[PATCH] D47950: [clangd] FuzzyMatch: forbid tail-tail matches after a miss: [pat] !~ "panther"

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov accepted this revision.
ilya-biryukov added a comment.
This revision is now accepted and ready to land.

LGTM with a few nits. And comment requests for things that were unclear when reading the code.



================
Comment at: clangd/FuzzyMatch.cpp:269
+                   : AwfulScore,
+           MissMatchScore = allowMatch(P, W, Miss)
+                                ? PreMatch[Miss].Score + matchBonus(P, W, Miss)
----------------
NIT: maybe split into two declarations?
```
auto MatchMatchScore = ...;
auto MissMatchScore = ....;
```


================
Comment at: clangd/FuzzyMatch.h:56
   //   - GCC 4.8 complains not all values fit if the type is unsigned
   using Action = bool;
   constexpr static Action Miss = false, Match = true;
----------------
Maybe add a small doc comment for `Action`? Found myself figuring out what it is while reading this patch.


================
Comment at: clangd/FuzzyMatch.h:79
   CharRole WordRole[MaxWord]; // Word segmentation info
   int WordTypeSet;            // Bitmask of 1<<CharType
   bool WordContainsPattern;   // Simple substring check
----------------
Maybe add a doc comment that this is the union of `CharType` of all chars in the word?
Seems obvious now, but was also a bit confusing when reading the code.


Repository:
  rCTE Clang Tools Extra

https://reviews.llvm.org/D47950