linux-toradex.git/scripts/Kbuild.include, branch v4.12-rc4

Merge tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2017-05-11T03:11:05+00:00

Pull Kbuild updates from Masahiro Yamada:

 - improve Clang support

 - clean up various Makefiles

 - improve build log visibility (objtool, alpha, ia64)

 - improve compiler flag evaluation for better build performance

 - fix GCC version-dependent warning

 - fix genksyms

* tag 'kbuild-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (23 commits)
  kbuild: dtbinst: remove unnecessary __dtbs_install_prep target
  ia64: beatify build log for gate.so and gate-syms.o
  alpha: make short build log available for division routines
  alpha: merge build rules of division routines
  alpha: add $(src)/ rather than $(obj)/ to make source file path
  Makefile: evaluate LDFLAGS_BUILD_ID only once
  objtool: make it visible in make V=1 output
  kbuild: clang: add -no-integrated-as to KBUILD_[AC]FLAGS
  kbuild: Add support to generate LLVM assembly files
  kbuild: Add better clang cross build support
  kbuild: drop -Wno-unknown-warning-option from clang options
  kbuild: fix asm-offset generation to work with clang
  kbuild: consolidate redundant sed script ASM offset generation
  frv: Use OFFSET macro in DEF_*REG()
  kbuild: avoid conflict between -ffunction-sections and -pg on gcc-4.7
  kbuild: Consolidate header generation from ASM offset information
  kbuild: use -Oz instead of -Os when using clang
  kbuild, LLVMLinux: Add -Werror to cc-option to support clang
  Kbuild: make designated_init attribute fatal
  kbuild: drop unneeded patterns '.*.orig' and '.*.rej' from distclean
  ...

kbuild, LLVMLinux: Add -Werror to cc-option to support clang

2017-04-11T19:34:20+00:00

Clang will warn about unknown warnings but will not return false
unless -Werror is set. GCC will return false if an unknown
warning is passed.

Adding -Werror make both compiler behave the same.

[arnd: it turns out we need the same patch for testing whether -ffunction-sections
       works right with gcc. I've build tested extensively with this patch
       applied, so let's just merge this one now.]

Signed-off-by: Mark Charlebois 
Signed-off-by: Behan Webster 
Reviewed-by: Jan-Simon Möller 
Signed-off-by: Arnd Bergmann 
Acked-by: Kees Cook 
Signed-off-by: Masahiro Yamada

x86/build: Mostly disable '-maccumulate-outgoing-args'

2017-03-30T09:53:04+00:00

The GCC '-maccumulate-outgoing-args' flag is enabled for most configs,
mostly because of issues which are no longer relevant.  For most
configs, and with most recent versions of GCC, it's no longer needed.

Clarify which cases need it, and only enable it for those cases.  Also
produce a compile-time error for the ftrace graph + mcount + '-Os' case,
which will otherwise cause runtime failures.

The main benefit of '-maccumulate-outgoing-args' is that it prevents an
ugly prologue for functions which have aligned stacks.  But removing the
option also has some benefits: more readable argument saves, smaller
text size, and (presumably) slightly improved performance.

Here are the object size savings for 32-bit and 64-bit defconfig
kernels:

      text	   data	    bss	     dec	    hex	filename
  10006710	3543328	1773568	15323606	 e9d1d6	vmlinux.x86-32.before
   9706358	3547424	1773568	15027350	 e54c96	vmlinux.x86-32.after

      text	   data	    bss	     dec	    hex	filename
  10652105	4537576	 843776	16033457	 f4a6b1	vmlinux.x86-64.before
  10639629	4537576	 843776	16020981	 f475f5	vmlinux.x86-64.after

That comes out to a 3% text size improvement on x86-32 and a 0.1% text
size improvement on x86-64.

Signed-off-by: Josh Poimboeuf 
Cc: Andrew Lutomirski 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Linus Torvalds 
Cc: Pavel Machek 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble
Signed-off-by: Ingo Molnar

Kbuild: Add cpp_its_S in ksym_dep_filter

2017-02-14T09:00:26+00:00

Add a new command cpp_its_S introduced in commit cf2a5e0bb4c6 ("MIPS:
Support generating Flattened Image Trees (.itb)") to ksym_dep_filter
handler - otherwise a warning is produced during the build of MIPS
platforms (when vmlinux.*.itb target is chosen).

Signed-off-by: Marcin Nowakowski 
Cc: Michal Marek 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15278/
Signed-off-by: James Hogan

kbuild: no gcc-plugins during cc-option tests

2016-08-09T00:49:05+00:00

The gcc-plugins arguments should not be included when performing
cc-option tests.

Steps to reproduce:
1) make mrproper
2) make defconfig
3) enable GCC_PLUGINS, GCC_PLUGIN_CYC_COMPLEXITY
4) enable FUNCTION_TRACER (it will select other options as well)
5) make && make modules

Build errors:
MODPOST 18 modules
ERROR: "__fentry__" [net/netfilter/xt_nat.ko] undefined!
ERROR: "__fentry__" [net/netfilter/xt_mark.ko] undefined!
ERROR: "__fentry__" [net/netfilter/xt_addrtype.ko] undefined!
ERROR: "__fentry__" [net/netfilter/xt_LOG.ko] undefined!
ERROR: "__fentry__" [net/netfilter/nf_nat_sip.ko] undefined!
ERROR: "__fentry__" [net/netfilter/nf_nat_irc.ko] undefined!
ERROR: "__fentry__" [net/netfilter/nf_nat_ftp.ko] undefined!
ERROR: "__fentry__" [net/netfilter/nf_nat.ko] undefined!

Reported-by: Laura Abbott 
Signed-off-by: Emese Revfy 
[kees: renamed variable, clarified commit message]
Signed-off-by: Kees Cook

Kbuild: don't add obj tree in additional includes

2016-07-18T19:31:35+00:00

When building with separate object directories and driver specific
Makefiles that add additional header include paths, Kbuild adjusts
the gcc flags so that we include both the directory in the source
tree and in the object tree.

However, due to another bug I fixed earlier, this did not actually
include the correct directory in the object tree, so we know that
we only really need the source tree here. Also, including the
object tree sometimes causes warnings about nonexisting directories
when the include path only exists in the source.

This changes the logic to only emit the -I argument for the srctree,
not for objects. We still need both $(srctree)/$(src) and $(obj)
though, so I'm adding them manually.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Michal Marek

Kbuild: don't add ../../ to include path

2016-07-18T19:31:35+00:00

When we build with O=objdir and objdir is directly below the source tree,
$(srctree) becomes '..'.

When a Makefile adds a CFLAGS option like -Ipath/to/headers and
we are building with a separate object directory, Kbuild tries to
add two -I options, one for the source tree and one for the object
tree. An absolute path is treated as a special case, and don't add
this one twice. This also normally catches -I$(srctree)/$(src)
as $(srctree) usually is an absolute directory like /home/arnd/linux/.

The combination of the two behaviors however results in an invalid
path name to be included: we get both ../$(src) and ../../$(src),
the latter one pointing outside of the source tree, usually to a
nonexisting directory. Building with 'make W=1' makes this obvious:

cc1: error: ../../arch/arm/mach-s3c24xx/include: No such file or directory [-Werror=missing-include-dirs]

This adds another special case, treating path names starting with ../
like those starting with / so we don't try to prefix that with
$(srctree).

Signed-off-by: Arnd Bergmann 
Signed-off-by: Michal Marek

kbuild: fix if_change and friends to consider argument order

2016-05-10T19:21:14+00:00

Currently, arg-check is implemented as follows:

  arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
                      $(filter-out $(cmd_$@),   $(cmd_$(1))) )

This does not care about the order of arguments that appear in
$(cmd_$(1)) and $(cmd_$@).  So, if_changed and friends never rebuild
the target if only the argument order is changed.  This is a problem
when the link order is changed.

Apparently,

  obj-y += foo.o
  obj-y += bar.o

and

  obj-y += bar.o
  obj-y += foo.o

should be distinguished because the link order determines the probe
order of drivers.  So, built-in.o should be rebuilt when the order
of objects is changed.

This commit fixes arg-check to compare the old/current commands
including the argument order.

Of course, this change has a side effect; Kbuild will react to the
change of compile option order.  For example, "-DFOO -DBAR" and
"-DBAR -DFOO" should give no difference to the build result, but
false positive should be better than false negative.

I am moving space_escape to the top of Kbuild.include just for a
matter of preference.  In practical terms, space_escape can be
defined after arg-check because arg-check uses "=" flavor, not ":=".
Having said that, collecting convenient variables in one place makes
sense from the point of readability.

Chaining "%%%SPACE%%%" to "_-_SPACE_-_" is also a matter of taste
at this point.  Actually, it can be arbitrary as long as it is an
unlikely used string.  The only problem I see in "%%%SPACE%%%" is
that "%" is a special character in "$(patsubst ...)" context.  This
commit just uses "$(subst ...)" for arg-check, but I am fixing it now
in case we might want to use it in $(patsubst ...) context in the
future.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Michal Marek

kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line

2016-05-10T15:24:15+00:00

In kernel/cgroup.c there is:

    #define SUBSYS(_x)                                             \
        DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_enabled_key);    \
        DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_on_dfl_key);     \
        EXPORT_SYMBOL_GPL(_x ## _cgrp_subsys_enabled_key);         \
        EXPORT_SYMBOL_GPL(_x ## _cgrp_subsys_on_dfl_key);

The expansion of this macro causes multiple EXPORT_SYMBOL_GPL() instances
to appear on the same preprocessor line output, confusing the sed script
expecting only one of them per line.  Unfortunately this can't be fixed
nicely in the sed script as sed's regexp can't do non greedy matching.

Fix this by turning any semicolon into a line break before filtering.

Reported-by: Arnd Bergmann 
Signed-off-by: Nicolas Pitre 
Signed-off-by: Michal Marek

kbuild: adjust ksym_dep_filter for some cmd_* renames

2016-04-27T08:36:38+00:00

The following renames occurred recently:

  cmd_cc_i_c --> cmd_cpp_i_c
  cmd_as_s_S --> cmd_cpp_s_S

The respective cc_*_c and as_*_S patterns no longer match the above
therefore additional patterns are needed.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Michal Marek