[benchmarks] Unbreak third-party/benchmark build on Solaris

[ro]

Summary

D112012 broke the Solaris buildbots (sparcv9 and amd64:

/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:447:2: error: #warning is a language extension [-Werror,-Wpedantic]
#warning "HOST_NAME_MAX not defined. using 64"
 ^
/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:447:2: error: "HOST_NAME_MAX not defined. using 64" [-Werror,-W#warnings]
/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:475:16: error: implicit conversion loses integer precision: 'long' to 'int' [-Werror,-Wshorten-64-to-32]
  int NumCPU = sysconf(_SC_NPROCESSORS_ONLN);
      ~~~~~~   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:653:42: error: cast from 'const char *' to 'char *' drops const qualifier [-Werror,-Wcast-qual]
  kstat_t *ksp = kstat_lookup(kc, (char*)"cpu_info", -1, (char*)"cpu_info0");
                                         ^
/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:653:65: error: cast from 'const char *' to 'char *' drops const qualifier [-Werror,-Wcast-qual]
  kstat_t *ksp = kstat_lookup(kc, (char*)"cpu_info", -1, (char*)"cpu_info0");
                                                                ^
/vol/llvm/src/llvm-project/local/third-party/benchmark/src/sysinfo.cc:663:53: error: cast from 'const char *' to 'char *' drops const qualifier [-Werror,-Wcast-qual]
      (kstat_named_t*)kstat_data_lookup(ksp, (char*)"current_clock_Hz");
                                                    ^

• Solaris uses MAXHOSTNAMELEN which, contrary to gethostname(3C) lives in <netdb.h>, not <unistd.h>`.
• sysconf returns long, not int, so account for that
• kstat_lookup etc. need const_casts

Tested on amd64-pc-solaris2.11.

[lebedev.ri]

Can you please submit this upstream first?

[mtrofin]

In D115342#3179396, @lebedev.ri wrote:

Can you please submit this upstream first?

+1, thanks - was just typing that. I wonder if a README under third_party explaining how to update benchmark would be discoverable? Or maybe a MAKING_CHANGES?

[lebedev.ri]

This review seems to be stuck/dead, consider abandoning if no longer relevant.

[ro]

The patch is no longer crucial: since third-party/benchmark doesn't build with -Werror anymore, so there are just warnings left. Besides, the patch is now upstream, so whenever someone imports the current version into LLVM, even those will be gone.

third-party/benchmark/src/sysinfo.cc

#if defined BENCHMARK_OS_FREEBSD || defined BENCHMARK_OS_MACOSX || \
     defined BENCHMARK_OS_NETBSD || defined BENCHMARK_OS_OPENBSD || \
     defined BENCHMARK_OS_DRAGONFLY
 #define BENCHMARK_HAS_SYSCTL
 #include <sys/sysctl.h>
 #endif
 #endif
 #if defined(BENCHMARK_OS_SOLARIS)
 #include <kstat.h>
+#include <netdb.h>
 #endif
 #if defined(BENCHMARK_OS_QNX)
 #include <sys/syspage.h>
 #endif
 
 #include <algorithm>
 #include <array>
 #include <bitset>

 #ifdef BENCHMARK_HAS_SYSCTL // BSD/Mac Doesnt have HOST_NAME_MAX defined
 #define HOST_NAME_MAX 64
 #elif defined(BENCHMARK_OS_NACL)
 #define HOST_NAME_MAX 64
 #elif defined(BENCHMARK_OS_QNX)
 #define HOST_NAME_MAX 154
 #elif defined(BENCHMARK_OS_RTEMS)
 #define HOST_NAME_MAX 256
+#elif defined(BENCHMARK_OS_SOLARIS)
+#define HOST_NAME_MAX MAXHOSTNAMELEN
 #else
 #warning "HOST_NAME_MAX not defined. using 64"
 #define HOST_NAME_MAX 64
 #endif
 #endif // def HOST_NAME_MAX
   char hostname[HOST_NAME_MAX];
   int retVal = gethostname(hostname, HOST_NAME_MAX);
   if (retVal != 0) return std::string("");
#elif defined(BENCHMARK_OS_WINDOWS)
   // positives.
   std::memset(&sysinfo, 0, sizeof(SYSTEM_INFO));
   GetSystemInfo(&sysinfo);
   return sysinfo.dwNumberOfProcessors;  // number of logical
                                         // processors in the current
                                         // group
 #elif defined(BENCHMARK_OS_SOLARIS)
   // Returns -1 in case of a failure.
-  int NumCPU = sysconf(_SC_NPROCESSORS_ONLN);
+  long NumCPU = sysconf(_SC_NPROCESSORS_ONLN);
   if (NumCPU < 0) {
     fprintf(stderr,
             "sysconf(_SC_NPROCESSORS_ONLN) failed with error: %s\n",
             strerror(errno));
   }
-  return NumCPU;
+  return (int)NumCPU;
 #elif defined(BENCHMARK_OS_QNX)
   return static_cast<int>(_syspage_ptr->num_cpu);
 #else
   int NumCPUs = 0;
   int MaxID = -1;
   std::ifstream f("/proc/cpuinfo");
   if (!f.is_open()) {
     std::cerr << "failed to open /proc/cpuinfo\n";
if (IsWindowsXPOrGreater() &&
     return static_cast<double>((int64_t)data *
                                (int64_t)(1000 * 1000));  // was mhz
 #elif defined (BENCHMARK_OS_SOLARIS)
   kstat_ctl_t *kc = kstat_open();
   if (!kc) {
     std::cerr << "failed to open /dev/kstat\n";
     return -1;
   }
-  kstat_t *ksp = kstat_lookup(kc, (char*)"cpu_info", -1, (char*)"cpu_info0");
+  kstat_t *ksp = kstat_lookup(kc, const_cast<char *>("cpu_info"), -1,
+                              const_cast<char *>("cpu_info0"));
   if (!ksp) {
     std::cerr << "failed to lookup in /dev/kstat\n";
     return -1;
   }
   if (kstat_read(kc, ksp, NULL) < 0) {
     std::cerr << "failed to read from /dev/kstat\n";
     return -1;
   }
-  kstat_named_t *knp =
-      (kstat_named_t*)kstat_data_lookup(ksp, (char*)"current_clock_Hz");
+  kstat_named_t *knp = (kstat_named_t *)kstat_data_lookup(
+      ksp, const_cast<char *>("current_clock_Hz"));
   if (!knp) {
     std::cerr << "failed to lookup data in /dev/kstat\n";
     return -1;
   }
   if (knp->data_type != KSTAT_DATA_UINT64) {
     std::cerr << "current_clock_Hz is of unexpected data type: "
               << knp->data_type << "\n";
     return -1;