[PATCH] D71707: clang-tidy: new bugprone-pointer-cast-widening

[Jan Kratochvil via Phabricator via cfe-commits]

jankratochvil created this revision.
jankratochvil added reviewers: labath, alexfh, lebedev.ri.
jankratochvil added a project: clang-tools-extra.
Herald added subscribers: cfe-commits, kristof.beyls, mgorny.
Herald added a project: clang.

Check for cast of a pointer to wider (even unsigned) integer. This will sign-extend the pointer which happens on 32-bit hosts for 64-bit integers:

  void *p=(void *)0x80000000;
  printf(  "%p"        "\n",                        p ); // 0x80000000
  printf("0x%" PRIxPTR "\n",             (uintptr_t)p ); // 0x80000000
  printf("0x%" PRIx64  "\n",
                         reinterpret_cast<uint64_t>(p)); // 0xffffffff80000000
  printf("0x%" PRIx64  "\n",             (uint64_t) p ); // 0xffffffff80000000
  printf("0x%" PRIx64  "\n",   (uint64_t)(uintptr_t)p ); // 0x80000000

It has caught a bug on ARM32: D71498 <https://reviews.llvm.org/D71498> (and D71514 <https://reviews.llvm.org/D71514>)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71707

Files:
  clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
  clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
  clang-tools-extra/clang-tidy/bugprone/PointerCastWideningCheck.cpp
  clang-tools-extra/clang-tidy/bugprone/PointerCastWideningCheck.h
  clang-tools-extra/test/clang-tidy/checkers/bugprone-pointer-cast-widening.cpp

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