private static IList<SyntaxNode> CreateGetHashCodeMethodStatements(
SyntaxGenerator factory,
Compilation compilation,
INamedTypeSymbol containingType,
IList<ISymbol> members,
CancellationToken cancellationToken)
{
const string HashCodeName = "hashCode";
// -1521134295
var permuteValue = factory.NegateExpression(
factory.LiteralExpression(1521134295));
var statements = new List<SyntaxNode>();
var hashCodeNameExpression = factory.IdentifierName(HashCodeName);
var firstHashValue = ComputeHashValue(factory, compilation, members[0]);
if (members.Count == 1)
{
#if false
return this.S1.GetHashCode();
#endif
statements.Add(factory.ReturnStatement(firstHashValue));
}
else
{
#if false
var hashCode = this.S1.GetHashCode();
#endif
statements.Add(factory.LocalDeclarationStatement(HashCodeName, firstHashValue));
for (var i = 1; i < members.Count; i++)
{
#if false
hashCode = hashCode * 0xA5555529 + value
#endif
statements.Add(factory.ExpressionStatement(
factory.AssignmentStatement(hashCodeNameExpression,
factory.AddExpression(
factory.MultiplyExpression(hashCodeNameExpression, permuteValue),
ComputeHashValue(factory, compilation, members[i])))));
}
#if false
return hashCode;
#endif
statements.Add(factory.ReturnStatement(hashCodeNameExpression));
}
return statements;
}