[libcxx-commits] [PATCH] D156783: [libc++] Fix `std::out_of_range` thrown from `basic_stringbuf::str() &&`

[Mark de Wever via Phabricator via libcxx-commits]

Mordante accepted this revision.
Mordante added a comment.
This revision is now accepted and ready to land.

Thanks for the quick fix! LGTM modulo a comment.

After you land the patch, can you put it up for backporting to LLVM-17? 
(The instructions are here https://www.llvm.org/docs/GitHub.html#backporting-fixes-to-the-release-branches)



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Comment at: libcxx/include/sstream:405
+        if (!__view.empty())
+            __result.assign(std::move(__str_), __view.data() - __str_.data(), __view.size());
         __str_.clear();
----------------
Depending on the order of evaluation `__view.data() - __str_.data()` may be used after `__str_` has been moved. Lets determine the size before `assign`. This is pre-existing.

Whether this is save depends on the order in which the function arguments are evaluated. Clang and GCC use a different order.


Repository:
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  https://reviews.llvm.org/D156783/new/

https://reviews.llvm.org/D156783