/3rd_party/llvm/autoconf/m4/func_mmap_file.m4

https://code.google.com/p/softart/ · m4 · 26 lines · 20 code · 0 blank · 6 comment · 0 complexity · 96d4ac0e6d3eb82864dd84f334412c3a MD5 · raw file

  1. #
  2. # Check for the ability to mmap a file.
  3. #
  4. AC_DEFUN([AC_FUNC_MMAP_FILE],
  5. [AC_CACHE_CHECK(for mmap of files,
  6. ac_cv_func_mmap_file,
  7. [ AC_LANG_PUSH([C])
  8. AC_RUN_IFELSE([
  9. AC_LANG_PROGRAM([[
  10. #include <sys/types.h>
  11. #include <sys/mman.h>
  12. #include <fcntl.h>
  13. ]],[[
  14. int fd;
  15. fd = creat ("foo",0777);
  16. fd = (int) mmap (0, 1, PROT_READ, MAP_SHARED, fd, 0);
  17. unlink ("foo");
  18. return (fd != (int) MAP_FAILED);]])],
  19. [ac_cv_func_mmap_file=yes],[ac_cv_func_mmap_file=no],[ac_cv_func_mmap_file=no])
  20. AC_LANG_POP([C])
  21. ])
  22. if test "$ac_cv_func_mmap_file" = yes; then
  23. AC_DEFINE([HAVE_MMAP_FILE],[],[Define if mmap() can map files into memory])
  24. AC_SUBST(MMAP_FILE,[yes])
  25. fi
  26. ])