[PATCH] D78652: [clang-tidy] Suppress reports to similarly used parameters in 'bugprone-easily-swappable-parameters'

[Whisperity via Phabricator via cfe-commits]

whisperity added inline comments.


================
Comment at: clang-tools-extra/clang-tidy/bugprone/EasilySwappableParametersCheck.cpp:529
+/// ReturnStmts return them from the function.
+class Returned {
+  llvm::SmallVector<const ParmVarDecl *, SmallDataStructureSize> ReturnedParams;
----------------
whisperity wrote:
> aaron.ballman wrote:
> > Question: would it make sense to (someday, not now) consider output parameters similar to return statements? e.g.,
> > ```
> > void int_swap(int &foo, int &bar) {
> >   int temp = foo;
> >   foo = bar;
> >   bar = temp;
> > }
> > ```
> > As a question for today: should `co_return` should be handled similarly as `return`?
> 1. Maybe. Unfortunately, one needs to be careful with that. Originally I did implement a "5th" heuristic that dealt with ignoring parameters that had the same builtin operator used on them. However, while it silenced a few false positives, it started creating **massive** amounts of false negatives.
> (In the concrete example, I think `foo = bar` will silence them because //"appears in the same expression"//.)
> 
> 2. I don't know. It would require a deeper understanding of Coroutines themselves, and how people use them.
If you don't mind me posting images, I can show a direct example. Things where the inability to track data flow really bites us in the backside.

Examples from Apache Xerces:

Here's a false positive that would be silenced by the logic of //"using the same operateur on the two params"//.
{F15891567}

And here is a false negative from the exact same logic.
{F15891568}

Maybe it could be //some// solace that we're restricting to non-const-lvalue-references (and pointers-to-non-const ??) and only assignment (**only** assignment?!))...


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D78652/new/

https://reviews.llvm.org/D78652