On Fri, 13 Nov 2026 at 22:51, Jason Merrill <[email protected]> wrote:
>
> Tested x86_64-pc-linux-gnu.
>
> I assume you don't want to condition this on only __cpp_contracts as in the
> current patch. And I don't know how you want to handle the view_interface
> empty() issue. But I think the rest of the patch could go in as is.
> Thoughts?
> diff --git a/libstdc++-v3/include/bits/c++config
> b/libstdc++-v3/include/bits/c++config
> index 0c2407ccd07..fa219b33690 100644
> --- a/libstdc++-v3/include/bits/c++config
> +++ b/libstdc++-v3/include/bits/c++config
> @@ -642,15 +642,26 @@ namespace std
> #if defined(_GLIBCXX_ASSERTIONS)
> // When _GLIBCXX_ASSERTIONS is defined we enable runtime assertion checks.
> // These checks will also be done during constant evaluation.
> +# if __cpp_contracts
> +# define __glibcxx_assert(cond) __contract_assert(cond)
> +# else
> # define __glibcxx_assert(cond)
> \
> do { \
> if (__builtin_expect(!bool(cond), false)) \
> _GLIBCXX_ASSERT_FAIL(cond); \
> } while (false)
> +# endif
This seems problematic. If I pass
-fcontract-evaluation-semantic=observe/ignore, that turns the
libstdc++ hardening off.
If I want to observe/ignore the program's own contracts, but keep
libstdc++ hardening on, I can't do that.
