From 338c4375153e39b95ddc82f2ed95f85dd73e0245 Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Thu, 7 Jun 2012 18:51:42 +0100 Subject: tools: pass EXTRA_CFLAGS via environment Currently qemu-xen will be compiled with CFLAGS only if CFLAGS was already in the environment during make invocation. If CFLAGS is in environment then make will append all of the various flags specified in xen Makefiles to this environment variable, which is then used in qemu configure. Since qemu-xen is not ready for compiler flags like "-std=gnu99" compilation will fail. If CFLAGS is not in environment, then configure will use just its own "-O2 -g" because make does not export its own CFLAGS variable. >From a distro perspective, it is required to build libraries and binaries with certain global cflags (arbitrary gcc options). Up to the point when qemu-xen was imported it worked as expected by exporting CFLAGS before 'make tools'. Now qemu-upstream reuses these CFLAGS, but it cant deal with the result. This patch extends the tools Makefiles so that three new environment variables are recognized: EXTRA_CFLAGS_XEN_TOOLS= specifies CFLAGS for the tools build. EXTRA_CFLAGS_QEMU_TRADITIONAL= specifies CFLAGS for old qemu. EXTRA_CFLAGS_QEMU_XEN= specifies CFLAGS for new qemu. Special care needs to be taken in tools/firmware because the resulting binaries are not linked with the hosts runtime libraries. These binaries run in guest context. To avoid build errors from gcc options like -fstack-protector, reuse existing practice to unset the new EXTRA_CFLAGS_XEN_TOOLS for the firmware dirs. The new feature can be used like this in a rpm xen.spec file: export EXTRA_CFLAGS_XEN_TOOLS="${RPM_OPT_FLAGS}" export EXTRA_CFLAGS_QEMU_TRADITIONAL="${RPM_OPT_FLAGS}" export EXTRA_CFLAGS_QEMU_XEN="${RPM_OPT_FLAGS}" ./configure \ --libdir=%{_libdir} \ --prefix=/usr make Acked-by: Ian Jackson Committed-by: Ian Jackson --- tools/Rules.mk | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/Rules.mk') diff --git a/tools/Rules.mk b/tools/Rules.mk index a2a1a5846a..1e928b7b22 100644 --- a/tools/Rules.mk +++ b/tools/Rules.mk @@ -76,6 +76,8 @@ endif CFLAGS-$(CONFIG_X86_32) += $(call cc-option,$(CC),-mno-tls-direct-seg-refs) CFLAGS += $(CFLAGS-y) +CFLAGS += $(EXTRA_CFLAGS_XEN_TOOLS) + # Require GCC v3.4+ (to avoid issues with alignment constraints in Xen headers) check-$(CONFIG_X86) = $(call cc-ver-check,CC,0x030400,\ "Xen requires at least gcc-3.4") -- cgit v1.2.3