/// <summary>
/// Reads the method header from the instruction stream.
/// </summary>
/// <param name="reader">The reader used to decode the instruction stream.</param>
/// <returns></returns>
public MethodHeader(EndianAwareBinaryReader reader)
{
Clauses = new List<ExceptionHandlingClause>();
// Read first byte
Flags = (MethodFlags)reader.ReadByte();
// Check least significant 2 bits
switch (Flags & MethodFlags.HeaderMask)
{
case MethodFlags.TinyFormat:
CodeSize = ((int)(Flags & MethodFlags.TinyCodeSizeMask) >> 2);
Flags &= MethodFlags.HeaderMask;
break;
case MethodFlags.FatFormat:
// Read second byte of flags
Flags = (MethodFlags)(reader.ReadByte() << 8 | (byte)Flags);
if (MethodFlags.ValidHeader != (Flags & MethodFlags.HeaderSizeMask))
throw new CompilerException("Invalid method ");
MaxStack = reader.ReadUInt16();
CodeSize = reader.ReadInt32();
LocalVarSigTok = new Token(reader.ReadUInt32()); // ReadStandAloneSigRow
break;
default:
throw new CompilerException("Invalid method header");
}
// Are there sections following the code?
if (MethodFlags.MoreSections != (Flags & MethodFlags.MoreSections))
return;
// Yes, seek to them and process those sections
long codepos = reader.BaseStream.Position;
// Seek to the end of the code...
long dataSectPos = codepos + CodeSize;
if (0 != (dataSectPos & 3))
dataSectPos += (4 - (dataSectPos % 4));
reader.BaseStream.Position = dataSectPos;
// Read all headers, so the IL decoder knows how to handle these...
byte flags;
do
{
flags = reader.ReadByte();
bool isFat = (0x40 == (flags & 0x40));
int length;
int blocks;
if (isFat)
{
byte a = reader.ReadByte();
byte b = reader.ReadByte();
byte c = reader.ReadByte();
length = (c << 24) | (b << 16) | a;
blocks = (length - 4) / 24;
}
else
{
length = reader.ReadByte();
blocks = (length - 4) / 12;
/* Read & skip the padding. */
reader.ReadInt16();
}
Debug.Assert(0x01 == (flags & 0x3F), "Unsupported method data section.");
// Read the clause
for (int i = 0; i < blocks; i++)
{
ExceptionHandlingClause clause = new ExceptionHandlingClause();
clause.Read(reader, isFat);
Clauses.Add(clause);
}
}
while (0x80 == (flags & 0x80));
reader.BaseStream.Position = codepos;
}
/// <summary>
/// Reads the method header from the instruction stream.
/// </summary>
/// <param name="reader">The reader used to decode the instruction stream.</param>
/// <returns></returns>
private MethodHeader ReadMethodHeader(EndianAwareBinaryReader reader)
{
MethodHeader header = new MethodHeader();
// Read first byte
header.Flags = (MethodFlags)reader.ReadByte();
// Check least significant 2 bits
switch (header.Flags & MethodFlags.HeaderMask)
{
case MethodFlags.TinyFormat:
header.CodeSize = ((uint)(header.Flags & MethodFlags.TinyCodeSizeMask) >> 2);
header.Flags &= MethodFlags.HeaderMask;
break;
case MethodFlags.FatFormat:
// Read second byte of flags
header.Flags = (MethodFlags)(reader.ReadByte() << 8 | (byte)header.Flags);
if (MethodFlags.ValidHeader != (header.Flags & MethodFlags.HeaderSizeMask))
throw new InvalidDataException(@"Invalid method header.");
header.MaxStack = reader.ReadUInt16();
header.CodeSize = reader.ReadUInt32();
header.LocalsSignature = new Token(reader.ReadUInt32()); // ReadStandAloneSigRow
break;
default:
throw new InvalidDataException(@"Invalid method header while trying to decode " + this.methodCompiler.Method.ToString() + ". (Flags = " + header.Flags.ToString("X") + ", Rva = " + this.methodCompiler.Method.Rva + ")");
}
// Are there sections following the code?
if (MethodFlags.MoreSections != (header.Flags & MethodFlags.MoreSections))
return header;
// Yes, seek to them and process those sections
long codepos = reader.BaseStream.Position;
// Seek to the end of the code...
long dataSectPos = codepos + header.CodeSize;
if (0 != (dataSectPos & 3))
dataSectPos += (4 - (dataSectPos % 4));
reader.BaseStream.Position = dataSectPos;
// Read all headers, so the IL decoder knows how to handle these...
byte flags;
do
{
flags = reader.ReadByte();
bool isFat = (0x40 == (flags & 0x40));
int length;
int blocks;
if (isFat)
{
byte a = reader.ReadByte();
byte b = reader.ReadByte();
byte c = reader.ReadByte();
length = (c << 24) | (b << 16) | a;
blocks = (length - 4) / 24;
}
else
{
length = reader.ReadByte();
blocks = (length - 4) / 12;
/* Read & skip the padding. */
reader.ReadInt16();
}
Debug.Assert(0x01 == (flags & 0x3F), @"Unsupported method data section.");
// Read the clause
for (int i = 0; i < blocks; i++)
{
ExceptionHandlingClause clause = new ExceptionHandlingClause();
clause.Read(reader, isFat);
methodCompiler.ExceptionClauseHeader.AddClause(clause);
}
}
while (0x80 == (flags & 0x80));
reader.BaseStream.Position = codepos;
return header;
}
/// <summary>
/// Reads the method header from the instruction stream.
/// </summary>
/// <param name="reader">The reader used to decode the instruction stream.</param>
/// <returns></returns>
public MethodHeader(EndianAwareBinaryReader reader)
{
Clauses = new List <ExceptionHandlingClause>();
// Read first byte
Flags = (MethodFlags)reader.ReadByte();
// Check least significant 2 bits
switch (Flags & MethodFlags.HeaderMask)
{
case MethodFlags.TinyFormat:
CodeSize = ((int)(Flags & MethodFlags.TinyCodeSizeMask) >> 2);
Flags &= MethodFlags.HeaderMask;
break;
case MethodFlags.FatFormat:
// Read second byte of flags
Flags = (MethodFlags)(reader.ReadByte() << 8 | (byte)Flags);
if (MethodFlags.ValidHeader != (Flags & MethodFlags.HeaderSizeMask))
{
throw new CompilerException("Invalid method ");
}
MaxStack = reader.ReadUInt16();
CodeSize = reader.ReadInt32();
LocalVarSigTok = new Token(reader.ReadUInt32()); // ReadStandAloneSigRow
break;
default:
throw new CompilerException("Invalid method header");
}
// Are there sections following the code?
if (MethodFlags.MoreSections != (Flags & MethodFlags.MoreSections))
{
return;
}
// Yes, seek to them and process those sections
long codepos = reader.BaseStream.Position;
// Seek to the end of the code...
long dataSectPos = codepos + CodeSize;
if (0 != (dataSectPos & 3))
{
dataSectPos += (4 - (dataSectPos % 4));
}
reader.BaseStream.Position = dataSectPos;
// Read all headers, so the IL decoder knows how to handle these...
byte flags;
do
{
flags = reader.ReadByte();
bool isFat = (0x40 == (flags & 0x40));
int length;
int blocks;
if (isFat)
{
byte a = reader.ReadByte();
byte b = reader.ReadByte();
byte c = reader.ReadByte();
length = (c << 24) | (b << 16) | a;
blocks = (length - 4) / 24;
}
else
{
length = reader.ReadByte();
blocks = (length - 4) / 12;
/* Read & skip the padding. */
reader.ReadInt16();
}
Debug.Assert(0x01 == (flags & 0x3F), "Unsupported method data section.");
// Read the clause
for (int i = 0; i < blocks; i++)
{
ExceptionHandlingClause clause = new ExceptionHandlingClause();
clause.Read(reader, isFat);
Clauses.Add(clause);
}
}while (0x80 == (flags & 0x80));
reader.BaseStream.Position = codepos;
}
