#defines in unistd.h

[John W. Eaton]

The current gnulib unistd.in.h file includes the following section:

  #if @GNULIB_GETHOSTNAME@
  /* Get all possible declarations of gethostname().  */
  # if @UNISTD_H_HAVE_WINSOCK2_H@
  #  if !defined _GL_SYS_SOCKET_H
  #   undef socket
  #   define socket               socket_used_without_including_sys_socket_h
  #   undef connect
  #   define connect              connect_used_without_including_sys_socket_h
  #   undef accept
  #   define accept               accept_used_without_including_sys_socket_h
  #   undef bind
  #   define bind                 bind_used_without_including_sys_socket_h
  #   undef getpeername
  #   define getpeername          
getpeername_used_without_including_sys_socket_h
  #   undef getsockname
  #   define getsockname          
getsockname_used_without_including_sys_socket_h
  #   undef getsockopt
  #   define getsockopt           getsockopt_used_without_including_sys_socket_h
  #   undef listen
  #   define listen               listen_used_without_including_sys_socket_h
  #   undef recv
  #   define recv                 recv_used_without_including_sys_socket_h
  #   undef send
  #   define send                 send_used_without_including_sys_socket_h
  #   undef recvfrom
  #   define recvfrom             recvfrom_used_without_including_sys_socket_h
  #   undef sendto
  #   define sendto               sendto_used_without_including_sys_socket_h
  #   undef setsockopt
  #   define setsockopt           setsockopt_used_without_including_sys_socket_h
  #   undef shutdown
  #   define shutdown             shutdown_used_without_including_sys_socket_h
  #  endif
  #  if !defined _GL_SYS_SELECT_H
  #   undef select
  #   define select               select_used_without_including_sys_select_h
  #  endif
  # endif
  #endif

I think these definitions can cause trouble for C++ programs that do
things like

  foo.h:
  -----
  class foo {
    public:
      foo (void) { }
      void accept (void);
  };

  foo.cc:
  ------
  #include <unistd.h>
  #include "foo.h"
  void foo::accept (void) { }
    // Oops, accept is not a member of class foo.

or C programs like this:

  foo.h:
  -----
  extern int accept;
  extern void doit (void);

  foo.c:
  -----
  #include <unistd.h>
  #include "foo.h"
  int accept = 0;
  void doit (void) { accept = 1; }

  main.c:
  ------
  #include "foo.h"
  int main (void) { accept = -1; doit (); return accept; }
    /* oops, what happened to the global variable accept? */


jwe