internal static BoundBlock Rewrite(SourceMethodSymbol sourceMethodSymbol, MethodContractSyntax contract, BoundBlock body, TypeCompilationState compilationState, DiagnosticBag diagsForCurrentMethod)
{
var binder = compilationState.Compilation.GetBinderFactory(sourceMethodSymbol.SyntaxTree)
.GetBinder(body.Syntax);
SyntheticBoundNodeFactory factory = new SyntheticBoundNodeFactory(sourceMethodSymbol, sourceMethodSymbol.SyntaxNode, compilationState, diagsForCurrentMethod);
var contractType = compilationState.Compilation.GetTypeByReflectionType(typeof(System.Diagnostics.Contracts.Contract), diagsForCurrentMethod);
var contractStatements = ArrayBuilder<BoundStatement>.GetInstance(contract.Requires.Count);
foreach (var requires in contract.Requires)
{
var condition = binder.BindExpression(requires.Condition, diagsForCurrentMethod);
var methodCall = factory.StaticCall(contractType, "Requires", condition);
var statement = factory.ExpressionStatement(methodCall);
contractStatements.Add(statement);
}
foreach (var requires in contract.Ensures)
{
var condition = binder.BindExpression(requires.Condition, diagsForCurrentMethod);
var methodCall = factory.StaticCall(contractType, "Ensures", condition);
var statement = factory.ExpressionStatement(methodCall);
contractStatements.Add(statement);
}
return body.Update(body.Locals, body.Statements.InsertRange(0, contractStatements.ToImmutableAndFree()));
}
private BoundExpression VisitExpression(ref BoundSpillSequenceBuilder builder, BoundExpression expression)
{
// wrap the node in a spill sequence to mark the fact that it must be moved up the tree.
// The caller will handle this node type if the result is discarded.
if (expression != null && expression.Kind == BoundKind.AwaitExpression)
{
// we force the await expression to be assigned to a temp variable
var awaitExpression = (BoundAwaitExpression)expression;
awaitExpression = awaitExpression.Update(
VisitExpression(ref builder, awaitExpression.Expression),
awaitExpression.GetAwaiter,
awaitExpression.IsCompleted,
awaitExpression.GetResult,
awaitExpression.Type);
var syntax = awaitExpression.Syntax;
Debug.Assert(syntax.IsKind(SyntaxKind.AwaitExpression));
_F.Syntax = syntax;
BoundAssignmentOperator assignToTemp;
var replacement = _F.StoreToTemp(awaitExpression, out assignToTemp, kind: SynthesizedLocalKind.AwaitSpill, syntaxOpt: syntax);
if (builder == null)
{
builder = new BoundSpillSequenceBuilder();
}
builder.AddLocal(replacement.LocalSymbol, _F.Diagnostics);
builder.AddStatement(_F.ExpressionStatement(assignToTemp));
return(replacement);
}
var e = (BoundExpression)this.Visit(expression);
if (e == null || e.Kind != SpillSequenceBuilder)
{
return(e);
}
var newBuilder = (BoundSpillSequenceBuilder)e;
if (builder == null)
{
builder = newBuilder.Update(null);
}
else
{
builder.Include(newBuilder);
}
return(newBuilder.Value);
}
internal void AddSequence(SyntheticBoundNodeFactory F, BoundSequence sequence)
{
locals.AddRange(sequence.Locals);
foreach (var sideEffect in sequence.SideEffects)
{
statements.Add(F.ExpressionStatement(sideEffect));
}
}
internal void AddSequence(SyntheticBoundNodeFactory F, BoundSequence sequence)
{
locals.AddRange(sequence.Locals);
foreach (var sideEffect in sequence.SideEffects)
{
statements.Add(F.ExpressionStatement(sideEffect));
}
}
private BoundExpression VisitExpression(ref BoundSpillSequence2 ss, BoundExpression expression)
{
// wrap the node in a spill sequence to mark the fact that it must be moved up the tree.
// The caller will handle this node type if the result is discarded.
if (expression != null && expression.Kind == BoundKind.AwaitExpression)
{
// we force the await expression to be assigned to a temp variable
var awaitExpression = (BoundAwaitExpression)expression;
awaitExpression = awaitExpression.Update(
VisitExpression(ref ss, awaitExpression.Expression), awaitExpression.GetAwaiter, awaitExpression.IsCompleted, awaitExpression.GetResult, awaitExpression.Type);
BoundAssignmentOperator assignToTemp;
var replacement = F.StoreToTemp(awaitExpression, out assignToTemp, kind: SynthesizedLocalKind.AwaitSpilledTemp);
if (ss == null)
{
ss = new BoundSpillSequence2();
}
ss.Add(replacement.LocalSymbol);
writeOnceTemps.Add(replacement.LocalSymbol);
F.Syntax = awaitExpression.Syntax;
ss.Add(F.ExpressionStatement(assignToTemp));
return(replacement);
}
var e = VisitExpression(expression);
if (e == null || e.Kind != SpillSequence2)
{
return(e);
}
var newss = (BoundSpillSequence2)e;
if (ss == null)
{
ss = newss.Update(null);
}
else
{
ss.IncludeSequence(newss);
}
return(newss.Value);
}
public override BoundNode VisitSequence(BoundSequence node)
{
ReadOnlyArray <BoundExpression> sideEffects = (ReadOnlyArray <BoundExpression>) this.VisitList(node.SideEffects);
BoundExpression value = (BoundExpression)this.Visit(node.Value);
TypeSymbol type = this.VisitType(node.Type);
if (!RequiresSpill(sideEffects) && value.Kind != BoundKind.SpillSequence)
{
return(node.Update(node.Locals, sideEffects, value, type));
}
var spillBuilder = new SpillBuilder();
spillBuilder.Locals.AddRange(node.Locals);
foreach (var sideEffect in sideEffects)
{
spillBuilder.Statements.Add(
(sideEffect.Kind == BoundKind.SpillSequence)
? RewriteSpillSequenceAsBlock((BoundSpillSequence)sideEffect)
: F.ExpressionStatement(sideEffect));
}
BoundExpression newValue;
if (value.Kind == BoundKind.SpillSequence)
{
var awaitEffect = (BoundSpillSequence)value;
spillBuilder.AddSpill(awaitEffect);
newValue = awaitEffect.Value;
}
else
{
newValue = value;
}
return(spillBuilder.BuildSequenceAndFree(F, newValue));
}
private void AddBindings(ArrayBuilder <BoundStatement> sectionBuilder, ImmutableArray <KeyValuePair <BoundExpression, BoundExpression> > bindings)
{
if (!bindings.IsDefaultOrEmpty)
{
foreach (var kv in bindings)
{
var source = kv.Key;
var dest = kv.Value;
var rewriter = this.LocalRewriter;
sectionBuilder.Add(_factory.ExpressionStatement(
rewriter.MakeStaticAssignmentOperator(
_factory.Syntax, rewriter.VisitExpression(dest), rewriter.VisitExpression(source), RefKind.None, dest.Type, false)));
}
}
}
private static BoundStatement ConstructThrowInvalidOperationExceptionHelperCall(SyntheticBoundNodeFactory factory)
{
Debug.Assert(factory.ModuleBuilderOpt is not null);
var module = factory.ModuleBuilderOpt !;
var diagnosticSyntax = factory.CurrentFunction.GetNonNullSyntaxNode();
var diagnostics = factory.Diagnostics.DiagnosticBag;
Debug.Assert(diagnostics is not null);
var throwMethod = module.EnsureThrowInvalidOperationExceptionExists(diagnosticSyntax, factory, diagnostics);
var call = factory.Call(
receiver: null,
throwMethod);
return(factory.HiddenSequencePoint(factory.ExpressionStatement(call)));
}
private static BoundStatement ConstructNullCheckHelperCall(ParameterSymbol parameter, ref MethodSymbol?throwIfNullMethod, SyntheticBoundNodeFactory factory)
{
if (throwIfNullMethod is null)
{
var module = factory.ModuleBuilderOpt !;
var diagnosticSyntax = factory.CurrentFunction.GetNonNullSyntaxNode();
var diagnostics = factory.Diagnostics.DiagnosticBag;
Debug.Assert(diagnostics is not null);
throwIfNullMethod = module.EnsureThrowIfNullFunctionExists(diagnosticSyntax, factory, diagnostics);
}
var call = factory.Call(
receiver: null,
throwIfNullMethod,
arg0: factory.Convert(factory.SpecialType(SpecialType.System_Object), factory.Parameter(parameter)),
arg1: factory.StringLiteral(parameter.Name));
return(factory.HiddenSequencePoint(factory.ExpressionStatement(call)));
}
private static BoundBlock PrependImplicitInitializations(BoundBlock body, MethodSymbol method, ImmutableArray <FieldSymbol> implicitlyInitializedFields, TypeCompilationState compilationState, BindingDiagnosticBag diagnostics)
{
Debug.Assert(method.MethodKind == MethodKind.Constructor);
Debug.Assert(method.ContainingType.IsStructType());
var F = new SyntheticBoundNodeFactory(method, body.Syntax, compilationState, diagnostics);
var builder = ArrayBuilder <BoundStatement> .GetInstance(implicitlyInitializedFields.Length);
foreach (var field in implicitlyInitializedFields)
{
builder.Add(
F.ExpressionStatement(
F.AssignmentExpression(
F.Field(F.This(), field),
F.Default(field.Type))));
}
var initializations = F.HiddenSequencePoint(F.Block(builder.ToImmutableAndFree()));
return(body.Update(body.Locals, body.LocalFunctions, body.Statements.Insert(index: 0, initializations)));
}
/// <summary>
/// Add a branch in the lowered decision tree to a label for a matched
/// pattern, and then produce a statement for the target of that branch
/// that binds the pattern variables.
/// </summary>
/// <param name="bindings">The source/destination pairs for the assignments</param>
/// <param name="addBindings">A builder to which the label and binding assignments are added</param>
private void AddBindingsForCase(
ImmutableArray <KeyValuePair <BoundExpression, BoundExpression> > bindings,
ArrayBuilder <BoundStatement> addBindings)
{
var patternMatched = _factory.GenerateLabel("patternMatched");
_loweredDecisionTree.Add(_factory.Goto(patternMatched));
// Hide the code that binds pattern variables in a hidden sequence point
addBindings.Add(_factory.HiddenSequencePoint());
addBindings.Add(_factory.Label(patternMatched));
if (!bindings.IsDefaultOrEmpty)
{
foreach (var kv in bindings)
{
var loweredRight = kv.Key;
var loweredLeft = kv.Value;
addBindings.Add(_factory.ExpressionStatement(
_localRewriter.MakeStaticAssignmentOperator(
_factory.Syntax, loweredLeft, loweredRight, RefKind.None, loweredLeft.Type, false)));
}
}
}
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);
}
private BoundExpression Spill(
BoundSpillSequenceBuilder builder,
BoundExpression expression,
RefKind refKind = RefKind.None,
bool sideEffectsOnly = false)
{
Debug.Assert(builder != null);
while (true)
{
switch (expression.Kind)
{
case BoundKind.ArrayInitialization:
Debug.Assert(refKind == RefKind.None);
Debug.Assert(!sideEffectsOnly);
var arrayInitialization = (BoundArrayInitialization)expression;
var newInitializers = VisitExpressionList(ref builder, arrayInitialization.Initializers, forceSpill: true);
return(arrayInitialization.Update(newInitializers));
case BoundKind.ArgListOperator:
Debug.Assert(refKind == RefKind.None);
Debug.Assert(!sideEffectsOnly);
var argumentList = (BoundArgListOperator)expression;
var newArgs = VisitExpressionList(ref builder, argumentList.Arguments, argumentList.ArgumentRefKindsOpt, forceSpill: true);
return(argumentList.Update(newArgs, argumentList.ArgumentRefKindsOpt, argumentList.Type));
case SpillSequenceBuilderKind:
var sequenceBuilder = (BoundSpillSequenceBuilder)expression;
builder.Include(sequenceBuilder);
expression = sequenceBuilder.Value;
continue;
case BoundKind.Sequence:
// neither the side-effects nor the value of the sequence contains await
// (otherwise it would be converted to a SpillSequenceBuilder).
if (refKind != RefKind.None)
{
return(expression);
}
goto default;
case BoundKind.ThisReference:
case BoundKind.BaseReference:
if (refKind != RefKind.None || expression.Type.IsReferenceType)
{
return(expression);
}
goto default;
case BoundKind.Parameter:
if (refKind != RefKind.None)
{
return(expression);
}
goto default;
case BoundKind.Local:
var local = (BoundLocal)expression;
if (local.LocalSymbol.SynthesizedKind == SynthesizedLocalKind.Spill || refKind != RefKind.None)
{
return(local);
}
goto default;
case BoundKind.FieldAccess:
var field = (BoundFieldAccess)expression;
var fieldSymbol = field.FieldSymbol;
if (fieldSymbol.IsStatic)
{
// no need to spill static fields if used as locations or if readonly
if (refKind != RefKind.None || fieldSymbol.IsReadOnly)
{
return(field);
}
goto default;
}
if (refKind == RefKind.None)
{
goto default;
}
var receiver = Spill(builder, field.ReceiverOpt, fieldSymbol.ContainingType.IsValueType ? refKind : RefKind.None);
return(field.Update(receiver, fieldSymbol, field.ConstantValueOpt, field.ResultKind, field.Type));
case BoundKind.Literal:
case BoundKind.TypeExpression:
return(expression);
case BoundKind.ConditionalReceiver:
// we will rewrite this as a part of rewriting whole LoweredConditionalAccess
// later, if needed
return(expression);
default:
if (expression.Type.IsVoidType() || sideEffectsOnly)
{
builder.AddStatement(_F.ExpressionStatement(expression));
return(null);
}
else
{
BoundAssignmentOperator assignToTemp;
var replacement = _F.StoreToTemp(
expression,
out assignToTemp,
refKind: refKind,
kind: SynthesizedLocalKind.Spill,
syntaxOpt: _F.Syntax);
builder.AddLocal(replacement.LocalSymbol);
builder.AddStatement(_F.ExpressionStatement(assignToTemp));
return(replacement);
}
}
}
}
/// <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));
}
private BoundStatement MakeLoweredForm(BoundPatternSwitchStatement node)
{
var expression = _localRewriter.VisitExpression(node.Expression);
var result = ArrayBuilder <BoundStatement> .GetInstance();
// EnC: We need to insert a hidden sequence point to handle function remapping in case
// the containing method is edited while methods invoked in the expression are being executed.
if (!node.WasCompilerGenerated && _localRewriter.Instrument)
{
var instrumentedExpression = _localRewriter._instrumenter.InstrumentSwitchStatementExpression(node, expression, _factory);
if (expression.ConstantValue == null)
{
expression = instrumentedExpression;
}
else
{
// If the expression is a constant, we leave it alone (the decision tree lowering code needs
// to see that constant). But we add an additional leading statement with the instrumented expression.
result.Add(_factory.ExpressionStatement(instrumentedExpression));
}
}
// output the decision tree part
LowerPatternSwitch(expression, node, result);
// if the endpoint is reachable, we exit the switch
if (!node.IsComplete)
{
result.Add(_factory.Goto(node.BreakLabel));
}
// at this point the end of result is unreachable.
_declaredTemps.AddRange(node.InnerLocals);
// output the sections of code
foreach (var section in node.SwitchSections)
{
// Lifetime of these locals is expanded to the entire switch body.
_declaredTemps.AddRange(section.Locals);
// Start with the part of the decision tree that is in scope of the section variables.
// Its endpoint is not reachable (it jumps back into the decision tree code).
var sectionSyntax = (SyntaxNode)section.Syntax;
var sectionBuilder = _switchSections[sectionSyntax];
// Add labels corresponding to the labels of the switch section.
foreach (var label in section.SwitchLabels)
{
sectionBuilder.Add(_factory.Label(label.Label));
}
// Add the translated body of the switch section
sectionBuilder.AddRange(_localRewriter.VisitList(section.Statements));
sectionBuilder.Add(_factory.Goto(node.BreakLabel));
ImmutableArray <BoundStatement> statements = sectionBuilder.ToImmutableAndFree();
if (section.Locals.IsEmpty)
{
result.Add(_factory.StatementList(statements));
}
else
{
result.Add(new BoundScope(section.Syntax, section.Locals, statements));
}
// at this point the end of result is unreachable.
}
result.Add(_factory.Label(node.BreakLabel));
BoundStatement translatedSwitch = _factory.Block(_declaredTemps.ToImmutableArray(), node.InnerLocalFunctions, result.ToImmutableAndFree());
// Only add instrumentation (such as a sequence point) if the node is not compiler-generated.
if (!node.WasCompilerGenerated && _localRewriter.Instrument)
{
translatedSwitch = _localRewriter._instrumenter.InstrumentPatternSwitchStatement(node, translatedSwitch);
}
return(translatedSwitch);
}
/// <summary>
/// Translate a statement that declares a given set of locals. Also allocates and frees hoisted temps as
/// required for the translation.
/// </summary>
/// <param name="locals">The set of locals declared in the original version of this statement</param>
/// <param name="wrapped">A delegate to return the translation of the body of this statement</param>
private BoundNode PossibleIteratorScope(ImmutableArray <LocalSymbol> locals, Func <BoundStatement> wrapped)
{
if (locals.IsDefaultOrEmpty)
{
return(wrapped());
}
var proxyFields = ArrayBuilder <SynthesizedFieldSymbolBase> .GetInstance();
foreach (var local in locals)
{
if (!VariablesCaptured.Contains(local))
{
continue;
}
CapturedSymbolReplacement proxy;
if (proxies.TryGetValue(local, out proxy))
{
// All of the user-declared variables have pre-allocated proxies
var field = proxy.HoistedField;
Debug.Assert((object)field != null);
Debug.Assert(local.DeclarationKind != LocalDeclarationKind.CompilerGenerated); // temps have lazily allocated proxies
if (local.DeclarationKind != LocalDeclarationKind.CompilerGenerated)
{
proxyFields.Add(field);
}
}
else
{
if (local.RefKind == RefKind.None)
{
SynthesizedFieldSymbolBase field = MakeHoistedTemp(local, TypeMap.SubstituteType(local.Type));
proxy = new CapturedToFrameSymbolReplacement(field);
proxies.Add(local, proxy);
}
// ref temporary variables have proxies that are allocated on demand
// See VisitAssignmentOperator.
}
}
var translatedStatement = wrapped();
// produce code to free (e.g. mark as available for reuse) and clear (e.g. set to null) the proxies for any temps for these locals
var clearTemps = ArrayBuilder <BoundAssignmentOperator> .GetInstance();
foreach (var local in locals)
{
ArrayBuilder <SynthesizedFieldSymbolBase> frees;
if (freeTempsMap.TryGetValue(local, out frees))
{
Debug.Assert(local.DeclarationKind == LocalDeclarationKind.CompilerGenerated); // only temps are managed this way
freeTempsMap.Remove(local);
foreach (var field in frees)
{
if (MightContainReferences(field.Type))
{
clearTemps.Add(F.AssignmentExpression(F.Field(F.This(), field), F.NullOrDefault(field.Type)));
}
FreeTemp(field);
}
frees.Free();
}
}
if (clearTemps.Count != 0)
{
translatedStatement = F.Block(
translatedStatement,
F.Block(clearTemps.Select(e => F.ExpressionStatement(e)).AsImmutable <BoundStatement>())
);
}
clearTemps.Free();
// wrap the node in an iterator scope for debugging
if (proxyFields.Count != 0)
{
translatedStatement = new BoundIteratorScope(F.Syntax, proxyFields.ToImmutable(), translatedStatement);
}
proxyFields.Free();
return(translatedStatement);
}
