private static Formatter?GetFormatter(
Compilation compilation,
AttributedMembers attrMembers,
SerializerTypes types,
ITypeSymbol toFormatType,
Location?location,
ImmutableArray <AttributeSyntax> attrs,
ref ImmutableArray <Diagnostic> diags
)
{
var formatter =
Utils.GetMethodFromAttribute(
attrMembers,
"FormatterType",
Diagnostics.FormatterTypeSpecifiedMultipleTimes,
"FormatterMethodName",
Diagnostics.FormatterMethodNameSpecifiedMultipleTimes,
Diagnostics.FormatterBothMustBeSet,
location,
attrs,
ref diags
);
if (formatter == null)
{
return(null);
}
var(type, mtd) = formatter.Value;
var formatterMtd = Utils.GetMethod(type, mtd, location, ref diags);
if (formatterMtd == null)
{
return(null);
}
if (formatterMtd.IsGenericMethod)
{
var diag = Diagnostics.MethodCannotBeGeneric(location, formatterMtd);
diags = diags.Add(diag);
return(null);
}
var accessible = formatterMtd.IsAccessible(attrMembers);
if (!accessible)
{
var diag = Diagnostics.MethodNotPublicOrInternal(location, formatterMtd);
diags = diags.Add(diag);
return(null);
}
if (!formatterMtd.IsStatic)
{
var diag = Diagnostics.MethodNotStatic(location, formatterMtd);
diags = diags.Add(diag);
return(null);
}
if (!formatterMtd.ReturnType.Equals(types.BuiltIn.Bool, SymbolEqualityComparer.Default))
{
var diag = Diagnostics.MethodMustReturnBool(location, formatterMtd);
diags = diags.Add(diag);
return(null);
}
var formatterParams = formatterMtd.Parameters;
if (formatterParams.Length != 3)
{
var diag = Diagnostics.BadFormatterParameters(location, formatterMtd, toFormatType);
diags = diags.Add(diag);
return(null);
}
var p0 = formatterParams[0];
if (!p0.IsNormalParameterOfType(compilation, toFormatType))
{
var diag = Diagnostics.BadFormatterParameters(location, formatterMtd, toFormatType);
diags = diags.Add(diag);
return(null);
}
var p1 = formatterParams[1];
if (!p1.IsInWriteContext(types.OurTypes))
{
var diag = Diagnostics.BadFormatterParameters(location, formatterMtd, toFormatType);
diags = diags.Add(diag);
return(null);
}
var p2 = formatterParams[2];
if (!p2.IsNormalParameterOfType(compilation, types.Framework.IBufferWriterOfChar))
{
var diag = Diagnostics.BadFormatterParameters(location, formatterMtd, toFormatType);
diags = diags.Add(diag);
return(null);
}
return(new Formatter(formatterMtd, toFormatType));
}