Previous to clang, MSVC would warn for 64-bit size_t -> 32-bit implicit conversions under warning 4267.
With the move to clang, we lost some of these warnings. They are all tracked by parent issue 588506 as part of -Wconversion.
This bug is to track enabling the equivalent -Wshorten-64-to-32 for clang.
-Wshorten-64-to-32 is a superset of the MSVC "size_t -> 32-bit" warning because it covers all 64-bit types. It also covers 64-bit to 32-bit conversions on 32-bit (e.g. long long -> size_t on 32-bit).
As this latter implicit conversion (64->32 on 32-bit builds) was never a warning as part of previous MSVC builds, enabling this for 32-bit builds will be tracked in a future issue as it involves far more code changes.
Comment 1 by bugdroid1@chromium.org
, Aug 31