kumquat-buildroot/package/audit/0001-Enable-cross-compiling.patch

From 6a9a6ee6dcffec6288bcccba92166ef6bec5efc7 Mon Sep 17 00:00:00 2001
From: Clayton Shotwell <clayton.shotwell@rockwellcollins.com>
Date: Thu, 26 Mar 2015 12:26:36 -0500
Subject: [PATCH] Enable cross compiling

During the audit build, several lookup tables are generated as header
files that are then linked in with the executables. This process is done
by a C application that needs to be able to be run on the host. The
current Makfile structure tries to build these executables for the
target instead of the host where they cannot be executed. This patch
reworks the Makefile structure to build for the correct platform.

This is revision 2 of this patch and is a complete rework of the
original patch. I have tested that it builds on an x86_64 ubuntu
platform and tested it running on an ARM cross compile platform.

The ax_prog_cc_for_build.m4 file was obtained from GNU at the link
below.
http://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html

Signed-off-by: Clayton Shotwell <clayton.shotwell@rockwellcollins.com>
---
 auparse/Makefile.am        | 185 ++++++++++++++++++++++++++++++++++++---------
 configure.ac               |   1 +
 lib/Makefile.am            |  85 ++++++++++++++++-----
 m4/ax_prog_cc_for_build.m4 | 125 ++++++++++++++++++++++++++++++
 4 files changed, 342 insertions(+), 54 deletions(-)
 create mode 100644 m4/ax_prog_cc_for_build.m4

diff --git a/auparse/Makefile.am b/auparse/Makefile.am
index 89b2d21..f9709de 100644
--- a/auparse/Makefile.am
+++ b/auparse/Makefile.am
@@ -74,191 +74,302 @@ noinst_PROGRAMS = gen_accesstabs_h gen_captabs_h gen_clock_h \
 	gen_umounttabs_h
 
 gen_accesstabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h accesstab.h
-gen_accesstabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="accesstab.h"'
+gen_accesstabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="accesstab.h"'
+$(gen_accesstabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_accesstabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_accesstabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 accesstabs.h: gen_accesstabs_h Makefile
 	./gen_accesstabs_h --i2s-transtab access > $@
 
 gen_captabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h captab.h
-gen_captabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="captab.h"'
+gen_captabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="captab.h"'
+$(gen_captabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_captabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_captabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 captabs.h: gen_captabs_h Makefile
 	./gen_captabs_h --i2s cap > $@
 
 gen_clock_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h clocktab.h
-gen_clock_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="clocktab.h"'
+gen_clock_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="clocktab.h"'
+$(gen_clock_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_clock_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_clock_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 clocktabs.h: gen_clock_h Makefile
 	./gen_clock_h --i2s clock > $@
 
 gen_clone_flagtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h \
 	clone-flagtab.h
-gen_clone_flagtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="clone-flagtab.h"'
+gen_clone_flagtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="clone-flagtab.h"'
+$(gen_clone_flagtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_clone_flagtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_clone-flagtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 clone-flagtabs.h: gen_clone-flagtabs_h Makefile
 	./gen_clone-flagtabs_h --i2s-transtab clone_flag > $@
 
 gen_epoll_ctls_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h epoll_ctl.h
-gen_epoll_ctls_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="epoll_ctl.h"'
+gen_epoll_ctls_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="epoll_ctl.h"'
+$(gen_epoll_ctls_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_epoll_ctls_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_epoll_ctls_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 epoll_ctls.h: gen_epoll_ctls_h Makefile
 	./gen_epoll_ctls_h --i2s epoll_ctl > $@
 
 gen_famtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h famtab.h
-gen_famtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="famtab.h"'
+gen_famtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="famtab.h"'
+$(gen_famtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_famtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_famtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 famtabs.h: gen_famtabs_h Makefile
 	./gen_famtabs_h --i2s fam > $@
 
 gen_flagtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h flagtab.h
 # ../auparse/ is used to avoid using ../lib/flagtab.h
-gen_flagtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="../auparse/flagtab.h"'
+gen_flagtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="../auparse/flagtab.h"'
+$(gen_flagtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_flagtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_flagtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 flagtabs.h: gen_flagtabs_h Makefile
 	./gen_flagtabs_h --i2s-transtab flag > $@
 
 gen_fcntl_cmdtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h \
 	fcntl-cmdtab.h
-gen_fcntl_cmdtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="fcntl-cmdtab.h"'
+gen_fcntl_cmdtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="fcntl-cmdtab.h"'
+$(gen_fcntl_cmdtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_fcntl_cmdtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_fcntl-cmdtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 fcntl-cmdtabs.h: gen_fcntl-cmdtabs_h Makefile
 	./gen_fcntl-cmdtabs_h --i2s fcntl > $@
 
 gen_icmptypetabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h icmptypetab.h
-gen_icmptypetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="icmptypetab.h"'
+gen_icmptypetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="icmptypetab.h"'
+$(gen_icmptypetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_icmptypetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_icmptypetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 icmptypetabs.h: gen_icmptypetabs_h Makefile
 	./gen_icmptypetabs_h --i2s icmptype > $@
 
 gen_ioctlreqtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ioctlreqtab.h
-gen_ioctlreqtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ioctlreqtab.h"'
+gen_ioctlreqtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ioctlreqtab.h"'
+$(gen_ioctlreqtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ioctlreqtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ioctlreqtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ioctlreqtabs.h: gen_ioctlreqtabs_h Makefile
 	./gen_ioctlreqtabs_h --i2s ioctlreq > $@
 
 gen_ipctabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ipctab.h
-gen_ipctabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ipctab.h"'
+gen_ipctabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ipctab.h"'
+$(gen_ipctabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ipctabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ipctabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ipctabs.h: gen_ipctabs_h Makefile
 	./gen_ipctabs_h --i2s ipc > $@
 
 gen_ipccmdtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ipccmdtab.h
-gen_ipccmdtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ipccmdtab.h"'
+gen_ipccmdtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ipccmdtab.h"'
+$(gen_ipccmdtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ipccmdtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ipccmdtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ipccmdtabs.h: gen_ipccmdtabs_h Makefile
 	./gen_ipccmdtabs_h --i2s-transtab ipccmd > $@
 
 gen_ipoptnametabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ipoptnametab.h
-gen_ipoptnametabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ipoptnametab.h"'
+gen_ipoptnametabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ipoptnametab.h"'
+$(gen_ipoptnametabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ipoptnametabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ipoptnametabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ipoptnametabs.h: gen_ipoptnametabs_h Makefile
 	./gen_ipoptnametabs_h --i2s ipoptname > $@
 
 gen_ip6optnametabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ip6optnametab.h
-gen_ip6optnametabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ip6optnametab.h"'
+gen_ip6optnametabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ip6optnametab.h"'
+$(gen_ip6optnametabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ip6optnametabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ip6optnametabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ip6optnametabs.h: gen_ip6optnametabs_h Makefile
 	./gen_ip6optnametabs_h --i2s ip6optname > $@
 
 gen_mmaptabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h mmaptab.h
-gen_mmaptabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="mmaptab.h"'
+gen_mmaptabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="mmaptab.h"'
+$(gen_mmaptabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_mmaptabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_mmaptabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 mmaptabs.h: gen_mmaptabs_h Makefile
 	./gen_mmaptabs_h --i2s-transtab mmap > $@
 
 gen_mounttabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h mounttab.h
-gen_mounttabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="mounttab.h"'
+gen_mounttabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="mounttab.h"'
+$(gen_mounttabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_mounttabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_mounttabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 mounttabs.h: gen_mounttabs_h Makefile
 	./gen_mounttabs_h --i2s-transtab mount > $@
 
 gen_nfprototabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h nfprototab.h
-gen_nfprototabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="nfprototab.h"'
+gen_nfprototabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="nfprototab.h"'
+$(gen_nfprototabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_nfprototabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_nfprototabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 nfprototabs.h: gen_nfprototabs_h Makefile
 	./gen_nfprototabs_h --i2s nfproto > $@
 
 gen_open_flagtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h \
 	open-flagtab.h
-gen_open_flagtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="open-flagtab.h"'
+gen_open_flagtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="open-flagtab.h"'
+$(gen_open_flagtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_open_flagtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_open-flagtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 open-flagtabs.h: gen_open-flagtabs_h Makefile
 	./gen_open-flagtabs_h --i2s-transtab open_flag > $@
 
 gen_persontabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h persontab.h
-gen_persontabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="persontab.h"'
+gen_persontabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="persontab.h"'
+$(gen_persontabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_persontabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_persontabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 persontabs.h: gen_persontabs_h Makefile
 	./gen_persontabs_h --i2s person > $@
 
 gen_ptracetabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h ptracetab.h
-gen_ptracetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ptracetab.h"'
+gen_ptracetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ptracetab.h"'
+$(gen_ptracetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ptracetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ptracetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ptracetabs.h: gen_ptracetabs_h Makefile
 	./gen_ptracetabs_h --i2s ptrace > $@
 
 gen_prctl_opttabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h prctl-opt-tab.h
-gen_prctl_opttabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="prctl-opt-tab.h"'
+gen_prctl_opttabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="prctl-opt-tab.h"'
+$(gen_prctl_opttabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_prctl_opttabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_prctl_opttabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 prctl_opttabs.h: gen_prctl_opttabs_h Makefile
 	./gen_prctl_opttabs_h --i2s prctl_opt > $@
 
 gen_pktoptnametabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h pktoptnametab.h
-gen_pktoptnametabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="pktoptnametab.h"'
+gen_pktoptnametabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="pktoptnametab.h"'
+$(gen_pktoptnametabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_pktoptnametabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_pktoptnametabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 pktoptnametabs.h: gen_pktoptnametabs_h Makefile
 	./gen_pktoptnametabs_h --i2s pktoptname > $@
 
 gen_prottabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h prottab.h
-gen_prottabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="prottab.h"'
+gen_prottabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="prottab.h"'
+$(gen_prottabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_prottabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_prottabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 prottabs.h: gen_prottabs_h Makefile
 	./gen_prottabs_h --i2s-transtab prot > $@
 
 gen_recvtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h recvtab.h
-gen_recvtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="recvtab.h"'
+gen_recvtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="recvtab.h"'
+$(gen_recvtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_recvtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_recvtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 recvtabs.h: gen_recvtabs_h Makefile
 	./gen_recvtabs_h --i2s-transtab recv > $@
 
 gen_rlimit_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h rlimittab.h
-gen_rlimit_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="rlimittab.h"'
+gen_rlimit_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="rlimittab.h"'
+$(gen_rlimit_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_rlimit_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_rlimit_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 rlimittabs.h: gen_rlimit_h Makefile
 	./gen_rlimit_h --i2s rlimit > $@
 
 gen_schedtabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h schedtab.h
-gen_schedtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="schedtab.h"'
+gen_schedtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="schedtab.h"'
+$(gen_schedtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_schedtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_schedtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 schedtabs.h: gen_schedtabs_h Makefile
 	./gen_schedtabs_h --i2s sched > $@
 
 gen_seccomptabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h seccomptab.h
-gen_seccomptabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="seccomptab.h"'
+gen_seccomptabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="seccomptab.h"'
+$(gen_seccomptabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_seccomptabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_seccomptabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 seccomptabs.h: gen_seccomptabs_h Makefile
 	./gen_seccomptabs_h --i2s seccomp > $@
 
 gen_seektabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h seektab.h
-gen_seektabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="seektab.h"'
+gen_seektabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="seektab.h"'
+$(gen_seektabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_seektabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_seektabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 seektabs.h: gen_seektabs_h Makefile
 	./gen_seektabs_h --i2s seek > $@
 
 gen_shm_modetabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h shm_modetab.h
-gen_shm_modetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="shm_modetab.h"'
+gen_shm_modetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="shm_modetab.h"'
+$(gen_shm_modetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_shm_modetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_shm_modetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 shm_modetabs.h: gen_shm_modetabs_h Makefile
 	./gen_shm_modetabs_h --i2s-transtab shm_mode > $@
 
 gen_signals_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h signaltab.h
-gen_signals_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="signaltab.h"'
+gen_signals_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="signaltab.h"'
+$(gen_signals_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_signals_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_signals_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 signaltabs.h: gen_signals_h Makefile
 	./gen_signals_h --i2s signal > $@
 
 gen_sockleveltabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h sockleveltab.h
-gen_sockleveltabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="sockleveltab.h"'
+gen_sockleveltabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="sockleveltab.h"'
+$(gen_sockleveltabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_sockleveltabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_sockleveltabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 sockleveltabs.h: gen_sockleveltabs_h Makefile
 	./gen_sockleveltabs_h --i2s socklevel > $@
 
 gen_sockoptnametabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h sockoptnametab.h
-gen_sockoptnametabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="sockoptnametab.h"'
+gen_sockoptnametabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="sockoptnametab.h"'
+$(gen_sockoptnametabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_sockoptnametabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_sockoptnametabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 sockoptnametabs.h: gen_sockoptnametabs_h Makefile
 	./gen_sockoptnametabs_h --i2s sockoptname > $@
 
 gen_socktabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h socktab.h
-gen_socktabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="socktab.h"'
+gen_socktabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="socktab.h"'
+$(gen_socktabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_socktabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_socktabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 socktabs.h: gen_socktabs_h Makefile
 	./gen_socktabs_h --i2s sock > $@
 
 gen_socktypetabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h socktypetab.h
-gen_socktypetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="socktypetab.h"'
+gen_socktypetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="socktypetab.h"'
+$(gen_socktypetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_socktypetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_socktypetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 socktypetabs.h: gen_socktypetabs_h Makefile
 	./gen_socktypetabs_h --i2s sock_type > $@
 
 gen_tcpoptnametabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h tcpoptnametab.h
-gen_tcpoptnametabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="tcpoptnametab.h"'
+gen_tcpoptnametabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="tcpoptnametab.h"'
+$(gen_tcpoptnametabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_tcpoptnametabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_tcpoptnametabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 tcpoptnametabs.h: gen_tcpoptnametabs_h Makefile
 	./gen_tcpoptnametabs_h --i2s tcpoptname > $@
 
 gen_typetabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h typetab.h
-gen_typetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="typetab.h"'
+gen_typetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="typetab.h"'
+$(gen_typetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_typetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_typetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 typetabs.h: gen_typetabs_h Makefile
 	./gen_typetabs_h --s2i type > $@
 
 gen_umounttabs_h_SOURCES = ../lib/gen_tables.c ../lib/gen_tables.h umounttab.h
-gen_umounttabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="umounttab.h"'
+gen_umounttabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="umounttab.h"'
+$(gen_umounttabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_umounttabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_umounttabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 umounttabs.h: gen_umounttabs_h Makefile
 	./gen_umounttabs_h --i2s-transtab umount > $@
 
diff --git a/configure.ac b/configure.ac
index ad9084b..f29fa41 100644
--- a/configure.ac
+++ b/configure.ac
@@ -51,6 +51,7 @@ echo Checking for programs
 AC_PROG_CC
 AC_PROG_INSTALL
 AC_PROG_AWK
+AX_PROG_CC_FOR_BUILD
 
 echo .
 echo Checking for header files
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 3560a88..97825bb 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -70,94 +70,145 @@ if USE_AARCH64
 noinst_PROGRAMS += gen_aarch64_tables_h
 endif
 gen_actiontabs_h_SOURCES = gen_tables.c gen_tables.h actiontab.h
-gen_actiontabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="actiontab.h"'
+gen_actiontabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="actiontab.h"'
+$(gen_actiontabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_actiontabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_actiontabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 actiontabs.h: gen_actiontabs_h Makefile
 	./gen_actiontabs_h --lowercase --i2s --s2i action > $@
 
 if USE_ALPHA
 gen_alpha_tables_h_SOURCES = gen_tables.c gen_tables.h alpha_table.h
-gen_alpha_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="alpha_table.h"'
+gen_alpha_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="alpha_table.h"'
+$(gen_alpha_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_alpha_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_alpha_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 alpha_tables.h: gen_alpha_tables_h Makefile
 	./gen_alpha_tables_h --lowercase --i2s --s2i alpha_syscall > $@
 endif
 
 if USE_ARM
 gen_arm_tables_h_SOURCES = gen_tables.c gen_tables.h arm_table.h
-gen_arm_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="arm_table.h"'
+gen_arm_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="arm_table.h"'
+$(gen_arm_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_arm_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_arm_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 arm_tables.h: gen_arm_tables_h Makefile
 	./gen_arm_tables_h --lowercase --i2s --s2i arm_syscall > $@
 endif
 
 if USE_AARCH64
 gen_aarch64_tables_h_SOURCES = gen_tables.c gen_tables.h aarch64_table.h
-gen_aarch64_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="aarch64_table.h"'
+gen_aarch64_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="aarch64_table.h"'
+$(gen_aarch64_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_aarch64_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_aarch64_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 aarch64_tables.h: gen_aarch64_tables_h Makefile
 	./gen_aarch64_tables_h --lowercase --i2s --s2i aarch64_syscall > $@
 endif
 
 gen_errtabs_h_SOURCES = gen_tables.c gen_tables.h errtab.h
-gen_errtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="errtab.h"'
+gen_errtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="errtab.h"'
+$(gen_errtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_errtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_errtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 errtabs.h: gen_errtabs_h Makefile
 	./gen_errtabs_h --duplicate-ints --uppercase --i2s --s2i err > $@
 
 gen_fieldtabs_h_SOURCES = gen_tables.c gen_tables.h fieldtab.h
-gen_fieldtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="fieldtab.h"'
+gen_fieldtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="fieldtab.h"'
+$(gen_fieldtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_fieldtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_fieldtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 fieldtabs.h: gen_fieldtabs_h Makefile
 	./gen_fieldtabs_h --duplicate-ints --lowercase --i2s --s2i field > $@
 
 gen_flagtabs_h_SOURCES = gen_tables.c gen_tables.h flagtab.h
-gen_flagtabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="flagtab.h"'
+gen_flagtabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="flagtab.h"'
+$(gen_flagtabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_flagtabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_flagtabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 flagtabs.h: gen_flagtabs_h Makefile
 	./gen_flagtabs_h --lowercase --i2s --s2i flag > $@
 
 gen_ftypetabs_h_SOURCES = gen_tables.c gen_tables.h ftypetab.h
-gen_ftypetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ftypetab.h"'
+gen_ftypetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ftypetab.h"'
+$(gen_ftypetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ftypetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ftypetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ftypetabs.h: gen_ftypetabs_h Makefile
 	./gen_ftypetabs_h --lowercase --i2s --s2i ftype > $@
 
 gen_i386_tables_h_SOURCES = gen_tables.c gen_tables.h i386_table.h
-gen_i386_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="i386_table.h"'
+gen_i386_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="i386_table.h"'
+$(gen_i386_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_i386_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_i386_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 i386_tables.h: gen_i386_tables_h Makefile
 	./gen_i386_tables_h --duplicate-ints --lowercase --i2s --s2i \
 		i386_syscall > $@
 
 gen_ia64_tables_h_SOURCES = gen_tables.c gen_tables.h ia64_table.h
-gen_ia64_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ia64_table.h"'
+gen_ia64_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ia64_table.h"'
+$(gen_ia64_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ia64_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ia64_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ia64_tables.h: gen_ia64_tables_h Makefile
 	./gen_ia64_tables_h --lowercase --i2s --s2i ia64_syscall > $@
 
 gen_machinetabs_h_SOURCES = gen_tables.c gen_tables.h machinetab.h
-gen_machinetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="machinetab.h"'
+gen_machinetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="machinetab.h"'
+$(gen_machinetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_machinetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_machinetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 machinetabs.h: gen_machinetabs_h Makefile
 	./gen_machinetabs_h --duplicate-ints --lowercase --i2s --s2i machine \
 		> $@
 
 gen_msg_typetabs_h_SOURCES = gen_tables.c gen_tables.h msg_typetab.h
-gen_msg_typetabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="msg_typetab.h"'
+gen_msg_typetabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="msg_typetab.h"'
+$(gen_msg_typetabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_msg_typetabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_msg_typetabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 msg_typetabs.h: gen_msg_typetabs_h Makefile
 	./gen_msg_typetabs_h --uppercase --i2s --s2i msg_type > $@
 
 gen_optabs_h_SOURCES = gen_tables.c gen_tables.h optab.h
-gen_optabs_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="optab.h"'
+gen_optabs_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="optab.h"'
+$(gen_optabs_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_optabs_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_optabs_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 optabs.h: gen_optabs_h Makefile
 	./gen_optabs_h --i2s op > $@
 
 gen_ppc_tables_h_SOURCES = gen_tables.c gen_tables.h ppc_table.h
-gen_ppc_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="ppc_table.h"'
+gen_ppc_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="ppc_table.h"'
+$(gen_ppc_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_ppc_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_ppc_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 ppc_tables.h: gen_ppc_tables_h Makefile
 	./gen_ppc_tables_h --lowercase --i2s --s2i ppc_syscall > $@
 
 gen_s390_tables_h_SOURCES = gen_tables.c gen_tables.h s390_table.h
-gen_s390_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="s390_table.h"'
+gen_s390_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="s390_table.h"'
+$(gen_s390_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_s390_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_s390_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 s390_tables.h: gen_s390_tables_h Makefile
 	./gen_s390_tables_h --lowercase --i2s --s2i s390_syscall > $@
 
 gen_s390x_tables_h_SOURCES = gen_tables.c gen_tables.h s390x_table.h
-gen_s390x_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="s390x_table.h"'
+gen_s390x_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="s390x_table.h"'
+$(gen_s390x_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_s390x_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_s390x_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 s390x_tables.h: gen_s390x_tables_h Makefile
 	./gen_s390x_tables_h --lowercase --i2s --s2i s390x_syscall > $@
 
 gen_x86_64_tables_h_SOURCES = gen_tables.c gen_tables.h x86_64_table.h
-gen_x86_64_tables_h_CFLAGS = $(AM_CFLAGS) '-DTABLE_H="x86_64_table.h"'
+gen_x86_64_tables_h_CFLAGS = $(CFLAGS_FOR_BUILD) '-DTABLE_H="x86_64_table.h"'
+$(gen_x86_64_tables_h_OBJECTS): CC=$(CC_FOR_BUILD)
+$(gen_x86_64_tables_h_OBJECTS): CPPFLAGS=$(CPPFLAGS_FOR_BUILD)
+gen_x86_64_tables_h$(BUILD_EXEEXT): CC=$(CC_FOR_BUILD)
 x86_64_tables.h: gen_x86_64_tables_h Makefile
 	./gen_x86_64_tables_h --lowercase --i2s --s2i x86_64_syscall > $@
diff --git a/m4/ax_prog_cc_for_build.m4 b/m4/ax_prog_cc_for_build.m4
new file mode 100644
index 0000000..77fd346
--- /dev/null
+++ b/m4/ax_prog_cc_for_build.m4
@@ -0,0 +1,125 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_PROG_CC_FOR_BUILD
+#
+# DESCRIPTION
+#
+#   This macro searches for a C compiler that generates native executables,
+#   that is a C compiler that surely is not a cross-compiler. This can be
+#   useful if you have to generate source code at compile-time like for
+#   example GCC does.
+#
+#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
+#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
+#   The value of these variables can be overridden by the user by specifying
+#   a compiler with an environment variable (like you do for standard CC).
+#
+#   It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
+#   file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
+#   the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
+#   substituted in the Makefile.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 8
+
+AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
+AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
+AC_REQUIRE([AC_PROG_CC])dnl
+AC_REQUIRE([AC_PROG_CPP])dnl
+AC_REQUIRE([AC_EXEEXT])dnl
+AC_REQUIRE([AC_CANONICAL_HOST])dnl
+
+dnl Use the standard macros, but make them use other variable names
+dnl
+pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
+pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
+pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
+pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
+pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
+pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
+pushdef([ac_cv_objext], ac_cv_build_objext)dnl
+pushdef([ac_exeext], ac_build_exeext)dnl
+pushdef([ac_objext], ac_build_objext)dnl
+pushdef([CC], CC_FOR_BUILD)dnl
+pushdef([CPP], CPP_FOR_BUILD)dnl
+pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
+pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
+pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
+pushdef([host], build)dnl
+pushdef([host_alias], build_alias)dnl
+pushdef([host_cpu], build_cpu)dnl
+pushdef([host_vendor], build_vendor)dnl
+pushdef([host_os], build_os)dnl
+pushdef([ac_cv_host], ac_cv_build)dnl
+pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
+pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
+pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
+pushdef([ac_cv_host_os], ac_cv_build_os)dnl
+pushdef([ac_cpp], ac_build_cpp)dnl
+pushdef([ac_compile], ac_build_compile)dnl
+pushdef([ac_link], ac_build_link)dnl
+
+save_cross_compiling=$cross_compiling
+save_ac_tool_prefix=$ac_tool_prefix
+cross_compiling=no
+ac_tool_prefix=
+
+AC_PROG_CC
+AC_PROG_CPP
+AC_EXEEXT
+
+ac_tool_prefix=$save_ac_tool_prefix
+cross_compiling=$save_cross_compiling
+
+dnl Restore the old definitions
+dnl
+popdef([ac_link])dnl
+popdef([ac_compile])dnl
+popdef([ac_cpp])dnl
+popdef([ac_cv_host_os])dnl
+popdef([ac_cv_host_vendor])dnl
+popdef([ac_cv_host_cpu])dnl
+popdef([ac_cv_host_alias])dnl
+popdef([ac_cv_host])dnl
+popdef([host_os])dnl
+popdef([host_vendor])dnl
+popdef([host_cpu])dnl
+popdef([host_alias])dnl
+popdef([host])dnl
+popdef([LDFLAGS])dnl
+popdef([CPPFLAGS])dnl
+popdef([CFLAGS])dnl
+popdef([CPP])dnl
+popdef([CC])dnl
+popdef([ac_objext])dnl
+popdef([ac_exeext])dnl
+popdef([ac_cv_objext])dnl
+popdef([ac_cv_exeext])dnl
+popdef([ac_cv_prog_cc_g])dnl
+popdef([ac_cv_prog_cc_cross])dnl
+popdef([ac_cv_prog_cc_works])dnl
+popdef([ac_cv_prog_gcc])dnl
+popdef([ac_cv_prog_CPP])dnl
+
+dnl Finally, set Makefile variables
+dnl
+BUILD_EXEEXT=$ac_build_exeext
+BUILD_OBJEXT=$ac_build_objext
+AC_SUBST(BUILD_EXEEXT)dnl
+AC_SUBST(BUILD_OBJEXT)dnl
+AC_SUBST([CFLAGS_FOR_BUILD])dnl
+AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
+AC_SUBST([LDFLAGS_FOR_BUILD])dnl
+])
-- 
1.9.1