[PATCH 4/5] kbuild: asm symlink support for arch/$ARCH/include

Sam Ravnborg
2008-06-22T22:07:59Z

Adjust the asm symlink support so we do not create the
symlink unless really needed.
We check the precense of include/asm-$ARCH by checking
for the system.h file. We may end up with a stale directory
so it is not enough to check if the directory is present.

For "make O=..." build if we see that asm is a symlink
then it is deleted. This happens when we apply this patch
to a kernel with a valid build - so we do not require
a "make mrproper".

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
---
Kbuild | 2 +-
Makefile | 50 ++++++++++++++++++++++++++++++++++++--------------
2 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/Kbuild b/Kbuild
index e750e9c..254a6af 100644
--- a/Kbuild
+++ b/Kbuild
@@ -43,7 +43,7 @@ $(obj)/$(bounds-file): kernel/bounds.s Kbuild
# 2) Generate asm-offsets.h
#

-offsets-file := include/asm-$(SRCARCH)/asm-offsets.h
+offsets-file := include/asm/asm-offsets.h

always += $(offsets-file)
targets += $(offsets-file)
diff --git a/Makefile b/Makefile
index 115eb48..aac0ae0 100644
--- a/Makefile
+++ b/Makefile
@@ -921,7 +921,9 @@ ifneq ($(KBUILD_SRC),)
/bin/false; \
fi;
$(Q)if [ ! -d include2 ]; then mkdir -p include2; fi;
- $(Q)ln -fsn $(srctree)/include/asm-$(SRCARCH) include2/asm
+ $(Q)if [ -e $(srctree)/include/asm-$(SRCARCH)/system.h ]; then \
+ ln -fsn $(srctree)/include/asm-$(SRCARCH) include2/asm; \
+ fi
endif

# prepare2 creates a makefile if using a separate output directory
@@ -947,22 +949,42 @@ export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)

# The asm symlink changes when $(ARCH) changes.
# Detect this and ask user to run make mrproper
-
-include/asm: FORCE
- $(Q)set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`; \
- if [ -L include/asm ]; then \
- if [ "$$asmlink" != "$(SRCARCH)" ]; then \
+define check-symlink
+ set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`; \
+ if [ -L include/asm ]; then \
+ if [ "$$asmlink" != "$(SRCARCH)" ]; then \
echo "ERROR: the symlink $@ points to asm-$$asmlink but asm-$(SRCARCH) was expected"; \
echo " set ARCH or save .config and run 'make mrproper' to fix it"; \
- exit 1; \
- fi; \
- else \
- echo ' SYMLINK $@ -> include/asm-$(SRCARCH)'; \
- if [ ! -d include ]; then \
- mkdir -p include; \
- fi; \
- ln -fsn asm-$(SRCARCH) $@; \
+ exit 1; \
+ fi; \
fi
+endef
+
+# For make O=... builds we create a directory when we create
+# asm-offsets so no need to try to create a symlink then
+ifneq ($(KBUILD_SRC),)
+define create-symlink
+ if [ -L include/asm ]; then \
+ rm include/asm; \
+ fi
+endef
+else
+define create-symlink
+ if [ ! -L include/asm ]; then \
+ if [ -e $(srctree)/include/asm-$(SRCARCH)/system.h ]; then \
+ echo ' SYMLINK $@ -> include/asm-$(SRCARCH)'; \
+ if [ ! -d include ]; then \
+ mkdir -p include; \
+ fi; \
+ ln -fsn asm-$(SRCARCH) $@; \
+ fi \
+ fi
+endef
+endif
+
+include/asm: FORCE
+ $(Q)$(check-symlink)
+ $(Q)$(create-symlink)

# Generate some files
# ---------------------------------------------------------------------------
--
1.5.4.1.143.ge7e51