[PATCH] D60507: [clang-tidy] new check: bugprone-unhandled-self-assignment

[Tamás Zolnai via Phabricator via cfe-commits]

ztamas added a comment.

On llvm source code the check finds three suspicious methods:

  /home/zolnai/libreoffice/clang/llvm-project/clang/lib/AST/NestedNameSpecifier.cpp:534:1: warning: operator=() might not handle self-assignment properly [bugprone-unhandled-self-assignment]
  operator=(const NestedNameSpecifierLocBuilder &Other) {
  
  /home/zolnai/libreoffice/clang/llvm-project/llvm/unittests/ADT/ArrayRefTest.cpp:75:10: warning: operator=() might not handle self-assignment properly [bugprone-unhandled-self-assignment]
      void operator=(const NonAssignable &RHS) { assert(RHS.Ptr != nullptr); }
  
  /home/zolnai/libreoffice/clang/llvm-project/llvm/lib/Analysis/TargetLibraryInfo.cpp:594:47: warning: operator=() might not handle self-assignment properly [bugprone-unhandled-self-assignment]
  TargetLibraryInfoImpl &TargetLibraryInfoImpl::operator=(const TargetLibraryInfoImpl &TLI) {

Two of them seems a good catch to me. NestedNameSpecifierLocBuilder and TargetLibraryInfoImpl are using `memcpy` without self-check, and using `memcpy` on overlapping regions leads to undefined behavior.

The third one is not an actual working copy assignment operator, as I see. It is used only for some testing purposes.


Repository:
  rCTE Clang Tools Extra

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D60507/new/

https://reviews.llvm.org/D60507