Hello
With the latest version of gcc-toolchain in Guix (14.2.0), macros from the
<cfenv> header aren't defined during compilation with g++. Version 13 of
gcc-toolchain doesn't have this problem.
Reproducer:
Create a file called test.cpp with contents:
#include <stdio.h>
#include <cfenv>
int main() {
#ifdef FE_DIVBYZERO
printf("FE_DIVBYZERO is defined\n");
#else
printf("FE_DIVBYZERO is NOT defined\n");
#endif
return 0;
}
$ guix shell -C gcc-toolchain@14 -- g++ test.cpp && ./a.out
FE_DIVBYZERO is NOT defined
$ guix shell -C gcc-toolchain@13 -- g++ test.cpp && ./a.out
FE_DIVBYZERO is defined
If we include the C equivalent <fenv.h> instead of <cfenv>, again g++ finds
it in version 13 but not in version 14 of gcc-toolchain.
Note that gcc from gcc-toolchain@14 does find the macro from <fenv.h>
(provided the source file has .c extension).
Other macros from <cfenv> are also affected with g++, including
FE_OVERFLOW, FE_UNDERFLOW, FE_INEXACT, and FE_INVALID.
This bug is probably the same as 43579 (feclearexcept with g++)
https://issues.guix.gnu.org/43579
I've copied in the members of core-packages team.
guix a53bd6f
Thanks!
Jake
