Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757493AbXI2UK0 (ORCPT ); Sat, 29 Sep 2007 16:10:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752767AbXI2UKT (ORCPT ); Sat, 29 Sep 2007 16:10:19 -0400 Received: from pasmtpa.tele.dk ([80.160.77.114]:43478 "EHLO pasmtpA.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753472AbXI2UKR (ORCPT ); Sat, 29 Sep 2007 16:10:17 -0400 Date: Sat, 29 Sep 2007 22:11:45 +0200 From: Sam Ravnborg To: kbuild devel , LKML Subject: [RFC] Extending kbuild syntax Message-ID: <20070929201145.GA20377@uranus.ravnborg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8652 Lines: 275 Over the last few weeks I have pondered with the idea to extend the current kbuild syntax. The idea have existed for long but only recently I started to think how to do this in a truely flexible manner. Two areas are in need for a bit of attention to improve current kbuild files in the kernel. The first issue is the EXTRA_CFLAGS. They are often conditionally assigned like in the following example: ifeq ($(DEBUG),y) EXTRA_CFLAGS := -DDEBUG endif Introducing the following new variable could make this a oneliner: ccflags-y ccflags-$(DEBUG) := -DDEBUG grep -r -C 1 -B 1 EXTRA_CFLAGS shows that the above is a very common pattern especially in drivers/ The kbuild variable is named 'ccflags' to match the CC prefix for the C compiler used in non-verose output. And then it does not clash with current cflags-y usage too. The second is the more controversial suggestion. In several Makefile we have simple if expression of the variants: if ($(CONFIG_FOO),y) obj-$(CONFIG_BAR) += fubar.o endif The pattern varies over this theme. The suggestion here is to introduce a few helpers: obj-y-if-$(CONFIG_FOO) += fubar.o This one shall read: if $(CONFIG_FOO) is y or m then set += to obj-y In several cases we will need it to be more complicated like the this: obj-y-ify-$(CONFIG_FOO) += fubar.o This one shall read: if $(CONFIG_FOO) is y (thats the ify thing) then += to obj-y And we can mix it like the following: obj-$(CONFIG_BAR)-ify-$(CONFIG_FOO) += fubar.o This one shall read: if $(CONFIG_FOO) equal y then += to obj-$(CONFIG_BAR) The full list of new variables are (for obj-y): obj-y-if-y obj-y-if-m obj-y-ify-y obj-y-ifm-m obj-y-ifn- And similar for obj-m: obj-m-if-y obj-m-if-m obj-m-ify-y obj-m-ifm-m obj-m-ifn- The 'y' and 'm' can be replaced by $(CONFIG_FOO) but the one right to the if are not supposed to be replaced. To better express how to use it I have tried to update a few Makefiles to use the new syntax. See below. On MAJOR drawback is the linking order. I have no way to keep the link order if the new syntax are sued. The .o files will either be put before .o files specified with obj-y or obj-m or after the same. For some places this does not matter but for other places (fs/Makefile) I will expect it to matter a lot. Comments? Is this just to magic for bare humans to grasp. Or mabe the linking order is so important that we do not want it? PS. The coming x86 merge triggered this. I would like to make the Makefiles readable and the above can help here. Sam fs/Makefile | 10 +++------- kernel/Makefile | 8 ++------ mm/Makefile | 7 +++---- sound/Makefile | 4 +--- sound/core/seq/Makefile | 9 +++------ sound/i2c/Makefile | 4 +--- sound/isa/sb/Makefile | 6 ++---- sound/oss/Makefile | 4 +--- 8 files changed, 16 insertions(+), 36 deletions(-) diff --git a/fs/Makefile b/fs/Makefile index 720c29d..1b0a48e 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -13,11 +13,8 @@ obj-y := open.o read_write.o file_table.o super.o \ pnode.o drop_caches.o splice.o sync.o utimes.o \ stack.o -ifeq ($(CONFIG_BLOCK),y) -obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o -else -obj-y += no-block.o -endif +obj-y-ify-$(CONFIG_BLOCK) := buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o +obj-y-ifn-$(CONFIG_BLOCK) := no-block.o obj-$(CONFIG_INOTIFY) += inotify.o obj-$(CONFIG_INOTIFY_USER) += inotify_user.o @@ -28,8 +25,7 @@ obj-$(CONFIG_TIMERFD) += timerfd.o obj-$(CONFIG_EVENTFD) += eventfd.o obj-$(CONFIG_COMPAT) += compat.o compat_ioctl.o -nfsd-$(CONFIG_NFSD) := nfsctl.o -obj-y += $(nfsd-y) $(nfsd-m) +obj-y-if-$(CONFIG_NFSD) += nfsctl.o obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o obj-$(CONFIG_BINFMT_EM86) += binfmt_em86.o diff --git a/kernel/Makefile b/kernel/Makefile index 2a99983..5d7706e 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -15,13 +15,9 @@ obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o obj-$(CONFIG_LOCKDEP) += lockdep.o -ifeq ($(CONFIG_PROC_FS),y) -obj-$(CONFIG_LOCKDEP) += lockdep_proc.o -endif +obj-$(CONFIG_LOCKDEP)-if-$(CONFIG_PROC_FS) += lockdep_proc.o obj-$(CONFIG_FUTEX) += futex.o -ifeq ($(CONFIG_COMPAT),y) -obj-$(CONFIG_FUTEX) += futex_compat.o -endif +obj-$(CONFIG_FUTEX)-if-$(CONFIG_COMPAT) += futex_compat.o obj-$(CONFIG_RT_MUTEXES) += rtmutex.o obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o diff --git a/mm/Makefile b/mm/Makefile index 245e33a..3a55991 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -2,16 +2,15 @@ # Makefile for the linux memory manager. # -mmu-y := nommu.o -mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ +obj-y-ifn-$(CONFIG_MMU) := nommu.o +obj-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ vmalloc.o obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ page_alloc.o page-writeback.o pdflush.o \ readahead.o swap.o truncate.o vmscan.o \ - prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \ - $(mmu-y) + prio_tree.o util.o mmzone.o vmstat.o backing-dev.o obj-$(CONFIG_BOUNCE) += bounce.o obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o diff --git a/sound/Makefile b/sound/Makefile index 3ead922..cc2bba0 100644 --- a/sound/Makefile +++ b/sound/Makefile @@ -11,8 +11,6 @@ obj-$(CONFIG_SND_AOA) += aoa/ # This one must be compilable even if sound is configured out obj-$(CONFIG_AC97_BUS) += ac97_bus.o -ifeq ($(CONFIG_SND),y) - obj-y += last.o -endif +objy-ify-$(CONFIG_SND) += last.o soundcore-objs := sound_core.o diff --git a/sound/core/seq/Makefile b/sound/core/seq/Makefile index 402e2b4..1e676d9 100644 --- a/sound/core/seq/Makefile +++ b/sound/core/seq/Makefile @@ -4,9 +4,7 @@ # obj-$(CONFIG_SND) += instr/ -ifeq ($(CONFIG_SND_SEQUENCER_OSS),y) - obj-$(CONFIG_SND_SEQUENCER) += oss/ -endif +obj-$(CONFIG_SND_SEQUENCER)-ify-$(CONFIG_SND_SEQUENCER_OSS) += oss/ snd-seq-device-objs := seq_device.o snd-seq-objs := seq.o seq_lock.o seq_clientmgr.o seq_memory.o seq_queue.o \ @@ -28,9 +26,8 @@ snd-seq-virmidi-objs := seq_virmidi.o sequencer = $(if $(subst y,,$(CONFIG_SND_SEQUENCER)),$(if $(1),m),$(if $(CONFIG_SND_SEQUENCER),$(1))) obj-$(CONFIG_SND_SEQUENCER) += snd-seq.o snd-seq-device.o -ifeq ($(CONFIG_SND_SEQUENCER_OSS),y) -obj-$(CONFIG_SND_SEQUENCER) += snd-seq-midi-event.o -endif + +obj-$(CONFIG_SND_SEQUENCER)-ify-$(CONFIG_SND_SEQUENCER_OSS) += snd-seq-midi-event.o obj-$(CONFIG_SND_SEQ_DUMMY) += snd-seq-dummy.o # Toplevel Module Dependency diff --git a/sound/i2c/Makefile b/sound/i2c/Makefile index 45902d4..521708f 100644 --- a/sound/i2c/Makefile +++ b/sound/i2c/Makefile @@ -7,9 +7,7 @@ snd-i2c-objs := i2c.o snd-cs8427-objs := cs8427.o snd-tea6330t-objs := tea6330t.o -ifeq ($(subst m,y,$(CONFIG_L3)),y) - obj-$(CONFIG_L3) += l3/ -endif +obj-$(CONFIG_L3)-ifm-$(CONFIG_L3) += l3/ obj-$(CONFIG_SND) += other/ diff --git a/sound/isa/sb/Makefile b/sound/isa/sb/Makefile index 556e669..4681c46 100644 --- a/sound/isa/sb/Makefile +++ b/sound/isa/sb/Makefile @@ -29,10 +29,8 @@ obj-$(CONFIG_SND_SB8) += snd-sb8.o obj-$(CONFIG_SND_SB16) += snd-sb16.o obj-$(CONFIG_SND_SBAWE) += snd-sbawe.o obj-$(CONFIG_SND_ES968) += snd-es968.o -ifeq ($(CONFIG_SND_SB16_CSP),y) - obj-$(CONFIG_SND_SB16) += snd-sb16-csp.o - obj-$(CONFIG_SND_SBAWE) += snd-sb16-csp.o -endif +obj-$(CONFIG_SND_SB16)-ify-$(CONFIG_SND_SB16_CSP) += snd-sb16-csp.o +obj-$(CONFIG_SND_SBAWE)-ify-$(CONFIG_SND_SB16_CSP) += snd-sb16-csp.o obj-$(call sequencer,$(CONFIG_SND_SBAWE)) += snd-emu8000-synth.o obj-m := $(sort $(obj-m)) diff --git a/sound/oss/Makefile b/sound/oss/Makefile index 1200670..de54e00 100644 --- a/sound/oss/Makefile +++ b/sound/oss/Makefile @@ -29,9 +29,7 @@ obj-$(CONFIG_SOUND_VIDC) += vidc_mod.o obj-$(CONFIG_SOUND_WAVEARTIST) += waveartist.o obj-$(CONFIG_SOUND_VIA82CXXX) += via82cxxx_audio.o ac97_codec.o -ifeq ($(CONFIG_MIDI_VIA82CXXX),y) - obj-$(CONFIG_SOUND_VIA82CXXX) += sound.o uart401.o -endif +obj-$(CONFIG_SOUND_VIA82CXXX)-ify-$(CONFIG_MIDI_VIA82CXXX) += sound.o uart401.o obj-$(CONFIG_SOUND_MSNDCLAS) += msnd.o msnd_classic.o obj-$(CONFIG_SOUND_MSNDPIN) += msnd.o msnd_pinnacle.o obj-$(CONFIG_SOUND_VWSND) += vwsnd.o - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/