linux/scripts/kconfig/confdata.c, branch v4.19

kconfig: allow all config targets to write auto.conf if missing

2018-07-25T14:25:30Z

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: Masahiro Yamada

kconfig: create directories needed for syncconfig by itself

2018-07-25T14:25:30Z

'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: Masahiro Yamada

kconfig: split out useful helpers in confdata.c

2018-07-25T14:25:29Z

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: Masahiro Yamada

kconfig: rename file_write_dep and move it to confdata.c

2018-07-25T14:25:28Z

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: Masahiro Yamada

kconfig: handle format string before calling conf_message_callback()

2018-07-25T14:24:35Z

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: Masahiro Yamada Reviewed-by: Dirk Gouders

kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE

2018-07-17T16:18:09Z

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 Signed-off-by: Masahiro Yamada

kconfig: Avoid format overflow warning from GCC 8.1

2018-06-05T13:07:21Z

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: Nathan Chancellor Signed-off-by: Masahiro Yamada

kconfig: reference environment variables directly and remove 'option env='

2018-05-28T18:28:58Z

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 Reviewed-by: Kees Cook

kconfig: drop localization support

2018-05-28T09:25:21Z

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 Suggested-by: Masahiro Yamada Signed-off-by: Sam Ravnborg Signed-off-by: Masahiro Yamada

kconfig: add xstrdup() helper

2018-03-01T15:26:47Z

We already have xmalloc(), xcalloc(), and xrealloc((). Add xstrdup() as well to save tedious error handling. Signed-off-by: Masahiro Yamada