void ValidateCatchBlock(ILTryCatchBlock.CatchBlock catchBlock)
{
if (catchBlock.ExceptionType == null || catchBlock.ExceptionType.Name != "Exception")
{
throw new SymbolicAnalysisFailedException();
}
if (catchBlock.Body.Count != 3)
{
throw new SymbolicAnalysisFailedException();
}
int stateID;
if (!(MatchStateAssignment(catchBlock.Body[0], out stateID) && stateID == finalState))
{
throw new SymbolicAnalysisFailedException();
}
MethodReference setExceptionMethod;
ILExpression builderExpr, exceptionExpr;
if (!catchBlock.Body[1].Match(ILCode.Call, out setExceptionMethod, out builderExpr, out exceptionExpr))
{
throw new SymbolicAnalysisFailedException();
}
if (!(setExceptionMethod.Name == "SetException" && IsBuilderFieldOnThis(builderExpr) && exceptionExpr.MatchLdloc(catchBlock.ExceptionVariable)))
{
throw new SymbolicAnalysisFailedException();
}
ILLabel label;
if (!(catchBlock.Body[2].Match(ILCode.Leave, out label) && label == exitLabel))
{
throw new SymbolicAnalysisFailedException();
}
}
List <ILNode> ConvertToAst(List <ByteCode> body, HashSet <ExceptionHandler> ehs)
{
List <ILNode> ast = new List <ILNode>();
while (ehs.Any())
{
ILTryCatchBlock tryCatchBlock = new ILTryCatchBlock();
// Find the first and widest scope
int tryStart = ehs.Min(eh => eh.TryStart.Offset);
int tryEnd = ehs.Where(eh => eh.TryStart.Offset == tryStart).Max(eh => eh.TryEnd.Offset);
var handlers = ehs.Where(eh => eh.TryStart.Offset == tryStart && eh.TryEnd.Offset == tryEnd).OrderBy(eh => eh.TryStart.Offset).ToList();
// Remember that any part of the body migt have been removed due to unreachability
// Cut all instructions up to the try block
{
int tryStartIdx = 0;
while (tryStartIdx < body.Count && body[tryStartIdx].Offset < tryStart)
{
tryStartIdx++;
}
ast.AddRange(ConvertToAst(body.CutRange(0, tryStartIdx)));
}
// Cut the try block
{
HashSet <ExceptionHandler> nestedEHs = new HashSet <ExceptionHandler>(ehs.Where(eh => (tryStart <= eh.TryStart.Offset && eh.TryEnd.Offset < tryEnd) || (tryStart < eh.TryStart.Offset && eh.TryEnd.Offset <= tryEnd)));
ehs.ExceptWith(nestedEHs);
int tryEndIdx = 0;
while (tryEndIdx < body.Count && body[tryEndIdx].Offset < tryEnd)
{
tryEndIdx++;
}
tryCatchBlock.TryBlock = new ILBlock(ConvertToAst(body.CutRange(0, tryEndIdx), nestedEHs));
}
// Cut all handlers
tryCatchBlock.CatchBlocks = new List <ILTryCatchBlock.CatchBlock>();
foreach (ExceptionHandler eh in handlers)
{
int handlerEndOffset = eh.HandlerEnd == null ? methodDef.Body.CodeSize : eh.HandlerEnd.Offset;
int startIdx = 0;
while (startIdx < body.Count && body[startIdx].Offset < eh.HandlerStart.Offset)
{
startIdx++;
}
int endIdx = 0;
while (endIdx < body.Count && body[endIdx].Offset < handlerEndOffset)
{
endIdx++;
}
HashSet <ExceptionHandler> nestedEHs = new HashSet <ExceptionHandler>(ehs.Where(e => (eh.HandlerStart.Offset <= e.TryStart.Offset && e.TryEnd.Offset < handlerEndOffset) || (eh.HandlerStart.Offset < e.TryStart.Offset && e.TryEnd.Offset <= handlerEndOffset)));
ehs.ExceptWith(nestedEHs);
List <ILNode> handlerAst = ConvertToAst(body.CutRange(startIdx, endIdx - startIdx), nestedEHs);
if (eh.HandlerType == ExceptionHandlerType.Catch)
{
ILTryCatchBlock.CatchBlock catchBlock = new ILTryCatchBlock.CatchBlock()
{
ExceptionType = eh.CatchType,
Body = handlerAst
};
// Handle the automatically pushed exception on the stack
ByteCode ldexception = ldexceptions[eh];
if (ldexception.StoreTo == null || ldexception.StoreTo.Count == 0)
{
// Exception is not used
catchBlock.ExceptionVariable = null;
}
else if (ldexception.StoreTo.Count == 1)
{
ILExpression first = catchBlock.Body[0] as ILExpression;
if (first != null &&
first.Code == ILCode.Pop &&
first.Arguments[0].Code == ILCode.Ldloc &&
first.Arguments[0].Operand == ldexception.StoreTo[0])
{
// The exception is just poped - optimize it all away;
if (context.Settings.AlwaysGenerateExceptionVariableForCatchBlocks)
{
catchBlock.ExceptionVariable = new ILVariable()
{
Name = "ex_" + eh.HandlerStart.Offset.ToString("X2"), IsGenerated = true
}
}
;
else
{
catchBlock.ExceptionVariable = null;
}
catchBlock.Body.RemoveAt(0);
}
else
{
catchBlock.ExceptionVariable = ldexception.StoreTo[0];
}
}
else
{
ILVariable exTemp = new ILVariable()
{
Name = "ex_" + eh.HandlerStart.Offset.ToString("X2"), IsGenerated = true
};
catchBlock.ExceptionVariable = exTemp;
foreach (ILVariable storeTo in ldexception.StoreTo)
{
catchBlock.Body.Insert(0, new ILExpression(ILCode.Stloc, storeTo, new ILExpression(ILCode.Ldloc, exTemp)));
}
}
tryCatchBlock.CatchBlocks.Add(catchBlock);
}
else if (eh.HandlerType == ExceptionHandlerType.Finally)
{
tryCatchBlock.FinallyBlock = new ILBlock(handlerAst);
}
else if (eh.HandlerType == ExceptionHandlerType.Fault)
{
tryCatchBlock.FaultBlock = new ILBlock(handlerAst);
}
else
{
// TODO: ExceptionHandlerType.Filter
}
}
ehs.ExceptWith(handlers);
ast.Add(tryCatchBlock);
}
// Add whatever is left
ast.AddRange(ConvertToAst(body));
return(ast);
}