[libFuzzer] Diff 26 - [AflDriver] Update afl driver to use std clocks instead of posix API.

[zturner]

lib/Fuzzer/afl/afl_driver.cpp

53

I think we should put c++ headers after c headers. That said, There is no other use of c++ / stl in this file, and I wonder if that is intentional. Should wait for kcc@

lib/Fuzzer/afl/afl_driver.cpp

 statistics to the file specified. Currently these are peak_rss_mb
 (the peak amount of virtual memory used in MB) and slowest_unit_time_secs. If
 the file does not exist it is created. If the file does exist then
 afl_driver assumes it was restarted by afl-fuzz and will try to read old
 statistics from the file. If that fails then the process will quit.
 
 */
 #include <assert.h>
+#include <chrono>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
 #include <signal.h>
 #include <sys/resource.h>
-#include <sys/time.h>
 // Platform detection. Copied from FuzzerInternal.h
 #ifdef __linux__
 #define LIBFUZZER_LINUX 1
 #define LIBFUZZER_APPLE 0
 #elif __APPLE__
 #define LIBFUZZER_LINUX 0
 #define LIBFUZZER_APPLE 1
 #else

 
 // Input buffer.
 static const size_t kMaxAflInputSize = 1 << 20;
 static uint8_t AflInputBuf[kMaxAflInputSize];
 
 // Variables we need for writing to the extra stats file.
 static FILE *extra_stats_file = NULL;
 static uint32_t previous_peak_rss = 0;
-static time_t slowest_unit_time_secs = 0;
+auto slowest_unit_time_secs = std::chrono::seconds::zero();
 static const int kNumExtraStats = 2;
 static const char *kExtraStatsFormatString = "peak_rss_mb            : %u\n"
                                              "slowest_unit_time_sec  : %u\n";
 
 // Copied from FuzzerUtil.cpp.
 size_t GetPeakRSSMb() {
   struct rusage usage;
   if (getrusage(RUSAGE_SELF, &usage))
int main(int argc, char **argv) {
   maybe_initialize_extra_stats();
 
   __afl_manual_init();
 
   int N = 1000;
   if (argc >= 2)
     N = atoi(argv[1]);
   assert(N > 0);
-  time_t unit_time_secs;
   int num_runs = 0;
   while (__afl_persistent_loop(N)) {
     ssize_t n_read = read(0, AflInputBuf, kMaxAflInputSize);
     if (n_read > 0) {
       // Copy AflInputBuf into a separate buffer to let asan find buffer
       // overflows. Don't use unique_ptr/etc to avoid extra dependencies.
       uint8_t *copy = new uint8_t[n_read];
       memcpy(copy, AflInputBuf, n_read);
 
-      struct timeval unit_start_time;
-      CHECK_ERROR(gettimeofday(&unit_start_time, NULL) == 0,
-                  "Calling gettimeofday failed");
+      auto unit_start_time = std::chrono::system_clock::now();
 
       num_runs++;
       LLVMFuzzerTestOneInput(copy, n_read);
 
-      struct timeval unit_stop_time;
-      CHECK_ERROR(gettimeofday(&unit_stop_time, NULL) == 0,
-                  "Calling gettimeofday failed");
+      auto unit_time_secs = std::chrono::duration_cast<std::chrono::seconds>(
+        std::chrono::system_clock::now() - unit_start_time);
 
       // Update slowest_unit_time_secs if we see a new max.
-      unit_time_secs = unit_stop_time.tv_sec - unit_start_time.tv_sec;
       if (slowest_unit_time_secs < unit_time_secs)
         slowest_unit_time_secs = unit_time_secs;
 
       delete[] copy;
     }
   }
   fprintf(stderr, "%s: successfully executed %d input(s)\n", argv[0], num_runs);
 }