/// <summary>
/// Visits the specified resource use statement.
/// </summary>
/// <param name="resourceUseStatement">The resource use statement.</param>
public override void Visit(IResourceUseStatement resourceUseStatement)
{
ResourceUseStatement mutableResourceUseStatement = new ResourceUseStatement(resourceUseStatement);
this.resultStatement = this.myCodeCopier.DeepCopy(mutableResourceUseStatement);
}
/// <summary>
/// Visits the specified resource use statement.
/// </summary>
/// <param name="resourceUseStatement">The resource use statement.</param>
/// <returns></returns>
protected virtual IStatement DeepCopy(ResourceUseStatement resourceUseStatement)
{
resourceUseStatement.ResourceAcquisitions = this.Substitute(resourceUseStatement.ResourceAcquisitions);
resourceUseStatement.Body = this.Substitute(resourceUseStatement.Body);
return resourceUseStatement;
}
/// <summary>
/// Looking for the pattern:
/// IDisposable<T> variable = e;
/// try {
/// using_body
/// } finally {
/// if (variable != null) {
/// variable.Dispose();
/// }
/// }
/// The type of the variable is *not* actually IDisposable, but some
/// type that implements IDisposable.
/// The assignment might be a local-declaration statement or else it
/// might be an assignment statement.
/// </summary>
public override void TraverseChildren(IBlockStatement block)
{
Contract.Assume(block is BlockStatement);
var decompiledBlock = (BlockStatement)block;
var statements = decompiledBlock.Statements;
for (int i = 2; i < statements.Count; ++i)
{
var tryFinally = statements[i] as TryCatchFinallyStatement;
if (tryFinally == null) continue;
var finallyBody = tryFinally.FinallyBody;
if (finallyBody == null) continue;
var finallyStatements = finallyBody.Statements;
if (tryFinally.CatchClauses.Any()) continue;
ILocalDefinition variable;
IStatement resourceAcquisition;
var variableDeclaration = statements[i - 2] as ILocalDeclarationStatement;
if (variableDeclaration == null) {
var es = statements[i - 2] as IExpressionStatement;
if (es == null) continue;
var assign = es.Expression as IAssignment;
if (assign == null) continue;
if (assign.Target.Instance != null) continue;
var loc = assign.Target.Definition as ILocalDefinition;
if (loc == null) continue;
variable = loc;
resourceAcquisition = es;
} else {
variable = variableDeclaration.LocalVariable;
resourceAcquisition = variableDeclaration;
}
// finally block either looks like:
// variable.Dispose();
// or
// if (variable != null) variable.Dispose();
// or
// iDisposableLocalVar := variable as IDisposable;
// if (iDisposableLocalVar != null) iDisposableLocalVar.Dispose();
var c = finallyStatements.Count();
if (c == 1)
{
var expression = finallyStatements.Single() as IExpressionStatement;
var isDispose = this.MatchMethodCall(expression.Expression, variable, "Dispose");
if (!isDispose) continue;
} else if (c == 3 || c == 4)
{
IBoundExpression be;
ILocalDefinition iDisposableVariable = variable;
var index = 0;
if (c == 4)
{
var es = finallyStatements.ElementAt(index++) as IExpressionStatement;
if (es == null) continue;
var assignment = es.Expression as IAssignment;
if (assignment == null) continue;
var castIfPossible = assignment.Source as ICastIfPossible;
if (castIfPossible == null) continue;
if (!TypeHelper.TypesAreEquivalent(castIfPossible.TargetType, this.IDisposable)) continue;
be = castIfPossible.ValueToCast as IBoundExpression;
if (be == null) continue;
if (be.Instance != null) continue;
if (be.Definition != variable) continue;
if (assignment.Target.Instance != null) continue;
iDisposableVariable = assignment.Target.Definition as ILocalDefinition;
if (iDisposableVariable == null) continue;
}
var conditional = finallyStatements.ElementAt(index++) as IConditionalStatement;
if (conditional == null) continue;
var expressionStatement = finallyStatements.ElementAt(index++) as IExpressionStatement;
if (expressionStatement == null) continue;
var lableledStatement = finallyStatements.ElementAt(index++) as ILabeledStatement;
if (lableledStatement == null) continue;
var equality = conditional.Condition as IEquality;
if (equality == null) continue;
be = equality.LeftOperand as IBoundExpression;
if (be == null) continue;
if (be.Instance != null) continue;
if (be.Definition != iDisposableVariable) continue;
if (!(conditional.FalseBranch is IEmptyStatement)) continue;
var gotoStatement = conditional.TrueBranch as IGotoStatement;
if (gotoStatement == null) continue;
if (gotoStatement.TargetStatement != lableledStatement) continue;
var methodCall = expressionStatement.Expression as IMethodCall;
if (methodCall == null) continue;
var ct = methodCall.MethodToCall.ContainingType;
if (!TypeHelper.TypesAreEquivalent(ct, this.IDisposable)) continue;
}
else
{
continue;
}
var resourceUse = new ResourceUseStatement()
{
Locations = tryFinally.Locations,
ResourceAcquisitions = resourceAcquisition,
Body = tryFinally.TryBody
};
statements[i] = resourceUse;
statements.RemoveAt(i - 2);
i--;
}
base.TraverseChildren(block);
}
/// <summary>
/// Visits the specified resource use statement.
/// </summary>
/// <param name="resourceUseStatement">The resource use statement.</param>
/// <returns></returns>
public virtual IStatement Visit(ResourceUseStatement resourceUseStatement)
{
resourceUseStatement.ResourceAcquisitions = Visit(resourceUseStatement.ResourceAcquisitions);
resourceUseStatement.Body = Visit(resourceUseStatement.Body);
return resourceUseStatement;
}
/// <summary>
/// Rewrites the children of the given resource usage statement.
/// </summary>
public virtual void RewriteChildren(ResourceUseStatement resourceUseStatement)
{
this.RewriteChildren((Statement)resourceUseStatement);
resourceUseStatement.ResourceAcquisitions = this.Rewrite(resourceUseStatement.ResourceAcquisitions);
resourceUseStatement.Body = this.Rewrite(resourceUseStatement.Body);
}
/// <summary>
/// Visits the specified resource use statement.
/// </summary>
/// <param name="resourceUseStatement">The resource use statement.</param>
public override void Visit(IResourceUseStatement resourceUseStatement)
{
ResourceUseStatement mutableResourceUseStatement = resourceUseStatement as ResourceUseStatement;
if (alwaysMakeACopy || mutableResourceUseStatement == null) mutableResourceUseStatement = new ResourceUseStatement(resourceUseStatement);
this.resultStatement = this.myCodeMutator.Visit(mutableResourceUseStatement);
}