Cleanup configure.in. Specifically:

- Don't call both AC_CHECK_FUNCS and AC_REPLACE_FUNC for 'hypot', as the
latter already does everything the former does (because it's implemented as
a call to the former.)

- Don't call AC_CHECK_FUNC() without any 'action' clauses or with an action
clause that just defines HAVE_<function>. Instead, call AC_CHECK_FUNCS,
which defines 'HAVE_<function>' of itself, possibly with aditional 'action'
clauses.

No checks are removed by this patch, only moved around, and some duplicates
are removed.

config.h.in

@@ -109,9 +109,6 @@
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
 
-/* Define this if you have gethostbyname() */
-#undef HAVE_GETHOSTBYNAME
-
 /* Define this if you have some version of gethostbyname_r() */
 #undef HAVE_GETHOSTBYNAME_R
 
@@ -335,6 +332,9 @@
 /* Define if you have the getgroups function.  */
 #undef HAVE_GETGROUPS
 
+/* Define if you have the gethostbyname function.  */
+#undef HAVE_GETHOSTBYNAME
+
 /* Define if you have the getlogin function.  */
 #undef HAVE_GETLOGIN
 

configure.in

@@ -790,7 +790,7 @@ LIBS="$LIBS -ldl -ldld"], AC_MSG_RESULT(no))
 
 # the dlopen() function means we might want to use dynload_shlib.o. some
 # platforms, such as AIX, have dlopen(), but don't want to use it.
-AC_CHECK_FUNC(dlopen)
+AC_CHECK_FUNCS(dlopen)
 
 # DYNLOADFILE specifies which dynload_*.o file we will use for dynamic
 # loading of modules.
@@ -820,14 +820,14 @@ then
 fi
 
 # checks for library functions
-AC_CHECK_FUNCS(alarm chown clock confstr ctermid ctermid_r dlopen execv \
+AC_CHECK_FUNCS(alarm chown clock confstr ctermid ctermid_r execv \
  flock fork fsync fdatasync fpathconf ftime ftruncate \
- getgroups getlogin getpeername getpgrp getpid getpwent gettimeofday getwd \
+ getgroups getlogin getpeername getpid getpwent getwd \
  kill link lstat mkfifo mktime mremap \
  nice pathconf pause plock pthread_init \
  putenv readlink \
  select setegid seteuid setgid \
- setlocale setregid setreuid setsid setpgid setpgrp setuid setvbuf \
+ setlocale setregid setreuid setsid setpgid setuid setvbuf \
  sigaction siginterrupt sigrelse strftime strptime symlink sysconf \
  tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
  truncate uname waitpid _getpty)
@@ -841,9 +841,9 @@ AC_CHECK_FUNCS(forkpty,, AC_CHECK_LIB(util,forkpty, [AC_DEFINE(HAVE_FORKPTY)] [L
 AC_CHECK_FUNCS(fseek64 fseeko fstatvfs ftell64 ftello statvfs)
 
 AC_REPLACE_FUNCS(dup2 getcwd strdup strerror memmove)
-AC_CHECK_FUNC(getpgrp, AC_TRY_COMPILE([#include <unistd.h>], [getpgrp(0);], AC_DEFINE(GETPGRP_HAVE_ARG)))
-AC_CHECK_FUNC(setpgrp, AC_TRY_COMPILE([#include <unistd.h>], [setpgrp(0,0);], AC_DEFINE(SETPGRP_HAVE_ARG)))
-AC_CHECK_FUNC(gettimeofday, AC_TRY_COMPILE([#include <sys/time.h>], [gettimeofday((struct timeval*)0,(struct timezone*)0);], ,AC_DEFINE(GETTIMEOFDAY_NO_TZ)))
+AC_CHECK_FUNCS(getpgrp, AC_TRY_COMPILE([#include <unistd.h>], [getpgrp(0);], AC_DEFINE(GETPGRP_HAVE_ARG)))
+AC_CHECK_FUNCS(setpgrp, AC_TRY_COMPILE([#include <unistd.h>], [setpgrp(0,0);], AC_DEFINE(SETPGRP_HAVE_ARG)))
+AC_CHECK_FUNCS(gettimeofday, AC_TRY_COMPILE([#include <sys/time.h>], [gettimeofday((struct timeval*)0,(struct timezone*)0);], ,AC_DEFINE(GETTIMEOFDAY_NO_TZ)))
 
 # checks for structures
 AC_HEADER_TIME
@@ -1003,7 +1003,7 @@ AC_CHECK_FUNC(gethostbyname_r, [
   ])
   CFLAGS=$OLD_CFLAGS
 ], [
-  AC_CHECK_FUNC(gethostbyname, AC_DEFINE(HAVE_GETHOSTBYNAME))
+  AC_CHECK_FUNCS(gethostbyname)
 ])
 AC_SUBST(HAVE_GETHOSTBYNAME_R_6_ARG)
 AC_SUBST(HAVE_GETHOSTBYNAME_R_5_ARG)
@@ -1066,7 +1066,6 @@ fi],
 # check for hypot() in math library
 LIBS_SAVE=$LIBS
 LIBS="$LIBS $LIBM"
-AC_CHECK_FUNCS(hypot)
 AC_REPLACE_FUNCS(hypot)
 LIBS=$LIBS_SAVE