On Fri, 20 Dec 2024, 17:19 Caden via Gcc-help, <gcc-help@xxxxxxxxxxx> wrote: > Hi! > > For work I've been trying to build a RISC-V compiler, configured to enable > a couple settings for libstdc++. For a custom SoC, I want to tailor the > compiler to specifically enable the use of both monotonic and realtime > clocks, so they can be utilized by clock_gettime(). > You seem to have things backwards. Those macros are used by the C++ library to configure whether the C++ library's std::chrono clocks can use clock_gettime. They don't affect clock_gettime in any way. If you want clock_gettime to work, you need the C library to provide it, and that's nothing to do with GCC. GCC does not provide a C library. You might want to use newlib as your C library. Once you have a working clock_gettime from your C library, then configuring GCC will automatically set those macros so that the C++ library can use clock_gettime. > I noticed the following macros in "c++config.h" which are disabled by > default for RISC-V GNU: > _GLIBCXX_USE_CLOCK_REALTIME > _GLIBCXX_USE_CLOCK_MONOTONIC > > Is there a way to customize the use of these settings in c++config.h? As > far as I know, there aren't any flags specifically for enabling these > clocks/macros. I've looked into the configure flag > '--enable-libstdcxx-time' but it seems to be unused on modern systems. > > Thank you and have a wonderful holiday season. >
