlerEnd].Code) :
!IsCatchExit(methodRepr[handlerEnd].Code) )
throw new VerifierException();
if(c.Kind == EHClauseKind.UserFilteredHandler)
if(!IsFilterExit(methodRepr[c.HandlerStart - 1].Code))
throw new VerifierException();
}
}
static internal void FreeStacks(MethodEx method)
{
foreach(Instruction i in method)
i.SetStack(null);
}
private static void ProcessMethod(ILGenerator generator, MethodEx methodEx, MethodBase method, MetaDataMapper mapper)
{
if(method.IsAbstract)
return;
MethodBodyBlock body = null;
if(methodEx == null)
throw new ExportException();
body = CreateBody(methodEx);
if(body == null)
throw new ExportException();
MetaDataResolver.Map(body,mapper);
bool verified = CFGVerifier.Check(body);
if(!verified)
throw new ExportException();
Emitter.Emit(generator,body);
}
