public static void Validate(MetadataType type, ComputedInstanceFieldLayout layout)
{
ExplicitLayoutValidator validator = new ExplicitLayoutValidator(type, layout.ByteCountUnaligned.AsInt);
foreach (FieldAndOffset fieldAndOffset in layout.Offsets)
{
validator.AddToFieldLayout(fieldAndOffset.Offset.AsInt, fieldAndOffset.Field.FieldType);
}
}
public override ComputedInstanceFieldLayout ComputeInstanceLayout(DefType type, InstanceLayoutKind layoutKind)
{
if (!type.IsTemplateUniversal() && (layoutKind == InstanceLayoutKind.TypeOnly))
{
// Non universal generics can just use the template's layout
DefType template = (DefType)type.ComputeTemplate();
return _noMetadataFieldLayoutAlgorithm.ComputeInstanceLayout(template, InstanceLayoutKind.TypeOnly);
}
// Only needed for universal generics, or when looking up an offset for a field for a universal generic
LowLevelList<int> fieldOffsets;
int[] position = ComputeTypeSizeAndAlignment(type, FieldLoadState.Instance, out fieldOffsets);
int numInstanceFields = 0;
foreach (NativeLayoutFieldDesc field in type.NativeLayoutFields)
{
if (!field.IsStatic)
{
numInstanceFields++;
}
}
int byteCountAlignment = position[InstanceAlignmentEntry];
byteCountAlignment = type.Context.Target.GetObjectAlignment(byteCountAlignment);
ComputedInstanceFieldLayout layout = new ComputedInstanceFieldLayout()
{
Offsets = new FieldAndOffset[numInstanceFields],
ByteCountAlignment = byteCountAlignment,
ByteCountUnaligned = position[(int)NativeFormat.FieldStorage.Instance],
PackValue = 0 // TODO, as we add more metadata handling logic, find out if its necessary to use a meaningful value here
};
if (!type.IsValueType)
{
layout.FieldAlignment = type.Context.Target.PointerSize;
layout.FieldSize = type.Context.Target.PointerSize;
}
else
{
layout.FieldAlignment = position[InstanceAlignmentEntry];
layout.FieldSize = MemoryHelpers.AlignUp(position[(int)NativeFormat.FieldStorage.Instance], layout.FieldAlignment);
}
int curInstanceField = 0;
foreach (NativeLayoutFieldDesc field in type.NativeLayoutFields)
{
if (!field.IsStatic)
{
layout.Offsets[curInstanceField] = new FieldAndOffset(field, fieldOffsets[curInstanceField]);
curInstanceField++;
}
}
return layout;
}
private static ComputedInstanceFieldLayout ComputeSequentialFieldLayout(MetadataType type, int numInstanceFields)
{
var offsets = new FieldAndOffset[numInstanceFields];
// For types inheriting from another type, field offsets continue on from where they left off
int cumulativeInstanceFieldPos = ComputeBytesUsedInParentType(type);
int largestAlignmentRequirement = 1;
int fieldOrdinal = 0;
int packingSize = ComputePackingSize(type);
foreach (var field in type.GetFields())
{
if (field.IsStatic)
{
continue;
}
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(field.FieldType, packingSize);
if (fieldSizeAndAlignment.Alignment > largestAlignmentRequirement)
{
largestAlignmentRequirement = fieldSizeAndAlignment.Alignment;
}
cumulativeInstanceFieldPos = AlignmentHelper.AlignUp(cumulativeInstanceFieldPos, fieldSizeAndAlignment.Alignment);
offsets[fieldOrdinal] = new FieldAndOffset(field, cumulativeInstanceFieldPos);
cumulativeInstanceFieldPos = checked (cumulativeInstanceFieldPos + fieldSizeAndAlignment.Size);
fieldOrdinal++;
}
if (type.IsValueType)
{
var layoutMetadata = type.GetClassLayout();
cumulativeInstanceFieldPos = Math.Max(cumulativeInstanceFieldPos, layoutMetadata.Size);
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, cumulativeInstanceFieldPos, largestAlignmentRequirement, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return(computedLayout);
}
public override ComputedInstanceFieldLayout ComputeInstanceLayout(DefType defType, InstanceLayoutKind layoutKind)
{
// Individual field offset layout for a RuntimeDeterminedType is not a supported operation
if (layoutKind != InstanceLayoutKind.TypeOnly)
{
throw new NotSupportedException();
}
RuntimeDeterminedType type = (RuntimeDeterminedType)defType;
DefType canonicalType = type.CanonicalType;
ComputedInstanceFieldLayout result = new ComputedInstanceFieldLayout
{
ByteCountUnaligned = canonicalType.InstanceByteCountUnaligned,
ByteCountAlignment = canonicalType.InstanceByteAlignment,
FieldAlignment = canonicalType.InstanceFieldAlignment,
FieldSize = canonicalType.InstanceFieldSize,
Offsets = Array.Empty <FieldAndOffset>()
};
return(result);
}
public override ComputedInstanceFieldLayout ComputeInstanceLayout(DefType defType, InstanceLayoutKind layoutKind)
{
MetadataType type = (MetadataType)defType;
if (type.IsGenericDefinition)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
// CLI - Partition 1, section 9.5 - Generic types shall not be marked explicitlayout.
if (type.HasInstantiation && type.IsExplicitLayout)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadExplicitGeneric, type.GetTypeDefinition());
}
// Count the number of instance fields in advance for convenience
int numInstanceFields = 0;
foreach (var field in type.GetFields())
{
if (field.IsStatic)
{
continue;
}
TypeDesc fieldType = field.FieldType;
// ByRef instance fields are not allowed.
if (fieldType.IsByRef)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
// ByRef-like instance fields on non-byref-like types are not allowed.
if (fieldType.IsByRefLike && !type.IsByRefLike)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
numInstanceFields++;
}
if (type.IsModuleType)
{
// This is a global type, it must not have instance fields.
if (numInstanceFields > 0)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
// Global types do not do the rest of instance field layout.
ComputedInstanceFieldLayout result = new ComputedInstanceFieldLayout();
result.Offsets = Array.Empty <FieldAndOffset>();
return(result);
}
// CLI - Partition 2, section 22.8
// A type has layout if it is marked SequentialLayout or ExplicitLayout. If any type within an inheritance chain has layout,
// then so shall all its base classes, up to the one that descends immediately from System.ValueType (if it exists in the type's
// hierarchy); otherwise, from System.Object
// Note: While the CLI isn't clearly worded, the layout needs to be the same for the entire chain.
// If the current type isn't ValueType or System.Object and has a layout and the parent type isn't
// ValueType or System.Object then the layout type attributes need to match
if ((!type.IsValueType && !type.IsObject) &&
(type.IsSequentialLayout || type.IsExplicitLayout) &&
(!type.BaseType.IsValueType && !type.BaseType.IsObject))
{
MetadataType baseType = type.MetadataBaseType;
if (type.IsSequentialLayout != baseType.IsSequentialLayout ||
type.IsExplicitLayout != baseType.IsExplicitLayout)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadBadFormat, type);
}
}
// Enum types must have a single instance field
if (type.IsEnum && numInstanceFields != 1)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
if (type.IsPrimitive)
{
// Primitive types are special - they may have a single field of the same type
// as the type itself. They do not do the rest of instance field layout.
if (numInstanceFields > 1)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadGeneral, type);
}
SizeAndAlignment instanceByteSizeAndAlignment;
var sizeAndAlignment = ComputeInstanceSize(
type,
type.Context.Target.GetWellKnownTypeSize(type),
type.Context.Target.GetWellKnownTypeAlignment(type),
0,
out instanceByteSizeAndAlignment
);
ComputedInstanceFieldLayout result = new ComputedInstanceFieldLayout
{
ByteCountUnaligned = instanceByteSizeAndAlignment.Size,
ByteCountAlignment = instanceByteSizeAndAlignment.Alignment,
FieldAlignment = sizeAndAlignment.Alignment,
FieldSize = sizeAndAlignment.Size,
};
if (numInstanceFields > 0)
{
FieldDesc instanceField = null;
foreach (FieldDesc field in type.GetFields())
{
if (!field.IsStatic)
{
Debug.Assert(instanceField == null, "Unexpected extra instance field");
instanceField = field;
}
}
Debug.Assert(instanceField != null, "Null instance field");
result.Offsets = new FieldAndOffset[] {
new FieldAndOffset(instanceField, LayoutInt.Zero)
};
}
else
{
result.Offsets = Array.Empty <FieldAndOffset>();
}
return(result);
}
// If the type has layout, read its packing and size info
// If the type has explicit layout, also read the field offset info
if (type.IsExplicitLayout || type.IsSequentialLayout)
{
if (type.IsEnum)
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadBadFormat, type);
}
var layoutMetadata = type.GetClassLayout();
// If packing is out of range or not a power of two, throw that the size is invalid
int packing = layoutMetadata.PackingSize;
if (packing < 0 || packing > 128 || ((packing & (packing - 1)) != 0))
{
ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadBadFormat, type);
}
Debug.Assert(layoutMetadata.Offsets == null || layoutMetadata.Offsets.Length == numInstanceFields);
}
// At this point all special cases are handled and all inputs validated
return(ComputeInstanceFieldLayout(type, numInstanceFields));
}
private static ComputedInstanceFieldLayout ComputeSequentialFieldLayout(MetadataType type, int numInstanceFields)
{
var offsets = new FieldAndOffset[numInstanceFields];
// For types inheriting from another type, field offsets continue on from where they left off
int cumulativeInstanceFieldPos = ComputeBytesUsedInParentType(type);
int largestAlignmentRequirement = 1;
int fieldOrdinal = 0;
int packingSize = ComputePackingSize(type);
foreach (var field in type.GetFields())
{
if (field.IsStatic)
continue;
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(field.FieldType, packingSize);
if (fieldSizeAndAlignment.Alignment > largestAlignmentRequirement)
largestAlignmentRequirement = fieldSizeAndAlignment.Alignment;
cumulativeInstanceFieldPos = AlignmentHelper.AlignUp(cumulativeInstanceFieldPos, fieldSizeAndAlignment.Alignment);
offsets[fieldOrdinal] = new FieldAndOffset(field, cumulativeInstanceFieldPos);
cumulativeInstanceFieldPos = checked(cumulativeInstanceFieldPos + fieldSizeAndAlignment.Size);
fieldOrdinal++;
}
if (type.IsValueType)
{
var layoutMetadata = type.GetClassLayout();
cumulativeInstanceFieldPos = Math.Max(cumulativeInstanceFieldPos, layoutMetadata.Size);
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, cumulativeInstanceFieldPos, largestAlignmentRequirement, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return computedLayout;
}
private static ComputedInstanceFieldLayout ComputeExplicitFieldLayout(MetadataType type, int numInstanceFields)
{
// Instance slice size is the total size of instance not including the base type.
// It is calculated as the field whose offset and size add to the greatest value.
int cumulativeInstanceFieldPos =
type.HasBaseType && !type.IsValueType ? type.BaseType.InstanceByteCount : 0;
int instanceSize = cumulativeInstanceFieldPos;
var layoutMetadata = type.GetClassLayout();
int packingSize = ComputePackingSize(type);
int largestAlignmentRequired = 1;
var offsets = new FieldAndOffset[numInstanceFields];
int fieldOrdinal = 0;
foreach (var fieldAndOffset in layoutMetadata.Offsets)
{
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(fieldAndOffset.Field.FieldType, packingSize);
if (fieldSizeAndAlignment.Alignment > largestAlignmentRequired)
largestAlignmentRequired = fieldSizeAndAlignment.Alignment;
if (fieldAndOffset.Offset == FieldAndOffset.InvalidOffset)
throw new TypeLoadException();
int computedOffset = checked(fieldAndOffset.Offset + cumulativeInstanceFieldPos);
switch (fieldAndOffset.Field.FieldType.Category)
{
case TypeFlags.Array:
case TypeFlags.Class:
{
int offsetModulo = computedOffset % type.Context.Target.PointerSize;
if (offsetModulo != 0)
{
// GC pointers MUST be aligned.
if (offsetModulo == 4)
{
// We must be attempting to compile a 32bit app targeting a 64 bit platform.
throw new TypeLoadException();
}
else
{
// Its just wrong
throw new TypeLoadException();
}
}
break;
}
}
offsets[fieldOrdinal] = new FieldAndOffset(fieldAndOffset.Field, computedOffset);
int fieldExtent = checked(computedOffset + fieldSizeAndAlignment.Size);
if (fieldExtent > instanceSize)
{
instanceSize = fieldExtent;
}
fieldOrdinal++;
}
if (type.IsValueType && layoutMetadata.Size > instanceSize)
{
instanceSize = layoutMetadata.Size;
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, instanceSize, largestAlignmentRequired, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return computedLayout;
}
public override ComputedInstanceFieldLayout ComputeInstanceLayout(DefType defType, InstanceLayoutKind layoutKind)
{
MetadataType type = (MetadataType)defType;
// CLI - Partition 1, section 9.5 - Generic types shall not be marked explicitlayout.
if (type.HasInstantiation && type.IsExplicitLayout)
{
throw new TypeLoadException();
}
// Count the number of instance fields in advance for convenience
int numInstanceFields = 0;
foreach (var field in type.GetFields())
if (!field.IsStatic)
numInstanceFields++;
if (type.IsModuleType)
{
// This is a global type, it must not have instance fields.
if (numInstanceFields > 0)
{
throw new TypeLoadException();
}
// Global types do not do the rest of instance field layout.
ComputedInstanceFieldLayout result = new ComputedInstanceFieldLayout();
result.PackValue = type.Context.Target.DefaultPackingSize;
result.Offsets = Array.Empty<FieldAndOffset>();
return result;
}
// CLI - Partition 2, section 22.8
// A type has layout if it is marked SequentialLayout or ExplicitLayout. If any type within an inheritance chain has layout,
// then so shall all its base classes, up to the one that descends immediately from System.ValueType (if it exists in the type’s
// hierarchy); otherwise, from System.Object
// Note: While the CLI isn't clearly worded, the layout needs to be the same for the entire chain.
// If the current type isn't ValueType or System.Object and has a layout and the parent type isn't
// ValueType or System.Object then the layout type attributes need to match
if ((!type.IsValueType && !type.IsObject) &&
(type.IsSequentialLayout || type.IsExplicitLayout) &&
(!type.BaseType.IsValueType && !type.BaseType.IsObject))
{
MetadataType baseType = type.MetadataBaseType;
if (type.IsSequentialLayout != baseType.IsSequentialLayout ||
type.IsExplicitLayout != baseType.IsExplicitLayout)
{
throw new TypeLoadException();
}
}
// Enum types must have a single instance field
if (type.IsEnum && numInstanceFields != 1)
{
throw new TypeLoadException();
}
if (type.IsPrimitive)
{
// Primitive types are special - they may have a single field of the same type
// as the type itself. They do not do the rest of instance field layout.
if (numInstanceFields > 1)
{
throw new TypeLoadException();
}
SizeAndAlignment instanceByteSizeAndAlignment;
var sizeAndAlignment = ComputeInstanceSize(
type,
type.Context.Target.GetWellKnownTypeSize(type),
type.Context.Target.GetWellKnownTypeAlignment(type),
out instanceByteSizeAndAlignment
);
ComputedInstanceFieldLayout result = new ComputedInstanceFieldLayout
{
ByteCountUnaligned = instanceByteSizeAndAlignment.Size,
ByteCountAlignment = instanceByteSizeAndAlignment.Alignment,
FieldAlignment = sizeAndAlignment.Alignment,
FieldSize = sizeAndAlignment.Size,
PackValue = type.Context.Target.DefaultPackingSize
};
if (numInstanceFields > 0)
{
FieldDesc instanceField = null;
foreach (FieldDesc field in type.GetFields())
{
if (!field.IsStatic)
{
Debug.Assert(instanceField == null, "Unexpected extra instance field");
instanceField = field;
}
}
Debug.Assert(instanceField != null, "Null instance field");
result.Offsets = new FieldAndOffset[] {
new FieldAndOffset(instanceField, 0)
};
}
else
{
result.Offsets = Array.Empty<FieldAndOffset>();
}
return result;
}
// Verify that no ByRef types present in this type's fields
foreach (var field in type.GetFields())
if (field.FieldType is ByRefType)
throw new TypeLoadException();
// If the type has layout, read its packing and size info
// If the type has explicit layout, also read the field offset info
if (type.IsExplicitLayout || type.IsSequentialLayout)
{
if (type.IsEnum)
{
throw new TypeLoadException();
}
var layoutMetadata = type.GetClassLayout();
// If packing is out of range or not a power of two, throw that the size is invalid
int packing = layoutMetadata.PackingSize;
if (packing < 0 || packing > 128 || ((packing & (packing - 1)) != 0))
{
throw new TypeLoadException();
}
Debug.Assert(layoutMetadata.Offsets == null || layoutMetadata.Offsets.Length == numInstanceFields);
}
// At this point all special cases are handled and all inputs validated
if (type.IsExplicitLayout)
{
return ComputeExplicitFieldLayout(type, numInstanceFields);
}
else
{
// Treat auto layout as sequential for now
return ComputeSequentialFieldLayout(type, numInstanceFields);
}
}
private static ComputedInstanceFieldLayout ComputeExplicitFieldLayout(MetadataType type, int numInstanceFields)
{
// Instance slice size is the total size of instance not including the base type.
// It is calculated as the field whose offset and size add to the greatest value.
int cumulativeInstanceFieldPos =
type.HasBaseType && !type.IsValueType ? type.BaseType.InstanceByteCount : 0;
int instanceSize = cumulativeInstanceFieldPos;
var layoutMetadata = type.GetClassLayout();
int packingSize = ComputePackingSize(type);
int largestAlignmentRequired = 1;
var offsets = new FieldAndOffset[numInstanceFields];
int fieldOrdinal = 0;
foreach (var fieldAndOffset in layoutMetadata.Offsets)
{
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(fieldAndOffset.Field.FieldType, packingSize);
if (fieldSizeAndAlignment.Alignment > largestAlignmentRequired)
{
largestAlignmentRequired = fieldSizeAndAlignment.Alignment;
}
if (fieldAndOffset.Offset == FieldAndOffset.InvalidOffset)
{
throw new TypeLoadException();
}
int computedOffset = checked (fieldAndOffset.Offset + cumulativeInstanceFieldPos);
switch (fieldAndOffset.Field.FieldType.Category)
{
case TypeFlags.Array:
case TypeFlags.Class:
{
int offsetModulo = computedOffset % type.Context.Target.PointerSize;
if (offsetModulo != 0)
{
// GC pointers MUST be aligned.
if (offsetModulo == 4)
{
// We must be attempting to compile a 32bit app targeting a 64 bit platform.
throw new TypeLoadException();
}
else
{
// Its just wrong
throw new TypeLoadException();
}
}
break;
}
}
offsets[fieldOrdinal] = new FieldAndOffset(fieldAndOffset.Field, computedOffset);
int fieldExtent = checked (computedOffset + fieldSizeAndAlignment.Size);
if (fieldExtent > instanceSize)
{
instanceSize = fieldExtent;
}
fieldOrdinal++;
}
if (type.IsValueType && layoutMetadata.Size > instanceSize)
{
instanceSize = layoutMetadata.Size;
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, instanceSize, largestAlignmentRequired, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return(computedLayout);
}
private static ComputedInstanceFieldLayout ComputeExplicitFieldLayout(MetadataType type, int numInstanceFields)
{
// Instance slice size is the total size of instance not including the base type.
// It is calculated as the field whose offset and size add to the greatest value.
LayoutInt cumulativeInstanceFieldPos =
type.HasBaseType && !type.IsValueType ? type.BaseType.InstanceByteCount : LayoutInt.Zero;
LayoutInt instanceSize = cumulativeInstanceFieldPos;
var layoutMetadata = type.GetClassLayout();
int packingSize = ComputePackingSize(type);
LayoutInt largestAlignmentRequired = LayoutInt.One;
var offsets = new FieldAndOffset[numInstanceFields];
int fieldOrdinal = 0;
foreach (var fieldAndOffset in layoutMetadata.Offsets)
{
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(fieldAndOffset.Field.FieldType, packingSize);
largestAlignmentRequired = LayoutInt.Max(fieldSizeAndAlignment.Alignment, largestAlignmentRequired);
if (fieldAndOffset.Offset == FieldAndOffset.InvalidOffset)
{
throw new TypeSystemException.TypeLoadException(ExceptionStringID.ClassLoadBadFormat, type);
}
LayoutInt computedOffset = fieldAndOffset.Offset + cumulativeInstanceFieldPos;
if (fieldAndOffset.Field.FieldType.IsGCPointer && !computedOffset.IsIndeterminate)
{
int offsetModulo = computedOffset.AsInt % type.Context.Target.PointerSize;
if (offsetModulo != 0)
{
// GC pointers MUST be aligned.
throw new TypeSystemException.TypeLoadException(ExceptionStringID.ClassLoadExplicitLayout, type, fieldAndOffset.Offset.ToStringInvariant());
}
}
offsets[fieldOrdinal] = new FieldAndOffset(fieldAndOffset.Field, computedOffset);
LayoutInt fieldExtent = computedOffset + fieldSizeAndAlignment.Size;
instanceSize = LayoutInt.Max(fieldExtent, instanceSize);
fieldOrdinal++;
}
if (type.IsValueType)
{
instanceSize = LayoutInt.Max(new LayoutInt(layoutMetadata.Size), instanceSize);
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, instanceSize, largestAlignmentRequired, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return(computedLayout);
}
private static ComputedInstanceFieldLayout ComputeExplicitFieldLayout(MetadataType type, int numInstanceFields)
{
// Instance slice size is the total size of instance not including the base type.
// It is calculated as the field whose offset and size add to the greatest value.
int cumulativeInstanceFieldPos =
type.HasBaseType && !type.IsValueType ? type.BaseType.InstanceByteCount : 0;
int instanceSize = cumulativeInstanceFieldPos;
var layoutMetadata = type.GetClassLayout();
int packingSize = ComputePackingSize(type);
int largestAlignmentRequired = 1;
var offsets = new FieldAndOffset[numInstanceFields];
int fieldOrdinal = 0;
foreach (var fieldAndOffset in layoutMetadata.Offsets)
{
var fieldSizeAndAlignment = ComputeFieldSizeAndAlignment(fieldAndOffset.Field.FieldType, packingSize);
if (fieldSizeAndAlignment.Alignment > largestAlignmentRequired)
largestAlignmentRequired = fieldSizeAndAlignment.Alignment;
if (fieldAndOffset.Offset == FieldAndOffset.InvalidOffset)
throw new TypeSystemException.TypeLoadException(ExceptionStringID.ClassLoadBadFormat, type);
int computedOffset = checked(fieldAndOffset.Offset + cumulativeInstanceFieldPos);
if (fieldAndOffset.Field.FieldType.IsGCPointer)
{
int offsetModulo = computedOffset % type.Context.Target.PointerSize;
if (offsetModulo != 0)
{
// GC pointers MUST be aligned.
throw new TypeSystemException.TypeLoadException(ExceptionStringID.ClassLoadExplicitLayout, type, fieldAndOffset.Offset.ToStringInvariant());
}
}
offsets[fieldOrdinal] = new FieldAndOffset(fieldAndOffset.Field, computedOffset);
int fieldExtent = checked(computedOffset + fieldSizeAndAlignment.Size);
if (fieldExtent > instanceSize)
{
instanceSize = fieldExtent;
}
fieldOrdinal++;
}
if (type.IsValueType && layoutMetadata.Size > instanceSize)
{
instanceSize = layoutMetadata.Size;
}
SizeAndAlignment instanceByteSizeAndAlignment;
var instanceSizeAndAlignment = ComputeInstanceSize(type, instanceSize, largestAlignmentRequired, out instanceByteSizeAndAlignment);
ComputedInstanceFieldLayout computedLayout = new ComputedInstanceFieldLayout();
computedLayout.FieldAlignment = instanceSizeAndAlignment.Alignment;
computedLayout.FieldSize = instanceSizeAndAlignment.Size;
computedLayout.ByteCountUnaligned = instanceByteSizeAndAlignment.Size;
computedLayout.ByteCountAlignment = instanceByteSizeAndAlignment.Alignment;
computedLayout.Offsets = offsets;
return computedLayout;
}
