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: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

If you run "make menuconfig" or "make nconfig" with -j<N> option in a
fresh source tree, you will see several "Can't open ..." messages:

  $ make -j8 menuconfig
    HOSTCC  scripts/basic/fixdep
    YACC    scripts/kconfig/zconf.tab.c
    LEX     scripts/kconfig/zconf.lex.c
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .:   HOSTCC  scripts/kconfig/lxdialog/checklist.o
  Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
    HOSTCC  scripts/kconfig/lxdialog/inputbox.o
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
    UPD     scripts/kconfig/.mconf-cfg
  /bin/sh: 1: .: Can't open scripts/kconfig/.mconf-cfg
    HOSTCC  scripts/kconfig/lxdialog/menubox.o
    HOSTCC  scripts/kconfig/lxdialog/textbox.o
    HOSTCC  scripts/kconfig/lxdialog/util.o
    HOSTCC  scripts/kconfig/lxdialog/yesno.o
    HOSTCC  scripts/kconfig/mconf.o
    HOSTCC  scripts/kconfig/zconf.tab.o
    HOSTLD  scripts/kconfig/mconf

Correct dependencies to fix this problem.

Fixes: 1c5af5cf ("kconfig: refactor ncurses package checks for building mconf and nconf")
Cc: linux-stable <stable@vger.kernel.org> # v4.18
Reported-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NBorislav Petkov <bp@suse.de>

This commit improves the messages of the recursive dependency.
Currently, sym->dir_dep.expr is not checked.  Hence, any dependency
in property visibility is regarded as the dependency of the symbol.

[Test Code 1]

  config A
          bool "a"
          depends on B

  config B
          bool "b"
          depends on A

[Test Code 2]

  config A
          bool "a" if B

  config B
          bool "b"
          depends on A

For both cases above, the same message is displayed:

        symbol B depends on A
        symbol A depends on B

This commit changes the message for the latter, like this:

        symbol B depends on A
        symbol A prompt is visible depending on B

Also, 'select' and 'imply' are distinguished.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NDirk Gouders <dirk@gouders.net>

Currently, Kconfig does not complain about the recursive dependency
where 'imply' keywords are involved.

[Test Code]

  config A
          bool "a"

  config B
          bool "b"
          imply A
          depends on A

In the code above, Kconfig cannot calculate the symbol values correctly
due to the circular dependency.  For example, allyesconfig followed by
syncconfig results in an odd behavior because CONFIG_B becomes visible
in syncconfig.

  $ make allyesconfig
  scripts/kconfig/conf  --allyesconfig Kconfig
  #
  # configuration written to .config
  #
  $ cat .config
  #
  # Automatically generated file; DO NOT EDIT.
  # Main menu
  #
  CONFIG_A=y
  $ make syncconfig
  scripts/kconfig/conf  --syncconfig Kconfig
  *
  * Restart config...
  *
  *
  * Main menu
  *
  a (A) [Y/n/?] y
    b (B) [N/y/?] (NEW)

To detect this correctly, sym_check_expr_deps() should recurse to
not only sym->rev_dep.expr but also sym->implied.expr .

At this moment, sym_check_print_recursive() cannot distinguish
'select' and 'imply' since it does not know the precise context
where the recursive dependency has been hit.  This will be solved
by the next commit.

In fact, even the document and the unit-test are confused.  Using
'imply' does not solve recursive dependency since 'imply' addresses
the unmet direct dependency, which 'select' could cause.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NDirk Gouders <dirk@gouders.net>

Originally, recursive dependency was a fatal error for Kconfig
because Kconfig cannot compute symbol values in such a situation.

Commit d595cea6 ("kconfig: print more info when we see a recursive
dependency") changed it to a warning, which I guess was not intentional.

Get it back to an error again.

Also, rename the unit test directory "warn_recursive_dep" to
"err_recursive_dep" so that it matches to the behavior.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NDirk Gouders <dirk@gouders.net>

Add build-only targets for build_menuconfig, build_nconfig,
build_xconfig, and build_gconfig.
(targets must end in "config" to qualify in top-level Makefile)

This allows these target to be built without execution (e.g., to
look for errors or warnings) and/or to be built and checked by sparse.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This property is not set by anyone since commit 104daea1 ("kconfig:
reference environment variables directly and remove 'option env='").
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>

This function is unused since commit 104daea1 ("kconfig: reference
environment variables directly and remove 'option env='").
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>

The rule of mainmenu_stmt does not have debug print of zconf_lineno(),
but if it had, it would print a wrong line number for the same reason
as commit b2d00d7c ("kconfig: fix line numbers for if-entries in
menu tree").

The mainmenu_stmt does not need to eat following empty lines because
they are reduced to common_stmt.
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>

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>

'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>

Commit 17263baf ("kconfig: Create include/generated for
localmodconfig") added the 'mkdir' line because local{yes,mod}config
ran streamline_config.pl followed by silentoldconfig at that time.

Since commit 81d2bc22 ("kconfig: invoke oldconfig instead of
silentoldconfig from local*config"), no sub-directory is required.
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>

Each of 'make {menu,n,g,x}config' uses (needs) pkg-config to make sure
that other required files are present and to determine build flags
settings, but none of these check that pkg-config itself is present.
Add a check for all 4 of these targets and update
Documentation/process/changes.rst to mention 'pkg-config'.

Fixes kernel bugzilla #77511:
https://bugzilla.kernel.org/show_bug.cgi?id=77511Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Bjørn Forsman <bjorn.forsman@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

In preparation for enabling command line LDLIBS, re-name HOST_LOADLIBES
to KBUILD_HOSTLDLIBS as the internal use only flags. Also rename
existing usage to HOSTLDLIBS for consistency. This should not have any
visible effects.
Signed-off-by: NLaura Abbott <labbott@redhat.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

If buf[-1] just happens to hold the byte 0x0A, then nread can wrap around
to (size_t)-1, leading to invalid memory accesses.

This has caused segmentation faults when trying to build the latest
kernel snapshots for i686 in Fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=1592374Signed-off-by: NJerry James <loganjerry@gmail.com>
[alexpl@fedoraproject.org: reformatted patch for submission]
Signed-off-by: NAlexander Ploumistos <alexpl@fedoraproject.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Each symbol has a property of type P_SYMBOL since commit
59e89e3d (kconfig: save location of config symbols).
Handle those properties in print_symbol().

Further, place a pointer to print_symbol() in the comment above the
list of known property type.
Signed-off-by: NDirk Gouders <dirk@gouders.net>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The line numers for if-entries in the menu tree are off by one or more
lines which is confusing when debugging for correctness of unrelated changes.

According to the git log, commit a02f0570 (kconfig: improve
error handling in the parser) was the last one that changed that part
of the parser and replaced

	"if_entry: T_IF expr T_EOL"
by
	"if_entry: T_IF expr nl"

but the commit message does not state why this has been done.

When reverting that part of the commit, only the line numers are
corrected (checked with cdebug = DEBUG_PARSE in zconf.y), otherwise
the menu tree remains unchanged (checked with zconfdump() enabled in
conf.c).

An example for the corrected line numbers:

drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig
drivers/soc/tegra/Kconfig:4:if
drivers/soc/tegra/Kconfig:6:if

changes to:

drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig
drivers/soc/tegra/Kconfig:1:if
drivers/soc/tegra/Kconfig:4:if
Signed-off-by: NDirk Gouders <dirk@gouders.net>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

When kconfig syntax moved to use $(FOO) for environment variables
localmodconfig was not updated.
Fix so it now works with the new syntax $(FOO)

Fixes: 104daea1 ("kconfig: reference environment variables directly and remove 'option env='")
Reported-by: NKevin Locke <kevin@kevinlocke.name>
Reported-by: NAndrei Vagin <avagin@virtuozzo.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Tested-by: NKevin Locke <kevin@kevinlocke.name>
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>

Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Here are the test cases I used for developing the text expansion
feature.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

When using a recursively expanded variable, it is a common mistake
to make circular reference.

For example, Make terminates the following code:

  X = $(X)
  Y := $(X)

Let's detect the circular expansion in Kconfig, too.

On the other hand, a function that recurses itself is a commonly-used
programming technique.  So, Make does not check recursion in the
reference with 'call'.  For example, the following code continues
running eternally:

  X = $(call X)
  Y := $(X)

Kconfig allows circular expansion if one or more arguments are given,
but terminates when the same function is recursively invoked 1000 times,
assuming it is a programming mistake.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The special variables, $(filename) and $(lineno), are expanded to a
file name and its line number being parsed, respectively.
Suggested-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>

Syntax:
  $(info,<text>)
  $(warning-if,<condition>,<text>)
  $(error-if,<condition>,<text)

The 'info' function prints a message to stdout as in Make.

The 'warning-if' and 'error-if' are similar to 'warning' and 'error'
in Make, but take the condition parameter.  They are effective only
when the <condition> part is y.

Kconfig does not implement the lazy expansion as used in the 'if'
'and, 'or' functions in Make.  In other words, Kconfig does not
support conditional expansion.  The unconditional 'error' function
would always terminate the parsing, hence would be useless in Kconfig.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>

Make expands the lefthand side of assignment statements.  In fact,
Kbuild relies on it since kernel makefiles mostly look like this:

  obj-$(CONFIG_FOO) += foo.o

Do likewise in Kconfig.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Support += operator.  This appends a space and the text on the
righthand side to a variable.

The timing of the evaluation of the righthand side depends on the
flavor of the variable.  If the lefthand side was originally defined
as a simple variable, the righthand side is expanded immediately.
Otherwise, the expansion is deferred.  Appending something to an
undefined variable results in a recursive variable.

To implement this, we need to remember the flavor of variables.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The previous commit added variable and user-defined function.  They
work similarly in the sense that the evaluation is deferred until
they are used.

This commit adds another type of variable, simply expanded variable,
as we see in Make.

The := operator defines a simply expanded variable, expanding the
righthand side immediately.  This works like traditional programming
language variables.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Now, we got a basic ability to test compiler capability in Kconfig.

config CC_HAS_STACKPROTECTOR
        def_bool $(shell,($(CC) -Werror -fstack-protector -E -x c /dev/null -o /dev/null 2>/dev/null) && echo y || echo n)

This works, but it is ugly to repeat this long boilerplate.

We want to describe like this:

config CC_HAS_STACKPROTECTOR
        bool
        default $(cc-option,-fstack-protector)

It is straight-forward to add a new function, but I do not like to
hard-code specialized functions like that.  Hence, here is another
feature, user-defined function.  This works as a textual shorthand
with parameterization.

A user-defined function is defined by using the = operator, and can
be referenced in the same way as built-in functions.  A user-defined
function in Make is referenced like $(call my-func,arg1,arg2), but I
omitted the 'call' to make the syntax shorter.

The definition of a user-defined function contains $(1), $(2), etc.
in its body to reference the parameters.  It is grammatically valid
to pass more or fewer arguments when calling it.  We already exploit
this feature in our makefiles; scripts/Kbuild.include defines cc-option
which takes two arguments at most, but most of the callers pass only
one argument.

By the way, a variable is supported as a subset of this feature since
a variable is "a user-defined function with zero argument".  In this
context, I mean "variable" as recursively expanded variable.  I will
add a different flavored variable in the next commit.

The code above can be written as follows:

[Example Code]

  success = $(shell,($(1)) >/dev/null 2>&1 && echo y || echo n)
  cc-option = $(success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null)

  config CC_HAS_STACKPROTECTOR
          def_bool $(cc-option,-fstack-protector)

[Result]
  $ make -s alldefconfig && tail -n 1 .config
  CONFIG_CC_HAS_STACKPROTECTOR=y
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Currently, any statement line starts with a keyword with TF_COMMAND
flag.  So, the following three lines are dead code.

        alloc_string(yytext, yyleng);
        zconflval.string = text;
        return T_WORD;

If a T_WORD token is returned in this context, it will cause syntax
error in the parser anyway.

The next commit will support the assignment statement where a line
starts with an arbitrary identifier.  So, I want the lexer to switch
to the PARAM state only when it sees a command keyword.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This accepts a single command to execute.  It returns the standard
output from it.

[Example code]

  config HELLO
          string
          default "$(shell,echo hello world)"

  config Y
          def_bool $(shell,echo y)

[Result]

  $ make -s alldefconfig && tail -n 2 .config
  CONFIG_HELLO="hello world"
  CONFIG_Y=y

Caveat:
Like environments, functions are expanded in the lexer.  You cannot
pass symbols to function arguments.  This is a limitation to simplify
the implementation.  I want to avoid the dynamic function evaluation,
which would introduce much more complexity.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This commit adds a new concept 'function' to do more text processing
in Kconfig.

A function call looks like this:

  $(function,arg1,arg2,arg3,...)

This commit adds the basic infrastructure to expand functions.
Change the text expansion helpers to take arguments.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

If "mainmenu" is not specified, "Linux Kernel Configuration" is used
as a default prompt.

Given that Kconfig is used in other projects than Linux, let's use
a more generic prompt, "Main menu".
Suggested-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

There is no more caller of sym_expand_string_value().
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>

Now that environments are expanded in the lexer, conf_parse() does
not need to expand them explicitly.

The hack introduced by commit 0724a7c3 ("kconfig: Don't leak
main menus during parsing") can go away.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>