public override void Initialize(AnalysisContext context)
{
context.EnableConcurrentExecution();
context.RegisterOperationAction(
ctx =>
{
var invoke = (IInvocationOperation)ctx.Operation;
bool hasAnyConstant = invoke.Arguments.Any(x => x.Value.ConstantValue.HasValue);
if (!hasAnyConstant)
{
return;
}
if (!FormatStringHelper.TryGetFormattingParameters(invoke, out var formatArgument, out var formatArguments, null, ctx.CancellationToken))
{
return;
}
var format = (string)formatArgument.Value.ConstantValue.Value;
var parsingResult = new CompositeFormatStringParser().Parse(format);
CheckSegments(ctx, parsingResult.Segments, formatArgument.Syntax.SpanStart + 1, formatArguments);
var argUsed = new HashSet <int>();
foreach (var item in parsingResult.Segments)
{
if (!(item is FormatItem fi))
{
continue;
}
argUsed.Add(fi.Index);
}
var text = GettextCatalog.GetString("Argument is not used in format string");
for (int i = 0; i < formatArguments.Count; i++)
{
if (!argUsed.Contains(i))
{
ctx.ReportDiagnostic(Diagnostic.Create(
descriptor,
formatArguments[i].Syntax.GetLocation(),
text
));
}
}
},
OperationKind.Invocation
);
}
void AnalyzeInvocation(SyntaxNodeAnalysisContext ctx)
{
var invocationExpression = (InvocationExpressionSyntax)ctx.Node;
// Speed up the inspector by discarding some invocations early
var hasEligibleArgument = invocationExpression.ArgumentList.Arguments.Any(argument => {
var primitiveArg = argument.Expression as LiteralExpressionSyntax;
return(primitiveArg != null && primitiveArg.Token.IsKind(SyntaxKind.StringLiteralToken));
});
if (!hasEligibleArgument)
{
return;
}
var invocationResolveResult = ctx.SemanticModel.GetSymbolInfo(invocationExpression);
if (invocationResolveResult.Symbol == null)
{
return;
}
ExpressionSyntax formatArgument;
IList <ExpressionSyntax> formatArguments;
if (!FormatStringHelper.TryGetFormattingParameters(ctx.SemanticModel, invocationExpression,
out formatArgument, out formatArguments, null, ctx.CancellationToken))
{
return;
}
var primitiveArgument = formatArgument as LiteralExpressionSyntax;
if (primitiveArgument == null || !primitiveArgument.Token.IsKind(SyntaxKind.StringLiteralToken))
{
return;
}
var format = primitiveArgument.Token.ValueText;
var parsingResult = new CompositeFormatStringParser().Parse(format);
CheckSegments(ctx, parsingResult.Segments, formatArgument.SpanStart + 1, formatArguments, invocationExpression);
var argUsed = new HashSet <int> ();
foreach (var item in parsingResult.Segments)
{
var fi = item as FormatItem;
if (fi == null)
{
continue;
}
argUsed.Add(fi.Index);
}
for (int i = 0; i < formatArguments.Count; i++)
{
if (!argUsed.Contains(i))
{
ctx.ReportDiagnostic(Diagnostic.Create(
descriptor,
formatArguments[i].GetLocation(),
GettextCatalog.GetString("Argument is not used in format string")
));
}
}
}