[patch 4/6] uml kbuild: avoid useless rebuilds [for 2.6.13]
From: blaisorblade
Date: Sun Apr 24 2005 - 13:23:51 EST
*) Fix some problems with usage of $(targets) (sometimes missing, sometimes
used badly) that trigger partial rebuilds when doing a rebuild.
*) At that purpose, also factor out some common code for symlinks creation.
*) Fix a x86-64 build warning, caused by -L/usr/lib, which is anyway useless,
and invalid in the x86-64 case.
Tested on x86_64 and x86.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx>
---
linux-2.6.12-paolo/arch/um/Makefile | 2 +-
linux-2.6.12-paolo/arch/um/kernel/Makefile | 4 ++--
linux-2.6.12-paolo/arch/um/kernel/tt/Makefile | 1 +
linux-2.6.12-paolo/arch/um/scripts/Makefile.rules | 16 +++++++++++++++-
linux-2.6.12-paolo/arch/um/sys-i386/Makefile | 15 ++-------------
linux-2.6.12-paolo/arch/um/sys-x86_64/Makefile | 15 ++-------------
6 files changed, 23 insertions(+), 30 deletions(-)
diff -puN arch/um/kernel/Makefile~uml-Makefile-avoid-rebuild arch/um/kernel/Makefile
--- linux-2.6.12/arch/um/kernel/Makefile~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/kernel/Makefile 2005-04-24 19:32:17.000000000 +0200
@@ -4,7 +4,7 @@
#
extra-y := vmlinux.lds
-clean-files := vmlinux.lds.S config.tmp
+clean-files := vmlinux.lds.S
obj-y = checksum.o config.o exec_kern.o exitcode.o \
helper.o init_task.o irq.o irq_user.o ksyms.o main.o mem.o mem_user.o \
@@ -34,7 +34,7 @@ USER_OBJS := $(user-objs-y) config.o hel
include arch/um/scripts/Makefile.rules
-targets += config.c
+targets := config.c config.tmp
# Be careful with the below Sed code - sed is pitfall-rich!
# We use sed to lower build requirements, for "embedded" builders for instance.
diff -puN arch/um/kernel/tt/Makefile~uml-Makefile-avoid-rebuild arch/um/kernel/tt/Makefile
--- linux-2.6.12/arch/um/kernel/tt/Makefile~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/kernel/tt/Makefile 2005-04-24 19:32:17.000000000 +0200
@@ -4,6 +4,7 @@
#
extra-y := unmap_fin.o
+targets := unmap.o
clean-files := unmap_tmp.o
obj-y = exec_kern.o exec_user.o gdb.o ksyms.o mem.o mem_user.o process_kern.o \
diff -puN arch/um/scripts/Makefile.rules~uml-Makefile-avoid-rebuild arch/um/scripts/Makefile.rules
--- linux-2.6.12/arch/um/scripts/Makefile.rules~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/scripts/Makefile.rules 2005-04-24 19:32:17.000000000 +0200
@@ -10,4 +10,18 @@ USER_OBJS := $(foreach file,$(USER_OBJS)
$(USER_OBJS): c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) $(CFLAGS_$(notdir $@))
quiet_cmd_make_link = SYMLINK $@
-cmd_make_link = rm -f $@; ln -sf $(srctree)/arch/$(SUBARCH)/$($(notdir $@)-dir)/$(notdir $@) $@
+cmd_make_link = ln -sf $(srctree)/arch/$(SUBARCH)/$($(notdir $@)-dir)/$(notdir $@) $@
+
+# this needs to be before the foreach, because targets does not accept
+# complete paths like $(obj)/$(f). To make sure this works, use a := assignment,
+# or we will get $(obj)/$(f) in the "targets" value.
+# Also, this forces you to use the := syntax when assigning to targets.
+# Otherwise the line below will cause an infinite loop (if you don't know why,
+# just do it).
+
+targets := $(targets) $(SYMLINKS)
+
+SYMLINKS := $(foreach f,$(SYMLINKS),$(obj)/$(f))
+
+$(SYMLINKS): FORCE
+ $(call if_changed,make_link)
diff -puN arch/um/sys-x86_64/Makefile~uml-Makefile-avoid-rebuild arch/um/sys-x86_64/Makefile
--- linux-2.6.12/arch/um/sys-x86_64/Makefile~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/sys-x86_64/Makefile 2005-04-24 19:32:17.000000000 +0200
@@ -10,19 +10,9 @@ lib-y = bitops.o bugs.o csum-partial.o d
USER_OBJS := ptrace_user.o sigcontext.o
-include arch/um/scripts/Makefile.rules
-
SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
semaphore.c thunk.S
-# this needs to be before the foreach, because clean-files does not accept
-# complete paths like $(src)/$f.
-clean-files := $(SYMLINKS)
-
-targets += $(SYMLINKS)
-
-SYMLINKS := $(foreach f,$(SYMLINKS),$(obj)/$f)
-
bitops.c-dir = lib
csum-copy.S-dir = lib
csum-partial.c-dir = lib
@@ -31,7 +21,6 @@ memcpy.S-dir = lib
semaphore.c-dir = kernel
thunk.S-dir = lib
-$(SYMLINKS): FORCE
- $(call if_changed,make_link)
-
CFLAGS_csum-partial.o := -Dcsum_partial=arch_csum_partial
+
+include arch/um/scripts/Makefile.rules
diff -puN arch/um/sys-i386/Makefile~uml-Makefile-avoid-rebuild arch/um/sys-i386/Makefile
--- linux-2.6.12/arch/um/sys-i386/Makefile~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/sys-i386/Makefile 2005-04-24 19:32:17.000000000 +0200
@@ -6,24 +6,13 @@ obj-$(CONFIG_MODULES) += module.o
USER_OBJS := bugs.o ptrace_user.o sigcontext.o fault.o
-include arch/um/scripts/Makefile.rules
-
SYMLINKS = bitops.c semaphore.c highmem.c module.c
-# this needs to be before the foreach, because clean-files does not accept
-# complete paths like $(src)/$f.
-clean-files := $(SYMLINKS)
-
-targets += $(SYMLINKS)
-
-SYMLINKS := $(foreach f,$(SYMLINKS),$(obj)/$f)
-
bitops.c-dir = lib
semaphore.c-dir = kernel
highmem.c-dir = mm
module.c-dir = kernel
-$(SYMLINKS): FORCE
- $(call if_changed,make_link)
-
subdir- := util
+
+include arch/um/scripts/Makefile.rules
diff -puN arch/um/Makefile~uml-Makefile-avoid-rebuild arch/um/Makefile
--- linux-2.6.12/arch/um/Makefile~uml-Makefile-avoid-rebuild 2005-04-24 19:32:17.000000000 +0200
+++ linux-2.6.12-paolo/arch/um/Makefile 2005-04-24 19:32:17.000000000 +0200
@@ -126,7 +126,7 @@ define cmd_vmlinux__
$(CC) $(CFLAGS_vmlinux) -o $@ \
-Wl,-T,$(vmlinux-lds) $(vmlinux-init) \
-Wl,--start-group $(vmlinux-main) -Wl,--end-group \
- -L/usr/lib -lutil \
+ -lutil \
$(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) \
FORCE ,$^) ; rm -f linux
endef
_
-
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