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: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Masahiro 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: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees 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: Ulf Magnusson <ulfalizer@gmail.com>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Surprisingly or not, disabling a CONFIG option (which is assumed to
be unneeded) may be not so trivial. Especially it is not trivial, when
this CONFIG option is selected by a dozen of other configs. Before the
moment commit 1ccb271433 ("kconfig: make "Selected by:" and
"Implied by:" readable") popped up in v4.16-rc1, it was an absolute pain
to break down the "Selected by" reverse dependency expression in order
to identify all those configs which select (IOW *do not allow
disabling*) a certain feature (assumed to be not needed).
This patch tries to make one step further by putting at users'
fingertips the revdep top level OR sub-expressions grouped/clustered by
the tristate value they evaluate to. This should allow the users to
directly concentrate on and tackle the _active_ reverse dependencies.
To give some numbers and quantify the complexity of certain reverse
dependencies, assuming commit 617aebe6a9 ("Merge tag
'usercopy-v4.16-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux"), ARCH=arm64
and vanilla arm64 defconfig, here is the top 10 CONFIG options with
the highest amount of top level "||" sub-expressions/tokens that make
up the final "Selected by" reverse dependency expression.
| Config | All revdep | Active revdep |
|-------------------|------------|---------------|
| REGMAP_I2C | 212 | 9 |
| CRC32 | 167 | 25 |
| FW_LOADER | 128 | 5 |
| MFD_CORE | 124 | 9 |
| FB_CFB_IMAGEBLIT | 114 | 2 |
| FB_CFB_COPYAREA | 111 | 2 |
| FB_CFB_FILLRECT | 110 | 2 |
| SND_PCM | 103 | 2 |
| CRYPTO_HASH | 87 | 19 |
| WATCHDOG_CORE | 86 | 6 |
The story behind the above is that users need to visually
review/evaluate 212 expressions which *potentially* select REGMAP_I2C
in order to identify the expressions which *actually* select REGMAP_I2C,
for a particular ARCH and for a particular defconfig used.
To make this experience smoother, change the way reverse dependencies
are displayed to the user from [1] to [2].
[1] Old representation of DMA_ENGINE_RAID:
Selected by:
- AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || 440SP)
- BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ...
- FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ...
- INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64
- MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ...
- MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y]
- XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ...
- DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y]
[2] New representation of DMA_ENGINE_RAID:
Selected by [y]:
- MV_XOR_V2 [=y] && DMADEVICES [=y] && ARM64 [=y]
Selected by [m]:
- BCM_SBA_RAID [=m] && DMADEVICES [=y] && (ARM64 [=y] || ...
Selected by [n]:
- AMCC_PPC440SPE_ADMA [=n] && DMADEVICES [=y] && (440SPe || ...
- FSL_RAID [=n] && DMADEVICES [=y] && FSL_SOC && ...
- INTEL_IOATDMA [=n] && DMADEVICES [=y] && PCI [=y] && X86_64
- MV_XOR [=n] && DMADEVICES [=y] && (PLAT_ORION || ARCH_MVEBU [=y] ...
- XGENE_DMA [=n] && DMADEVICES [=y] && (ARCH_XGENE [=y] || ...
- DMATEST [=n] && DMADEVICES [=y] && DMA_ENGINE [=y]
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit splits out the special E_OR handling ('-' instead of '||')
into a dedicated helper expr_print_revdev().
Restore the original expr_print() prior to commit 1ccb271433
("kconfig: make "Selected by:" and "Implied by:" readable").
This makes sense because:
- We need to chop those expressions only when printing the reverse
dependency, and only when E_OR is encountered
- Otherwise, it should be printed as before, so fall back to
expr_print()
This also improves the behavior; for a single line, it was previously
displayed in the same line as "Selected by", like this:
Selected by: A [=n] && B [=n]
This will be displayed in a new line, consistently:
Selected by:
- A [=n] && B [=n]
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
The 'defconfig_list' is a weird attribute. If the '.config' is
missing, conf_read_simple() iterates over all visible defaults,
then it uses the first one for which fopen() succeeds.
config DEFCONFIG_LIST
string
depends on !UML
option defconfig_list
default "/lib/modules/$UNAME_RELEASE/.config"
default "/etc/kernel-config"
default "/boot/config-$UNAME_RELEASE"
default "$ARCH_DEFCONFIG"
default "arch/$ARCH/defconfig"
However, like other symbols, the first visible default is always
written out to the .config file. This might be different from what
has been actually used.
For example, on my machine, the third one "/boot/config-$UNAME_RELEASE"
is opened, like follows:
$ rm .config
$ make oldconfig 2>/dev/null
scripts/kconfig/conf --oldconfig Kconfig
#
# using defaults found in /boot/config-4.4.0-112-generic
#
*
* Restart config...
*
*
* IRQ subsystem
*
Expose irq internals in debugfs (GENERIC_IRQ_DEBUGFS) [N/y/?] (NEW)
However, the resulted .config file contains the first one since it is
visible:
$ grep CONFIG_DEFCONFIG_LIST .config
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
In order to stop confusing people, prevent this CONFIG option from
being written to the .config file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
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: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It is not obvious that the last two cases refer to menus and ifs,
respectively, in the conditional that sets 'parentdep'.
Automatic submenu creation is done later, so the parent can't be a
symbol here.
No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It is not obvious that this might refer to an 'if', making the code
pretty cryptic:
if (menu->list && (!menu->prompt || !menu->prompt->text)) {
Kconfig keeps the 'if' menu nodes even after flattening. Reflect that in
the example to be accurate.
No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It's easy to miss that choices are special-cased to pass on their mode
as the parent dependency.
No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Not obvious, especially if you don't already know how choices are
implemented.
No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
No more users of this keyword. Drop it according to the notice by
commit 6341e62b21 ("kconfig: use bool instead of boolean for type
definition attributes").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
menu_end_entry() is empty and completely unused as far as I can tell:
$ git log -G menu_end_entry --oneline
a02f057 [PATCH] kconfig: improve error handling in the parser
1da177e Linux-2.6.12-rc2
Last one is the initial Git commit, where menu_end_entry() is empty as
well. I couldn't find anything that redefined it on Google either.
It might be a debugging helper for setting a breakpoint after each
config, menuconfig, and comment is parsed. IMO it hurts more than it
helps in that case by making the parsing code look more complicated at a
glance than it really is, and I suspect it doesn't get used much.
Tested by running the Kconfiglib test suite, which indirectly verifies
that the .config files generated by the C implementation for each
defconfig file in the kernel stays the same.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
It's tricky to figure out what it does (and how) without staring at the
code for a long time. Document it to make it more transparent.
No functional changes. Only comments added.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When propagating dependencies from parents after parsing, an expression
node is allocated if the parent symbol is a 'choice'. This node was
never freed.
Outline of leak:
if (sym && sym_is_choice(sym)) {
...
*Allocate (in this case only)*
parentdep = expr_alloc_symbol(sym);
} else if (parent->prompt)
parentdep = parent->prompt->visible.expr;
else
parentdep = parent->dep;
for (menu = parent->list; menu; menu = menu->next) {
...
*Copy*
basedep = expr_alloc_and(expr_copy(parentdep), basedep);
...
}
*parentdep lost if the parent is a choice!*
Fix by freeing 'parentdep' after the loop if the parent symbol is a
choice. Note that this only frees the expression node and not the choice
symbol itself.
Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:
LEAK SUMMARY:
definitely lost: 1,608 bytes in 67 blocks
...
Summary after the fix:
LEAK SUMMARY:
definitely lost: 0 bytes in 0 blocks
...
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
expr_trans_compare() always allocates and returns a new expression,
giving the following leak outline:
...
*Allocate*
basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
...
for (menu = parent->next; menu; menu = menu->next) {
...
*Copy*
dep2 = expr_copy(basedep);
...
*Free copy*
expr_free(dep2);
}
*basedep lost!*
Fix by freeing 'basedep' after the loop.
Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:
LEAK SUMMARY:
definitely lost: 344,376 bytes in 14,349 blocks
...
Summary after the fix:
LEAK SUMMARY:
definitely lost: 44,448 bytes in 1,852 blocks
...
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Kconfig currently doesn't handle 'm' appearing in a Kconfig file before
the modules symbol is defined (the symbol with 'option modules'). The
problem is the following code, which runs during parsing:
/* change 'm' into 'm' && MODULES */
if (e->left.sym == &symbol_mod)
return expr_alloc_and(e, expr_alloc_symbol(modules_sym));
If the modules symbol has not yet been defined, modules_sym is NULL,
giving an invalid expression.
Here is a test file where both BEFORE_1 and BEFORE_2 trigger a segfault.
If the modules symbol is removed, all symbols trigger segfaults.
config BEFORE_1
def_tristate y if m
if m
config BEFORE_2
def_tristate y
endif
config MODULES
def_bool y
option modules
config AFTER_1
def_tristate y if m
if m
config AFTER_2
def_tristate y
endif
Fix the issue by rewriting 'm' in menu_finalize() instead. This function
runs after parsing and is the proper place to do it. The following
existing code in conf_parse() in zconf.y ensures that the modules symbol
exists at that point:
if (!modules_sym)
modules_sym = sym_find( "n" );
...
menu_finalize(&rootmenu);
The following tests were done to ensure no functional changes for
configurations that don't reference 'm' before the modules symbol:
- zconfdump(stdout) was run with ARCH=x86 and ARCH=arm before
and after the change and verified to produce identical output.
This function prints all symbols, choices, and menus together
with their properties and their dependency expressions. A
rewritten 'm' appears as 'm && MODULES'.
A small annoyance is that the assert(len != 0) in xfwrite()
needs to be disabled in order to use zconfdump(), because it
chokes on e.g. 'default ""'.
- The Kconfiglib test suite was run to indirectly verify that
alldefconfig, allyesconfig, allnoconfig, and all defconfigs in
the kernel still generate the same final .config.
- Valgrind was used to check for memory errors and (new) memory
leaks.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
menu_finalize() is one of the more opaque parts of Kconfig, and I need
to make some changes to it to fix an issue related to modules. Add some
comments related to expression rewriting and dependency propagation as a
review aid. They will also help other people trying to understand the
code.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This will catch mistakes like in the following real-world example, where
a "CONFIG_" prefix snuck in, making an undefined symbol the default:
choice
prompt "Compiler optimization level"
default CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
config CC_OPTIMIZE_FOR_PERFORMANCE
...
config CC_OPTIMIZE_FOR_SIZE
...
endchoice
This now prints the following warning:
init/Kconfig:1036:warning: choice default symbol 'CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE' is not contained in the choice
Cases where the default symbol belongs to the wrong choice are also
detected.
(The mistake is harmless here: Since the default symbol is not visible,
the choice falls back on using the first visible symbol as the default,
which is CC_OPTIMIZE_FOR_PERFORMANCE, as intended.)
Discovered while playing around with Kconfiglib
(https://github.com/ulfalizer/Kconfiglib).
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The "imply" keyword is a weak version of "select" where the target
config symbol can still be turned off, avoiding those pitfalls that come
with the "select" keyword.
This is useful e.g. with multiple drivers that want to indicate their
ability to hook into a secondary subsystem while allowing the user to
configure that subsystem out without also having to unset these drivers.
Currently, the same effect can almost be achieved with:
config DRIVER_A
tristate
config DRIVER_B
tristate
config DRIVER_C
tristate
config DRIVER_D
tristate
[...]
config SUBSYSTEM_X
tristate
default DRIVER_A || DRIVER_B || DRIVER_C || DRIVER_D || [...]
This is unwieldy to maintain especially with a large number of drivers.
Furthermore, there is no easy way to restrict the choice for SUBSYSTEM_X
to y or n, excluding m, when some drivers are built-in. The "select"
keyword allows for excluding m, but it excludes n as well. Hence
this "imply" keyword. The above becomes:
config DRIVER_A
tristate
imply SUBSYSTEM_X
config DRIVER_B
tristate
imply SUBSYSTEM_X
[...]
config SUBSYSTEM_X
tristate
This is much cleaner, and way more flexible than "select". SUBSYSTEM_X
can still be configured out, and it can be set as a module when none of
the drivers are configured in or all of them are modular.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-2-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
menu_is_visible() is a bool function and should use boolean return
values. "no" is a tristate value which happens to also have a value
of 0, but we should nevertheless use the right symbol for it.
This is a very minor cleanup with no semantic change.
Fixes: 86e187ff9 ("kconfig: add an option to determine a menu's visibility")
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Warning:
In file included from scripts/kconfig/zconf.tab.c:2537:0:
scripts/kconfig/menu.c: In function ‘get_symbol_str’:
scripts/kconfig/menu.c:590:18: warning: ‘jump’ may be used uninitialized in this function [-Wmaybe-uninitialized]
jump->offset = strlen(r->s);
Simplifies the test logic because (head && local) means (jump != 0)
and makes GCC happy when checking if the jump pointer was initialized.
Signed-off-by: Peter Kümmel <syntheticpp@gmx.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
