[PATCH] D131528: [Clang] Restrict non fixed enum to a value outside the range of the enumeration values warning to context requiring a constant expression

[Erich Keane via Phabricator via cfe-commits]

erichkeane added a comment.

In D131528#3715217 <https://reviews.llvm.org/D131528#3715217>, @mstorsjo wrote:

> There are still some cases that were broken by D131307 <https://reviews.llvm.org/D131307>, that aren't fixed by this patch. Building https://martin.st/temp/qt-enum.cpp with `clang -target i686-w64-mingw32 -c -std=c++17 qt-enum.cpp -Wno-ignored-attributes -Wno-user-defined-literals` succeeded before the change to make those errors downgradable, and those are still an error now.

Diagnostic I'm getting is:

  <source>:135567:18: error: integer value -1 is outside the valid range of values [0, 1] for this enumeration type [-Wenum-constexpr-conversion]
      if (order == Qt::SortOrder(-1))

SortOrder is:

   enum SortOrder {
      AscendingOrder,
      DescendingOrder
  };

So looks like at least the range diagnosed is correct.  Latest godbolt shows the issue:
https://godbolt.org/z/vKn57PbGf

BUT I believe this is exactly the case that this patch should have made no longer a problem.  Hopefully @shafik  can look into this to confirm, and see why this wasn't suppressed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D131528/new/

https://reviews.llvm.org/D131528