turn off unused-but-set-variable for gcc-4.6

[ipfw.git] / ipfw / Makefile

diff --git a/ipfw/Makefile b/ipfw/Makefile
index 387c987..439bed9 100644 (file)
--- a/ipfw/Makefile
+++ b/ipfw/Makefile
@@ -1,6 +1,4 @@
 #
-# $Id$
-#
 # GNUMakefile to build the userland part of ipfw on Linux and Windows
 #
 # enable extra debugging information
@@ -9,6 +7,28 @@ XOSARCH := $(shell uname)
 OSARCH ?= $(XOSARCH)
 $(warning Building userland ipfw for $(VER) $(OSARCH))
 
+# utility to figure if gcc has a given option
+#################### extract from Kbuild.include
+# try-run
+# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
+# Exit code chooses option. "$$TMP" is can be used as temporary file and
+# is automatically cleaned up.
+try-run = $(shell set -e;               \
+        TMP="$(TMPOUT).$$$$.tmp";       \
+        TMPO="$(TMPOUT).$$$$.o";        \
+        if ($(1)) >/dev/null 2>&1;      \
+        then echo "$(2)";               \
+        else echo "$(3)";               \
+        fi;                             \
+        rm -f "$$TMP" "$$TMPO")
+
+# cc-option
+# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
+
+cc-option = $(call try-run,\
+        $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
+#################### 
+
 #TCC=c:/tesi/tcc
 
 # common flags
@@ -22,6 +42,7 @@ ifneq ($(VER),openwrt)
 ifeq ($(OSARCH),Linux)
     EXTRA_CFLAGS += -D__BSD_VISIBLE
     EXTRA_CFLAGS += -Werror
+    EXTRA_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable)
 else # must be Cygwin ?
 ifeq ($(TCC),)
     EXTRA_CFLAGS += -I/cygdrive/c/WinDDK/7600.16385.0/inc/ddk