private static Reset?GetReset(
Compilation compilation,
AttributedMembers attrMembers,
DeserializerTypes types,
INamedTypeSymbol rowType,
Location?location,
ImmutableArray <AttributeSyntax> attrs,
ref ImmutableArray <Diagnostic> diags
)
{
var reset =
Utils.GetMethodFromAttribute(
attrMembers,
"ResetType",
Diagnostics.ResetTypeSpecifiedMultipleTimes,
"ResetMethodName",
Diagnostics.ResetMethodNameSpecifiedMultipleTimes,
Diagnostics.ResetBothMustBeSet,
location,
attrs,
ref diags
);
if (reset == null)
{
return(null);
}
var(type, name) = reset.Value;
var resetMtd = Utils.GetMethod(type, name, location, ref diags);
if (resetMtd == null)
{
return(null);
}
var methodReturnType = resetMtd.ReturnType;
if (methodReturnType.SpecialType != SpecialType.System_Void)
{
var diag = Diagnostics.MethodMustReturnVoid(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
if (resetMtd.IsGenericMethod)
{
var diag = Diagnostics.MethodCannotBeGeneric(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
var accessible = resetMtd.IsAccessible(attrMembers);
if (!accessible)
{
var diag = Diagnostics.MethodNotPublicOrInternal(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
var ps = resetMtd.Parameters;
bool isStatic;
bool takesRow;
bool takesRowByRef;
bool takesContext;
if (resetMtd.IsStatic)
{
isStatic = true;
// Options:
// - zero parameters or
// - a single parameter of the row type or
// - a single parameter of `in ReadContext` or
// - two parameters, the first of the row type (which may be by ref) and the second of `in ReadContext`
if (ps.Length == 0)
{
// zero parameters
takesRow = false;
takesRowByRef = false;
takesContext = false;
}
else if (ps.Length == 1)
{
var p0 = ps[0];
if (p0.RefKind == RefKind.In)
{
// a single parameter of `in ReadContext`
if (!p0.IsInReadContext(types.OurTypes))
{
var diag = Diagnostics.BadResetParameters_StaticOne(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
takesRow = false;
takesRowByRef = false;
takesContext = true;
}
else if (p0.RefKind == RefKind.None)
{
// a single parameter of the row type
if (!p0.IsNormalParameterOfType(compilation, rowType))
{
var diag = Diagnostics.BadResetParameters_StaticOne(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
takesRow = true;
takesRowByRef = false;
takesContext = false;
}
else
{
var diag = Diagnostics.BadResetParameters_StaticOne(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
}
else if (ps.Length == 2)
{
// two parameters, the first of the row type (which may be by ref) and the second of `in ReadContext`
var p0 = ps[0];
if (!p0.RefKind.IsNormalOrByRef())
{
var diag = Diagnostics.BadResetParameters_StaticTwo(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
if (!p0.Type.Equals(rowType, SymbolEqualityComparer.Default))
{
var diag = Diagnostics.BadResetParameters_StaticTwo(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
var p1 = ps[1];
if (!p1.IsInReadContext(types.OurTypes))
{
var diag = Diagnostics.BadResetParameters_StaticTwo(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
takesRow = true;
takesRowByRef = p0.RefKind == RefKind.Ref;
takesContext = true;
}
else
{
var diag = Diagnostics.BadResetParameters_TooMany(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
}
else
{
isStatic = false;
// be on the row type...
var declaredOn = Utils.NonNull(resetMtd.ContainingType);
var conversion = compilation.ClassifyConversion(rowType, declaredOn);
var canConvert = conversion.IsImplicit || conversion.IsIdentity;
if (!canConvert)
{
var diag = Diagnostics.BadReset_NotOnRow(location, resetMtd, rowType);
diags = diags.Add(diag);
return(null);
}
// Options:
// - zero parameters or
// - a single `in ReadContext` parameter.
if (ps.Length == 0)
{
takesRow = true;
takesRowByRef = false;
takesContext = false;
}
else if (ps.Length == 1)
{
var p0 = ps[0];
if (!p0.IsInReadContext(types.OurTypes))
{
var diag = Diagnostics.BadResetParameters_InstanceOne(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
takesRow = true;
takesRowByRef = false;
takesContext = true;
}
else
{
var diag = Diagnostics.BadResetParameters_TooMany(location, resetMtd);
diags = diags.Add(diag);
return(null);
}
}
return(new Reset(resetMtd, isStatic, takesRow, takesRowByRef, takesContext));
}
