/// <summary>
/// Initializes a new instance of the <see cref="CSharpOverLoopInstruction"/> class.
/// </summary>
/// <param name="context">The creation context.</param>
/// <param name="parentFeature">The parent feature.</param>
/// <param name="source">The Easly instruction from which the C# instruction is created.</param>
protected CSharpOverLoopInstruction(ICSharpContext context, ICSharpFeature parentFeature, IOverLoopInstruction source)
: base(context, parentFeature, source)
{
OverList = CSharpExpression.Create(context, (IExpression)source.OverList);
LoopInstructions = CSharpScope.Create(context, parentFeature, (IScope)source.LoopInstructions);
foreach (IName Name in source.IndexerList)
{
string IndexerName = Name.ValidText.Item;
IScopeAttributeFeature IndexerFeature = Source.InnerLoopScope[IndexerName];
ICSharpScopeAttributeFeature NewIndexer = CSharpScopeAttributeFeature.Create(context, ParentFeature.Owner, IndexerFeature);
IndexerList.Add(NewIndexer);
}
if (source.ExitEntityName.IsAssigned)
{
ExitEntityName = ((IIdentifier)source.ExitEntityName.Item).ValidText.Item;
}
foreach (IAssertion Item in Source.InvariantList)
{
ICSharpAssertion NewAssertion = CSharpAssertion.Create(context, Item);
InvariantList.Add(NewAssertion);
}
}
public override void VisitTypeNode(TypeNode typeNode)
{
if (typeNode == null)
{
return;
}
// we might have copied this type already
if (this.duplicatedMembers[typeNode.UniqueKey] != null)
{
return;
}
TypeNode targetType = typeNode.FindShadow(this.targetAssembly);
if (targetType != null)
{
if (targetType.Contract == null)
{
targetType.Contract = new TypeContract(targetType, true);
}
this.outOfBandDuplicator.TargetType = targetType;
if (typeNode.Contract != null)
{
InvariantList duplicatedInvariants =
this.outOfBandDuplicator.VisitInvariantList(typeNode.Contract.Invariants);
targetType.Contract.Invariants = duplicatedInvariants;
}
CopyAttributesWithoutDuplicateUnlessAllowMultiple(targetType, typeNode);
base.VisitTypeNode(typeNode);
}
else
{
// target type does not exist. Copy it
if (typeNode.DeclaringType != null)
{
// nested types are members and have been handled by CopyMissingMembers
}
else
{
this.outOfBandDuplicator.VisitTypeNode(typeNode);
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="CSharpForLoopInstruction"/> class.
/// </summary>
/// <param name="context">The creation context.</param>
/// <param name="parentFeature">The parent feature.</param>
/// <param name="source">The Easly instruction from which the C# instruction is created.</param>
protected CSharpForLoopInstruction(ICSharpContext context, ICSharpFeature parentFeature, IForLoopInstruction source)
: base(context, parentFeature, source)
{
foreach (IEntityDeclaration Declaration in source.EntityDeclarationList)
{
ICSharpScopeAttributeFeature NewDeclaration = CSharpScopeAttributeFeature.Create(context, parentFeature.Owner, Declaration.ValidEntity.Item);
EntityDeclarationList.Add(NewDeclaration);
}
foreach (IInstruction Instruction in source.InitInstructionList)
{
ICSharpInstruction NewInstruction = Create(context, parentFeature, Instruction);
InitInstructionList.Add(NewInstruction);
}
WhileCondition = CSharpExpression.Create(context, (IExpression)source.WhileCondition);
foreach (IInstruction Instruction in source.LoopInstructionList)
{
ICSharpInstruction NewInstruction = Create(context, parentFeature, Instruction);
LoopInstructionList.Add(NewInstruction);
}
foreach (IInstruction Instruction in source.IterationInstructionList)
{
ICSharpInstruction NewInstruction = Create(context, parentFeature, Instruction);
IterationInstructionList.Add(NewInstruction);
}
if (source.Variant.IsAssigned)
{
VariantExpression = CSharpExpression.Create(context, (IExpression)source.Variant.Item);
}
foreach (IAssertion Item in Source.InvariantList)
{
ICSharpAssertion NewAssertion = CSharpAssertion.Create(context, Item);
InvariantList.Add(NewAssertion);
}
}
public void CheckInvariants(TypeNode t, InvariantList invariants)
{
Contract.Requires(invariants != null);
this.assignmentFound = false;
foreach (var i in invariants)
{
if (i == null) continue;
this.lastSourceContext = i.SourceContext;
this.CurrentMethod = i;
this.Visit(i);
Contract.Assume(this.CurrentMethod != null);
if (this.assignmentFound)
{
this.errorHandler(
new Error(1003,
"Malformed contract. Found Invariant after assignment in method '" + this.CurrentMethod.FullName + "'.",
i.SourceContext));
break;
}
}
}
private void ExtractIndividualInvariants(TypeNode type, InvariantList result, Method invariantMethod)
{
if (invariantMethod == null || invariantMethod.Body == null || invariantMethod.Body.Statements == null ||
invariantMethod.Body.Statements.Count == 0)
{
return;
}
Block invariantMethodBody = invariantMethod.Body;
int n = invariantMethodBody.Statements.Count;
int beginning = 0;
while (beginning < invariantMethodBody.Statements.Count &&
invariantMethodBody.Statements[beginning] is PreambleBlock)
{
beginning++;
}
for (int i = beginning; i < n; i++)
{
Block b = (Block) invariantMethodBody.Statements[i];
int seginning = 0;
for (int j = 0, m = b.Statements == null ? 0 : b.Statements.Count; j < m; j++)
{
ExpressionStatement s = b.Statements[j] as ExpressionStatement;
if (s == null) continue;
Literal invariantName;
Literal sourceText;
Expression invariantCondition = this.contractNodes.IsInvariant(s, out invariantName, out sourceText);
if (invariantCondition == null)
{
Method called = HelperMethods.IsMethodCall(s);
if (called != null)
{
if (HelperMethods.IsVoidType(called.ReturnType))
{
this.CallErrorFound(new Error(1045,
"Invariant methods must be a sequence of calls to Contract.Invariant(...)",
s.SourceContext));
return;
}
}
continue;
}
// construct a clump from
// invariantMethodBody.Statements[beginning].Statements[seginning] to
// invariantMethodBody.Statements[i].Statements[j]
Block currentClump = new Block(HelperMethods.ExtractClump(invariantMethodBody.Statements, beginning, seginning, i, j));
BlockExpression be = new BlockExpression(currentClump, SystemTypes.Void);
Invariant inv = new Invariant(type, be, invariantMethod.Name.Name);
inv.UserMessage = invariantName;
inv.SourceConditionText = sourceText;
SourceContext sctx;
if (HelperMethods.FindContext(currentClump, s.SourceContext, out sctx))
{
inv.SourceContext = sctx;
inv.Condition.SourceContext = sctx;
}
inv.ILOffset = s.ILOffset;
inv.UsesModels = CodeInspector.UsesModel(inv.Condition, this.contractNodes);
if (inv.UsesModels)
{
this.HandleError(invariantMethod, 1072, "Invariants cannot refer to model members.", sctx);
}
else
{
result.Add(inv);
}
// Re-initialize current state
beginning = i;
seginning = j + 1;
b = (Block) invariantMethodBody.Statements[i]; // IMPORTANT! Need this to keep "b" in sync
}
}
}
public virtual InvariantList VisitInvariantList(InvariantList invariants){
if (invariants == null) return null;
for (int i = 0, n = invariants.Count; i < n; i++)
invariants[i] = this.VisitInvariant(invariants[i]);
return invariants;
}
public override void VisitTypeNode(TypeNode typeNode) {
if (typeNode == null) return;
if (HelperMethods.IsContractTypeForSomeOtherType(typeNode, this.rewriterNodes) != null) {
return;
}
Method savedInvariantMethod = this.InvariantMethod;
Field savedReentrancyFlag = this.ReentrancyFlag;
this.InvariantMethod = null;
this.ReentrancyFlag = null;
var savedState = this.currentState;
this.currentState = new CurrentState(typeNode);
var savedEmitFlags = this.AdaptRuntimeOptionsBasedOnAttributes(typeNode.Attributes);
try
{
if (this.Emit(RuntimeContractEmitFlags.Invariants) && rewriterNodes.InvariantMethod != null)
{
InvariantList userWrittenInvariants = typeNode.Contract == null ? null : typeNode.Contract.Invariants;
Class asClass = typeNode as Class;
Field baseReentrancyFlag;
Method baseInvariantMethod = FindAndInstantiateBaseClassInvariantMethod(asClass, out baseReentrancyFlag);
if ((userWrittenInvariants != null && 0 < userWrittenInvariants.Count) || baseInvariantMethod != null)
{
Field reEntrancyFlag = null;
var isStructWithExplicitLayout = IsStructWithExplicitLayout(typeNode as Struct);
if (isStructWithExplicitLayout)
{
this.HandleError(new Warning(1044, String.Format("Struct '{0}' has explicit layout and an invariant. Invariant recursion guards will not be emitted and evaluation of invariants may occur too eagerly.", typeNode.FullName), new SourceContext()));
}
else
{
#region Find or create re-entrancy flag to the class
if (baseReentrancyFlag != null)
{
// grab base reEntrancyFlag
reEntrancyFlag = baseReentrancyFlag;
}
else
{
FieldFlags reentrancyFlagProtection;
if (typeNode.IsSealed)
{
reentrancyFlagProtection = FieldFlags.Private | FieldFlags.CompilerControlled;
}
else if (this.InheritInvariantsAcrossAssemblies)
{
reentrancyFlagProtection = FieldFlags.Family | FieldFlags.CompilerControlled;
}
else
{
reentrancyFlagProtection = FieldFlags.FamANDAssem | FieldFlags.CompilerControlled;
}
reEntrancyFlag = new Field(typeNode, null, reentrancyFlagProtection, Identifier.For("$evaluatingInvariant$"), SystemTypes.Boolean, null);
RewriteHelper.TryAddCompilerGeneratedAttribute(reEntrancyFlag);
RewriteHelper.TryAddDebuggerBrowsableNeverAttribute(reEntrancyFlag);
typeNode.Members.Add(reEntrancyFlag);
}
#endregion Add re-entrancy flag to the class
}
Block newBody = new Block(new StatementList(3));
// newBody ::=
// if (this.$evaluatingInvariant$){
// return (true); // don't really return true since this is a void method, but it means the invariant is assumed to hold
// this.$evaluatingInvariant$ := true;
// try{
// <evaluate invariants and call base invariant method>
// } finally {
// this.$evaluatingInvariant$ := false;
// }
Method invariantMethod =
new Method(
typeNode,
new AttributeList(),
Identifier.For("$InvariantMethod$"),
null,
SystemTypes.Void,
newBody);
RewriteHelper.TryAddCompilerGeneratedAttribute(invariantMethod);
invariantMethod.CallingConvention = CallingConventionFlags.HasThis;
if (this.InheritInvariantsAcrossAssemblies)
invariantMethod.Flags = MethodFlags.Family | MethodFlags.Virtual;
else
invariantMethod.Flags = MethodFlags.FamANDAssem | MethodFlags.Virtual;
invariantMethod.Attributes.Add(new AttributeNode(new MemberBinding(null, this.runtimeContracts.ContractNodes.InvariantMethodAttribute.GetConstructor()), null));
#region call base class invariant
if (baseInvariantMethod != null)
{
newBody.Statements.Add(
new ExpressionStatement(
new MethodCall(
new MemberBinding(invariantMethod.ThisParameter, baseInvariantMethod), null, NodeType.Call, SystemTypes.Void)));
}
#endregion
#region Add re-entrancy test to the method
Block invariantExit = new Block();
if (reEntrancyFlag != null)
{
Block reEntrancyTest = new Block(new StatementList());
reEntrancyTest.Statements.Add(
new Branch(new MemberBinding(invariantMethod.ThisParameter, reEntrancyFlag), invariantExit));
reEntrancyTest.Statements.Add(
new AssignmentStatement(new MemberBinding(invariantMethod.ThisParameter, reEntrancyFlag), Literal.True)
);
newBody.Statements.Add(reEntrancyTest);
}
#endregion Add re-entrancy test to the method
Block invariantChecks = new Block(new StatementList());
if (userWrittenInvariants != null)
{
#region Filter out invariants that aren't runtime checkable
var filteredInvariants = new InvariantList();
foreach (var i in userWrittenInvariants) {
if (!EmitInvariant(i, this.skipQuantifiers)) continue;
filteredInvariants.Add(i);
}
#endregion Filter out invariants that aren't runtime checkable
#region Duplicate the invariants
// need to duplicate the invariants so they aren't shared
Duplicator d = new Duplicator(typeNode.DeclaringModule, typeNode);
InvariantList duplicatedInvariants = d.VisitInvariantList(filteredInvariants);
// F: seems to have the invariant duplictedInvariants != null
Contract.Assume(duplicatedInvariants != null);
#endregion Duplicate the invariants
#region Rewrite the body of the invariant method
// then we need to replace calls to Contract.Invariant with calls to Contract.RewriterInvariant
// in the body of the invariant method
RewriteInvariant rc = new RewriteInvariant(this.runtimeContracts);
rc.VisitInvariantList(duplicatedInvariants);
#endregion Rewrite the body of the invariant method
for (int i = 0, n = duplicatedInvariants.Count; i < n; i++)
{
Expression e = duplicatedInvariants[i].Condition;
var blockExpr = e as BlockExpression;
if (blockExpr != null)
{
invariantChecks.Statements.Add(blockExpr.Block);
}
else
{
invariantChecks.Statements.Add(new ExpressionStatement(e));
}
}
}
Block finallyB = new Block(new StatementList(1));
if (reEntrancyFlag != null)
{
finallyB.Statements.Add(
new AssignmentStatement(new MemberBinding(invariantMethod.ThisParameter, reEntrancyFlag), Literal.False)
);
}
this.cleanUpCodeCoverage.VisitBlock(invariantChecks);
Block b = RewriteHelper.CreateTryFinallyBlock(invariantMethod, invariantChecks, finallyB);
newBody.Statements.Add(b);
newBody.Statements.Add(invariantExit);
newBody.Statements.Add(new Return());
// set the field "this.InvariantMethod" to this one so it is used in calls within each method
// but don't add it yet to the class so it doesn't get visited!
this.InvariantMethod = invariantMethod;
this.ReentrancyFlag = reEntrancyFlag;
}
}
base.VisitTypeNode(typeNode);
// Now add invariant method to the class
if (this.InvariantMethod != null)
{
typeNode.Members.Add(this.InvariantMethod);
}
return;
}
finally
{
this.InvariantMethod = savedInvariantMethod;
this.ReentrancyFlag = savedReentrancyFlag;
this.currentState = savedState;
this.contractEmitFlags = savedEmitFlags;
}
}
public virtual void VisitInvariantList(InvariantList invariants)
{
if (invariants == null) return;
for (int i = 0, n = invariants.Count; i < n; i++)
this.VisitInvariant(invariants[i]);
}
public override InvariantList VisitInvariantList(InvariantList Invariants){
if (Invariants == null) return null;
return base.VisitInvariantList(Invariants.Clone());
}
public virtual InvariantList VisitInvariantList(InvariantList Invariants1, InvariantList Invariants2){
if (Invariants1 == null) return null;
for (int i = 0, n = Invariants1.Count, m = Invariants2 == null ? 0 : Invariants2.Count; i < n; i++){
//^ assert Invariants2 != null;
if (i >= m)
Invariants1[i] = this.VisitInvariant(Invariants1[i], null);
else
Invariants1[i] = this.VisitInvariant(Invariants1[i], Invariants2[i]);
}
return Invariants1;
}
/// <summary>
/// Implements the runtime check for invariants of class C. Also implements the runtime check for modelfields.
/// ensures: If c declares invariants or modelfields, then c.Contract.InvariantMethod contains their runtime checking code;
/// Adds the CheckInvariant method to c.Members if it wasn't a member already.
/// </summary>
void ImplementCheckInvariantMethod(Class c) { // c is the class to which all of this code is going to get attached to.
Method m = null;
#region Get a handle m on the invariant method, create one if necessary
if (c.Contract == null || c.Contract.InvariantMethod == null) {
Method invariantMethod = new Method(
c,
new AttributeList(),
Identifier.For("SpecSharp::CheckInvariant"),
new ParameterList(new Parameter(Identifier.For("throwException"), SystemTypes.Boolean)),
SystemTypes.Boolean,
null);
invariantMethod.CallingConvention = CallingConventionFlags.HasThis;
invariantMethod.Flags = MethodFlags.Private;
m = invariantMethod;
} else
m = c.Contract.InvariantMethod;
#endregion Get a handle on the invariant method, create one if necessary
StatementList stmts = new StatementList();
#region Create code for all of the invariants, implicit and explicit. Add that code to stmts.
Parameter throwException = m.Parameters[0];
InvariantList consolidatedInvariants = new InvariantList();
InvariantList invariants = c.Contract == null ? null : c.Contract.Invariants;
for (int i = 0, n = invariants == null ? 0 : invariants.Count; i < n; i++)
if (!invariants[i].IsStatic)
consolidatedInvariants.Add(invariants[i]);
// InterfaceList ifaces = this.GetTypeView(c).Interfaces;
InterfaceList ifaces = c.Interfaces;
for (int i = 0, n = ifaces.Count; i < n; i++){
Interface iface = ifaces[i];
if (iface == null) continue;
GatherInheritedInstanceInvariants(iface, consolidatedInvariants);
}
for (int i = 0; i < consolidatedInvariants.Count; i++){
Invariant inv = consolidatedInvariants[i];
stmts.Add(new If(new UnaryExpression(inv.Condition, NodeType.LogicalNot, SystemTypes.Boolean),
new Block(new StatementList(
new If(throwException,
new Block(new StatementList(
new Throw(new Construct(new MemberBinding(null, SystemTypes.ObjectInvariantException.GetConstructor()), null, SystemTypes.ObjectInvariantException), inv.SourceContext)
)),
new Block(new StatementList(new Return(Literal.False)))))),
null));
}
#endregion
#region Create code for all of the modelfields defined by c. Add that code to stmts.
StatementList mfStats = new StatementList();
ExpressionList modifiesList = new ExpressionList(); // synthesize modifies clause
foreach (ModelfieldContract mfC in c.Contract.ModelfieldContracts) {
//Add the following code to the method:
// if (!E) {
// <mfC.Modelfield> = value(mfC.Witness);
// if (!E) throw exception;
// }
//where E is the conjunction of (1) all satisfies clauses of the contract, and (2) all satisfies clauses of overridden contracts in superclasses.
//Note that satisifes clauses of contracts implemented by mfC (i.e., contracts in interfaces) have been copied to mfC.
//Note that if f in C overrides f in D, and f in D overrides f in E, then f in C overrides f in E.
Expression E = Literal.True;
for (ModelfieldContract currentMfC = mfC; currentMfC != null; currentMfC = currentMfC.NearestOverriddenContract) {
foreach (Expression satClause in currentMfC.SatisfiesList) {
if (satClause == null) continue; //error will have been dealt with elsewhere
E = new BinaryExpression(satClause, E, NodeType.LogicalAnd, SystemTypes.Boolean);
}
}
Expression notE = new UnaryExpression(E, NodeType.LogicalNot, SystemTypes.Boolean);
#region create the if statement
//Start with the creation of the body of the if.
MemberBinding lhs = new MemberBinding(new This(c), mfC.Modelfield);
Statement setF = new AssignmentStatement(lhs, mfC.Witness);
modifiesList.Add(lhs); // synthesize modifies clause
String mfAsString = mfC.Modelfield.FullName;
MemberBinding exc = new MemberBinding(null,SystemTypes.ModelfieldException.GetConstructor(SystemTypes.String));
Construct exception = new Construct(exc, new ExpressionList(new Literal(mfAsString,SystemTypes.String)), SystemTypes.ModelfieldException);
Block innerIfBody = new Block(new StatementList(
new If(throwException,
new Block(new StatementList(
new Throw(exception, mfC.Modelfield.SourceContext)
)),
new Block(new StatementList(new Return(Literal.False))))));
Statement innerIf = new If(notE, innerIfBody, null);
StatementList body = new StatementList();
body.Add(setF);
body.Add(innerIf);
Statement outerIf = new If(notE, new Block(body), null);
#endregion
mfStats.Add(outerIf);
}
#endregion
#region If c declares invariants or modelfields, then add a contract to c if it has none, and make sure that m is c's InvariantMethod.
if (stmts.Count > 0 || mfStats.Count > 0) {
Duplicator dup = new Duplicator(this.currentModule, this.currentType);
dup.DuplicateFor[throwException.UniqueKey] = throwException;
stmts = dup.VisitStatementList(stmts);
mfStats = dup.VisitStatementList(mfStats);
m.Body = new Block(stmts);
m.Body.Statements.Add(new Block(mfStats)); //The model field code should be wrapped in a ContractMarkerException block, but I can't get it to work
m.Body.Statements.Add(new Return(Literal.True));
m.Body.HasLocals = true; //who knows? there might be locals in the invariants or model fields (quantifier bound variables).
#region Slap on NoDefaultContract and (what is roughly the equivalent of) a requires this.PreValid. //I doubt if this is still needed
//No need for a runtime check of this precondition though, so directly add an attribute.
//Bit of a hack, but there does not seem to be a really good place to do this.
InstanceInitializer ndCtor = SystemTypes.NoDefaultContractAttribute.GetConstructor();
if (ndCtor != null)
m.Attributes.Add(new AttributeNode(new MemberBinding(null, ndCtor), null, AttributeTargets.Method));
TypeNode guard = SystemTypes.Guard;
if (guard != null) {
Method method = guard.GetMethod(Identifier.For("FrameIsPrevalid"), SystemTypes.Object, SystemTypes.Type);
if (method != null)
{
This t = new This(c);
Expression req = new MethodCall(
new MemberBinding(null, method),
new ExpressionList(t, new UnaryExpression(new Literal(t.Type, SystemTypes.Type), NodeType.Typeof, OptionalModifier.For(SystemTypes.NonNullType, SystemTypes.Type))));
// Place it in the method contract so downstream tools that are in the compiler pipeline see it
if (m.Contract == null)
{
m.Contract = new MethodContract(m);
}
if (m.Contract.Requires == null)
{
m.Contract.Requires = new RequiresList(1);
}
m.Contract.Requires.Add(new RequiresPlain(req));
m.Contract.Modifies = modifiesList; // needed for model fields
// Since this happens after contracts are serialized, serialize the precondition and stick it in the method's attributes.
ContractSerializer cs = new ContractSerializer(this.currentModule);
cs.Visit(req);
string val = cs.SerializedContract;
InstanceInitializer ctor = SystemTypes.RequiresAttribute.GetConstructor(SystemTypes.String);
MemberBinding attrBinding = new MemberBinding(null, ctor);
ExpressionList args = new ExpressionList();
args.Add(new Literal(val, SystemTypes.String));
AttributeNode a = new AttributeNode(attrBinding, args, (AttributeTargets)0);
m.Attributes.Add(a);
if (modifiesList.Count > 0)
{
ctor = SystemTypes.ModifiesAttribute.GetConstructor(SystemTypes.String);
for (int i = 0, n = modifiesList.Count; i < n; i++)
{
Expression e = modifiesList[i];
a = Checker.SerializeExpression(ctor, e, this.currentModule);
m.Attributes.Add(a);
}
}
}
}
#endregion
if (c.Contract == null) {
c.Contract = new TypeContract(c);
c.Contract.DeclaringType = c;
}
if (c.Contract.InvariantMethod == null) {
c.Contract.InvariantMethod = m;
c.Members.Add(m);
} //else assert (m == c.Contract.InvairantMethod)
}
#endregion
}
void GatherInheritedInstanceInvariants(Interface iface, InvariantList invs){
if (iface == null) return;
if (iface.Contract != null && iface.Contract.InvariantCount > 0){
for (int i = 0, n = iface.Contract.Invariants.Count; i < n; i++){
if (!iface.Contract.Invariants[i].IsStatic)
invs.Add(iface.Contract.Invariants[i]);
}
}
// InterfaceList iface_ifaces = this.GetTypeView(iface).Interfaces;
InterfaceList iface_ifaces = iface.Interfaces;
for (int i = 0, n = iface_ifaces == null ? 0 : iface_ifaces.Count; i < n; i++){
GatherInheritedInstanceInvariants(iface_ifaces[i],invs);
}
return;
}
public EventingVisitor(Action<InvariantList> visitInvariantList) { VisitedInvariantList += visitInvariantList; } public event Action<InvariantList> VisitedInvariantList; public override InvariantList VisitInvariantList(InvariantList invariants) { if (VisitedInvariantList != null) VisitedInvariantList(invariants); return base.VisitInvariantList(invariants); }
