id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
11199	dhcp: Fix compiler error	thomas	thomas	"(Reported by Clayton J. on blfs-dev)

Instructions in book leads to errors like
{{{
discover.c:646:4: error: 'strncpy' output may be truncated copying 15 bytes from a string of length 15 [-Werror=stringop-truncation]
    strncpy(tmp->name, info.name, sizeof(tmp->name) - 1);
}}}

This is caused by a strange handling of set/unset CFLAGS. Doing an
{{{
export CFLAGS=""-D...
}}}
makes it compile. Most likely it has been missed because we might had CFLAGS exported while testing. With this export of CFLAGS, our -D's are recognized but but `-fno-strict-aliasing` gets not set but it would be if CFLAGS are not spezified.

Remove the -Werror flag by doing a 
{{{
sed -e ""/STD_CWARNINGS=/ s/-Werror//"" -i configure
}}}
This would make it compile too but the CFLAGS we set (without the export) will not be used. See summary of configure script.

I'd propose to solve it like this:
{{{
export CFLAGS=""$CFLAGS -Wall -fno-strict-aliasing \
        -D_PATH_DHCLIENT_SCRIPT='\""/sbin/dhclient-script\""' \
        -D_PATH_DHCPD_CONF='\""/etc/dhcp/dhcpd.conf\""' \
        -D_PATH_DHCLIENT_CONF='\""/etc/dhcp/dhclient.conf\""'""
./configure --prefix=/usr                                           \
            --sysconfdir=/etc/dhcp                                  \
            --localstatedir=/var                                    \
            --with-srv-lease-file=/var/lib/dhcpd/dhcpd.leases       \
            --with-srv6-lease-file=/var/lib/dhcpd/dhcpd6.leases     \
            --with-cli-lease-file=/var/lib/dhclient/dhclient.leases \
            --with-cli6-lease-file=/var/lib/dhclient/dhclient6.leases
}}}
The summary of configure than looks like (note the CFLAGS line):
{{{

     ISC DHCP source configure results:
    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Package:
  Name:          DHCP
  Version:       4.4.1

C Compiler:      gcc

Flags:
  DEFS:          -DHAVE_CONFIG_H
  CFLAGS:         -Wall -fno-strict-aliasing         -D_PATH_DHCLIENT_SCRIPT='""/sbin/dhclient-script""'         -D_PATH_DHCPD_CONF='""/etc/dhcp/dhcpd.conf""'         -D_PATH_DHCLIENT_CONF='""/etc/dhcp/dhclient.conf""'  -I$(top_srcdir)/includes -I/home/lfs/dhcp-4.4.1/bind/include

DHCP versions:   DHCPv4 and DHCPv6

Features:
  debug:         no
  failover:      yes
  execute:       yes
  binary-leases: no
  dhcpv6:        yes
  delayed-ack:   yes
  dhcpv4o6:      no
  relay-port:    no

Developer:
  ATF unittests : no


Now you can type make to build ISC DHCP
}}}


Please add comments!"	defect	closed	normal	8.4	BOOK	SVN	medium	fixed