Test for existence of inet_aton on the system, and only include inet_aton.c if

required

Pointed out by Brian E. Gallew

src/backend/port/Makefile

-#-------------------------------------------------------------------------
-#
-# Makefile--
-#    Makefile for the port-specific subsystem of the backend
-#
-# You must invoke this make file with the PORTNAME variable set to the
-# name of a port, i.e. the name of a subdirectory of the current directory.
-# Example: 
-#
-#    make SUBSYS.o PORTNAME=linux
-#
-# We have two different modes of operation: 1) put stuff specific to Port X
-# in subdirectory X and have that subdirectory's make file make it all, and 
-# 2) use conditional statements in the present make file to include what's
-# necessary for a specific port in our own output.  (1) came first, but (2)
-# is superior for many things, like when the same thing needs to be done for
-# multiple ports and you don't want to duplicate files in multiple 
-# subdirectories.  Much of the stuff done via Method 1 today should probably
-# be converted to Method 2.  
-#
-# IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/port/Makefile,v 1.9 1997/01/23 15:58:34 scrappy Exp $
-#
-#-------------------------------------------------------------------------
-
-ifndef PORTNAME
-.DEFAULT all: 
-	@echo "Error:  Must invoke make with PORTNAME= argument."
-	@false
-else
-
-OBJS = $(PORTNAME)/SUBSYS.o
-
-ifneq (,$(findstring /$(PORTNAME)/, /i386_solaris/sparc_solaris/ultrix4/nextstep/svr4))
-# Other ports get the inet_aton() function from their standard C libraries.
-OBJS += inet_aton.o
-endif
-
-all: submake SUBSYS.o
-
-SUBSYS.o: $(OBJS)
-	$(LD) -r -o SUBSYS.o $(OBJS)
-
-.PHONY: submake clean dep
-
-submake:
-	$(MAKE) -C $(PORTNAME) SUBSYS.o
-
-clean:
-	rm -f $(OBJS)
-	$(MAKE) -C $(PORTNAME) clean
-
-depend dep:
-	$(CC) -MM $(INCLUDE_OPT) *.c >depend
-	$(MAKE) -C $(PORTNAME) $@
-
-ifeq (depend,$(wildcard depend))
-include depend
-endif
-
-endif
-