On 7/20/2021 4:01 PM, Marek Polacek via Gcc-patches wrote:
This quashes -Wundef warnings in ansidecl.h when compiled in C or C++. In C, __cpp_constexpr and __cplusplus aren't defined so we evaluate them to 0; conversely, __STDC_VERSION__ is not defined in C++. This has caused grief when -Wundef is used with -Werror. I've also tested -traditional-cpp. Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? include/ChangeLog: * ansidecl.h: Check if __cplusplus is defined before checking the value of __cpp_constexpr and __cplusplus. Don't check __STDC_VERSION__ in C++.
OK jeff