public override Statement VisitThrow(Throw Throw)
{
WriteLine("raise {0};", ((Identifier)Throw.Expression).Name);
return Throw;
}
private static Statement WrapTryCatch(Method method, Statement statement)
{
Block afterCatches = new Block(new StatementList());
Block tryBlock = new Block(new StatementList());
Block blockAfterTryBody = new Block(null);
tryBlock.Statements.Add(statement);
tryBlock.Statements.Add(new Branch(null, afterCatches, false, true, true));
tryBlock.Statements.Add(blockAfterTryBody);
Block catchBlock = new Block(new StatementList());
// emit code that pops the exception and fools fxcop
Block branchTargetToFoolFxCop = new Block(null);
var branch = new Branch(new Expression(NodeType.Pop), branchTargetToFoolFxCop);
SourceContext hiddenContext = new SourceContext(HiddenDocument.Document);
branch.SourceContext = hiddenContext;
catchBlock.Statements.Add(branch);
var rethrowStatement = new Throw();
rethrowStatement.SourceContext = hiddenContext;
rethrowStatement.NodeType = NodeType.Rethrow;
catchBlock.Statements.Add(rethrowStatement);
catchBlock.Statements.Add(branchTargetToFoolFxCop);
var leave = new Branch(null, afterCatches, false, true, true);
leave.SourceContext = hiddenContext;
catchBlock.Statements.Add(leave);
Block tryCatch = new Block(new StatementList());
tryCatch.Statements.Add(tryBlock);
tryCatch.Statements.Add(catchBlock);
tryCatch.Statements.Add(afterCatches);
if (method.ExceptionHandlers == null) method.ExceptionHandlers = new ExceptionHandlerList();
ExceptionHandler exHandler = new ExceptionHandler();
exHandler.TryStartBlock = tryBlock;
exHandler.BlockAfterTryEnd = blockAfterTryBody;
exHandler.HandlerStartBlock = catchBlock;
exHandler.BlockAfterHandlerEnd = afterCatches;
exHandler.FilterType = SystemTypes.Exception;
exHandler.HandlerType = NodeType.Catch;
method.ExceptionHandlers.Add(exHandler);
return tryCatch;
}
public virtual Statement VisitThrow(Throw Throw)
{
if (Throw == null) return null;
Throw.Expression = this.VisitExpression(Throw.Expression);
return Throw;
}
//[ContractVerification(true)]
private void VisitMethodInternal(Method method) {
if (method.IsAbstract || IsRewriterGenerated(method)) {
return;
}
Block origBody = method.Body;
if (origBody == null || origBody.Statements == null || origBody.Statements.Count == 0) return;
#if DEBUG
if (!RewriteHelper.PostNormalizedFormat(method))
throw new RewriteException("The method body for '" + method.FullName + "' is not structured correctly");
#endif
#region Rewrite all Assert and Assume methods
// Happens in-place so any modifications made are persisted even if nothing else is done to method
RewriteAssertAssumeAndCallSiteRequires raa = new RewriteAssertAssumeAndCallSiteRequires(this.AssertAssumeRewriteMethodTable, this.runtimeContracts, this.contractEmitFlags, this, method);
method.Body = raa.VisitBlock(method.Body);
#endregion Rewrite all Assert and Assume methods (if user specified)
#region Bail out early if publicSurfaceOnly and method is not visible (but not for contract validators!) or contract abbreviator
if (this.runtimeContracts.PublicSurfaceOnly && !IsCallableFromOutsideAssembly(method) && !ContractNodes.IsValidatorMethod(method)
|| ContractNodes.IsAbbreviatorMethod(method)) return;
#endregion
int oldLocalUniqueNameCounter = 0;
List<Block> contractInitializationBlocks = new List<Block>();
Block postPreambleBlock = null;
Dictionary<TypeNode, Local> closureLocals = new Dictionary<TypeNode, Local>();
Block oldExpressionPreStateValues = new Block(new StatementList());
#region Gather pre- and postconditions from supertypes and from method contract
// Create lists of unique preconditions and postconditions.
List<Requires> preconditions = new List<Requires>();
List<Ensures> postconditions = new List<Ensures>();
List<Ensures> asyncPostconditions = new List<Ensures>();
RequiresList validations = null;
// For postconditions, wrap all parameters within an old expression (if they are not already within one)
var wrap = new WrapParametersInOldExpressions();
EmitAsyncClosure asyncBuilder = null;
#region Copy the method's contracts.
if (method.Contract != null && (method.Contract.RequiresCount > 0 || method.Contract.EnsuresCount > 0 ||
method.Contract.ValidationsCount > 0 || method.Contract.AsyncEnsuresCount > 0))
{
// Use duplicate of contract because it is going to get modified from processing Old(...) and
// Result(). Can't have the modified contract get inherited (or else the Old(...) processing
// will not work properly.)
// Can't use MethodContract.CopyFrom or HelperMethods.DuplicateMethodBodyAndContract
// because they assume the new contract is in a different method. Plus the latter duplicates
// any closure classes needed for anonymous delegates in the contract.
MethodContract mc = HelperMethods.DuplicateContractAndClosureParts(method, method, this.runtimeContracts.ContractNodes, true);
validations = mc.Validations;
if (mc != null) {
contractInitializationBlocks.Add(mc.ContractInitializer);
postPreambleBlock = mc.PostPreamble;
RecordEnsures(method, ref oldLocalUniqueNameCounter, contractInitializationBlocks, closureLocals, oldExpressionPreStateValues, postconditions, asyncPostconditions, wrap, ref asyncBuilder, mc);
}
}
#endregion Copy the method's contracts.
#region Search the class hierarchy for overridden methods to propagate their contracts.
if (this.Emit(RuntimeContractEmitFlags.InheritContracts) && method.OverridesBaseClassMember && method.DeclaringType != null && method.OverriddenMethod != null) {
for (TypeNode super = method.DeclaringType.BaseType; super != null; super = HelperMethods.DoesInheritContracts(super)?super.BaseType:null) {
var baseMethod = super.GetImplementingMethod(method.OverriddenMethod, false);
Method baseContractMethod = HelperMethods.GetContractMethod(baseMethod);
if (baseContractMethod != null) {
MethodContract mc = HelperMethods.DuplicateContractAndClosureParts(method, baseContractMethod, this.runtimeContracts.ContractNodes, false);
RewriteHelper.ReplacePrivateFieldsThatHavePublicProperties(method.DeclaringType, super, mc, this.rewriterNodes);
if (mc != null) {
contractInitializationBlocks.Add(mc.ContractInitializer);
// can't have post preambles in overridden methods, since they cannot be constructors.
// only add requires if baseMethod is the root method
if (mc.Requires != null && baseMethod.OverriddenMethod == null)
{
foreach (RequiresPlain requires in mc.Requires) {
if (!EmitRequires(requires, this.skipQuantifiers)) continue;
// Debug.Assert(!preconditions.Contains(requires));
preconditions.Add(requires);
}
}
RecordEnsures(method, ref oldLocalUniqueNameCounter, contractInitializationBlocks, closureLocals, oldExpressionPreStateValues, postconditions, asyncPostconditions, wrap, ref asyncBuilder, mc);
}
}
// bail out if this base type does not inherit contracts
if (!HelperMethods.DoesInheritContracts(super)) break;
}
}
#endregion Search the class hierarchy for overridden methods to propagate their contracts.
#region Propagate explicit interface method contracts.
if (this.Emit(RuntimeContractEmitFlags.InheritContracts) && method.ImplementedInterfaceMethods != null) {
foreach (Method interfaceMethod in method.ImplementedInterfaceMethods) {
if (interfaceMethod != null)
{
Method contractMethod = HelperMethods.GetContractMethod(interfaceMethod);
if (contractMethod != null)
{ // if null, then no contract for this interface method
// Maybe it would be easier to just duplicate the entire method and then pull the
// initialization code from the duplicate?
MethodContract mc=HelperMethods.DuplicateContractAndClosureParts(method, contractMethod, this.runtimeContracts.ContractNodes, false);
if (mc != null)
{
contractInitializationBlocks.Add(mc.ContractInitializer);
// can't have post preambles in interface methods (not constructors)
if (mc.Requires != null)
{
foreach (RequiresPlain requires in mc.Requires)
{
if (!EmitRequires(requires, this.skipQuantifiers)) continue;
// Debug.Assert(!preconditions.Contains(requires));
preconditions.Add(requires);
}
}
RecordEnsures(method, ref oldLocalUniqueNameCounter, contractInitializationBlocks, closureLocals, oldExpressionPreStateValues, postconditions, asyncPostconditions, wrap, ref asyncBuilder, mc);
}
}
}
}
}
#endregion Propagate explicit interface method contracts.
#region Propagate implicit interface method contracts.
if (this.Emit(RuntimeContractEmitFlags.InheritContracts) && method.ImplicitlyImplementedInterfaceMethods != null) {
foreach (Method interfaceMethod in method.ImplicitlyImplementedInterfaceMethods) {
if (interfaceMethod != null) {
Method contractMethod = HelperMethods.GetContractMethod(interfaceMethod);
if (contractMethod != null)
{ // if null, then no contract for this method
// Maybe it would be easier to just duplicate the entire method and then pull the
// initialization code from the duplicate?
MethodContract mc = HelperMethods.DuplicateContractAndClosureParts(method, contractMethod, this.runtimeContracts.ContractNodes, false);
if (mc != null)
{
contractInitializationBlocks.Add(mc.ContractInitializer);
// can't have post preambles in implicit interface method implementations, as they are not constructors.
if (mc.Requires != null)
{
foreach (RequiresPlain requires in mc.Requires)
{
if (!EmitRequires(requires, this.skipQuantifiers)) continue;
// Debug.Assert(!preconditions.Contains(requires));
preconditions.Add(requires);
}
}
RecordEnsures(method, ref oldLocalUniqueNameCounter, contractInitializationBlocks, closureLocals, oldExpressionPreStateValues, postconditions, asyncPostconditions, wrap, ref asyncBuilder, mc);
}
}
}
}
}
#endregion Propagate implicit interface method contracts.
#endregion Gather pre- and postconditions from supertypes and from method contract
#region Return if there is nothing to do
if (preconditions.Count < 1 && postconditions.Count < 1 && asyncPostconditions.Count < 1 && (validations == null || validations.Count == 0) && this.InvariantMethod == null)
return;
#endregion Return if there is nothing to do
#region Change all short branches to long because code modifications can add code
{
// REVIEW: This does *not* remove any short branches in the contracts.
// I think that is okay, but we should think about it.
RemoveShortBranches rsb = new RemoveShortBranches();
rsb.VisitBlock(method.Body);
}
#endregion Change all short branches to long because code modifications can add code
#region Modify method body to change all returns into assignments and branch to unified exit
// now modify the method body to change all return statements
// into assignments to the local "result" and a branch to a
// block at the end that can check the post-condition using
// "result" and then finally return it.
// [MAF] we do it later once we know if the branches are leaves or just branch.
Local result = null;
if (!HelperMethods.IsVoidType(method.ReturnType)) {
// don't write huge names. The debugger chokes on them and shows no locals at all.
// result = new Local(Identifier.For("Contract.Result<" + typeName + ">()"), method.ReturnType);
result = new Local(Identifier.For("Contract.Result()"), method.ReturnType);
if (method.LocalList == null) {
method.LocalList = new LocalList();
}
method.LocalList.Add(result);
}
Block newExit = new Block(new StatementList());
#endregion Modify method body to change all returns into assignments and branch to unified exit
#region Create the new method's body
Block newBody = new Block(new StatementList());
newBody.HasLocals = true;
#endregion Create the new method's body
#region If there had been any closure initialization code, put it first in the new body
if (0 < contractInitializationBlocks.Count) {
foreach (Block b in contractInitializationBlocks) {
newBody.Statements.Add(b);
}
}
#endregion
EmitInterleavedValidationsAndRequires(method, preconditions, validations, newBody);
#region Turn off invariant checking until the end
Local oldReEntrancyFlagLocal = null;
if (MethodShouldHaveInvariantChecked(method) && this.ReentrancyFlag != null && BodyHasCalls(method.Body))
{
oldReEntrancyFlagLocal = new Local(SystemTypes.Boolean);
newBody.Statements.Add(new Block(new StatementList(
new AssignmentStatement(oldReEntrancyFlagLocal, new MemberBinding(method.ThisParameter, this.ReentrancyFlag)),
new AssignmentStatement(new MemberBinding(method.ThisParameter, this.ReentrancyFlag), Literal.True))));
}
#endregion
#region Put all of the collected initializations from "old" expressions into the method
if (oldExpressionPreStateValues.Statements.Count > 0) {
newBody.Statements.Add(oldExpressionPreStateValues);
}
#endregion
// if there are preamble blocks we need to move them from the origBody in case we will wrap a try-catch
var preambleIndex = 0;
while (origBody.Statements.Count > preambleIndex && origBody.Statements[preambleIndex] is PreambleBlock) {
newBody.Statements.Add(origBody.Statements[preambleIndex]);
origBody.Statements[preambleIndex] = null;
preambleIndex++;
}
Block newBodyBlock = new Block(new StatementList());
newBody.Statements.Add(newBodyBlock); // placeholder for eventual body
newBody.Statements.Add(newExit);
#region Replace "result" in postconditions (both for method return and out parameters)
if (result != null)
{
foreach (Ensures e in postconditions)
{
if (e == null) continue;
ReplaceResult repResult = new ReplaceResult(method, result, this.assemblyBeingRewritten);
repResult.Visit(e);
// now need to initialize closure result fields
foreach (var target in repResult.NecessaryResultInitialization(closureLocals))
{
newBody.Statements.Add(new AssignmentStatement(target, result));
}
}
}
#endregion
#region Emit potential post preamble block (from contract duplicate) in constructors
if (postPreambleBlock != null)
{
newBody.Statements.Add(postPreambleBlock);
}
#endregion
#region Emit normal postconditions
SourceContext lastEnsuresSourceContext = default(SourceContext);
bool hasLastEnsuresContext = false;
bool containsExceptionalPostconditions = false;
var ensuresChecks = new StatementList();
foreach (Ensures e in postconditions) {
// Exceptional postconditions are handled separately.
if (e is EnsuresExceptional) {
containsExceptionalPostconditions = true;
continue;
}
lastEnsuresSourceContext = e.SourceContext;
hasLastEnsuresContext = true;
// call Contract.RewriterEnsures
Method ensMethod = this.runtimeContracts.EnsuresMethod;
ExpressionList args = new ExpressionList();
args.Add(e.PostCondition);
if (e.UserMessage != null)
args.Add(e.UserMessage);
else
args.Add(Literal.Null);
if (e.SourceConditionText != null) {
args.Add(e.SourceConditionText);
} else {
args.Add(Literal.Null);
}
ensuresChecks.Add(new ExpressionStatement(
new MethodCall(new MemberBinding(null, ensMethod),
args, NodeType.Call, SystemTypes.Void), e.SourceContext));
}
this.cleanUpCodeCoverage.VisitStatementList(ensuresChecks);
EmitRecursionGuardAroundChecks(method, newBody, ensuresChecks);
#endregion Normal postconditions
#region Emit object invariant
if (MethodShouldHaveInvariantChecked(method)) {
// Now turn checking on by restoring old reentrancy flag
if (this.ReentrancyFlag != null && oldReEntrancyFlagLocal != null)
{
newBody.Statements.Add(new AssignmentStatement(new MemberBinding(method.ThisParameter, this.ReentrancyFlag), oldReEntrancyFlagLocal));
}
var callType = (method is InstanceInitializer) || this.InvariantMethod.DeclaringType.IsValueType ? NodeType.Call : NodeType.Callvirt;
// just add a call to the already existing invariant method, "this.InvariantMethod();"
// all of the processing needed is done as part of VisitClass
newBody.Statements.Add(
new ExpressionStatement(
new MethodCall(
new MemberBinding(method.ThisParameter, this.InvariantMethod), null, callType, SystemTypes.Void)));
}
#endregion Object invariant
#region Emit exceptional postconditions
ReplaceReturns rr;
if (containsExceptionalPostconditions)
{
// -- The following code comes from System.Compiler.Normalizer.CreateTryCatchBlock --
// The tryCatch holds the try block, the catch blocks, and an empty block that is the
// target of an unconditional branch for normal execution to go from the try block
// around the catch blocks.
if (method.ExceptionHandlers == null) method.ExceptionHandlers = new ExceptionHandlerList();
Block afterCatches = new Block(new StatementList());
Block tryCatch = newBodyBlock;
Block tryBlock = new Block(new StatementList());
tryBlock.Statements.Add(origBody);
rr = new ReplaceReturns(result, newExit, leaveExceptionBody:true);
rr.Visit(origBody);
tryBlock.Statements.Add(new Branch(null, afterCatches, false, true, true));
// the EH needs to have a pointer to this block so the writer can
// calculate the length of the try block. So it should be the *last*
// thing in the try body.
Block blockAfterTryBody = new Block(null);
tryBlock.Statements.Add(blockAfterTryBody);
tryCatch.Statements.Add(tryBlock);
for (int i = 0, n = postconditions.Count; i < n; i++)
{
// Normal postconditions are handled separately.
EnsuresExceptional e = postconditions[i] as EnsuresExceptional;
if (e == null)
continue;
// The catchBlock contains the catchBody, and then
// an empty block that is used in the EH.
Block catchBlock = new Block(new StatementList());
Local l = new Local(e.Type);
Throw rethrow = new Throw();
rethrow.NodeType = NodeType.Rethrow;
// call Contract.RewriterEnsures
ExpressionList args = new ExpressionList();
args.Add(e.PostCondition);
if (e.UserMessage != null)
args.Add(e.UserMessage);
else
args.Add(Literal.Null);
if (e.SourceConditionText != null)
{
args.Add(e.SourceConditionText);
}
else
{
args.Add(Literal.Null);
}
args.Add(l);
var checks = new StatementList();
checks.Add(new ExpressionStatement(
new MethodCall(new MemberBinding(null, this.runtimeContracts.EnsuresOnThrowMethod),
args, NodeType.Call, SystemTypes.Void), e.SourceContext));
catchBlock.Statements.Add(new AssignmentStatement(l, new Expression(NodeType.Pop), e.SourceContext));
this.cleanUpCodeCoverage.VisitStatementList(checks);
EmitRecursionGuardAroundChecks(method, catchBlock, checks);
#region Emit object invariant on EnsuresOnThrow check
if (MethodShouldHaveInvariantChecked(method, inExceptionCase: true))
{
// Now turn checking on by restoring old reentrancy flag
if (this.ReentrancyFlag != null && oldReEntrancyFlagLocal != null)
{
catchBlock.Statements.Add(new AssignmentStatement(new MemberBinding(method.ThisParameter, this.ReentrancyFlag), oldReEntrancyFlagLocal));
}
// just add a call to the already existing invariant method, "this.InvariantMethod();"
// all of the processing needed is done as part of VisitClass
catchBlock.Statements.Add(
new ExpressionStatement(
new MethodCall(
new MemberBinding(method.ThisParameter, this.InvariantMethod), null, NodeType.Call, SystemTypes.Void)));
}
#endregion Object invariant
catchBlock.Statements.Add(rethrow);
// The last thing in each catch block is an empty block that is the target of
// BlockAfterHandlerEnd in each exception handler.
// It is used in the writer to determine the length of each catch block
// so it should be the last thing added to each catch block.
Block blockAfterHandlerEnd = new Block(new StatementList());
catchBlock.Statements.Add(blockAfterHandlerEnd);
tryCatch.Statements.Add(catchBlock);
// add information to the ExceptionHandlers of this method
ExceptionHandler exHandler = new ExceptionHandler();
exHandler.TryStartBlock = origBody;
exHandler.BlockAfterTryEnd = blockAfterTryBody;
exHandler.HandlerStartBlock = catchBlock;
exHandler.BlockAfterHandlerEnd = blockAfterHandlerEnd;
exHandler.FilterType = l.Type;
exHandler.HandlerType = NodeType.Catch;
method.ExceptionHandlers.Add(exHandler);
}
tryCatch.Statements.Add(afterCatches);
}
else // no exceptional post conditions
{
newBodyBlock.Statements.Add(origBody);
rr = new ReplaceReturns(result, newExit, leaveExceptionBody: false);
rr.Visit(origBody);
}
#endregion Exceptional and finally postconditions
#region Create a block for the return statement and insert it
// this is the block that contains the return statements
// it is (supposed to be) the single exit from the method
// that way, anything that must always be done can be done
// in this block
Block returnBlock = new Block(new StatementList(1));
if (asyncPostconditions != null && asyncPostconditions.Count > 0)
{
asyncBuilder.AddAsyncPost(asyncPostconditions);
var funcLocal = new Local(asyncBuilder.FuncCtor.DeclaringType);
var ldftn = new UnaryExpression(new MemberBinding(null, asyncBuilder.CheckMethod), NodeType.Ldftn, CoreSystemTypes.IntPtr);
returnBlock.Statements.Add(new AssignmentStatement(funcLocal, new Construct(new MemberBinding(null, asyncBuilder.FuncCtor), new ExpressionList(asyncBuilder.ClosureLocal, ldftn))));
returnBlock.Statements.Add(new AssignmentStatement(result, new MethodCall(new MemberBinding(result, asyncBuilder.ContinueWithMethod), new ExpressionList(funcLocal))));
}
Statement returnStatement;
if (!HelperMethods.IsVoidType(method.ReturnType)) {
returnStatement = new Return(result);
}
else
{
returnStatement = new Return();
}
if (hasLastEnsuresContext)
{
returnStatement.SourceContext = lastEnsuresSourceContext;
}
else
{
returnStatement.SourceContext = rr.LastReturnSourceContext;
}
returnBlock.Statements.Add(returnStatement);
newBody.Statements.Add(returnBlock);
#endregion
method.Body = newBody;
#region Make sure InitLocals is marked for this method
// 15 April 2003
// Since each method has locals added to it, need to make sure this flag is
// on. Otherwise, the generated code cannot pass peverify.
if (!method.InitLocals) {
method.InitLocals = true;
//WriteToLog("Setting InitLocals for method: {0}", method.FullName);
}
#endregion
}
public void AddAsyncPost(List<Ensures> asyncPostconditions)
{
var origBody = new Block(this.checkBody);
origBody.HasLocals = true;
var newBodyBlock = new Block(new StatementList());
newBodyBlock.HasLocals = true;
var methodBody = new StatementList();
var methodBodyBlock = new Block(methodBody);
methodBodyBlock.HasLocals = true;
checkMethod.Body = methodBodyBlock;
methodBody.Add(newBodyBlock);
Block newExitBlock = new Block();
methodBody.Add(newExitBlock);
#region Map closure locals to fields and initialize closure fields
foreach (Ensures e in asyncPostconditions)
{
if (e == null) continue;
this.Visit(e);
if (this.forwarder != null) { this.forwarder.Visit(e); }
ReplaceResult repResult = new ReplaceResult(this.checkMethod, this.originalResultLocal, this.parent.assemblyBeingRewritten);
repResult.Visit(e);
// now need to initialize closure result fields
foreach (var target in repResult.NecessaryResultInitializationAsync(this.closureLocals))
{
// note: target here
methodBody.Add(new AssignmentStatement(target, this.originalResultLocal));
}
}
#endregion
#region Emit normal postconditions
SourceContext lastEnsuresSourceContext = default(SourceContext);
bool hasLastEnsuresContext = false;
bool containsExceptionalPostconditions = false;
var ensuresChecks = new StatementList();
foreach (Ensures e in asyncPostconditions)
{
// Exceptional postconditions are handled separately.
if (e is EnsuresExceptional)
{
containsExceptionalPostconditions = true;
continue;
}
if (IsVoidTask()) break; // something is wrong in the original contract
lastEnsuresSourceContext = e.SourceContext;
hasLastEnsuresContext = true;
// call Contract.RewriterEnsures
Method ensMethod = this.parent.runtimeContracts.EnsuresMethod;
ExpressionList args = new ExpressionList();
args.Add(e.PostCondition);
if (e.UserMessage != null)
args.Add(e.UserMessage);
else
args.Add(Literal.Null);
if (e.SourceConditionText != null)
{
args.Add(e.SourceConditionText);
}
else
{
args.Add(Literal.Null);
}
ensuresChecks.Add(new ExpressionStatement(
new MethodCall(new MemberBinding(null, ensMethod),
args, NodeType.Call, SystemTypes.Void), e.SourceContext));
}
this.parent.cleanUpCodeCoverage.VisitStatementList(ensuresChecks);
this.parent.EmitRecursionGuardAroundChecks(this.checkMethod, methodBodyBlock, ensuresChecks);
#endregion Normal postconditions
#region Exceptional postconditions
if (containsExceptionalPostconditions)
{
// Because async tasks wrap exceptions into Aggregate exceptions, we have to catch AggregateException
// and iterate over the internal exceptions of the Aggregate.
// We thus emit the following handler:
//
// catch(AggregateException ae) {
// ae.Handle(this.CheckException);
// rethrow;
// }
//
// alternatively, if the Task has no Result, we emit
//
// var ae = t.Exception as AggregateException;
// if (ae != null) {
// ae.Handle(this.CheckException);
// throw ae;
// }
var aggregateType = AggregateExceptionType.Value;
var exnParameter = new Parameter(Identifier.For("e"), SystemTypes.Exception);
this.checkExceptionMethod = new Method(this.closureClass, null, this.checkExceptionMethodId, new ParameterList(exnParameter), SystemTypes.Boolean, new Block(new StatementList()));
this.checkExceptionMethod.Body.HasLocals = true;
checkExceptionMethod.CallingConvention = CallingConventionFlags.HasThis;
checkExceptionMethod.Flags |= MethodFlags.Public;
this.closureClass.Members.Add(checkExceptionMethod);
if (this.IsVoidTask())
{
var blockAfterTest = new Block();
methodBody.Add(origBody);
methodBody.Add(new Branch(new UnaryExpression(this.newResultLocal, NodeType.LogicalNot), blockAfterTest));
var funcType = Func2Type.Value;
funcType = funcType.GetTemplateInstance(this.parent.assemblyBeingRewritten, SystemTypes.Exception, SystemTypes.Boolean);
var handleMethod = aggregateType.GetMethod(Identifier.For("Handle"), funcType);
var funcLocal = new Local(funcType);
var ldftn = new UnaryExpression(new MemberBinding(null, this.checkExceptionMethod), NodeType.Ldftn, CoreSystemTypes.IntPtr);
methodBody.Add(new AssignmentStatement(funcLocal, new Construct(new MemberBinding(null, funcType.GetConstructor(SystemTypes.Object, SystemTypes.IntPtr)), new ExpressionList(this.checkMethod.ThisParameter, ldftn))));
methodBody.Add(new ExpressionStatement(new MethodCall(new MemberBinding(this.newResultLocal, handleMethod), new ExpressionList(funcLocal))));
methodBody.Add(new Throw(this.newResultLocal));
methodBody.Add(blockAfterTest);
}
else
{
// The tryCatch holds the try block, the catch blocks, and an empty block that is the
// target of an unconditional branch for normal execution to go from the try block
// around the catch blocks.
if (this.checkMethod.ExceptionHandlers == null) this.checkMethod.ExceptionHandlers = new ExceptionHandlerList();
Block afterCatches = new Block(new StatementList());
Block tryCatch = newBodyBlock;
Block tryBlock = new Block(new StatementList());
tryBlock.Statements.Add(origBody);
tryBlock.Statements.Add(new Branch(null, afterCatches, false, true, true));
// the EH needs to have a pointer to this block so the writer can
// calculate the length of the try block. So it should be the *last*
// thing in the try body.
Block blockAfterTryBody = new Block(null);
tryBlock.Statements.Add(blockAfterTryBody);
tryCatch.Statements.Add(tryBlock);
// The catchBlock contains the catchBody, and then
// an empty block that is used in the EH.
Block catchBlock = new Block(new StatementList());
Local l = new Local(aggregateType);
Throw rethrow = new Throw();
rethrow.NodeType = NodeType.Rethrow;
catchBlock.Statements.Add(new AssignmentStatement(l, new Expression(NodeType.Pop)));
var funcType = Func2Type.Value;
funcType = funcType.GetTemplateInstance(this.parent.assemblyBeingRewritten, SystemTypes.Exception, SystemTypes.Boolean);
var handleMethod = aggregateType.GetMethod(Identifier.For("Handle"), funcType);
var funcLocal = new Local(funcType);
var ldftn = new UnaryExpression(new MemberBinding(null, this.checkExceptionMethod), NodeType.Ldftn, CoreSystemTypes.IntPtr);
catchBlock.Statements.Add(new AssignmentStatement(funcLocal, new Construct(new MemberBinding(null, funcType.GetConstructor(SystemTypes.Object, SystemTypes.IntPtr)), new ExpressionList(this.checkMethod.ThisParameter, ldftn))));
catchBlock.Statements.Add(new ExpressionStatement(new MethodCall(new MemberBinding(l, handleMethod), new ExpressionList(funcLocal))));
// Handle method should return if all passes
catchBlock.Statements.Add(rethrow);
// The last thing in each catch block is an empty block that is the target of
// BlockAfterHandlerEnd in each exception handler.
// It is used in the writer to determine the length of each catch block
// so it should be the last thing added to each catch block.
Block blockAfterHandlerEnd = new Block(new StatementList());
catchBlock.Statements.Add(blockAfterHandlerEnd);
tryCatch.Statements.Add(catchBlock);
// add information to the ExceptionHandlers of this method
ExceptionHandler exHandler = new ExceptionHandler();
exHandler.TryStartBlock = origBody;
exHandler.BlockAfterTryEnd = blockAfterTryBody;
exHandler.HandlerStartBlock = catchBlock;
exHandler.BlockAfterHandlerEnd = blockAfterHandlerEnd;
exHandler.FilterType = l.Type;
exHandler.HandlerType = NodeType.Catch;
this.checkMethod.ExceptionHandlers.Add(exHandler);
tryCatch.Statements.Add(afterCatches);
}
EmitCheckExceptionBody(asyncPostconditions);
}
else // no exceptional post conditions
{
newBodyBlock.Statements.Add(origBody);
}
#endregion Exceptional and finally postconditions
#region Create a block for the return statement and insert it
// this is the block that contains the return statements
// it is (supposed to be) the single exit from the method
// that way, anything that must always be done can be done
// in this block
Statement returnStatement;
if (this.IsVoidTask())
{
returnStatement = new Return();
}
else
{
returnStatement = new Return(this.newResultLocal);
}
if (hasLastEnsuresContext)
{
returnStatement.SourceContext = lastEnsuresSourceContext;
}
Block returnBlock = new Block(new StatementList(1));
returnBlock.Statements.Add(returnStatement);
methodBody.Add(returnBlock);
#endregion
}
public override Statement VisitThrow(Throw Throw)
{
if (Throw == null) return null;
if (!(Throw.Expression is Identifier))
{
this.HandleError(Throw.Expression, Error.InvalidExceptionExpression);
return null;
}
AddExceptionName(((Identifier)Throw.Expression).Name);
return Throw;
}
public override Statement VisitThrow(Throw Throw)
{
if (Throw == null) return null;
return base.VisitThrow((Throw)Throw.Clone());
}
private Throw ParseThrow(TokenSet followers){
Throw Throw = new Throw();
Throw.SourceContext = this.scanner.CurrentSourceContext;
Debug.Assert(this.currentToken == Token.Throw);
this.GetNextToken();
if (this.currentToken != Token.Semicolon){
Expression expr = Throw.Expression = this.ParseExpression(followers|Token.Semicolon);
if (expr != null)
Throw.SourceContext.EndPos = expr.SourceContext.EndPos;
}
this.SkipSemiColon(followers);
return Throw;
}
public override Statement VisitThrow(Throw Throw)
{
if (Throw == null) return null;
return Throw;
}
/// <param name="Throw">Cloned</param>
public override Statement VisitThrow(Throw Throw)
{
Throw = (Throw)Throw.Clone();
if (Throw.Expression != null)
{
Throw.Expression = simplify(Throw.Expression);
}
return Throw;
}
public override Statement VisitThrow(Throw Throw)
{
this.lastBranchWasUnconditional = true;
return Throw;
}
// After they have been duplicated for each "leave" instruction, the "finally"
// handlers are transformed into catch handlers that rethrow their exceptions.
//
public void ConvertFinallyHandlerIntoCatchHandler () {
foreach (ExceptionHandler eh in this.allExceptionHandlers) {
if (eh.HandlerType == NodeType.Finally ||
eh.HandlerType == NodeType.FaultHandler) {
// transform the finally / fault handler into a catch handler ...
eh.HandlerType = NodeType.Catch;
// ... that catches all exceptions ... (cont'd at alpha)
// (btw: in MSIL, one can throw any object, including non-Exceptions)
eh.FilterType = Cci.SystemTypes.Object;
// variable to store the caught exception (we can't leave it on the stack because the
// code of the original finally handler must start with an empty stack).
Variable exceptionVariable = new Local(new Identifier(FINALLYVARPREFIX + (finally_var_count++)), eh.FilterType);
// the new catch handler must start with FINALLYVARPREFIX<n> := EPOP ...
Block firstBlock = eh.HandlerStartBlock;
StatementList stats = firstBlock.Statements;
StatementList newBlockStatements = new StatementList();
AssignmentStatement exceptionAssignment =
new AssignmentStatement(exceptionVariable, new Expression(NodeType.Pop));
if (stats.Count > 0) {
exceptionAssignment.SourceContext = stats[0].SourceContext;
exceptionAssignment.Source.SourceContext = stats[0].SourceContext;
}
newBlockStatements.Add(exceptionAssignment);
for(int i = 0; i < stats.Count; i++) {
newBlockStatements.Add(stats[i]);
}
firstBlock.Statements = newBlockStatements;
// (alpha) ... and rethrows the exception.
// replace the last instruction of eh with a throw exceptionVariable
Block lastBlock = (Block) this.lastHandledBlock[eh];
Statement lastStatement = lastBlock.Statements[lastBlock.Statements.Count - 1];
if (lastStatement is EndFinally) {
// replace the endfinally with a rethrow; this is OK because (re)throw flushes the stack too.
Statement throwStatement;
{
#if EXPLICIT_THROW_OF_CAPTURED_VARIABLE_RATHER_THAN_RETHROW_IN_FINALLY_EXPANDED_CATCH
if (false) // for now
{
throwStatement = new Throw(exceptionVariable);
}
else
#endif
throwStatement = new Throw(null);
throwStatement.NodeType = NodeType.Rethrow;
}
throwStatement.SourceContext = lastBlock.Statements[lastBlock.Statements.Count - 1].SourceContext;
lastBlock.Statements[lastBlock.Statements.Count - 1] = throwStatement;
}
else {
Debug.Assert(lastStatement is Throw,
"finally/fault not terminated in endfinally/endfault or throw! " +
CodePrinter.StatementToString(lastBlock.Statements[lastBlock.Statements.Count - 1]));
}
}
}
}
public override Statement VisitThrow(Throw Throw)
{
Statement setExceptionStmt = Templates.GetStatementTemplate("SetException");
Debug.Assert(Throw.Expression is Identifier);
Replacer.Replace(setExceptionStmt, "_exception", Throw.Expression);
BasicBlock raiseBlock = new BasicBlock(null);
raiseBlock.SkipNormalizer = true;
raiseBlock.SourceContext = Throw.SourceContext;
raiseBlock.MiddleOfTransition = true;
AddBlock(raiseBlock);
if (this.CurrentHandlerBlock != null)
{
// If we have a handler, pass control locally
raiseBlock.Statement = setExceptionStmt;
raiseBlock.UnconditionalTarget = this.CurrentHandlerBlock;
}
else
{
// No local handler, so propagate outward immediately.
Block b = new Block(new StatementList());
b.Statements.Add(setExceptionStmt);
b.Statements.Add(Templates.GetStatementTemplate("PropagateException"));
raiseBlock.Statement = b;
raiseBlock.PropagatesException = true;
}
CurrentContinuation = raiseBlock;
return Throw;
}
public override Statement VisitThrow(Throw Throw)
{
// The base Checker will complain that we haven't resolved Throw.Expression
// but for us that's ok because exceptions are just names.
return Throw;
}
public override Statement VisitThrow(Throw Throw)
{
WriteStart("throw");
if (Throw.Expression != null)
{
Write(" ");
this.VisitExpression(Throw.Expression);
}
WriteFinish(";");
return Throw;
}
public EventingVisitor(Action<Throw> visitThrow) { VisitedThrow += visitThrow; } public event Action<Throw> VisitedThrow; public override Statement VisitThrow(Throw Throw) { if (VisitedThrow != null) VisitedThrow(Throw); return base.VisitThrow(Throw); }
