aviralgarg05 opened a new pull request, #18374: URL: https://github.com/apache/nuttx/pull/18374
## Summary This addresses the unresolved case in issue #18232 after #18308 was merged. When `CONFIG_LIBM_TOOLCHAIN=y`, `include/cxx/cmath` should not try to populate `std::*` from the NuttX shim path. In this mode, `cmath` now delegates to the toolchain C++ wrapper via: ```c #include_next <cmath> ``` This lets libstdc++/toolchain `<cmath>` pull in its matching C `math.h` (`include_next <math.h>`) and correctly provide `std::abs`, `std::acos`, etc. For non-toolchain-libm configurations, existing NuttX behavior in `include/cxx/cmath` is unchanged. ## Why this is needed In the reported configuration: - `CONFIG_LIBM_TOOLCHAIN=y` - `CONFIG_LIBCXXTOOLCHAIN=y` - `CONFIG_LIBSUPCXX_TOOLCHAIN=y` users still hit errors like: - `'abs' has not been declared in 'std'` - `'acos' has not been declared in 'std'` (Reference: https://github.com/apache/nuttx/issues/18232#issuecomment-3861302869) ## Impact - Fixes toolchain-libm + toolchain-libstdc++ interoperability in `<math.h>/<cmath>` include flows. - Keeps non-`CONFIG_LIBM_TOOLCHAIN` behavior unchanged. - Changes only one file: `include/cxx/cmath`. ## Testing Host: macOS (Apple Silicon) 1. Reproducer compile with `g++-15` and `CONFIG_LIBM_TOOLCHAIN` stubs: - `#include <math.h>` with `using namespace std;` passed. - `#include <cmath>` with `using namespace std;` passed. 2. Repeated the above reproducer 3 consecutive iterations: all passed. 3. Cross-check with `clang++` in the same include configuration: passed. 4. Style checks: - `tools/checkpatch.sh -f include/cxx/cmath` passed. - `git diff --check -- include/cxx/cmath` passed. Fixes #18232 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
