Commit aeacb019 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: define KBUILD_MODNAME even if multiple modules share objects 



Currently, KBUILD_MODNAME is defined only when $(modname) contains
just one word.  If an object is shared among multiple modules,
undefined KBUILD_MODNAME could cause a build error.  For example,
if CONFIG_DYNAMIC_DEBUG is enabled, any call of printk() populates
.modname, then fails to build due to undefined KBUILD_MODNAME.

Take the following code as an example:

  obj-m += foo.o
  obj-m += bar.o
  foo-objs := foo-bar-common.o foo-only.o
  bar-objs := foo-bar-common.o bar-only.o

In this case, there is room for argument what to define for
KBUILD_MODNAME when foo-bar-common.o is being compiled.
"foo", "bar", or what else?

One idea is to define colon-separated modules that share the object,
in this case, "bar:foo" (modules are sorted alphabetically by
$(sort ...)).

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: default avatarCao jin <caoj.fnst@cn.fujitsu.com>
parent 8cd0e46d

scripts/Makefile.lib

+5 −7
Original line number Diff line number Diff line
@@ -87,13 +87,9 @@ subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 
# These flags are needed for modversions and compiling, so we define them here

# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will

# end up in (or would, if it gets compiled in)

# Note: Files that end up in two or more modules are compiled without the

#       KBUILD_MODNAME definition. The reason is that any made-up name would

#       differ in different configs.

name-fix = $(squote)$(quote)$(subst $(comma),_,$(subst -,_,$1))$(quote)$(squote)

basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))

modname_flags  = $(if $(filter 1,$(words $(modname))),\

                 -DKBUILD_MODNAME=$(call name-fix,$(modname)))

modname_flags  = -DKBUILD_MODNAME=$(call name-fix,$(modname))



orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \

                 $(ccflags-y) $(CFLAGS_$(basetarget).o)
@@ -174,8 +170,10 @@ dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \ 
		 -undef -D__DTS__



# Finds the multi-part object the current object will be linked into

modname-multi = $(sort $(foreach m,$(multi-used),\

		$(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=))))

# If the object belongs to two or more multi-part objects, all of them are

# concatenated with a colon separator.

modname-multi = $(subst $(space),:,$(sort $(foreach m,$(multi-used),\

		$(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=)))))



# Useful for describing the dependency of composite objects

# Usage:

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