The additional warnings are causing compile errors on gcc version 4.1.2 as a host compiler. cc -c -Wall -Wdeclaration-after-statement -Wpointer-arith -Wpointer-sign -Wno-unused -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts -Wmissing-prototypes -Wdeclaration-after-statement -Wempty-body -Wmissing-parameter-type -Wold-style-declaration -Wold- style-definition -Wformat-nonliteral -I. -I. -I./../../include filter_host.c cc1: error: unrecognized command line option "-Wempty-body" cc1: error: unrecognized command line option "-Wmissing-parameter-type" cc1: error: unrecognized command line option "-Wold-style-declaration" cc1: error: unrecognized command line option "-Wempty-body" cc1: error: unrecognized command line option "-Wmissing-parameter-type" cc1: error: unrecognized command line option "-Wold-style-declaration" Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>