compiler-rt/test/fuzzer/SanCovDump.cpp

   1 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   2 // See https://llvm.org/LICENSE.txt for license information.
   3 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   4
   5 // Link this tiny library to a binary compiled with
   6 // -fsanitize-coverage=inline-8bit-counters.
   7 // When passed SANCOV_OUT=OUTPUT_PATH, the process will
   8 // dump the 8-bit coverage counters to the file, assuming
   9 // the regular exit() is called.
  10 //
  11 // See OutOfProcessFuzzTarget.cpp for usage.
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14
  15 static char *CovStart, *CovEnd;
  16
  17 static void DumpCoverage() {
  18   if (const char *DumpPath = getenv("SANCOV_OUT")) {
  19     fprintf(stderr, "SanCovDump: %p %p %s\n", CovStart, CovEnd, DumpPath);
  20     if (FILE *f = fopen(DumpPath, "w")) {
  21       fwrite(CovStart, 1, CovEnd - CovStart, f);
  22       fclose(f);
  23     }
  24   }
  25 }
  26
  27 extern "C" void __sanitizer_cov_8bit_counters_init(char *Start, char *End) {
  28   CovStart = Start;
  29   CovEnd = End;
  30   atexit(DumpCoverage);
  31 }