From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Raeman Date: Mon, 25 Jul 2016 15:52:26 -0400 Subject: [Buildroot] [PATCH 1/2] package/Makefile.in should grab HOST_DIR headers using -isystem instead of -I. Message-ID: <20160725195227.21112-1-draeman@bbn.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net HOST_CFLAGS includes a search path for HOST_DIR/usr/include using -I. When HOST_CFLAGS is used by a package, these flags are passed to the compiler ahead of flags passed by the package's internal make system. If a package has a header file with the same name as a header file in HOST_DIR, this causes the toolchain to prefer the file from the system include directory because its -I appears first on the command line. I believe conflicts should prefer the file provided by the package. This can be accomplished by using -isystem, which is more appropriate then -I for system-level include paths. Real-world example: I need libfdt present in my HOST_DIR to install a patched version of QEMU. Meanwhile, the u-boot package provides its own copy of libfdt.h that is modified from upstream. If I have libfdt installed into HOST_DIR, then host-uboot-tools fails to build because it grabs the libfdt.h from the HOST_DIR area instead of using the patched version from its own source tree. This patch corrects this issue. This assumes the -isystem flag is supported by the host compiler. Signed-off-by: David Raeman --- package/Makefile.in | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/package/Makefile.in b/package/Makefile.in index afd5d3a..b0ef706 100644 --- a/package/Makefile.in +++ b/package/Makefile.in @@ -222,7 +222,7 @@ UNZIP := $(shell which unzip || type -p unzip) -q APPLY_PATCHES = support/scripts/apply-patches.sh $(if $(QUIET),-s) -HOST_CPPFLAGS = -I$(HOST_DIR)/usr/include +HOST_CPPFLAGS = -isystem $(HOST_DIR)/usr/include HOST_CFLAGS ?= -O2 HOST_CFLAGS += $(HOST_CPPFLAGS) HOST_CXXFLAGS += $(HOST_CFLAGS) -- 2.7.4