// TODO: First search the moveNextBody to see if there are any contracts at all.
/// <summary>
///
/// </summary>
/// <param name="host"></param>
/// <param name="extractor"></param>
/// <param name="iteratorMethodBody"></param>
/// <param name="moveNextBody"></param>
/// <param name="pdbReader"></param>
/// <returns></returns>
public static MethodContract GetMethodContractFromMoveNext(
IContractAwareHost host,
ContractExtractor extractor,
ISourceMethodBody iteratorMethodBody,
ISourceMethodBody moveNextBody,
PdbReader pdbReader
)
{
// Walk the iterator method and collect all of the state that is assigned to fields in the iterator class
// That state needs to replace any occurrences of the fields in the contracts (if they exist...)
var iteratorStmts = new List <IStatement>(iteratorMethodBody.Block.Statements);
Dictionary <uint, IExpression> capturedThings = new Dictionary <uint, IExpression>();
// Find all of the state captured for the IEnumerable
// REVIEW: Is this state ever used in the contracts? Since they're all sitting in the MoveNext
// method, maybe they always use the IEnumerator state?
if (1 < iteratorStmts.Count)
{
// First statement should be the creation of the iterator class
int j = 1;
while (j < iteratorStmts.Count)
{
var es = iteratorStmts[j++] as IExpressionStatement;
if (es == null)
{
break;
}
var assign = es.Expression as IAssignment;
if (assign == null)
{
break;
}
var field = assign.Target.Definition as IFieldReference;
var capturedThing = assign.Source;
var k = field.InternedKey;
var spec = field as ISpecializedFieldReference;
if (spec != null)
{
k = spec.UnspecializedVersion.InternedKey;
}
capturedThings.Add(k, capturedThing);
}
}
else
{
var ret = iteratorStmts[0] as IReturnStatement;
if (ret != null)
{
var be = ret.Expression as IBlockExpression;
if (be != null)
{
var beStmts = new List <IStatement>(be.BlockStatement.Statements);
var j = 1;
while (j < beStmts.Count)
{
var es = beStmts[j++] as IExpressionStatement;
if (es == null)
{
break;
}
var assign = es.Expression as IAssignment;
if (assign == null)
{
break;
}
var field = assign.Target.Definition as IFieldReference;
var capturedThing = assign.Source;
var k = field.InternedKey;
var spec = field as ISpecializedFieldReference;
if (spec != null)
{
k = spec.UnspecializedVersion.InternedKey;
}
capturedThings.Add(k, capturedThing);
}
}
}
}
// Find all of the state captured for the IEnumerator
// That state is captured at the beginning of the IEnumerable<T>.GetEnumerator method
IMethodDefinition getEnumerator = null;
var t = moveNextBody.MethodDefinition.ContainingTypeDefinition;
foreach (IMethodImplementation methodImplementation in t.ExplicitImplementationOverrides)
{
if (methodImplementation.ImplementedMethod.Name == host.NameTable.GetNameFor("GetEnumerator"))
{
var gtir = methodImplementation.ImplementedMethod.ContainingType as IGenericTypeInstanceReference;
if (gtir != null && TypeHelper.TypesAreEquivalent(gtir.GenericType, host.PlatformType.SystemCollectionsGenericIEnumerable))
{
getEnumerator = methodImplementation.ImplementingMethod.ResolvedMethod as IMethodDefinition;
break;
}
}
}
if (getEnumerator != null)
{
IMethodBody geBody = getEnumerator.Body;
var sourceGeBody = geBody as ISourceMethodBody;
if (sourceGeBody == null)
{
sourceGeBody = Decompiler.GetCodeModelFromMetadataModel(host, geBody, pdbReader, DecompilerOptions.AnonymousDelegates);
}
foreach (var stmt in sourceGeBody.Block.Statements)
{
var es = stmt as IExpressionStatement;
if (es == null)
{
continue;
}
var assign = es.Expression as IAssignment;
if (assign == null)
{
continue;
}
var field2 = assign.Target.Definition as IFieldReference;
if (field2 == null)
{
continue;
}
var k = field2.InternedKey;
var spec = field2 as ISpecializedFieldReference;
if (spec != null)
{
k = spec.UnspecializedVersion.InternedKey;
}
var sourceBe = assign.Source as IBoundExpression;
if (sourceBe == null)
{
continue;
}
var field3 = sourceBe.Definition as IFieldReference;
if (field3 == null)
{
continue;
}
var k3 = field3.InternedKey;
var spec3 = field3 as ISpecializedFieldReference;
if (spec3 != null)
{
k3 = spec3.UnspecializedVersion.InternedKey;
}
IExpression capturedThing = null;
if (!capturedThings.TryGetValue(k3, out capturedThing))
{
continue;
}
capturedThings[k] = capturedThing;
}
}
var mc = HermansAlwaysRight.ExtractContracts(host, pdbReader, extractor, moveNextBody);
if (mc == null)
{
return(mc);
}
// substitute all field references in contract with the captured state
var replacer = new Replacer(host, capturedThings, iteratorMethodBody.MethodDefinition, moveNextBody.MethodDefinition);
replacer.RewriteChildren(mc);
if (moveNextBody.MethodDefinition.ContainingTypeDefinition.IsGeneric)
{
var genericParameterMapper = new GenericMethodParameterMapper(host, iteratorMethodBody.MethodDefinition, moveNextBody.MethodDefinition.ContainingType as INestedTypeReference);
mc = genericParameterMapper.Rewrite(mc) as MethodContract;
}
return(mc);
}