Kconfig updates the .config when it exits even if its content is
exactly the same as before. Since its timestamp becomes newer than
that of other build artifacts, additional processing is invoked,
which is annoying.

- syncconfig is invoked to update include/config/auto.conf, etc.

- kernel/configs.o is recompiled if CONFIG_IKCONFIG is enabled,
  then vmlinux is relinked as well.

If the .config is not changed at all, we do not have to even
touch it. Just bail out showing "No change to .config".

  $ make allmodconfig
  scripts/kconfig/conf  --allmodconfig Kconfig
  #
  # configuration written to .config
  #
  $ make allmodconfig
  scripts/kconfig/conf  --allmodconfig Kconfig
  #
  # No change to .config
  #
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently, conf_write() can be called with a directory name instead
of a file name. As far as I see, this can happen for menuconfig,
nconfig, gconfig.

If it is given with a directory path, conf_write() kindly appends
getenv("KCONFIG_CONFIG"), but this ends up with hacky dir/basename
handling, and screwed up in corner-cases like "what if KCONFIG_CONFIG
is an absolute path?" as discussed before:

  https://patchwork.kernel.org/patch/9910037/

Since conf_write() is already messed up, I'd say "do not do it".
Please pass a file path all the time. If a directory path is specified
for the configuration output, conf_write() will simply error out.

Now that the tmp file is created in the same directory as the .config,
the previously reported "what if KCONFIG_CONFIG points to a different
file system?" has been solved.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nicolas Porcel <nicolasporcel06@gmail.com>

I want to compile each C file independently instead of including all
of them from zconf.y.

Split out confdata.c, expr.c, symbol.c, and preprocess.c .
These are low-hanging fruits.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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

The S_OTHER type could be set only when conf_read_simple() is reading
include/config/auto.conf file.

For example, CONFIG_FOO=y exists in include/config/auto.conf but it is
missing from the currently parsed Kconfig files, sym_lookup() allocates
a new symbol, and sets its type to S_OTHER.

Strangely, it will be set to S_STRING by conf_set_sym_val() a few lines
below while it is obviously bool or tristate type. On the other hand,
when CONFIG_BAR="bar" is being dropped from include/config/auto.conf,
its type remains S_OTHER. Because for_all_symbols() omits S_OTHER
symbols, conf_touch_deps() misses to touch include/config/bar.h

This behavior has been a pretty mystery for me, and digging the git
histroy did not help. At least, touching depfiles is broken for string
type symbols.

I removed S_OTHER entirely, and reimplemented it more simply.

If CONFIG_FOO was visible in the previous syncconfig, but is missing
now, what we want to do is quite simple; just call conf_touch_dep()
to touch include/config/foo.h instead of allocating a new symbol data.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

conf_touch_deps() iterates over symbols, touching corresponding
include/config/*.h files as needed.

Split the part that touches a single file into a new helper so it can
be reused.

The new helper, conf_touch_dep(), takes a symbol name as a parameter,
and touches the corresponding include/config/*.h file.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

According to commit 2e3646e5 ("kconfig: integrate split config
into silentoldconfig"), this function was named after split-include
tool, which used to exist in old versions of Linux.

Setting aside the historical reason, rename it into a more intuitive
name. This function touches timestamp files under include/config/
in order to interact with the fixdep tool.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The two 'goto setsym' statements are reachable only when sym == NULL.

The code below the 'setsym:' label does nothing when sym == NULL
since there is just one if-block guarded by 'if (sym && ...)'.

Hence, 'goto setsym' can be replaced with 'continue'.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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>

'make syncconfig' creates some files such as include/config/auto.conf,
include/generate/autoconf.h, etc. but the necessary directory creation
relies on scripts/kconfig/Makefile.

To make Kconfig self-contained, create directories as needed in
conf_write_autoconf().

This change allows scripts/kconfig/Makefile cleanups; syncconfig can
be merged into simple-targets.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Split out helpers:
 is_present() - check if the given path exists
 is_dir() - check if the given path exists and it is a directory
 make_parent_dir() - create the parent directories of the given path

These helpers will be reused in later commits.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

file_write_dep() is called only from conf_write_autoconf().
Move it from util.c to confdata.c to make it static.
Also, rename it to conf_write_dep() since it should belong to
the group of conf_write* functions.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

As you see in mconf.c and nconf.c, conf_message_callback() hooks are
likely to end up with the boilerplate of vsnprintf().  Process the
string format before calling conf_message_callback() so that it
receives a simple string.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NDirk Gouders <dirk@gouders.net>

Over time, the use of the flag SYMBOL_AUTO changed from initially
marking three automatically generated symbols ARCH, KERNELRELEASE and
UNAME_RELEASE to today's effect of protecting symbols from being
written out.

Currently, only symbols of type CHOICE and those with option
defconf_list set have that flag set.

Reflect that change in semantics in the flag's name.
Signed-off-by: NDirk Gouders <dirk@gouders.net>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

In file included from scripts/kconfig/zconf.tab.c:2485:
scripts/kconfig/confdata.c: In function ‘conf_write’:
scripts/kconfig/confdata.c:773:22: warning: ‘%s’ directive writing likely 7 or more bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
  sprintf(newname, "%s%s", dirname, basename);
                      ^~
scripts/kconfig/confdata.c:773:19: note: assuming directive output of 7 bytes
  sprintf(newname, "%s%s", dirname, basename);
                   ^~~~~~
scripts/kconfig/confdata.c:773:2: note: ‘sprintf’ output 1 or more bytes (assuming 4104) into a destination of size 4097
  sprintf(newname, "%s%s", dirname, basename);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
scripts/kconfig/confdata.c:776:23: warning: ‘.tmpconfig.’ directive writing 11 bytes into a region of size between 1 and 4097 [-Wformat-overflow=]
   sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
                       ^~~~~~~~~~~
scripts/kconfig/confdata.c:776:3: note: ‘sprintf’ output between 13 and 4119 bytes into a destination of size 4097
   sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Increase the size of tmpname and newname to make GCC happy.

Cc: stable@vger.kernel.org
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

To get access to environment variables, Kconfig needs to define a
symbol using "option env=" syntax.  It is tedious to add a symbol entry
for each environment variable given that we need to define much more
such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability
in Kconfig.

Adding '$' for symbol references is grammatically inconsistent.
Looking at the code, the symbols prefixed with 'S' are expanded by:
 - conf_expand_value()
   This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list'
 - sym_expand_string_value()
   This is used to expand strings in 'source' and 'mainmenu'

All of them are fixed values independent of user configuration.  So,
they can be changed into the direct expansion instead of symbols.

This change makes the code much cleaner.  The bounce symbols 'SRCARCH',
'ARCH', 'SUBARCH', 'KERNELVERSION' are gone.

sym_init() hard-coding 'UNAME_RELEASE' is also gone.  'UNAME_RELEASE'
should be replaced with an environment variable.

ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced
without '$' prefix.

The new syntax is addicted by Make.  The variable reference needs
parentheses, like $(FOO), but you can omit them for single-letter
variables, like $F.  Yet, in Makefiles, people tend to use the
parenthetical form for consistency / clarification.

At this moment, only the environment variable is supported, but I will
extend the concept of 'variable' later on.

The variables are expanded in the lexer so we can simplify the token
handling on the parser side.

For example, the following code works.

[Example code]

  config MY_TOOLCHAIN_LIST
          string
          default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)"

[Result]

  $ make -s alldefconfig && tail -n 1 .config
  CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E"
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>

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 already have xmalloc(), xcalloc(), and xrealloc(().  Add xstrdup()
as well to save tedious error handling.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

We already have xmalloc(), xcalloc().  Add xrealloc() as well
to save tedious error handling.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

conf_unsaved is initialized by conf_read_simple(), but it is possible
to move it to conf_read() so that it can be a local variable.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

No more users of this keyword.  Drop it according to the notice by
commit 6341e62b ("kconfig: use bool instead of boolean for type
definition attributes").
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NLuis R. Rodriguez <mcgrof@kernel.org>

If the .config parser runs into unexpected data it emits warnings like:
    .config:6911:warning: unexpected data

Add the unexpected data itself to this warning. That makes it easier to
discover what is actually going wrong:
     .config:6911:warning: unexpected data: CONFOG_CHARGER_TPS65217=m
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NMichal Marek <mmarek@suse.com>

	Prior to 3.13 make allmodconfig KCONFIG_ALLCONFIG=/dev/null used
to be equivalent to make allmodconfig; these days it hardwires MODULES to n.
In fact, any KCONFIG_ALLCONFIG that doesn't set MODULES explicitly is
treated as if it set it to n.

	Regression had been introduced by commit cfa98f ("kconfig: do not
override symbols already set"); what happens is that conf_read_simple()
does sym_calc_value(modules_sym) on exit, which leaves SYMBOL_VALID set and
has conf_set_all_new_symbols() skip modules_sym.

	It's pretty easy to fix - simply move that call of sym_calc_value()
into the callers, except for the ones in KCONFIG_ALLCONFIG handling.
Objections?
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Fixes: cfa98f2e ("kconfig: do not override symbols already set")
Signed-off-by: NMichal Marek <mmarek@suse.com>

The sym_calc_value() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NMichal Marek <mmarek@suse.com>

Signed-off-by: NMichal Marek <mmarek@suse.cz>

Although on some systems va_end is a no-op, it is good practice
to use va_end, especially since the manual states:

"Each invocation of va_start() must be matched by a corresponding
invocation of va_end() in the same function."
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

"make allnoconfig" exists to ease testing of minimal configurations.
Documentation/SubmitChecklist includes a note to test with allnoconfig.
This helps catch missing dependencies on common-but-not-required
functionality, which might otherwise go unnoticed.

However, allnoconfig still leaves many symbols enabled, because they're
hidden behind CONFIG_EMBEDDED or CONFIG_EXPERT.  For instance, allnoconfig
still has CONFIG_PRINTK and CONFIG_BLOCK enabled, so drivers don't
typically get build-tested with those disabled.

To address this, introduce a new Kconfig option "allnoconfig_y", used on
symbols which only exist to hide other symbols.  Set it on CONFIG_EMBEDDED
(which then selects CONFIG_EXPERT).  allnoconfig will then disable all the
symbols hidden behind those.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Tested-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a symbol changes type from tristate to bool, and was previously set to
'm', a subsequent silentoldconfig would warn about inconsistency, such as:

    include/config/auto.conf:3014:warning: symbol value 'm' invalid for
    HOTPLUG_PCI_PCIE

Seen by Linus with the merge in aa8032b6 (sequence to reproduce by Michal):
    git checkout 1fe0135b
    make mrproper
    make allmodconfig
    make silentoldconfig
    git checkout aa8032b6
    make allmodconfig
    make silentoldconfig

Since HOTPLUG_PCI_PCIE changed from tristate to bool in aa8032b6, it was
previously set to 'm' in auto.conf by the first allmodconfig+silentoldconfig,
but then was set to 'y' by the second allmodconfig. Then the second
silentoldconfig prints the warning.

The warning in this case is a spurious warning, which happens at the time
kconfig tries to detect symbols that have changed, to touch the empty
header files in include/config used for dependency-tracking by make.

Silence the warning when we read the old auto.conf file, since it is
perfectly legit that a symbol changed type since the previous call.

Thread in:
    http://marc.info/?l=linux-pci&m=137569198904000&w=2Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This reverts commit 8357b485.

It breaks more stuff than it fixes.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Reported-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Currently, randconfig does randomise choice entries, unless KCONFIG_ALLCONFIG
is specified.

For example, given those two files (Thomas' test-case):

    ---8<--- Config.test.in
    config OPTIONA
        bool "Option A"

    choice
        prompt "This is a choice"

    config CHOICE_OPTIONA
        bool "Choice Option A"

    config CHOICE_OPTIONB
        bool "Choice Option B"

    endchoice

    config OPTIONB
        bool "Option B"
    ---8<--- Config.test.in

    ---8<--- config.defaults
    CONFIG_OPTIONA=y
    ---8<--- config.defaults

And running:
    ./scripts/kconfig/conf --randconfig Config.test.in

does properly randomise the two choice symbols (and the two booleans).

However, running:
    KCONFIG_ALLCONFIG=config.defaults \
    ./scripts/kconfig/conf --randconfig Config.test.in

does *not* reandomise the two choice entries, and only CHOICE_OPTIONA
will ever be selected. (OPTIONA will always be set (expected), and
OPTIONB will be be properly randomised (expected).)

This patch defers setting that a choice has a value until a symbol for
that choice is indeed set, so that choices are properly randomised when
KCONFIG_ALLCONFIG is set, but not if a symbol for that choice is set.
Reported-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>

---
Changes v3 -> v4
  - fix previous issue where some choices would not be set, which would
    cause silentoldconfig to ask for them and was then breaking this
    workflow (as reported by Arnd and Sedat):
        KCONFIG_ALLCONFIG=foo.defconfig make randconfig
        make silentoldconfig </dev/nullo
    which I have tested (3h28min!) with:
        touch defconfig
        for(( i=0; i<10000; i++ )); do
            KCONFIG_ALLCONFIG=$(pwd)/defconfig make randconfig >/dev/null 2>&1
            make silentoldconfig </dev/null >/dev/null 2>&1 || break
        done
    which did not break at all.
  - change done in v3 (below) is already fixed by a previous patch

Changes v2 -> v3
  - ensure only one symbol is set in a choice

Changes v1 -> v2:
  - further postpone setting that a choice has a value until
    one is indeed set
  - do not print symbols that are part of an invisible choice

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>

Currently, randconfig may set more than one symbol in a given choice.
Given this config file:
    config A
        bool "A"
    if A
    choice
        bool "B/C/D"
    config B
        bool "B"
    config C
        bool "C"
    config D
        bool "D"
    endchoice
    endif # A

Then randconfig generates such .config files (case where A is not set is not
shown below for brevity), and where only the right-most .config is valid:
  CONFIG_A=y                  CONFIG_A=y                  CONFIG_A=y
  CONFIG_B=y                  CONFIG_B=y                  CONFIG_B=y
  CONFIG_C=y                  # CONFIG_C is not set       # CONFIG_C is not set
  # CONFIG_D is not set       CONFIG_D=y                  # CONFIG_D is not set

That is, in a randomised choice, the first symbol is always selected,
and at most one other symbol may be selected.

This is due to symbol randomised in a choice not being properly flagged
as having a value.

Fix that by flagging those symbols adequately: have a user-defined value,
and be not valid (to force recalculation of the symbol).

Note: if the choice is not conditional, then the randomisation is properly
done.
Reported-by: NMatthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: NMatthieu CASTET <matthieu.castet@parrot.com>
[yann.morin.1998@free.fr: independently re-done the same patch as Matthieu,
                          as pointed out by Sedat]
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

The defconfig and Kconfig combination below, which is based on 3.10-rc4
Kconfigs, resulted in several options getting set to "m" instead of "y".

defconfig.choice:
---8<---
CONFIG_MODULES=y
CONFIG_USB_ZERO=y
---8<---

Kconfig.choice:
---8<---
menuconfig MODULES
	bool "Enable loadable module support"

config CONFIGFS_FS
	tristate "Userspace-driven configuration filesystem"

config OCFS2_FS
        tristate "OCFS2 file system support"
        depends on CONFIGFS_FS
        select CRC32

config USB_LIBCOMPOSITE
	tristate
	select CONFIGFS_FS

choice
	tristate "USB Gadget Drivers"
	default USB_ETH

config USB_ZERO
	tristate "Gadget Zero (DEVELOPMENT)"
	select USB_LIBCOMPOSITE

config USB_ETH
	tristate "Ethernet Gadget (with CDC Ethernet support)"
	select USB_LIBCOMPOSITE

endchoice

config CRC32
        tristate "CRC32/CRC32c functions"
        default y

choice
        prompt "CRC32 implementation"
        depends on CRC32
        default CRC32_SLICEBY8

config CRC32_SLICEBY8
        bool "Slice by 8 bytes"

endchoice
---8<---

$ scripts/kconfig/conf --defconfig=defconfig.choice Kconfig.choice

would result in:

.config:
---8<---
CONFIG_MODULES=y
CONFIG_CONFIGFS_FS=m
CONFIG_USB_LIBCOMPOSITE=m
CONFIG_USB_ZERO=m
CONFIG_CRC32=y
CONFIG_CRC32_SLICEBY8=y
---8<---

when the expected result would be:

.config:
---8<---
CONFIG_MODULES=y
CONFIG_CONFIGFS_FS=y
CONFIG_USB_LIBCOMPOSITE=y
CONFIG_USB_ZERO=y
CONFIG_CRC32=y
CONFIG_CRC32_SLICEBY8=y
---8<---
Signed-off-by: NArve Hjønnevåg <arve@android.com>
[yann.morin.1998@free.fr: add the resulting .config to commit log,
                          remove unneeded USB_GADGET from the defconfig]
Tested-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: NYann E. MORIN <yann.morin.1998@free.fr>

This reverts commit 422c809f.
It causes more harm than it solves issues.
Reported-by: NSedat Dilek <sedat.dilek@gmail.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Tested-by: NSedat Dilek <sedat.dilek@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Greg KH <greg@kroah.com>

Currently the odds to set each symbol is (rounded):
    booleans:   y: 50%          n: 50%
    tristates:  y: 33%  m: 33%  n: 33%

Introduce a KCONFIG_PROBABILITY environment variable to tweak the
probabilities (in percentage), as such:
    KCONFIG_PROBABILITY     y:n split           y:m:n split
    -----------------------------------------------------------------
[1] unset or empty          50  : 50            33  : 33  : 34
[2] N                        N  : 100-N         N/2 : N/2 : 100-N
    N:M                     N+M : 100-(N+M)      N  :  M  : 100-(N+M)
    N:M:L                    N  : 100-N          M  :  L  : 100-(M+L)

[1] The current behaviour is kept as default, for backward compatibility
[2] The solution initially implemented by Peter for Buildroot, see:
    http://git.buildroot.org/buildroot/commit/?id=3435c1afb5Signed-off-by: NPeter Korsgaard <jacmet@uclibc.org>
[yann.morin.1998@free.fr: add to Documentation/]
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

Currently, randconfig does randomise choice entries, unless KCONFIG_ALLCONFIG
is specified.

For example, given those two files (Thomas' test-case):

    ---8<--- Config.test.in
    config OPTIONA
        bool "Option A"

    choice
        prompt "This is a choice"

    config CHOICE_OPTIONA
        bool "Choice Option A"

    config CHOICE_OPTIONB
        bool "Choice Option B"

    endchoice

    config OPTIONB
        bool "Option B"
    ---8<--- Config.test.in

    ---8<--- config.defaults
    CONFIG_OPTIONA=y
    ---8<--- config.defaults

And running:
    ./scripts/kconfig/conf --randconfig Config.test.in

does properly randomise the two choice symbols (and the two booleans).

However, running:
    KCONFIG_ALLCONFIG=config.defaults \
    ./scripts/kconfig/conf --randconfig Config.test.in

does *not* reandomise the two choice entries, and only CHOICE_OPTIONA
will ever be selected. (OPTIONA will always be set (expected), and
OPTIONB will be be properly randomised (expected).)

This patch defers setting that a choice has a value until a symbol for
that choice is indeed set, so that choices are properly randomised when
KCONFIG_ALLCONFIG is set, but not if a symbol for that choice is set.

Also, as a side-efect, this patch fixes the following case:

    ---8<---
    choice
    config OPTION_A
        bool "Option A"
    config OPTION_B
        bool "Option B"
    config OPTION_C
        bool "Option C"
    endchoice
    ---8<---

which could previously generate such .config files:

    ---8<---                            ---8<---
    CONFIG_OPTION_A=y                   CONFIG_OPTION_A=y
    CONFIG_OPTION_B=y                   # CONFIG_OPTION_B is not set
    # CONFIG_OPTION_C is not set        CONFIG_OPTION_C=y
    ---8<---                            ---8<---

Ie., the first entry in a choice is always set, plus zero or one of
the other options may be set.

This patch ensures that only one option may be set for a choice.
Reported-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Arnaud Lacombe <lacombar@gmail.com>

---
Changes v2 -> v3
  - ensure only one symbol is set in a choice

Changes v1 -> v2:
  - further postpone setting that a choice has a value until
    one is indeed set
  - do not print symbols that are part of an invisible choice

For randconfig, if a list of required symbols is specified with
KCONFIG_ALLCONFIG, such symbols do not "have a value" as per
sym_has_value(), but have the "valid" flag set.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

Because the modules' symbole (CONFIG_MODULES) may not yet be set when
we check a symbol's tristate capabilty, we'll always find that tristate
symbols are booleans, even if we randomly decided that to enable modules:
sym_get_type(sym) always return boolean for tristates when modules_sym
has not been previously set to 'y' *and* its value calculated *and* its
visibility calculated, both of which only occur after we randomly assign
values to symbols.

Fix that by looking at the raw type of symbols. Tristate set to 'm' will
be promoted to 'y' when their values will be later calculated.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

For some config options (CONFIG_EXTRA_FIRMWARE, for example), the length
of a config file line can exceed the 1024 byte buffer.

Switch from fgets to compat_getline to fix. compat_getline is an
internally implimented getline work-alike for portability purposes.
Signed-off-by: NCody Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

We've now fixed IS_ENABLED() and friends to not require any special
"__enabled_" prefixed versions of the normal Kconfig options, so delete
the last traces of them being generated.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>