Re: lib/52756: sysctl(2) in C++ constructor does not work any more

[christos%zoulas.com@localhost (Christos Zoulas)]

The following reply was made to PR lib/52756; it has been noted by GNATS.

From: christos%zoulas.com@localhost (Christos Zoulas)
To: gnats-bugs%NetBSD.org@localhost, lib-bug-people%netbsd.org@localhost, 
	gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: lib/52756: sysctl(2) in C++ constructor does not work any more
Date: Thu, 23 Nov 2017 10:58:57 -0500

 On Nov 23,  9:35am, n54%gmx.com@localhost (n54%gmx.com@localhost) wrote:
 -- Subject: lib/52756: sysctl(2) in C++ constructor does not work any more
 
 
 CPU_FPU_PRESENT only exists in the header file, fixing the test prints
 No such file or directory as expected. If I change the test to use
 CPU_FPU_SAVE, it works: 
 
 /* g++ std=c++11 prog.c */
 
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #include <machine/cpu.h>
 #include <iostream>
 #include <stdlib.h>
 #include <err.h>
 
 const int fpu_save = []() -> int {
   int mib[2];
   int error;
   size_t len;                                                                                                                                                                                 
   int val;
 
   len = sizeof(val);
   mib[0] = CTL_MACHDEP;
   mib[1] = CPU_FPU_SAVE;
 
   error = sysctl(mib, __arraycount(mib), &val, &len, NULL, 0);
   if (error == -1)
     err(EXIT_FAILURE, "sysctl");
 
   return val;
 }();
 
 int
 main(int argc, char **argv)
 {
         std::cout << "fpu_save=" << fpu_save << std::endl;
 
         return 0;
 }