Reverse dependency expressions can get rather unwieldy, especially if
a symbol is selected by more than a handful of other symbols. I.e. it's
possible to have near endless expressions like:
   A && B && !C || D || F && (G || H) || [...]

Chop these expressions into actually readable chunks:
   - A && B && !C
   - D
   - F && (G || H)
   - [...]

I.e. transform the top level OR tokens into newlines and prepend each
line with a minus. This makes the "Selected by:" and "Implied by:" blurb
much easier to read. This is done only if there is more than one top
level OR. "Depends on:" and "Range :" were deliberately left as they are.

Based on idea from Paul Bolle.
Suggested-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NPetr Vorel <petr.vorel@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Many of these functions are quite the head scratchers if you don't know
what they're trying to do. Document them.

Also make it clear which functions rewrite expressions in-place and
which return new expressions. This prevents memory errors.

No functional changes. Only comments added.
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Only the E_NOT operand and not the E_NOT node itself was freed, due to
accidentally returning too early in expr_free(). Outline of leak:

	switch (e->type) {
	...
	case E_NOT:
		expr_free(e->left.expr);
		return;
	...
	}
	*Never reached, 'e' leaked*
	free(e);

Fix by changing the 'return' to a 'break'.

Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:

	LEAK SUMMARY:
	   definitely lost: 44,448 bytes in 1,852 blocks
	   ...

Summary after the fix:

	LEAK SUMMARY:
	   definitely lost: 1,608 bytes in 67 blocks
	   ...
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Fixes: 31847b67 ("kconfig: allow use of relations other than (in)equality")
Signed-off-by: NMichal Sojka <sojkam1@fel.cvut.cz>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Over the years I found it desirable to be able to use all sorts of
relations, not just (in)equality. And apparently I'm not the only one,
as there's at least one example in the tree where the programmer
assumed this would work (see DEBUG_UART_8250_WORD in
arch/arm/Kconfig.debug). Another possible use would e.g. be to fold the
two SMP/NR_CPUS prompts into one: SMP could be promptless, simply
depending on NR_CPUS > 1.

A (desirable) side effect of this change - resulting from numeric
values now necessarily being compared as numbers rather than as
strings - is that comparing hex values now works as expected: Other
than int ones (which aren't allowed to have leading zeroes), zeroes
following the 0x prefix made them compare unequal even if their values
were equal.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

expr_eliminate_dups2() in scripts/kconfig/expr.c applies two invalid
inference rules:

(FOO || BAR) && (!FOO && !BAR) -> n
(FOO && BAR) || (!FOO || !BAR) -> y

They would be correct in propositional logic, but this is a three-valued
logic, and here it is wrong in that it changes semantics. It becomes
immediately visible when assigning the value 1 to both, FOO and BAR:

(FOO || BAR) && (!FOO && !BAR)
-> min(max(1, 1), min(2-1, 2-1)) = min(1, 1) = 1

while n evaluates to 0 and

(FOO && BAR) || (!FOO || !BAR)
-> max(min(1, 1), max(2-1, 2-1)) = max(1, 1) = 1

with y evaluating to 2.

Fix it by removing expr_eliminate_dups2() and the functions that have no
use anywhere else: expr_extract_eq_and(), expr_extract_eq_or(),
and expr_extract_eq() from scripts/kconfig/expr.c

Currently the bug is not triggered in mainline, so this patch does not
modify the configuration space there. To observe the bug consider this
example:

config MODULES
        def_bool y
        option modules

config FOO
        def_tristate m

config BAR
        def_tristate m

config TEST1
        def_tristate y
        depends on (FOO || BAR) && (!FOO && !BAR)

if TEST1 = n
comment "TEST1 broken"
endif

config TEST2
        def_tristate y
        depends on (FOO && BAR) || (!FOO || !BAR)

if TEST2 = y
comment "TEST2 broken"
endif

config TEST3
        def_tristate y
        depends on m && !m

if TEST3 = n
comment "TEST3 broken"
endif

TEST1, TEST2 and TEST3 should all evaluate to m, but without the patch,
none of them does. It is probably not obvious that TEST3 is the same bug,
but it becomes clear when considering what happens internally to the
expression
m && !m":
First it expands to
(m && MODULES) && !(m && MODULES),
then it is transformed into
(m && MODULES) && (!m || !MODULES),
and finally due to the bug it is replaced with n.

As a side effect, this patch reduces code size in expr.c by roughly 10%
and slightly improves startup time for all configuration frontends.
Signed-off-by: NMartin Walch <walch.martin@web.de>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

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

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

(and get them out of the noise in the audit work)
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

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>

Fixes
scripts/kconfig/expr.c: In function ‘expr_get_leftmost_symbol’:
scripts/kconfig/expr.c:1026:2: warning: passing argument 1 of ‘expr_copy’ discards qualifiers from pointer target type
scripts/kconfig/expr.c:67:14: note: expected ‘struct expr *’ but argument is of type ‘const struct expr *’
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This is an attempt to simplify the expressing printed by kconfig when a
symbol is selected but still has direct unmet dependency.

First, the symbol reverse dependency is split in sub-expression. Then,
each sub-expression is checked to ensure that it does not contains the
unmet dependency. This removes the false-positive symbols and fixed symbol
which already have the correct dependency. Finally, only the symbol
responsible of the "select" is printed, instead of its full dependency tree.

CC: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This fix facilitates fwrite() in both confdata.c and expr.c, either it
succeeds in writing, or an error occurs, or the end of file is reached.
Signed-off-by: NJean Sacren <sakiwit@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Without this patch, one has to refer to the Kconfig file to find
out the range of an integer/hex symbol.

  │ Symbol: NR_CPUS [=4]
  │ Type  : integer
  │ Range : [2 8]
  │ Prompt: Maximum number of CPUs
  │   Defined at arch/x86/Kconfig:761
  │   Depends on: SMP [=y] && !MAXSMP [=n]
  │   Location:
  │     -> Processor type and features
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Help text for certain config options is very extensive (the text
includes the names of all  other options the option in question depends
on). Long lines are not wrapped, making it impossible to see the list
without scrolling horizontally.

This patch adds some logic which wraps help screen lines at word
boundaries to prevent truncating.

Tested by running

  ARCH=powerpc make menuconfig O=/tmp/build

which shows that the long lines are now wrapped, and

 ARCH=powerpc make xconfig O=/tmp/build

to demonstrate that it still compiles and operates as expected.
Signed-off-by: NVadim Bendebury <vbendeb@google.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Warnings found via gcc -Wmissing-prototypes.
Signed-off-by: NTrevor Keith <tsrk@tsrk.net>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Sometimes when configuring need to disable some unused item, but the item is
selected by many other items, it's hard to find the real dependency which
selected it, This patch add every symbol's value accompanied to make it
possible to find the real dependency easily.

An example is CONFIG_RFKILL,

  ---------------------- RF switch subsystem support ----------------------
  | CONFIG_RFKILL:                                                        |
  |                                                                       |
  | Say Y here if you want to have control over RF switches               |
  | found on many WiFi and Bluetooth cards.                               |
  |                                                                       |
  | To compile this driver as a module, choose M here: the                |
  | module will be called rfkill.                                         |
  |                                                                       |
  | Symbol: RFKILL [=m]                                                   |
  | Prompt: RF switch subsystem support                                   |
  |   Defined at net/rfkill/Kconfig:4                                     |
  |   Depends on: NET [=y]                                                |
  |   Location:                                                           |
  |     -> Networking support (NET [=y])                                  |
  |   Selected by: IWLCORE [=n] && NETDEVICES [=y] && !S390 [=S390] && PC |
  |                                                                       |
  ----------------------------------------------------------------( 99%)---
Signed-off-by: NCheng Renquan <crquan@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Change kconfig behavior so that mixing bool and tristate config
settings in a choice is possible and has the desired effect of offering
just the tristate options individually if the choice gets set to M, and
a normal boolean selection if the choice gets set to Y.

Also fix scripts/kconfig/conf's handling of children of choice values -
there may be more than one immediate child, and all of them need to be
processed.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: "Roman Zippel" <zippel@linux-m68k.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Rename E_CHOICE to E_LIST to explicitly add support for expression
lists. Add a helper macro expr_list_for_each_sym to more easily iterate
over the list.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

We had macros named the same as a set of enumeration values.
It is legal code but very confusing to read - so rename
the macros from E_* to EXPR_*
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Roman Zippel <zippel@linux-m68k.org>

Extend the expression print helper function to allow customization of the
symbol output and use it to add links to the info window.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

The SYMBOL_{YES,MOD,NO} are not really used anymore (they were more used be
the cml1 converter), so just remove them.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!