linux-toradex.git/scripts/kconfig/conf.c, branch v5.1-rc4

kbuild: move ".config not found!" message from Kconfig to Makefile

2019-02-27T13:25:10+00:00

If you run "make" in a pristine source tree, currently Kbuild will
start to build Kconfig to let it show the error message.

It would be more straightforward to check it in Makefile and let
it fail immediately.

Signed-off-by: Masahiro Yamada

kconfig: convert to SPDX License Identifier

2018-12-28T13:22:28+00:00

All files in lxdialog/ are licensed under GPL-2.0+, and the rest are
under GPL-2.0. I added GPL-2.0 tags to test scripts in tests/.

Documentation/process/license-rules.rst does not suggest anything
about the flex/bison files. Because flex does not accept the C++
comment style at the very top of a file, I used the C style for
zconf.l, and so for zconf.y for consistency.

Signed-off-by: Masahiro Yamada

kconfig: remove oldnoconfig target

2018-11-01T15:15:25+00:00

As commit 312ee68752fa ("kconfig: announce removal of oldnoconfig if
used") announced, it is time for the removal.

Signed-off-by: Masahiro Yamada

kconfig: suppress "configuration written to .config" for syncconfig

2018-08-22T14:21:41+00:00

The top-level Makefile invokes "make syncconfig" when necessary.
Then, Kconfig displays the following message when .config is updated.

  #
  # configuration written to .config
  #

It is distracting because "make syncconfig" happens during the build
stage, and does nothing important in most cases.

Suggested-by: Linus Torvalds 
Signed-off-by: Masahiro Yamada

kconfig: allow all config targets to write auto.conf if missing

2018-07-25T14:25:30+00:00

Currently, only syncconfig creates or updates include/config/auto.conf
and some other files.  Other config targets create or update only the
.config file.

When you configure and build the kernel from a pristine source tree,
any config target is followed by syncconfig in the build stage since
include/config/auto.conf is missing.

We are moving compiler tests from Makefile to Kconfig.  It means that
parsing Kconfig files will be more costly since Kconfig invokes the
compiler commands internally.  Thus, we want to avoid invoking Kconfig
twice (one for *config to create the .config, and one for syncconfig
to synchronize the auto.conf).  If auto.conf does not exist, we can
generate all configuration files in the first configuration stage,
which will save the syncconfig in the build stage.

Please note this should be done only when auto.conf is missing.  If
*config blindly did this, time stamp files under include/config/ would
be unnecessarily touched, triggering unneeded rebuild of objects.

I assume a scenario like this:

 1. You have a source tree that has already been built
    with CONFIG_FOO disabled

 2. Run "make menuconfig" to enable CONFIG_FOO

 3. CONFIG_FOO turns out to be unnecessary.
    Run "make menuconfig" again to disable CONFIG_FOO

 4. Run "make"

In this case, include/config/foo.h should not be touched since there
is no change in CONFIG_FOO.  The sync process should be delayed until
the user really attempts to build the kernel.

This commit has another motivation; I want to suppress the 'No such
file or directory' warning from the 'include' directive.

The top-level Makefile includes auto.conf with '-include' directive,
like this:

  ifeq ($(dot-config),1)
  -include include/config/auto.conf
  endif

This looks strange because auto.conf is mandatory when dot-config is 1.
I guess only the reason of using '-include' is to suppress the warning
'include/config/auto.conf: No such file or directory' when building
from a clean tree.  However, this has a side-effect; Make considers
the files included by '-include' are optional.  Hence, Make continues
to build even if it fails to generate include/config/auto.conf.  I will
change this in the next commit, but the warning message is annoying.
(At least, kbuild test robot reports it as a regression.)

With this commit, Kconfig will generate all configuration files together
with the .config and I guess it is a solution good enough to suppress
the warning.

Note:
GNU Make 4.2 or later does not display the warning from the 'include'
directive if include files are successfully generated.  See GNU Make
commit 87a5f98d248f ("[SV 102] Don't show unnecessary include file
errors.")  However, older GNU Make versions are still widely used.

Signed-off-by: Masahiro Yamada

kconfig: make syncconfig update .config regardless of sym_change_count

2018-07-25T14:25:30+00:00

syncconfig updates the .config only when sym_change_count > 0, i.e.
any change in config symbols has been detected.

Not only symbols but also comments are contained in the .config file.
If only comments are updated, they are not fed back to the .config,
then the stale comments are left-over.  Of course, this is just a
matter of comments, but why not fix it.

I see some scenarios where this happens.

Scenario A:

 1. You have a source tree that has already been configured.

 2. Linus increments the version number in the top-level Makefile
    (i.e. he commits a new release)

 3. You pull it, and run 'make'

 4. syncconfig is invoked because the environment variable,
    KERNELVERSION is updated, but the .config is not updated since
    no config symbol is changed.

 5. The .config file contains a kernel version in the top line:

    # Automatically generated file; DO NOT EDIT.
    # Linux/arm64 4.18.0-rc2 Kernel Configuration

    ... which points to a previous version.

Scenario B:

 1. You have a source tree that has already been configured.

 2. You upgrade the compiler, but it still has the same version number.
    This may happen if you regularly build the latest compiler from
    the source code.

 3. You run 'make'

 4. syncconfig is invoked because the environment variable,
    CC_VERSION_TEXT is updated, but the .config is not updated since
    no config symbol is changed.

 5. The .config file contains the version string of the compiler:

    #
    # Compiler: aarch64-linux-gcc (GCC) 9.0.0 20180628 (experimental)
    #

    ... which carries the information of the old compiler.

If KCONFIG_NOSILENTUPDATE is set, syncconfig is not allowed to update
the .config file.  Otherwise, it is fine to update it regardless of
sym_change_count.

Signed-off-by: Masahiro Yamada

kconfig: drop localization support

2018-05-28T09:25:21+00:00

The localization support is broken and appears unused.
There is no google hits on the update-po-config target.
And there is no recent (5 years) activity related to the localization.

So lets just drop this as it is no longer used.

Suggested-by: Ulf Magnusson 
Suggested-by: Masahiro Yamada 
Signed-off-by: Sam Ravnborg 
Signed-off-by: Masahiro Yamada

kconfig: extend output of 'listnewconfig'

2018-04-13T14:23:11+00:00

We at Red Hat/Fedora have generally tried to have a per file breakdown of
every config option we set.  This makes it easy for us to add new options
when they are exposed and keep a changelog of why they were set.

A Fedora example is here:
  https://src.fedoraproject.org/cgit/rpms/kernel.git/tree/configs/fedora/generic

Using various merge scripts, we build up a config file and run it through
'make listnewconfig' and 'make oldnoconfig'.   The idea is to print out new
config options that haven't been manually set and use the default until
a patch is posted to set it properly.

To speed things up, it would be nice to make it easier to generate a
patch to post the default setting.  The output of 'make listnewconfig'
has two issues that limit us:

- it doesn't provide the default value
- it doesn't provide the new 'choice' options that get flagged in
  'oldconfig'

This patch extends 'listnewconfig' to address the above two issues.

This allows us to run a script

make listnewconfig | rhconfig-tool -o patches; git send-email patches/

The output of 'make listnewconfig':

CONFIG_NET_EMATCH_IPT
CONFIG_IPVLAN
CONFIG_ICE
CONFIG_NET_VENDOR_NI
CONFIG_IEEE802154_MCR20A
CONFIG_IR_IMON_DECODER
CONFIG_IR_IMON_RAW

The new output of 'make listnewconfig':

CONFIG_KERNEL_XZ=n
CONFIG_KERNEL_LZO=n
CONFIG_NET_EMATCH_IPT=n
CONFIG_IPVLAN=n
CONFIG_ICE=n
CONFIG_NET_VENDOR_NI=y
CONFIG_IEEE802154_MCR20A=n
CONFIG_IR_IMON_DECODER=n
CONFIG_IR_IMON_RAW=n

Signed-off-by: Don Zickus 
Signed-off-by: Masahiro Yamada

kconfig: rename silentoldconfig to syncconfig

2018-03-25T17:04:00+00:00

As commit cedd55d49dee ("kconfig: Remove silentoldconfig from help
and docs; fix kconfig/conf's help") mentioned, 'silentoldconfig' is a
historical misnomer.  That commit removed it from help and docs since
it is an internal interface.  If so, it should be allowed to rename
it to something more intuitive.  'syncconfig' is the one I came up
with because it updates the .config if necessary, then synchronize
include/generated/autoconf.h and include/config/* with it.

You should not manually invoke 'silentoldcofig'.  Display warning if
used in case existing scripts are doing wrong.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Ulf Magnusson

kconfig: hide irrelevant sub-menus for oldconfig

2018-03-25T17:03:59+00:00

Historically, "make oldconfig" has changed its behavior several times,
quieter or louder.  (I attached the history below.)  Currently, it is
not as quiet as it should be.  This commit addresses it.

  Test Case
  ---------

---------------------------(Kconfig)----------------------------
menu "menu"

config FOO
        bool "foo"

menu "sub menu"

config BAR
        bool "bar"

endmenu

endmenu

menu "sibling menu"

config BAZ
        bool "baz"

endmenu
----------------------------------------------------------------

---------------------------(.config)----------------------------
CONFIG_BAR=y
CONFIG_BAZ=y
----------------------------------------------------------------

With the Kconfig and .config above, "make silentoldconfig" and
"make oldconfig" work differently, like follows:

  $ make silentoldconfig
  scripts/kconfig/conf  --silentoldconfig Kconfig
  *
  * Restart config...
  *
  *
  * menu
  *
  foo (FOO) [N/y/?] (NEW) y
  #
  # configuration written to .config
  #

  $ make oldconfig
  scripts/kconfig/conf  --oldconfig Kconfig
  *
  * Restart config...
  *
  *
  * menu
  *
  foo (FOO) [N/y/?] (NEW) y
  *
  * sub menu
  *
  bar (BAR) [Y/n/?] y
  #
  # configuration written to .config
  #

Both hide "sibling node" since it is irrelevant.  The difference is
that silentoldconfig hides "sub menu" whereas oldconfig does not.
The behavior of silentoldconfig is preferred since the "sub menu"
does not contain any new symbol.

The root cause is in conf().  There are three input modes that can
call conf(); oldaskconfig, oldconfig, and silentoldconfig.

Everytime conf() encounters a menu entry, it calls check_conf() to
check if it contains new symbols.  If no new symbol is found, the
menu is just skipped.

Currently, this happens only when input_mode == silentoldconfig.
The oldaskconfig enters into the check_conf() loop as silentoldconfig,
so oldaskconfig works likewise for the second loop or later, but it
never happens for oldconfig.  So, irrelevant sub-menus are shown for
oldconfig.

Change the test condition to "input_mode != oldaskconfig".  This is
false only for the first loop of oldaskconfig; it must ask the user
all symbols, so no need to call check_conf().

  History of oldconfig
  --------------------

[0] Originally, "make oldconfig" was as loud as "make config"  (It
    showed the entire .config file)

[1] Commit cd9140e1e73a ("kconfig: make oldconfig is now less chatty")
    made oldconfig quieter, but it was still less quieter than
    silentoldconfig.  (oldconfig did not hide sub-menus)

[2] Commit 204c96f60904 ("kconfig: fix silentoldconfig") changed
    the input_mode of oldconfig to "ask_silent" from "ask_new".
    So, oldconfig really became as quiet as silentoldconfig.
    (oldconfig hided irrelevant sub-menus)

[3] Commit 4062f1a4c030 ("kconfig: use long options in conf") made
    oldconfig as loud as [0] due to misconversion.

[4] Commit 14828349719a ("kconfig: fix make oldconfig") addressed
    the misconversion of [3], but it made oldconfig quieter only to
    the same level as [1], not [2].

This commit is restoring the behavior of [2].

Signed-off-by: Masahiro Yamada 
Reviewed-by: Ulf Magnusson