diff options
author | Christoph Lameter <clameter@sgi.com> | 2008-04-28 11:12:44 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-28 17:58:21 +0200 |
commit | 1cdf25d704f7951d02a04064c97db547d6021872 (patch) | |
tree | 2571b70c1d95ea66086500b362a0f7fe2999acbc | |
parent | sparsemem: vmemmap does not need section bits (diff) | |
download | linux-1cdf25d704f7951d02a04064c97db547d6021872.tar.xz linux-1cdf25d704f7951d02a04064c97db547d6021872.zip |
kbuild: create a way to create preprocessor constants from C expressions
The use of enums create constants that are not available to the preprocessor
when building the kernel (f.e. MAX_NR_ZONES).
Arch code already has a way to export constants calculated to the preprocessor
through the asm-offsets.c file. Generate something similar for the core
kernel through kbuild.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | Kbuild | 56 | ||||
-rw-r--r-- | kernel/bounds.c | 19 |
2 files changed, 67 insertions, 8 deletions
@@ -1,19 +1,54 @@ # # Kbuild for top-level directory of the kernel # This file takes care of the following: -# 1) Generate asm-offsets.h -# 2) Check for missing system calls +# 1) Generate bounds.h +# 2) Generate asm-offsets.h (may need bounds.h) +# 3) Check for missing system calls ##### -# 1) Generate asm-offsets.h +# 1) Generate bounds.h + +bounds-file := include/linux/bounds.h + +always := $(bounds-file) +targets := $(bounds-file) kernel/bounds.s + +quiet_cmd_bounds = GEN $@ +define cmd_bounds + (set -e; \ + echo "#ifndef __LINUX_BOUNDS_H__"; \ + echo "#define __LINUX_BOUNDS_H__"; \ + echo "/*"; \ + echo " * DO NOT MODIFY."; \ + echo " *"; \ + echo " * This file was generated by Kbuild"; \ + echo " *"; \ + echo " */"; \ + echo ""; \ + sed -ne $(sed-y) $<; \ + echo ""; \ + echo "#endif" ) > $@ +endef + +# We use internal kbuild rules to avoid the "is up to date" message from make +kernel/bounds.s: kernel/bounds.c FORCE + $(Q)mkdir -p $(dir $@) + $(call if_changed_dep,cc_s_c) + +$(obj)/$(bounds-file): kernel/bounds.s Kbuild + $(Q)mkdir -p $(dir $@) + $(call cmd,bounds) + +##### +# 2) Generate asm-offsets.h # offsets-file := include/asm-$(SRCARCH)/asm-offsets.h -always := $(offsets-file) -targets := $(offsets-file) +always += $(offsets-file) +targets += $(offsets-file) targets += arch/$(SRCARCH)/kernel/asm-offsets.s -clean-files := $(addprefix $(objtree)/,$(targets)) + # Default sed regexp - multiline due to syntax constraints define sed-y @@ -40,7 +75,8 @@ define cmd_offsets endef # We use internal kbuild rules to avoid the "is up to date" message from make -arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c FORCE +arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c \ + $(obj)/$(bounds-file) FORCE $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c) @@ -49,7 +85,7 @@ $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s Kbuild $(call cmd,offsets) ##### -# 2) Check for missing system calls +# 3) Check for missing system calls # quiet_cmd_syscalls = CALL $< @@ -58,3 +94,7 @@ quiet_cmd_syscalls = CALL $< PHONY += missing-syscalls missing-syscalls: scripts/checksyscalls.sh FORCE $(call cmd,syscalls) + +# Delete all targets during make clean +clean-files := $(addprefix $(objtree)/,$(targets)) + diff --git a/kernel/bounds.c b/kernel/bounds.c new file mode 100644 index 000000000000..85bb281858cb --- /dev/null +++ b/kernel/bounds.c @@ -0,0 +1,19 @@ +/* + * Generate definitions needed by the preprocessor. + * This code generates raw asm output which is post-processed + * to extract and format the required data. + */ + +#define __GENERATING_BOUNDS_H +/* Include headers that define the enum constants of interest */ + +#define DEFINE(sym, val) \ + asm volatile("\n->" #sym " %0 " #val : : "i" (val)) + +#define BLANK() asm volatile("\n->" : : ) + +void foo(void) +{ + /* The enum constants to put into include/linux/bounds.h */ + /* End of constants */ +} |