[PATCH] D124726: Suggest typoed directives in preprocessor conditionals

[Ken Matsui via Phabricator via cfe-commits]

ken-matsui added inline comments.


================
Comment at: clang/include/clang/Tooling/LevDistance.h:1
+//===--- LevDistance.h ------------------------------------------*- C++ -*-===//
+//
----------------
ken-matsui wrote:
> aaron.ballman wrote:
> > You shouldn't need this file or the implementation file -- we have this functionality already in: https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/ADT/edit_distance.h and https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/ADT/StringRef.h#L240.
> I totally missed the implementations! Sorry.
> 
> But where should I put both `findSimilarStr` & `findSimilarStr`?
> It seems that their same implementations aren't there.
@aaron.ballman 

The computation results are not matched with my implementation and another language implementation.

So, several directives that could be suggested in my implementation are no longer possible to be suggested, such as `#id` -> `#if`, `#elid` -> `#elif`, and `#elsi` -> `#else`, when using `llvm::ComputeEditDistance`.

The implementation of `llvm::ComputeEditDistance` might be also correct, but some distances seem to be calculated longer, which causes fewer suggestions.

Should I keep going with this implementation or not?

---

[llvm::ComputeEditDistance](https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/ADT/edit_distance.h):

```
size_t Dist = Str1.edit_distance(Str2, false);
```

```
Str1: id, Str2: if, Dist: 2 # <-- here
Str1: id, Str2: ifdef, Dist: 3
Str1: id, Str2: ifndef, Dist: 4
Str1: ifd, Str2: if, Dist: 1
Str1: ifd, Str2: ifdef, Dist: 2
Str1: ifd, Str2: ifndef, Dist: 3
```

[My implementation](https://wandbox.org/permlink/zRjT41alOHdwcf00):

```
Str1: id, Str2: if, Dist: 1 # <-- here
Str1: id, Str2: ifdef, Dist: 3
Str1: id, Str2: ifndef, Dist: 4
Str1: ifd, Str2: if, Dist: 1
Str1: ifd, Str2: ifdef, Dist: 2
Str1: ifd, Str2: ifndef, Dist: 3
```

[Rustc implementation](https://wandbox.org/permlink/08SB08JFF5G4awx4):

```
Str1: id, Str2: if, Dist: 1 # <-- here
Str1: id, Str2: ifdef, Dist: 3
Str1: id, Str2: ifndef, Dist: 4
Str1: ifd, Str2: if, Dist: 1
Str1: ifd, Str2: ifdef, Dist: 2
Str1: ifd, Str2: ifndef, Dist: 3
```


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D124726