[PATCH] D137205: [clang-tidy] Add performance-unnecessary-copy-on-last-use check

[Aaron Gokaslan via Phabricator via cfe-commits]

Skylion007 added a comment.

The main false positive I also keep seeing is in pybind11 where it suggests call an std::move() for an implicit conversion, but the target of the implicit conversion does not have an rvalue. (In this case, we have a py::object which inherits from py::handle, and is just py::handle with ownership semantics. This allows implicit conversion to a reference at anytime, and therefore std::move has no effect here except to complicate the code a bit.



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Comment at: clang-tools-extra/clang-tidy/performance/UnnecessaryCopyOnLastUseCheck.cpp:114-115
+static Usage definiteLastUse(ASTContext *Context, CFG *const TheCFG,
+                             DeclRefExpr const *DeclRef) {
+  assert(TheCFG != nullptr);
+
----------------
This assertion is not valid. The crash I linked above is due to "TheCFG" sometimes being null unfortunately. Making it return Usage::Error stops the crash at least. Seems to happen when it cannot find an include . 




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https://reviews.llvm.org/D137205