static bool GetRootEntityTypeFromLinqQuery(ExpressionSyntax expr, SyntaxNodeAnalysisContext context, EFUsageContext efContext, out EFCodeFirstClassInfo clsInfo)
{
clsInfo = null;
// from $var in ???
var memberExpr = expr as MemberAccessExpressionSyntax;
var ident = expr as IdentifierNameSyntax;
if (memberExpr != null) //??? = $ident.$prop
{
return(LinqExpressionValidator.MemberAccessIsAccessingDbContext(memberExpr, context, efContext, out clsInfo));
}
else if (ident != null)
{
var si = context.SemanticModel.GetSymbolInfo(ident);
var local = si.Symbol as ILocalSymbol;
if (local != null)
{
var nts = local.Type as INamedTypeSymbol;
if (nts != null && nts.TypeArguments.Length == 1)
{
var typeArg = nts.TypeArguments[0];
clsInfo = efContext.GetClassInfo(typeArg);
if (clsInfo != null)
{
return(LinqExpressionValidator.SymbolCanBeTracedBackToDbContext(local, context, efContext, clsInfo));
}
}
}
}
return(false);
}
public static Dictionary <string, ContextualLinqParameter> BuildContext(QueryExpressionSyntax query, SyntaxNodeAnalysisContext context, EFUsageContext efContext)
{
var cparams = new Dictionary <string, ContextualLinqParameter>();
//From x
var fromExpr = query.FromClause.Identifier;
//in <expr>
var inExpr = query.FromClause.Expression;
string name = fromExpr.ValueText;
var memberExpr = inExpr as MemberAccessExpressionSyntax;
if (memberExpr != null)
{
EFCodeFirstClassInfo cls;
if (LinqExpressionValidator.MemberAccessIsAccessingDbContext(memberExpr, context, efContext, out cls))
{
cparams[name] = new ContextualLinqParameter(name, cls);
}
}
//Still not set, just set as a contextual parameter with no known type
if (!cparams.ContainsKey(name))
{
cparams[name] = new ContextualLinqParameter(name);
}
return(cparams);
}
private static void AnalyzeQueryExpression(SyntaxNodeAnalysisContext context, EFUsageContext efContext, QueryExpressionSyntax query)
{
//I can't believe how much easier this is compared to Extension Method syntax! Then again
//query syntax does mean its own dedicated set of C# keywords, which would means its own
//dedicated set of syntax node types
//First item on checklist, find out our root queryable
EFCodeFirstClassInfo cls;
bool isConnectedToDbContext = GetRootEntityTypeFromLinqQuery(query.FromClause.Expression, context, efContext, out cls);
if (cls != null)
{
bool treatAsWarning = !isConnectedToDbContext;
var paramNodes = ContextualLinqParameter.BuildContext(query, context, efContext);
var descendants = query.Body.DescendantNodes();
LinqExpressionValidator.ValidateLinqToEntitiesUsageInSyntaxNodes(descendants, cls, context, efContext, paramNodes, treatAsWarning);
}
}
private static void AnalyzeLambdaInLinqExpression(SyntaxNodeAnalysisContext context, EFUsageContext efContext, LambdaExpressionSyntax lambda)
{
var lambdaAssign = lambda.Parent as EqualsValueClauseSyntax;
var arg = lambda.Parent as ArgumentSyntax;
if (arg != null) //The lambda in question is being passed as an argument
{
var parent = arg.Parent;
while (parent != null && !(parent is ArgumentListSyntax))
{
parent = parent.Parent;
}
if (parent != null) //Which should be part of an ArgumentList
{
var argList = parent;
var invoc = argList?.Parent as InvocationExpressionSyntax;
if (invoc != null) //Which should be part of an invocation
{
var memberExpr = invoc.Expression as MemberAccessExpressionSyntax;
if (memberExpr != null)
{
if (CanonicalMethodNames.IsLinqOperator(memberExpr?.Name?.Identifier.ValueText))
{
var si = context.SemanticModel.GetSymbolInfo(memberExpr.Expression);
var lts = si.Symbol as ILocalSymbol;
var pts = si.Symbol as IPropertySymbol;
//Is this method called on a property?
if (pts != null)
{
var nts = pts.Type as INamedTypeSymbol;
if (nts != null)
{
//Like a DbSet<T>?
if (nts.IsDbSet())
{
//That is part of a class derived from DbContext?
if (pts?.ContainingType?.BaseType?.Name == EFSpecialIdentifiers.DbContext)
{
var typeArg = nts.TypeArguments[0];
//Let's give our method some assistance, by checking what T actually is
var clsInfo = efContext.GetClassInfo(typeArg);
if (clsInfo != null)
{
//Okay now let's see if this lambda is valid in the EF context
LinqExpressionValidator.ValidateLinqToEntitiesExpression(lambda, clsInfo, context, efContext);
}
}
}
}
}
else if (lts != null) //The linq method was called on a local variable
{
var nts = lts.Type as INamedTypeSymbol;
if (nts != null && nts.TypeArguments.Length == 1)
{
//This is some generic type with one type argument
var typeArg = nts.TypeArguments[0];
var clsInfo = efContext.GetClassInfo(typeArg);
if (clsInfo != null)
{
if (nts.IsDbSet())
{
//TODO: Should still actually check that it is ultimately assigned
//from a DbSet<T> property of a DbContext derived class
LinqExpressionValidator.ValidateLinqToEntitiesExpression(lambda, clsInfo, context, efContext);
}
else if (nts.IsQueryable())
{
bool treatAsWarning = !LinqExpressionValidator.SymbolCanBeTracedBackToDbContext(lts, context, efContext, clsInfo);
LinqExpressionValidator.ValidateLinqToEntitiesExpression(lambda, clsInfo, context, efContext, treatAsWarning);
}
}
}
}
}
}
}
}
}
else if (lambdaAssign != null) //The lambda in question is being assigned
{
var localLambdaDecl = lambdaAssign?.Parent?.Parent?.Parent as LocalDeclarationStatementSyntax;
if (localLambdaDecl != null)
{
var declType = localLambdaDecl?.Declaration?.Type as GenericNameSyntax;
if (declType != null)
{
//Is Expression<T>
if (declType.Identifier.ValueText == EFSpecialIdentifiers.Expression && declType.TypeArgumentList.Arguments.Count == 1)
{
//The T is Func<TInput, TOutput>
var exprTypeArg = declType.TypeArgumentList.Arguments[0] as GenericNameSyntax;
if (exprTypeArg != null &&
exprTypeArg.Identifier.ValueText == EFSpecialIdentifiers.Func &&
exprTypeArg.TypeArgumentList.Arguments.Count == 2)
{
var inputType = exprTypeArg.TypeArgumentList.Arguments[0] as IdentifierNameSyntax;
var outputType = exprTypeArg.TypeArgumentList.Arguments[1] as PredefinedTypeSyntax;
//The TOutput in Func<TInput, TOutput> is bool
if (inputType != null && outputType != null && outputType.Keyword.ValueText == EFSpecialIdentifiers.BooleanShort)
{
var si = context.SemanticModel.GetSymbolInfo(inputType);
var ts = efContext.EntityTypes.FirstOrDefault(t => t == si.Symbol);
if (ts != null)
{
var clsInfo = efContext.GetClassInfo(ts);
if (clsInfo != null)
{
LinqExpressionValidator.ValidateLinqToEntitiesExpression(lambda, clsInfo, context, efContext);
}
}
}
}
}
}
}
}
}
