[PATCH] D157027: [lld-macho][nfc]Add bounds check before attempting to dereferencing iterators.

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: lld/MachO/Arch/ARM64.cpp:608
         [](uint64_t off, const Section *sec) { return off < sec->addr; }));
+    if (secIt < obj.sections.begin() || secIt > obj.sections.end() ||
+        secIt == obj.sections.end())
----------------
`secIt >= obj.sections.end()` should be impossible.

It's better to check whether the `upper_bound` result is out-of-bounds before invoking `std::prev`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157027/new/

https://reviews.llvm.org/D157027