[RFC PATCH 3/8] kbuild: convert include and source paths

[Peter Oberparleiter <peter.oberparleiter@de.ibm.com>]

From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>

Modify kbuild to convert relative include and source paths to absolute
form. Also change the module versioning mechanism to alter object file
names only after compiling.

Required by the gcov profiling infrastructure: source paths are
referenced by the compiled object files. Using relative paths or
object file names which are different from the source name would
prevent the gcov tool from finding the corresponding source files.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
---
 Makefile               |    6 +++---
 scripts/Kbuild.include |    2 ++
 scripts/Makefile.build |    7 +++++--
 scripts/Makefile.lib   |    2 +-
 4 files changed, 11 insertions(+), 6 deletions(-)

Index: linux-2.6.25/scripts/Makefile.build
===================================================================
--- linux-2.6.25.orig/scripts/Makefile.build
+++ linux-2.6.25/scripts/Makefile.build
@@ -167,7 +167,8 @@ $(obj)/%.symtypes : $(src)/%.c FORCE
 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 
 ifndef CONFIG_MODVERSIONS
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
+cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ \
+	     $(if $(filter-out /%,$<),$(objtree)/$<,$<)
 
 else
 # When module versioning is enabled the following steps are executed:
@@ -182,7 +183,9 @@ else
 #   replace the unresolved symbols __crc_exported_symbol with
 #   the actual value of the checksum generated by genksyms
 
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
+cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/$(@F) \
+	     $(if $(filter-out /%,$<),$(objtree)/$<,$<) ; \
+             mv -f $(@D)/$(@F) $(@D)/.tmp_$(@F)
 cmd_modversions =							\
 	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then	\
 		$(CPP) -D__GENKSYMS__ $(c_flags) $<			\
Index: linux-2.6.25/scripts/Makefile.lib
===================================================================
--- linux-2.6.25.orig/scripts/Makefile.lib
+++ linux-2.6.25/scripts/Makefile.lib
@@ -113,7 +113,7 @@ else
 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
 #   and locates generated .h files
 # FIXME: Replace both with specific CFLAGS* statements in the makefiles
-__c_flags	= $(call addtree,-I$(obj)) $(call flags,_c_flags)
+__c_flags	= $(call addtree,-I$(obj)) $(call addtree2,-I$(obj)) $(call flags,_c_flags)
 __a_flags	=                          $(call flags,_a_flags)
 __cpp_flags     =                          $(call flags,_cpp_flags)
 endif
Index: linux-2.6.25/scripts/Kbuild.include
===================================================================
--- linux-2.6.25.orig/scripts/Kbuild.include
+++ linux-2.6.25/scripts/Kbuild.include
@@ -145,6 +145,8 @@ build := -f $(if $(KBUILD_SRC),$(srctree
 
 # Prefix -I with $(srctree) if it is not an absolute path.
 addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1))
+# Prefix -I with $(objtree) if it is not an absolute path.
+addtree2 = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(objtree)/%,$(1)),$(1))
 
 # Find all -I options and call addtree
 flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
Index: linux-2.6.25/Makefile
===================================================================
--- linux-2.6.25.orig/Makefile
+++ linux-2.6.25/Makefile
@@ -324,9 +324,9 @@ AFLAGS_KERNEL	=
 
 # Use LINUXINCLUDE when you must reference the include/ directory.
 # Needed to be compatible with the O= option
-LINUXINCLUDE    := -Iinclude \
-                   $(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include) \
-		   -include include/linux/autoconf.h
+LINUXINCLUDE    := -I$(objtree)/include -I$(srctree) -I$(objtree) \
+                   $(if $(KBUILD_SRC),-I$(objtree)/include2 \
+		   -I$(srctree)/include) -include include/linux/autoconf.h
 
 KBUILD_CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)