/// <summary>
/// Parses the #elif-#else-#endif part of an #if-#elif-#else-#endif construct, starting at the character following "elif".
/// Updates the last IfDirective instance added to this.preprocessorInformation with an additional ElifPart.
/// Leaves this.fragmentIndex pointing to the start of the first line after the #endif directive.
/// Returns all source locations that are to be included in the preprocessor output. (No locations are returned if the include parameter is false.)
/// </summary>
/// <param name="include">True if the definition is part of an included block. If false, the directive is parsed but ignored. (No locations are returned.)</param>
private IEnumerable<ISourceLocation> ParseElif(bool include) {
Expression condition = this.ParseExpression();
ElifPart elif = new ElifPart(condition, this.GetSourceLocation(this.startOfCurrentLine, this.fragmentIndex-this.startOfCurrentLine));
this.preprocessorInformation.AddElif(elif);
this.SkipPastBlanksCommentAndNewLine();
bool allowElseToInclude = include;
if (include) {
include = condition.IsDefined(this.preprocessorDefinedSymbols);
if (include) allowElseToInclude = false;
}
foreach (ISourceLocation includedSourceFragment in this.ParseSection(true, true, false, include, allowElseToInclude))
yield return includedSourceFragment;
}
internal void AddElif(ElifPart elif) {
for (int i = this.directives.Count; i > 0; i--) {
IfDirective/*?*/ ifDirective = this.directives[i-1] as IfDirective;
if (ifDirective == null) continue;
ifDirective.elifs.Add(elif);
return;
}
}