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: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NUlf Magnusson <ulfalizer@gmail.com>
Suggested-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

As commit cedd55d4 ("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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

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 cd9140e1 ("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 204c96f6 ("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 4062f1a4 ("kconfig: use long options in conf") made
    oldconfig as loud as [0] due to misconversion.

[4] Commit 14828349 ("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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

check_conf() never increments conf_cnt for listnewconfig, so conf_cnt
is always zero.

In other words, conf_cnt is not zero, "input_mode != listnewconfig"
is met.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

conf() is never called for listnewconfig / olddefconfig.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

check_conf() traverses the menu tree, but it is completely no-op for
olddefconfig because the following if-else block does nothing.

    if (input_mode == listnewconfig) {
            ...
    } else if (input_mode != olddefconfig) {
            ...
    }

As the help message says, olddefconfig automatically sets new symbols
to their default value.  There is no room for manual intervention.
So, calling check_conf() for olddefconfig is odd in the first place.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

These messages should be directed to stderr.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

If stdio is not tty, conf_askvalue() puts additional new line to
prevent prompts from being concatenated into a single line.  This
care is missing in conf_choice(), so a 'choice' prompt and the next
prompt are shown in the same line.

Move the code into xfgets() to cater to all cases.  To improve this
more, let's echo stdin to stdout.  This clarifies what keys were
input from stdio and the stdout looks like as if it were from tty.

I removed the isatty(2) check since stderr is unrelated here.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

Except silentoldconfig, valid_stdin is 1, so check_stdin() is no-op.

oldconfig and silentoldconfig work almost in the same way except that
the latter generates additional files under include/.  Both ask users
for input for new symbols.

I do not know why only silentoldconfig requires stdio be tty.

  $ rm -f .config; touch .config
  $ yes "" | make oldconfig > stdout
  $ rm -f .config; touch .config
  $ yes "" | make silentoldconfig > stdout
  make[1]: *** [silentoldconfig] Error 1
  make: *** [silentoldconfig] Error 2
  $ tail -n 4 stdout
  Console input/output is redirected. Run 'make oldconfig' to update configuration.

  scripts/kconfig/Makefile:40: recipe for target 'silentoldconfig' failed
  Makefile:507: recipe for target 'silentoldconfig' failed

Redirection is useful, for example, for testing where we want to give
particular key inputs from a test file, then check the result.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

'make config', 'make oldconfig', etc. always receive '?' as a valid
input and show useful information even if no help text is available.

------------------------>8------------------------
foo (FOO) [N/y] (NEW) ?

There is no help available for this option.
Symbol: FOO [=n]
Type  : bool
Prompt: foo
  Defined at Kconfig:1
------------------------>8------------------------

However, '?' is not shown in the prompt if its help text is missing.
Let's show '?' all the time so that the prompt and the behavior match.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

As explained by Michal Marek at https://lkml.org/lkml/2011/8/31/189
silentoldconfig has become a misnomer. It has become an internal interface
so remove it from "make help" and Documentation/ to stop confusing people
using it as seen for instance at
https://chromium-review.googlesource.com/835632 Don't remove it from
kconfig/Makefile yet not to break any (other) tool using it.

On the other hand, correct and expand its description in the help of
the (internal) scripts/kconfig/conf.c
Signed-off-by: NMarc Herbert <marc.herbert@intel.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Sparse reports:
  warning: symbol 'xfgets' was not declared. Should it be static?

It is declared as static, but it is missing in the definition part.
Move the definition up and remove the forward declaration.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Sparse reports:
  warning: symbol 'input_mode' was not declared. Should it be static?
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The current (arbitrary) limit of 128 characters for path names has
proven too short for Android builds, as longer path names are used
there.

Change conf.c, so it can handle path lengths up to PATH_MAX characters.
Signed-off-by: NMarkus Mayer <mmayer@broadcom.com>
Signed-off-by: NMichal Marek <mmarek@suse.com>

Add an -s option to the various frontends and pass it when make -s is
used. Also, use $(kecho) instead of @echo in the Makefile.
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Because of choice-in-a-choice constructs, it can happen that not all
symbols are assigned a value during randconfig, leading in rare cases
to this situation:

    ---8<--- choice-in-choice.in
    choice
        bool "A/B/C"
    config A
        bool "A"

    config B
        bool "B"
    if B
    choice
        bool "E/F"
    config E
        bool "E"
    config F
        bool "F"
    endchoice
    endif # B

    config C
        bool "C"
    endchoice
    ---8<---

    $ ./scripts/kconfig/conf --randconfig choice-in-choice.in
    [--SNIP--]
    $ ./scripts/kconfig/conf --silentoldconfig choice-in-choice.in </dev/null
    [--SNIP--]
    A/B/C
      1. A (A)
    > 2. B (B)
      3. C (C)
    choice[1-3]: 2
      E/F
      > 1. E (E) (NEW)
        2. F (F) (NEW)
      choice[1-2]: aborted!

    Console input/output is redirected. Run 'make oldconfig' to update
    configuration.

Fix this by looping in randconfig for as long as some symbol gets assigned
a value.

Note: this was spotted with the USB EHCI Debug Device Gadget (USB_G_DBGP),
which uses this choice-in-a-choice construct, and exhibits this problem.
The example above is just a stripped-down minimalist test-case.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

... so the user has a chance to reproduce a test-case.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

For reproducibility, it can be useful to be able to specify the
seed to use to seed the RNG.

Add a new KCONFIG_SEED environment variable which can be set to
the seed to use:
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config

It's very usefull for eg. debugging the kconfig parser.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

According to Documentation/kbuild/kconfig.txt, the commands:

    yes "" | make oldconfig >conf.new
    grep "(NEW)" conf.new

should list the new config symbols with their default values.
However, currently there is no line break after each new symbol.  When
kconfig is interactive the user will type a new-line at this point,
but when non-interactive kconfig must print it.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Reference: http://bugs.debian.org/636029
[regid23@nt1.in: Adjusted Ben's work to apply cleanly to this tree]
Reported-and-tested-by: NRegid Ichira <regid23@nt1.in>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

As 67d34a6a said, 'oldnoconfig' doesn't
set new symbols to 'n', but instead sets it to their default values.

So, this patch replaces 'oldnoconfig' with 'olddefconfig', stop making
people confused, and keep the old name 'oldnoconfig' as an alias,
because people already are dependent on its behavior with the
counter-intuitive name.
Signed-off-by: NAdam Lee <adam8157@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

As 67d34a6a said, the make target
'oldnoconfig' is a misnomer. It doesn't set new symbols to 'n', but
instead sets it to their default values.

This patch fixes the document in conf.c, and will submit another patch
to replace 'oldnoconfig' to 'olddefconfig'
Signed-off-by: NAdam Lee <adam8157@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Prevent subtle surprises to both people working on the kconfig code
and people using make allnoconfig allyesconfig allmoconfig and
randconfig by only attempting to read a config file if
KCONFIG_ALLCONFIG is set.

Common sense suggests attempting to read the extra config files does
not make sense unless requested.  The documentation says the code
won't attempt to read the extra config files unless requested.
Current usage does not appear to include people depending on the code
reading the config files without the variable being set So do the
simple thing and stop reading config files when passed
all{no,yes,mod,def,rand}config unless KCONFIG_ALLCONFIG environment
variable is set.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

- Only try to read the file specified if KCONFIG_ALL_CONFIG is set to
  something other than the empty string or "1".

- Don't use stat to check the name passed to conf_read_simple so that
  zconf_fopen can find the file in the current directory or in SRCTREE
  removing a extremely source of confusing failure, where KCONFIG_ALL_CONFIG
  was not interpreted with respect to the directory make was called in.

- If conf_read_simple fails complain clearly and stop processing.
  Allowing the simple debugging of typos.

- Clearly document the behavior so it is clear to users which
  values are treated as flags and which values are treated as
  filenames.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This function has not much reason to be public. In the mean time, convert
declaration from K&R C to ISO C.
Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>

This variable is not used outside of main() so there is not much reason keeping
it global. Ensure it is initialized as gcc has no way to know that normal
execution path expect only one option switch to be given on the command line
(except when we request help). As a result, we always initialize
`defconfig_file' before using it.
Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>

This interface is not (and has never been ?) used by any frontend, just get rid
of it.
Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>

Commit 40aee729 ('kconfig: fix default value for choice input')
fixed some cases where kconfig would select the wrong option from a
choice with a single valid option and thus enter an infinite loop.

However, this broke the test for user input of the form 'N?', because
when kconfig selects the single valid option the input is zero-length
and the test will read the byte before the input buffer.  If this
happens to contain '?' (as it will in a mips build on Debian unstable
today) then kconfig again enters an infinite loop.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: stable@kernel.org [2.6.17+]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 40aee729 ('kconfig: fix default
value for choice input') fixed some cases where kconfig would select
the wrong option from a choice with a single valid option and thus
enter an infinite loop.

However, this broke the test for user input of the form 'N?', because
when kconfig selects the single valid option the input is zero-length
and the test will read the byte before the input buffer.  If this
happens to contain '?' (as it will in a mips build on Debian unstable
today) then kconfig again enters an infinite loop.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: stable@kernel.org [2.6.17+]
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Commit 861b4ea4 broke oldnoconfig when removed the oldnoconfig checks on
                       if (input_mode == nonint_oldconfig ||
                           input_mode == oldnoconfig) {
                               if (input_mode == nonint_oldconfig &&
                                   sym->name &&
                                    !sym_is_choice_value(sym)) {
to avoid oldnoconfig chugging through the else stanza.

Fix that to restore expected behaviour (which I've confirmed in the
Fedora kernel build that the configs end up looking the same.)
Signed-off-by: NKyle McMartin <kyle@redhat.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Reviewed-by: NRandy Dunlap <rdunlap@xenotime.net>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Reviewed-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Reviewed-by: NMichal Marek <mmarek@suse.cz>

Commit 861b4ea4 broke oldnoconfig when removed the oldnoconfig checks on
                       if (input_mode == nonint_oldconfig ||
                           input_mode == oldnoconfig) {
                               if (input_mode == nonint_oldconfig &&
                                   sym->name &&
                                    !sym_is_choice_value(sym)) {
to avoid oldnoconfig chugging through the else stanza.

Fix that to restore expected behaviour (which I've confirmed in the
Fedora kernel build that the configs end up looking the same.)
Signed-off-by: NKyle McMartin <kyle@redhat.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>