private static Getter?GetGetterForMethod(
Compilation compilation,
SerializerTypes types,
ITypeSymbol rowType,
IMethodSymbol method,
Location?location,
ref ImmutableArray <Diagnostic> diags
)
{
if (method.MethodKind != MethodKind.Ordinary)
{
var diag = Diagnostics.MethodMustBeOrdinary(location, method);
diags = diags.Add(diag);
return(null);
}
var methodReturnType = method.ReturnType;
if (methodReturnType.SpecialType == SpecialType.System_Void)
{
var diag = Diagnostics.MethodMustReturnNonVoid(location, method);
diags = diags.Add(diag);
return(null);
}
if (method.IsGenericMethod)
{
var diag = Diagnostics.MethodCannotBeGeneric(location, method);
diags = diags.Add(diag);
return(null);
}
bool takesContext;
bool takesRow;
if (method.IsStatic)
{
// 0 parameters are allow
// if there is 1 parameter, it may be an `in WriteContext` or the row type
// if there are 2 parameters, the first must be the row type, and the second must be `in WriteContext`
var ps = method.Parameters;
if (ps.Length == 0)
{
takesContext = false;
takesRow = false;
}
else if (ps.Length == 1)
{
var p0 = ps[0];
if (p0.IsInWriteContext(types.OurTypes))
{
takesContext = true;
takesRow = false;
}
else if (p0.IsNormalParameterOfType(compilation, rowType))
{
takesContext = false;
takesRow = true;
}
else
{
var diag = Diagnostics.BadGetterParameters_StaticOne(location, method, rowType);
diags = diags.Add(diag);
return(null);
}
}
else if (ps.Length == 2)
{
var p0 = ps[0];
if (!p0.IsNormalParameterOfType(compilation, rowType))
{
var diag = Diagnostics.BadGetterParameters_StaticTwo(location, method, rowType);
diags = diags.Add(diag);
return(null);
}
var p1 = ps[1];
if (!p1.IsInWriteContext(types.OurTypes))
{
var diag = Diagnostics.BadGetterParameters_StaticTwo(location, method, rowType);
diags = diags.Add(diag);
return(null);
}
takesContext = true;
takesRow = true;
}
else
{
var diag = Diagnostics.BadGetterParameters_TooMany(location, method);
diags = diags.Add(diag);
return(null);
}
}
else
{
// 0 is allowed
// if it takes a parameter, it must be an `in WriteContext`
takesRow = false;
var ps = method.Parameters;
if (ps.Length == 0)
{
takesContext = false;
}
else if (ps.Length == 1)
{
var p0 = ps[0];
if (!p0.IsInWriteContext(types.OurTypes))
{
var diag = Diagnostics.BadGetterParameters_InstanceOne(location, method);
diags = diags.Add(diag);
return(null);
}
takesContext = true;
}
else
{
var diag = Diagnostics.BadGetterParameters_TooMany(location, method);
diags = diags.Add(diag);
return(null);
}
}
return(new Getter(method, takesRow, takesContext));
}
