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path: root/scripts/kconfig/preprocess.c
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2019-06-09kconfig: add static qualifier to expand_string()Masahiro Yamada
Now expand_string() is only used in preprocess.c Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-28kconfig: split some C files out of zconf.yMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22kconfig: stop supporting '.' and '/' in unquoted wordsMasahiro Yamada
In my understanding, special characters such as '.' and '/' are supported in unquoted words to use bare file paths in the "source" statement. With the previous commit surrounding all file paths with double quotes, we can drop this. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-28kconfig: loop boundary condition fixJerry James
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=1592374 Signed-off-by: Jerry James <loganjerry@gmail.com> [alexpl@fedoraproject.org: reformatted patch for submission] Signed-off-by: Alexander Ploumistos <alexpl@fedoraproject.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: error out if a recursive variable references itselfMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: add 'filename' and 'lineno' built-in variablesMasahiro Yamada
The special variables, $(filename) and $(lineno), are expanded to a file name and its line number being parsed, respectively. Suggested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29kconfig: add 'info', 'warning-if', and 'error-if' built-in functionsMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29kconfig: support append assignment operatorMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: support simply expanded variableMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: support user-defined function and recursively expanded variableMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: add 'shell' built-in functionMasahiro Yamada
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: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: add built-in function supportMasahiro Yamada
This commit adds a new concept 'function' to do more text processing in Kconfig. A function call looks like this: $(function,arg1,arg2,arg3,...) This commit adds the basic infrastructure to expand functions. Change the text expansion helpers to take arguments. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29kconfig: reference environment variables directly and remove 'option env='Masahiro Yamada
To get access to environment variables, Kconfig needs to define a symbol using "option env=" syntax. It is tedious to add a symbol entry for each environment variable given that we need to define much more such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability in Kconfig. Adding '$' 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>