/// <summary>
/// Encodes a method body and adds it to the method body stream.
/// </summary>
/// <param name="codeSize">Number of bytes to be reserved for instructions.</param>
/// <param name="maxStack">Max stack.</param>
/// <param name="exceptionRegionCount">Number of exception regions.</param>
/// <param name="hasSmallExceptionRegions">True if the exception regions should be encoded in 'small' format.</param>
/// <param name="localVariablesSignature">Local variables signature handle.</param>
/// <param name="attributes">Attributes.</param>
/// <param name="hasDynamicStackAllocation">True if the method allocates from dynamic local memory pool (<c>localloc</c> instruction).</param>
/// <returns>The offset of the encoded body within the method body stream.</returns>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="codeSize"/>, <paramref name="exceptionRegionCount"/>, or <paramref name="maxStack"/> is out of allowed range.
/// </exception>
public MethodBody AddMethodBody(
int codeSize,
int maxStack = 8,
int exceptionRegionCount = 0,
bool hasSmallExceptionRegions = true,
StandaloneSignatureHandle localVariablesSignature = default,
MethodBodyAttributes attributes = MethodBodyAttributes.InitLocals,
bool hasDynamicStackAllocation = false)
{
if (codeSize < 0)
{
Throw.ArgumentOutOfRange(nameof(codeSize));
}
if (unchecked ((uint)maxStack) > ushort.MaxValue)
{
Throw.ArgumentOutOfRange(nameof(maxStack));
}
if (!ExceptionRegionEncoder.IsExceptionRegionCountInBounds(exceptionRegionCount))
{
Throw.ArgumentOutOfRange(nameof(exceptionRegionCount));
}
int bodyOffset = SerializeHeader(codeSize, (ushort)maxStack, exceptionRegionCount, attributes, localVariablesSignature, hasDynamicStackAllocation);
var instructions = Builder.ReserveBytes(codeSize);
var regionEncoder = (exceptionRegionCount > 0) ?
ExceptionRegionEncoder.SerializeTableHeader(Builder, exceptionRegionCount, hasSmallExceptionRegions) : default;
return(new MethodBody(bodyOffset, instructions, regionEncoder));
}
/// <summary>
/// Encodes a method body and adds it to the method body stream.
/// </summary>
/// <param name="instructionEncoder">Instruction encoder.</param>
/// <param name="maxStack">Max stack.</param>
/// <param name="localVariablesSignature">Local variables signature handle.</param>
/// <param name="attributes">Attributes.</param>
/// <param name="hasDynamicStackAllocation">True if the method allocates from dynamic local memory pool (the IL contains <c>localloc</c> instruction).
/// </param>
/// <returns>The offset of the encoded body within the method body stream.</returns>
/// <exception cref="ArgumentNullException"><paramref name="instructionEncoder"/> has default value.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="maxStack"/> is out of range [0, <see cref="ushort.MaxValue"/>].</exception>
/// <exception cref="InvalidOperationException">
/// A label targeted by a branch in the instruction stream has not been marked,
/// or the distance between a branch instruction and the target label doesn't fit the size of the instruction operand.
/// </exception>
public int AddMethodBody(
InstructionEncoder instructionEncoder,
int maxStack = 8,
StandaloneSignatureHandle localVariablesSignature = default,
MethodBodyAttributes attributes = MethodBodyAttributes.InitLocals,
bool hasDynamicStackAllocation = false)
{
if (unchecked ((uint)maxStack) > ushort.MaxValue)
{
Throw.ArgumentOutOfRange(nameof(maxStack));
}
// The branch fixup code expects the operands of branch instructions in the code builder to be contiguous.
// That's true when we emit thru InstructionEncoder. Taking it as a parameter instead of separate
// code and flow builder parameters ensures they match each other.
var codeBuilder = instructionEncoder.CodeBuilder;
var flowBuilder = instructionEncoder.ControlFlowBuilder;
if (codeBuilder == null)
{
Throw.ArgumentNull(nameof(instructionEncoder));
}
int exceptionRegionCount = flowBuilder?.ExceptionHandlerCount ?? 0;
if (!ExceptionRegionEncoder.IsExceptionRegionCountInBounds(exceptionRegionCount))
{
Throw.ArgumentOutOfRange(nameof(instructionEncoder), SR.TooManyExceptionRegions);
}
// Note (see also https://github.com/dotnet/corefx/issues/26910)
//
// We could potentially automatically determine whether a tiny method with no variables and InitLocals flag set
// has localloc instruction and thus needs a fat header. We could parse the IL stored in codeBuilder.
// However, it would unnecessarily slow down emit of virtually all tiny methods, which do not use localloc
// and would only address uninitialized memory issues in very rare scenarios when the pointer returned by
// localloc is not stored in a local variable but passed to a method call or stored in a field.
//
// Since emitting code with localloc is already a pretty advanced scenario that emits unsafe code
// that can be potentially incorrect in many other ways we decide that it's not worth the complexity
// and a perf regression to do so. Instead we rely on the caller to let us know if there is a localloc
// in the code they emitted.
int bodyOffset = SerializeHeader(codeBuilder.Count, (ushort)maxStack, exceptionRegionCount, attributes, localVariablesSignature, hasDynamicStackAllocation);
if (flowBuilder?.BranchCount > 0)
{
flowBuilder.CopyCodeAndFixupBranches(codeBuilder, Builder);
}
else
{
codeBuilder.WriteContentTo(Builder);
}
flowBuilder?.SerializeExceptionTable(Builder);
return(bodyOffset);
}
/// <summary>
/// Adds catch region.
/// </summary>
/// <param name="tryStart">Label marking the first instruction of the try block.</param>
/// <param name="tryEnd">Label marking the instruction immediately following the try block.</param>
/// <param name="handlerStart">Label marking the first instruction of the handler.</param>
/// <param name="handlerEnd">Label marking the instruction immediately following the handler.</param>
/// <param name="catchType">The type of exception to be caught: <see cref="TypeDefinitionHandle"/>, <see cref="TypeReferenceHandle"/> or <see cref="TypeSpecificationHandle"/>.</param>
/// <exception cref="ArgumentException">A label was not defined by an instruction encoder this builder is associated with.</exception>
/// <exception cref="ArgumentException"><paramref name="catchType"/> is not a valid type handle.</exception>
/// <exception cref="ArgumentNullException">A label has default value.</exception>
public void AddCatchRegion(LabelHandle tryStart, LabelHandle tryEnd, LabelHandle handlerStart, LabelHandle handlerEnd, EntityHandle catchType)
{
if (!ExceptionRegionEncoder.IsValidCatchTypeHandle(catchType))
{
Throw.InvalidArgument_Handle(nameof(catchType));
}
AddExceptionRegion(ExceptionRegionKind.Catch, tryStart, tryEnd, handlerStart, handlerEnd, catchType: catchType);
}
internal void SerializeExceptionTable(BlobBuilder builder)
{
if (_lazyExceptionHandlers == null || _lazyExceptionHandlers.Count == 0)
{
return;
}
var regionEncoder = ExceptionRegionEncoder.SerializeTableHeader(builder, _lazyExceptionHandlers.Count, HasSmallExceptionRegions());
foreach (var handler in _lazyExceptionHandlers)
{
// Note that labels have been validated when added to the handler list,
// they might not have been marked though.
int tryStart = GetLabelOffsetChecked(handler.TryStart);
int tryEnd = GetLabelOffsetChecked(handler.TryEnd);
int handlerStart = GetLabelOffsetChecked(handler.HandlerStart);
int handlerEnd = GetLabelOffsetChecked(handler.HandlerEnd);
if (tryStart > tryEnd)
{
Throw.InvalidOperation(StarkPlatform.Reflection.Resources.SR.Format(SR.InvalidExceptionRegionBounds, tryStart, tryEnd));
}
if (handlerStart > handlerEnd)
{
Throw.InvalidOperation(StarkPlatform.Reflection.Resources.SR.Format(SR.InvalidExceptionRegionBounds, handlerStart, handlerEnd));
}
int catchTokenOrOffset;
switch (handler.Kind)
{
case ExceptionRegionKind.Catch:
catchTokenOrOffset = MetadataTokens.GetToken(handler.CatchType);
break;
case ExceptionRegionKind.Filter:
catchTokenOrOffset = GetLabelOffsetChecked(handler.FilterStart);
break;
default:
catchTokenOrOffset = 0;
break;
}
regionEncoder.AddUnchecked(
handler.Kind,
tryStart,
tryEnd - tryStart,
handlerStart,
handlerEnd - handlerStart,
catchTokenOrOffset);
}
}
private bool HasSmallExceptionRegions()
{
Debug.Assert(_lazyExceptionHandlers != null);
if (!ExceptionRegionEncoder.IsSmallRegionCount(_lazyExceptionHandlers.Count))
{
return(false);
}
foreach (var handler in _lazyExceptionHandlers)
{
if (!ExceptionRegionEncoder.IsSmallExceptionRegionFromBounds(GetLabelOffsetChecked(handler.TryStart), GetLabelOffsetChecked(handler.TryEnd)) ||
!ExceptionRegionEncoder.IsSmallExceptionRegionFromBounds(GetLabelOffsetChecked(handler.HandlerStart), GetLabelOffsetChecked(handler.HandlerEnd)))
{
return(false);
}
}
return(true);
}
internal MethodBody(int bodyOffset, Blob instructions, ExceptionRegionEncoder exceptionRegions)
{
Offset = bodyOffset;
Instructions = instructions;
ExceptionRegions = exceptionRegions;
}