private static List <SEHBlock> ReadSehBlocks(BufferedBinaryReader reader)
{
const int FatSize = 24;
const int TinySize = 12;
var blocks = new List <SEHBlock>();
bool next = true;
while (next)
{
// Goto 4 byte boundary (each section has to start at 4 byte boundary)
reader.Align4();
uint header = reader.ReadUInt32();
var sf = (SectionFlags)(header & 0xFF);
int size = (int)(header >> 8); //in bytes
if ((sf & SectionFlags.OptILTable) != 0)
{
}
else if ((sf & SectionFlags.FatFormat) == 0)
{
// tiny header
size &= 0xFF; // 1 byte size (filter out the padding)
int n = size / TinySize;
for (int i = 0; i < n; ++i)
{
var block = new SEHBlock(reader, false);
blocks.Add(block);
}
}
else
{
//make sure this is an exception block , otherwise skip
if ((sf & SectionFlags.EHTable) != 0)
{
int n = size / FatSize;
for (int i = 0; i < n; ++i)
{
var block = new SEHBlock(reader, true);
blocks.Add(block);
}
}
else
{
reader.Position += size;
}
}
next = (sf & SectionFlags.MoreSects) != 0;
}
return(blocks);
}
private static TryCatchBlock EnshureTryBlock(IList <SEHBlock> blocks, int i, TryCatchBlock tryBlock, ILStream code, SEHBlock block, ICollection <TryCatchBlock> list)
{
if (tryBlock == null)
{
tryBlock = CreateTryBlock(code, block.TryOffset, block.TryLength);
list.Add(tryBlock);
}
else
{
var prev = blocks[i - 1];
if (prev.TryOffset != block.TryOffset ||
prev.TryLength != block.TryLength)
{
tryBlock = CreateTryBlock(code, block.TryOffset, block.TryLength);
list.Add(tryBlock);
}
}
return(tryBlock);
}
private HandlerBlock CreateHandlerBlock(IMethod method, IMethodContext context, IInstructionList code, SEHBlock block)
{
switch (block.Type)
{
case SEHFlags.Catch:
{
int token = block.Value;
var type = context.ResolveType(method, token);
if (!HasGenericExceptions && type.IsGenericContext())
{
_genericFlags |= GenericFlags.HasGenericExceptions;
}
var h = new HandlerBlock(BlockType.Catch)
{
ExceptionType = type
};
return(h);
}
case SEHFlags.Filter:
{
var h = new HandlerBlock(BlockType.Filter)
{
FilterIndex = code.GetOffsetIndex(block.Value)
};
return(h);
}
case SEHFlags.Finally:
return(new HandlerBlock(BlockType.Finally));
case SEHFlags.Fault:
return(new HandlerBlock(BlockType.Fault));
default:
throw new IndexOutOfRangeException();
}
}
