[PATCH] D107450: [clang-tidy] Fix wrong FIxIt in performance-move-const-arg

[Arthur O'Dwyer via Phabricator via cfe-commits]

Quuxplusone added inline comments.


================
Comment at: clang-tools-extra/test/clang-tidy/checkers/performance-move-const-arg.cpp:263
+  forwardToShowInt(std::move(a));
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: std::move of the variable 'a' of the trivially-copyable type 'int' has no effect; consider changing forwardToShowInt's parameter from 'int'&& to 'int'&
+}
----------------
`forwardToShowInt` takes `T&&`, not `int&&`, and so it can't be changed in the way the diagnostic is suggesting. I think the right answer here is not to emit the diagnostic at all, when the offending function is a template.

(Relatively minor nits, all moot because this diagnostic should not be emitted at all: `'int'&&` should be `'int&&'`, `trivially copyable` should not be hyphenated, and `int&` is a strictly worse suggestion than either `const int&` or plain `int`.  IMVHO it would be reasonable to land a very trivial patch to remove the hyphen from `trivially copyable` and update the tests, and then rebase this PR on top of that.)


================
Comment at: clang-tools-extra/test/clang-tidy/checkers/performance-move-const-arg.cpp:271
+  showTmp(std::move(t));
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: std::move of the variable 't' of the trivially-copyable type 'Tmp' has no effect; remove std::move()
+}
----------------
This is precisely the bogus message you're trying to eliminate, isn't it? Removing `std::move` would make the code fail to compile because `t` is an lvalue but `showTmp` requires an rvalue.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107450/new/

https://reviews.llvm.org/D107450