[PATCH] D149550: [clang][Interp] Fix compound assign operator evaluation order

[Timm Bäder via Phabricator via cfe-commits]

tbaeder added inline comments.


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Comment at: clang/lib/AST/Interp/ByteCodeExprGen.cpp:683-685
+  // C++17 onwards require that we evaluate the RHS first.
+  // Compute RHS and save it in a temporary variable so we can
+  // load it again later.
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aaron.ballman wrote:
> In C, the evaluation of the operands are unsequenced. C doesn't currently have constexpr functions, only constexpr objects, but that eliminates mutating operations like compound assignment... for the moment. Perhaps a FIXME comment for figuring out how to handle C?
> 
> (The situation I'm worried about in C is with UB dealing with unsequenced operations, like rejecting: https://godbolt.org/z/W11jchrKc)
Could C make them sequenced when introducing constexpr functions? :)


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  https://reviews.llvm.org/D149550/new/

https://reviews.llvm.org/D149550