private static ImmutableArray <AliasAndExternAliasDirective> BuildExternAliases(
SyntaxList <ExternAliasDirectiveSyntax> syntaxList,
InContainerBinder binder,
DiagnosticBag diagnostics
)
{
CSharpCompilation compilation = binder.Compilation;
var builder = ArrayBuilder <AliasAndExternAliasDirective> .GetInstance();
foreach (ExternAliasDirectiveSyntax aliasSyntax in syntaxList)
{
compilation.RecordImport(aliasSyntax);
// Extern aliases not allowed in interactive submissions:
if (compilation.IsSubmission)
{
diagnostics.Add(ErrorCode.ERR_ExternAliasNotAllowed, aliasSyntax.Location);
continue;
}
// some n^2 action, but n should be very small.
foreach (var existingAlias in builder)
{
if (existingAlias.Alias.Name == aliasSyntax.Identifier.ValueText)
{
diagnostics.Add(
ErrorCode.ERR_DuplicateAlias,
existingAlias.Alias.Locations[0],
existingAlias.Alias.Name
);
break;
}
}
if (aliasSyntax.Identifier.ContextualKind() == SyntaxKind.GlobalKeyword)
{
diagnostics.Add(
ErrorCode.ERR_GlobalExternAlias,
aliasSyntax.Identifier.GetLocation()
);
}
builder.Add(
new AliasAndExternAliasDirective(
new AliasSymbol(binder, aliasSyntax),
aliasSyntax
)
);
}
return(builder.ToImmutableAndFree());
}