/// <summary>
/// <![CDATA[
/// fixed(int* ptr = &v){ ... } == becomes ===>
///
/// pinned ref int pinnedTemp = ref v; // pinning managed ref
/// int* ptr = (int*)&pinnedTemp; // unsafe cast to unmanaged ptr
/// . . .
/// ]]>
/// </summary>
private BoundStatement InitializeFixedStatementRegularLocal(
BoundLocalDeclaration localDecl,
LocalSymbol localSymbol,
BoundFixedLocalCollectionInitializer fixedInitializer,
SyntheticBoundNodeFactory factory,
out LocalSymbol pinnedTemp)
{
TypeSymbol localType = localSymbol.Type;
BoundExpression initializerExpr = VisitExpression(fixedInitializer.Expression);
// initializer expr should be either an address(&) of something or a fixed field access.
// either should lower into addressof
Debug.Assert(initializerExpr.Kind == BoundKind.AddressOfOperator);
TypeSymbol initializerType = ((PointerTypeSymbol)initializerExpr.Type).PointedAtType;
// initializer expressions are bound/lowered right into addressof operators here
// that is a bit too far
// we need to pin the underlying field, and only then take the address.
initializerExpr = ((BoundAddressOfOperator)initializerExpr).Operand;
// intervening parens may have been skipped by the binder; find the declarator
VariableDeclaratorSyntax declarator = fixedInitializer.Syntax.FirstAncestorOrSelf <VariableDeclaratorSyntax>();
Debug.Assert(declarator != null);
pinnedTemp = factory.SynthesizedLocal(
initializerType,
syntax: declarator,
isPinned: true,
//NOTE: different from the array and string cases
// RefReadOnly to allow referring to readonly variables. (technically we only "read" through the temp anyways)
refKind: RefKind.RefReadOnly,
kind: SynthesizedLocalKind.FixedReference);
// NOTE: we pin the reference, not the pointer.
Debug.Assert(pinnedTemp.IsPinned);
Debug.Assert(!localSymbol.IsPinned);
// pinnedTemp = ref v;
BoundStatement pinnedTempInit = factory.Assignment(factory.Local(pinnedTemp), initializerExpr, isRef: true);
// &pinnedTemp
var addr = new BoundAddressOfOperator(
factory.Syntax,
factory.Local(pinnedTemp),
type: fixedInitializer.ElementPointerType);
// (int*)&pinnedTemp
var pointerValue = factory.Convert(
localType,
addr,
fixedInitializer.ElementPointerTypeConversion);
// ptr = (int*)&pinnedTemp;
BoundStatement localInit = InstrumentLocalDeclarationIfNecessary(localDecl, localSymbol,
factory.Assignment(factory.Local(localSymbol), pointerValue));
return(factory.Block(pinnedTempInit, localInit));
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
BoundSpillSequenceBuilder builder = null;
var expr = VisitExpression(ref builder, node.Operand);
return(UpdateExpression(builder, node.Update(expr, node.IsManaged, node.Type)));
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
// Pretend address-of is a pure read (i.e. no write) - would we see an
// unassigned diagnostic?
VisitRvalue(node.Operand);
return(null);
}
private BoundExpression MakeFieldAccess(
SyntaxNode syntax,
BoundExpression rewrittenReceiver,
FieldSymbol fieldSymbol,
ConstantValue constantValueOpt,
LookupResultKind resultKind,
TypeSymbol type,
BoundFieldAccess oldNodeOpt = null)
{
if (fieldSymbol.IsTupleField)
{
return(MakeTupleFieldAccess(syntax, fieldSymbol, rewrittenReceiver, constantValueOpt, resultKind));
}
BoundExpression result = oldNodeOpt != null?
oldNodeOpt.Update(rewrittenReceiver, fieldSymbol, constantValueOpt, resultKind, type) :
new BoundFieldAccess(syntax, rewrittenReceiver, fieldSymbol, constantValueOpt, resultKind, type);
if (fieldSymbol.IsFixedSizeBuffer)
{
// a reference to a fixed buffer is translated into its address
result = new BoundAddressOfOperator(syntax, result, type, false);
}
return(result);
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
BoundSpillSequence2 ss = null;
var expr = VisitExpression(ref ss, node.Operand);
return(UpdateExpression(ss, node.Update(expr, node.IsFixedStatementAddressOf, node.Type)));
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
// Pretend address-of is a pure read (i.e. no write) - would we see an
// unassigned diagnostic?
VisitRvalue(node.Operand);
return null;
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
CheckUnsafeType(node);
BoundExpression operand = node.Operand;
if (operand.Kind == BoundKind.FieldAccess)
{
CheckFieldAddress((BoundFieldAccess)operand, consumerOpt: null);
}
return(base.VisitAddressOfOperator(node));
}
private BoundStatement InitializeFixedStatementArrayLocal(
LocalSymbol localSymbol,
BoundFixedLocalCollectionInitializer fixedInitializer,
SyntheticBoundNodeFactory factory,
out LocalSymbol arrayTemp)
{
// From ExpressionBinder::BindPtrToArray:
// (((temp = array) != null && temp.Length > 0) ? loc = &temp[0] : loc = null)
// NOTE: The assignment needs to be inside the EK_QUESTIONMARK. See Whidbey bug #397859.
// We can't do loc = (... ? ... : ...) since the CLR type of &temp[0] is a managed
// pointer and null is a UIntPtr - which confuses the JIT. We can't just convert
// &temp[0] to UIntPtr with a conv.u instruction because then if a GC occurs between
// the time of the cast and the assignment to the local, we're toast.
TypeSymbol localType = localSymbol.Type;
BoundExpression initializerExpr = VisitExpression(fixedInitializer.Expression);
TypeSymbol initializerType = initializerExpr.Type;
arrayTemp = factory.SynthesizedLocal(initializerType);
ArrayTypeSymbol arrayType = (ArrayTypeSymbol)arrayTemp.Type;
TypeSymbol arrayElementType = arrayType.ElementType;
int arrayRank = arrayType.Rank;
// NOTE: we pin the pointer, not the array.
Debug.Assert(!arrayTemp.IsPinned);
Debug.Assert(localSymbol.IsPinned);
//(temp = array)
BoundExpression arrayTempInit = factory.AssignmentExpression(factory.Local(arrayTemp), initializerExpr);
//(temp = array) != null
BoundExpression notNullCheck = MakeNullCheck(factory.Syntax, arrayTempInit, BinaryOperatorKind.NotEqual);
BoundExpression lengthCall;
if (arrayRank == 1)
{
lengthCall = factory.ArrayLength(factory.Local(arrayTemp));
}
else
{
MethodSymbol lengthMethod;
if (TryGetWellKnownTypeMember(fixedInitializer.Syntax, WellKnownMember.System_Array__get_Length, out lengthMethod))
{
lengthCall = factory.Call(factory.Local(arrayTemp), lengthMethod);
}
else
{
lengthCall = new BoundBadExpression(fixedInitializer.Syntax, LookupResultKind.NotInvocable, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(factory.Local(arrayTemp)), ErrorTypeSymbol.UnknownResultType);
}
}
// NOTE: dev10 comment says ">", but code actually checks "!="
//temp.Length != 0
BoundExpression lengthCheck = factory.Binary(BinaryOperatorKind.IntNotEqual, factory.SpecialType(SpecialType.System_Boolean), lengthCall, factory.Literal(0));
//((temp = array) != null && temp.Length != 0)
BoundExpression condition = factory.Binary(BinaryOperatorKind.LogicalBoolAnd, factory.SpecialType(SpecialType.System_Boolean), notNullCheck, lengthCheck);
//temp[0]
BoundExpression firstElement = factory.ArrayAccessFirstElement(factory.Local(arrayTemp));
// NOTE: this is a fixed statement address-of in that it's the initial value of pinned local.
//&temp[0]
BoundExpression firstElementAddress = new BoundAddressOfOperator(factory.Syntax, firstElement, isFixedStatementAddressOf: true, type: new PointerTypeSymbol(arrayElementType));
BoundExpression convertedFirstElementAddress = factory.Convert(
localType,
firstElementAddress,
fixedInitializer.ElementPointerTypeConversion);
//loc = &temp[0]
BoundExpression consequenceAssignment = factory.AssignmentExpression(factory.Local(localSymbol), convertedFirstElementAddress);
//loc = null
BoundExpression alternativeAssignment = factory.AssignmentExpression(factory.Local(localSymbol), factory.Null(localType));
//(((temp = array) != null && temp.Length != 0) ? loc = &temp[0] : loc = null)
BoundStatement localInit = factory.ExpressionStatement(
new BoundConditionalOperator(factory.Syntax, condition, consequenceAssignment, alternativeAssignment, ConstantValue.NotAvailable, localType));
return(AddLocalDeclarationSequencePointIfNecessary(fixedInitializer.Syntax.Parent.Parent, localSymbol, localInit));
}
private BoundStatement InitializeFixedStatementArrayLocal(
LocalSymbol localSymbol,
BoundFixedLocalCollectionInitializer fixedInitializer,
SyntheticBoundNodeFactory factory,
out LocalSymbol arrayTemp)
{
// From ExpressionBinder::BindPtrToArray:
// (((temp = array) != null && temp.Length > 0) ? loc = &temp[0] : loc = null)
// NOTE: The assignment needs to be inside the EK_QUESTIONMARK. See Whidbey bug #397859.
// We can't do loc = (... ? ... : ...) since the CLR type of &temp[0] is a managed
// pointer and null is a UIntPtr - which confuses the JIT. We can't just convert
// &temp[0] to UIntPtr with a conv.u instruction because then if a GC occurs between
// the time of the cast and the assignment to the local, we're toast.
TypeSymbol localType = localSymbol.Type;
BoundExpression initializerExpr = VisitExpression(fixedInitializer.Expression);
TypeSymbol initializerType = initializerExpr.Type;
arrayTemp = factory.SynthesizedLocal(initializerType);
ArrayTypeSymbol arrayType = (ArrayTypeSymbol)arrayTemp.Type;
TypeSymbol arrayElementType = arrayType.ElementType;
int arrayRank = arrayType.Rank;
// NOTE: we pin the pointer, not the array.
Debug.Assert(!arrayTemp.IsPinned);
Debug.Assert(localSymbol.IsPinned);
//(temp = array)
BoundExpression arrayTempInit = factory.AssignmentExpression(factory.Local(arrayTemp), initializerExpr);
//(temp = array) != null
BoundExpression notNullCheck = MakeNullCheck(factory.Syntax, arrayTempInit, BinaryOperatorKind.NotEqual);
BoundExpression lengthCall;
if (arrayRank == 1)
{
lengthCall = factory.ArrayLength(factory.Local(arrayTemp));
}
else
{
MethodSymbol lengthMethod;
if (TryGetWellKnownTypeMember(fixedInitializer.Syntax, WellKnownMember.System_Array__get_Length, out lengthMethod))
{
lengthCall = factory.Call(factory.Local(arrayTemp), lengthMethod);
}
else
{
lengthCall = new BoundBadExpression(fixedInitializer.Syntax, LookupResultKind.NotInvocable, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(factory.Local(arrayTemp)), ErrorTypeSymbol.UnknownResultType);
}
}
// NOTE: dev10 comment says ">", but code actually checks "!="
//temp.Length != 0
BoundExpression lengthCheck = factory.Binary(BinaryOperatorKind.IntNotEqual, factory.SpecialType(SpecialType.System_Boolean), lengthCall, factory.Literal(0));
//((temp = array) != null && temp.Length != 0)
BoundExpression condition = factory.Binary(BinaryOperatorKind.LogicalBoolAnd, factory.SpecialType(SpecialType.System_Boolean), notNullCheck, lengthCheck);
//temp[0]
BoundExpression firstElement = factory.ArrayAccessFirstElement(factory.Local(arrayTemp));
// NOTE: this is a fixed statement address-of in that it's the initial value of pinned local.
//&temp[0]
BoundExpression firstElementAddress = new BoundAddressOfOperator(factory.Syntax, firstElement, isFixedStatementAddressOf: true, type: new PointerTypeSymbol(arrayElementType));
BoundExpression convertedFirstElementAddress = factory.Convert(
localType,
firstElementAddress,
fixedInitializer.ElementPointerTypeConversion);
//loc = &temp[0]
BoundExpression consequenceAssignment = factory.AssignmentExpression(factory.Local(localSymbol), convertedFirstElementAddress);
//loc = null
BoundExpression alternativeAssignment = factory.AssignmentExpression(factory.Local(localSymbol), factory.Null(localType));
//(((temp = array) != null && temp.Length != 0) ? loc = &temp[0] : loc = null)
BoundStatement localInit = factory.ExpressionStatement(
new BoundConditionalOperator(factory.Syntax, condition, consequenceAssignment, alternativeAssignment, ConstantValue.NotAvailable, localType));
return AddLocalDeclarationSequencePointIfNecessary(fixedInitializer.Syntax.Parent.Parent, localSymbol, localInit);
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
BoundSpillSequence2 ss = null;
var expr = VisitExpression(ref ss, node.Operand);
return UpdateExpression(ss, node.Update(expr, node.IsFixedStatementAddressOf, node.Type));
}
/// <summary>
/// <![CDATA[
/// fixed(int* ptr = arr){ ... } == becomes ===>
///
/// pinned int[] pinnedTemp = arr; // pinning managed ref
/// int* ptr = pinnedTemp != null && pinnedTemp.Length != 0
/// (int*)&pinnedTemp[0]: // unsafe cast to unmanaged ptr
/// 0;
/// . . .
/// ]]>
/// </summary>
private BoundStatement InitializeFixedStatementArrayLocal(
BoundLocalDeclaration localDecl,
LocalSymbol localSymbol,
BoundFixedLocalCollectionInitializer fixedInitializer,
SyntheticBoundNodeFactory factory,
out LocalSymbol pinnedTemp)
{
TypeSymbol localType = localSymbol.Type;
BoundExpression initializerExpr = VisitExpression(fixedInitializer.Expression);
TypeSymbol initializerType = initializerExpr.Type;
pinnedTemp = factory.SynthesizedLocal(initializerType, isPinned: true);
ArrayTypeSymbol arrayType = (ArrayTypeSymbol)pinnedTemp.Type;
TypeWithAnnotations arrayElementType = arrayType.ElementTypeWithAnnotations;
// NOTE: we pin the array, not the pointer.
Debug.Assert(pinnedTemp.IsPinned);
Debug.Assert(!localSymbol.IsPinned);
//(pinnedTemp = array)
BoundExpression arrayTempInit = factory.AssignmentExpression(factory.Local(pinnedTemp), initializerExpr);
//(pinnedTemp = array) != null
BoundExpression notNullCheck = MakeNullCheck(factory.Syntax, arrayTempInit, BinaryOperatorKind.NotEqual);
BoundExpression lengthCall;
if (arrayType.IsSZArray)
{
lengthCall = factory.ArrayLength(factory.Local(pinnedTemp));
}
else
{
MethodSymbol lengthMethod;
if (TryGetWellKnownTypeMember(fixedInitializer.Syntax, WellKnownMember.System_Array__get_Length, out lengthMethod))
{
lengthCall = factory.Call(factory.Local(pinnedTemp), lengthMethod);
}
else
{
lengthCall = new BoundBadExpression(fixedInitializer.Syntax, LookupResultKind.NotInvocable, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundExpression>(factory.Local(pinnedTemp)), ErrorTypeSymbol.UnknownResultType);
}
}
// NOTE: dev10 comment says ">", but code actually checks "!="
//temp.Length != 0
BoundExpression lengthCheck = factory.Binary(BinaryOperatorKind.IntNotEqual, factory.SpecialType(SpecialType.System_Boolean), lengthCall, factory.Literal(0));
//((temp = array) != null && temp.Length != 0)
BoundExpression condition = factory.Binary(BinaryOperatorKind.LogicalBoolAnd, factory.SpecialType(SpecialType.System_Boolean), notNullCheck, lengthCheck);
//temp[0]
BoundExpression firstElement = factory.ArrayAccessFirstElement(factory.Local(pinnedTemp));
// NOTE: this is a fixed statement address-of in that it's the initial value of the pointer.
//&temp[0]
BoundExpression firstElementAddress = new BoundAddressOfOperator(factory.Syntax, firstElement, type: new PointerTypeSymbol(arrayElementType));
BoundExpression convertedFirstElementAddress = factory.Convert(
localType,
firstElementAddress,
fixedInitializer.ElementPointerTypeConversion);
//loc = &temp[0]
BoundExpression consequenceAssignment = factory.AssignmentExpression(factory.Local(localSymbol), convertedFirstElementAddress);
//loc = null
BoundExpression alternativeAssignment = factory.AssignmentExpression(factory.Local(localSymbol), factory.Null(localType));
//(((temp = array) != null && temp.Length != 0) ? loc = &temp[0] : loc = null)
BoundStatement localInit = factory.ExpressionStatement(
new BoundConditionalOperator(factory.Syntax, false, condition, consequenceAssignment, alternativeAssignment, ConstantValue.NotAvailable, localType));
return(InstrumentLocalDeclarationIfNecessary(localDecl, localSymbol, localInit));
}
/// <summary>
/// <![CDATA[
/// fixed(int* ptr = &v){ ... } == becomes ===>
///
/// pinned ref int pinnedTemp = ref v; // pinning managed ref
/// int* ptr = (int*)&pinnedTemp; // unsafe cast to unmanaged ptr
/// . . .
/// ]]>
/// </summary>
private BoundStatement InitializeFixedStatementGetPinnable(
BoundLocalDeclaration localDecl,
LocalSymbol localSymbol,
BoundFixedLocalCollectionInitializer fixedInitializer,
SyntheticBoundNodeFactory factory,
out LocalSymbol pinnedTemp)
{
TypeSymbol localType = localSymbol.Type;
BoundExpression initializerExpr = VisitExpression(fixedInitializer.Expression);
var initializerType = initializerExpr.Type;
var initializerSyntax = initializerExpr.Syntax;
var getPinnableMethod = fixedInitializer.GetPinnableOpt;
// intervening parens may have been skipped by the binder; find the declarator
VariableDeclaratorSyntax declarator = fixedInitializer.Syntax.FirstAncestorOrSelf <VariableDeclaratorSyntax>();
Debug.Assert(declarator != null);
// pinned ref int pinnedTemp
pinnedTemp = factory.SynthesizedLocal(
getPinnableMethod.ReturnType,
syntax: declarator,
isPinned: true,
//NOTE: different from the array and string cases
// RefReadOnly to allow referring to readonly variables. (technically we only "read" through the temp anyways)
refKind: RefKind.RefReadOnly,
kind: SynthesizedLocalKind.FixedReference);
BoundExpression callReceiver;
int currentConditionalAccessID = 0;
bool needNullCheck = !initializerType.IsValueType;
if (needNullCheck)
{
currentConditionalAccessID = ++_currentConditionalAccessID;
callReceiver = new BoundConditionalReceiver(
initializerSyntax,
currentConditionalAccessID,
initializerType);
}
else
{
callReceiver = initializerExpr;
}
// .GetPinnable()
var getPinnableCall = getPinnableMethod.IsStatic ?
factory.Call(null, getPinnableMethod, callReceiver) :
factory.Call(callReceiver, getPinnableMethod);
// temp =ref .GetPinnable()
var tempAssignment = factory.AssignmentExpression(
factory.Local(pinnedTemp),
getPinnableCall,
isRef: true);
// &pinnedTemp
var addr = new BoundAddressOfOperator(
factory.Syntax,
factory.Local(pinnedTemp),
type: fixedInitializer.ElementPointerType);
// (int*)&pinnedTemp
var pointerValue = factory.Convert(
localType,
addr,
fixedInitializer.ElementPointerTypeConversion);
// {pinnedTemp =ref .GetPinnable(), (int*)&pinnedTemp}
BoundExpression pinAndGetPtr = factory.Sequence(
locals: ImmutableArray <LocalSymbol> .Empty,
sideEffects: ImmutableArray.Create <BoundExpression>(tempAssignment),
result: pointerValue);
if (needNullCheck)
{
// initializer?.{temp =ref .GetPinnable(), (int*)&pinnedTemp} ?? default;
pinAndGetPtr = new BoundLoweredConditionalAccess(
initializerSyntax,
initializerExpr,
hasValueMethodOpt: null,
whenNotNull: pinAndGetPtr,
whenNullOpt: null, // just return default(T*)
currentConditionalAccessID,
localType);
}
// ptr = initializer?.{temp =ref .GetPinnable(), (int*)&pinnedTemp} ?? default;
BoundStatement localInit = InstrumentLocalDeclarationIfNecessary(localDecl, localSymbol, factory.Assignment(factory.Local(localSymbol), pinAndGetPtr));
return(localInit);
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
CheckUnsafeType(node);
BoundExpression operand = node.Operand;
if (operand.Kind == BoundKind.FieldAccess)
{
CheckFieldAddress((BoundFieldAccess)operand, consumerOpt: null);
}
return base.VisitAddressOfOperator(node);
}
public override BoundNode VisitAddressOfOperator(BoundAddressOfOperator node)
{
_mightAssignSomething = true;
return(null);
}