[patch] Actually check for vfork()

[Andrew Cagney <ac131313 at cygnus dot com>]

FYI,

No one thought to actually check that vfork() was available :-/.  With
that in mind, the C code testing for VFORK:

	#if defined (USG) && !defined (HAVE_VFORK)
	   use fork()
	#else
	   use vfork()
	#endif

was even more bizare :-)

	enjoy,
		Andrew
Sun Dec  3 02:28:26 2000  Andrew Cagney  <cagney@b1.cygnus.com>

	* ser-pipe.c (pipe_open): Only use vfork when available.
	* fork-child.c (fork_inferior): Fix #ifdef HAVE_VFORK test.
	(clone_and_follow_inferior): Ditto.

	* configure.in (AC_CHECK_FUNCS): Check for vfork.
	* configure, config.in: Regenerate.

Index: configure.in
===================================================================
RCS file: /cvs/src/src/gdb/configure.in,v
retrieving revision 1.46
diff -p -r1.46 configure.in
*** configure.in	2000/12/01 18:01:37	1.46
--- configure.in	2000/12/02 15:33:58
*************** AC_HEADER_STAT
*** 129,135 ****
  
  AC_C_CONST
  
! AC_CHECK_FUNCS(setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask)
  AC_FUNC_ALLOCA
  
  # See if machine/reg.h supports the %fs and %gs i386 segment registers.
--- 129,135 ----
  
  AC_C_CONST
  
! AC_CHECK_FUNCS(setpgid sbrk sigaction isascii bzero bcopy btowc poll sigprocmask vfork)
  AC_FUNC_ALLOCA
  
  # See if machine/reg.h supports the %fs and %gs i386 segment registers.
Index: fork-child.c
===================================================================
RCS file: /cvs/src/src/gdb/fork-child.c,v
retrieving revision 1.6
diff -p -r1.6 fork-child.c
*** fork-child.c	2000/09/01 23:39:11	1.6
--- fork-child.c	2000/12/02 15:33:58
*************** fork_inferior (char *exec_file, char *al
*** 244,256 ****
    if (pre_trace_fun != NULL)
      (*pre_trace_fun) ();
  
! #if defined(USG) && !defined(HAVE_VFORK)
!   pid = fork ();
! #else
    if (debug_fork)
      pid = fork ();
    else
      pid = vfork ();
  #endif
  
    if (pid < 0)
--- 244,256 ----
    if (pre_trace_fun != NULL)
      (*pre_trace_fun) ();
  
! #ifdef HAVE_VFORK
    if (debug_fork)
      pid = fork ();
    else
      pid = vfork ();
+ #else
+   pid = fork ();
  #endif
  
    if (pid < 0)
*************** clone_and_follow_inferior (int child_pid
*** 416,428 ****
      error ("error getting pipe for handoff semaphore");
  
    /* Clone the debugger. */
! #if defined(USG) && !defined(HAVE_VFORK)
!   debugger_pid = fork ();
! #else
    if (debug_fork)
      debugger_pid = fork ();
    else
      debugger_pid = vfork ();
  #endif
  
    if (debugger_pid < 0)
--- 416,428 ----
      error ("error getting pipe for handoff semaphore");
  
    /* Clone the debugger. */
! #ifdef HAVE_VFORK
    if (debug_fork)
      debugger_pid = fork ();
    else
      debugger_pid = vfork ();
+ #else
+   debugger_pid = fork ();
  #endif
  
    if (debugger_pid < 0)
Index: ser-pipe.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-pipe.c,v
retrieving revision 1.2
diff -p -r1.2 ser-pipe.c
*** ser-pipe.c	2000/02/09 08:52:47	1.2
--- ser-pipe.c	2000/12/02 15:34:01
*************** pipe_open (serial_t scb, const char *nam
*** 64,70 ****
--- 64,74 ----
    if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
      return -1;
  
+ #ifdef HAVE_VFORK
    pid = vfork ();
+ #else
+   pid = fork ();
+ #endif
    
    /* Error. */
    if (pid == -1)