[PATCH] KBUILD_MODNAME define for build system

By Kai Germaschewski.

This patch adds a -DKBUILD_MODNAME to the kernel compile, which
contains the base of the module name which is being built.

 - Some sreorganization of the c_flags since they're needed for
   generating modversions (.ver) and compiling
 - Use the right KBUILD_MODNAME also when the user just wants a .i/.s/.lst
   file for debugging and also when generating modversions
 - It looks like with your current approach you can't have a ',' or '-' in
   KBUILD_MODNAME - however, that means that KBUILD_MODNAME is not quite
   right for passing module parameters for built-in modules on the command
   line, it would be confusing to pass parameters for ide-cd as
   ide_cd.foo=whatever. So that part could use a little more thought.
 - If you think your module_names trick makes a noticable difference, feel
   free to re-add it.
 - It's possible that objects are linked into more than one module - I
   suppose this shouldn't be a problem, since these objects hopefully
   don't have a module_init() nor do they export symbols. Not sure if your
   patch did handle this.

net/unix/af_unix.c

@@ -79,6 +79,8 @@
  *		  with BSD names.
  */
 
+#undef unix	/* KBUILD_MODNAME */
+
 #include <linux/module.h>
 #include <linux/config.h>
 #include <linux/kernel.h>

scripts/Makefile.build

@@ -56,6 +56,7 @@ modkern_cflags := $(CFLAGS_KERNEL)
 
 $(real-objs-m)        : modkern_cflags := $(CFLAGS_MODULE)
 $(real-objs-m:.o=.i)  : modkern_cflags := $(CFLAGS_MODULE)
+$(real-objs-m:.o=.s)  : modkern_cflags := $(CFLAGS_MODULE)
 $(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)
 
 $(export-objs)        : export_flags   := $(EXPORT_FLAGS)
@@ -63,10 +64,17 @@ $(export-objs:.o=.i)  : export_flags   := $(EXPORT_FLAGS)
 $(export-objs:.o=.s)  : export_flags   := $(EXPORT_FLAGS)
 $(export-objs:.o=.lst): export_flags   := $(EXPORT_FLAGS)
 
-c_flags = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
-	  $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
-	  -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F))) \
-	  $(export_flags) 
+# Default for not multi-part modules
+modname = $(*F)
+
+$(multi-objs-m)         : modname = $(modname-multi)
+$(multi-objs-m:.o=.i)   : modname = $(modname-multi)
+$(multi-objs-m:.o=.s)   : modname = $(modname-multi)
+$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
+$(multi-objs-y)         : modname = $(modname-multi)
+$(multi-objs-y:.o=.i)   : modname = $(modname-multi)
+$(multi-objs-y:.o=.s)   : modname = $(modname-multi)
+$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
 
 quiet_cmd_cc_s_c = CC      $@
 cmd_cc_s_c       = $(CC) $(c_flags) -S -o $@ $< 

scripts/Makefile.lib

@@ -5,6 +5,8 @@
 # Standard vars
 
 comma   := ,
+empty   :=
+space   := $(empty) $(empty)
 
 # Figure out what we need to build from the various variables
 # ===========================================================================
@@ -40,11 +42,13 @@ __obj-m = $(filter-out export.o,$(obj-m))
 # if $(foo-objs) exists, foo.o is a composite object 
 multi-used-y := $(sort $(foreach m,$(__obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
 multi-used-m := $(sort $(foreach m,$(__obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m))))
+multi-used   := $(multi-used-y) $(multi-used-m)
 
 # Build list of the parts of our composite objects, our composite
 # objects depend on those (obviously)
 multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))
 multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
+multi-objs   := $(multi-objs-y) $(multi-objs-m)
 
 # $(subdir-obj-y) is the list of objects in $(obj-y) which do not live
 # in the local directory
@@ -112,6 +116,23 @@ host-cshobjs	:= $(addprefix $(obj)/,$(host-cshobjs))
 # contain a comma
 depfile = $(subst $(comma),_,$(@D)/.$(@F).d)
 
+# These flags are needed for modversions and compiling, so we define them here
+# already
+# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will 
+# end up in (or would, if it gets compiled in)
+# Note: It's possible that one object gets potentially linked into more
+#       than one module. In that case KBUILD_MODNAME will be set to foo_bar,
+#       where foo and bar are the name of the modules.
+basename_flags = -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F)))
+modname_flags  = -DKBUILD_MODNAME=$(subst $(comma),_,$(subst -,_,$(modname)))
+c_flags        = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
+	         $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
+	         $(basename_flags) $(modname_flags) $(export_flags) 
+
+# Finds the multi-part object the current object will be linked into
+modname-multi = $(subst $(space),_,$(strip $(foreach m,$(multi-used),\
+		$(if $(filter $(*F).o,$($(m:.o=-objs))),$(m:.o=)))))
+
 # Shipped files
 # ===========================================================================
 

scripts/Makefile.modver

@@ -48,11 +48,10 @@ CFLAGS_MODULE := $(filter-out -include include/linux/modversions.h,$(CFLAGS_MODU
 $(addprefix $(MODVERDIR)/,$(real-objs-y:.o=.ver)): modkern_cflags := $(CFLAGS_KERNEL)
 $(addprefix $(MODVERDIR)/,$(real-objs-m:.o=.ver)): modkern_cflags := $(CFLAGS_MODULE)
 $(addprefix $(MODVERDIR)/,$(export-objs:.o=.ver)): export_flags   := -D__GENKSYMS__
+# Default for not multi-part modules
+modname = $(*F)
 
-c_flags = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
-	  $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
-	  -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F))) \
-	  $(export_flags) 
+$(addprefix $(MODVERDIR)/,$(multi-objs:.o=.ver)) : modname = $(modname-multi)
 
 # Our objects only depend on modversions.h, not on the individual .ver
 # files (fix-dep filters them), so touch modversions.h if any of the .ver