[PATCH] D140551: [include-cleaner] Don't count references to operators as uses

[Haojian Wu via Phabricator via cfe-commits]

hokein added inline comments.


================
Comment at: clang-tools-extra/include-cleaner/lib/WalkAST.cpp:69
 
+  bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *S) {
+    // Operators are always ADL extension points, by design references to them
----------------
sammccall wrote:
> Rather than override TraverseCXXOperatorCallExpr to do everything *except* call WalkUpFrom, maybe override WalkUpFromCXXOperatorCallExpr to call VisitCXXOperatorCallExpr but not WalkUpFromCallExpr? (With a comment that we don't want to treat operators as calls)
> 
> Rather than override TraverseCXXOperatorCallExpr to do everything *except* call WalkUpFrom.

Ah, not really (it is my fault that I missed to call `WalkUpFrom`, but it is not the key point) .
The key point is to traverse every child of `CXXOperatorCallExpr` *except* the operator.  E.g. for the AST node below, we don't want to traverse its first child which is the operator.

```
-CXXOperatorCallExpr 0x5591a97f5280 <col:9, col:27> 'int' '+'
    |-ImplicitCastExpr 0x5591a97f5268 <col:18> 'int (*)(string, string)' <FunctionToPointerDecay>
    | `-DeclRefExpr 0x5591a97f51e8 <col:18> 'int (string, string)' lvalue Function 0x5591a97f4878 'operator+' 'int (string, string)'
    |-CXXTemporaryObjectExpr 0x5591a97f5068 <col:9, col:16> 'string':'string' 'void () noexcept' zeroing
    `-CXXTemporaryObjectExpr 0x5591a97f51b8 <col:20, col:27>
```

I added the `WalkUpFromCXXOperatorCallExpr` back (I think it doesn't have any effect on the current code because we don't do anything on the `CXXOperatorCallExpr` hierarchy classes).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140551/new/

https://reviews.llvm.org/D140551