[PATCH] Option parsing: support case-insensitive option matching.

[Hans Wennborg]

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Comment at: lib/Option/OptTable.cpp:213
@@ -211,3 +212,3 @@
   // Search for the first next option which could be a prefix.
   Start = std::lower_bound(Start, End, Name.data());
 
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I'm worried about how the sort order of the table interacts with case-insensitive options.

The option parser will do a binary search into the option table to find a matching option. If the option in the table is spelled in uppercase (e.g. Foo), but the user supplies a lower-case argument (e.g. foo), the binary search will go too far into the table, since f comes after F, and the option will not be found.

Maybe this can be fixed by making the sort order of the table based on case-insensitive comparison, and use a case-insensitive comparator for the binary search.

Or, if all options in a table are to be matched case-insensitively, maybe it would be easier to add that as a flag to the whole option table, assert that all options in the table are spelled in lower-case if that flag is true, and just transform arguments to lowercase when trying to match them?


http://llvm-reviews.chandlerc.com/D1485