kernel/linux.git/scripts/kconfig/zconf.l, branch v4.20.5

kconfig: fix memory leak when EOF is encountered in quotation

2019-01-26T08:20:46+00:00

[ Upstream commit fbac5977d81cb2b2b7e37b11c459055d9585273c ] An unterminated string literal followed by new line is passed to the parser (with "multi-line strings not supported" warning shown), then handled properly there. On the other hand, an unterminated string literal at end of file is never passed to the parser, then results in memory leak. [Test Code] ----------(Kconfig begin)---------- source "Kconfig.inc" config A bool "a" -----------(Kconfig end)----------- --------(Kconfig.inc begin)-------- config B bool "b\No new line at end of file ---------(Kconfig.inc end)--------- [Summary from Valgrind] Before the fix: LEAK SUMMARY: definitely lost: 16 bytes in 1 blocks ... After the fix: LEAK SUMMARY: definitely lost: 0 bytes in 0 blocks ... Eliminate the memory leak path by handling this case. Of course, such a Kconfig file is wrong already, so I will add an error message later. Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kconfig: fix file name and line number of warn_ignored_character()

2019-01-26T08:20:46+00:00

[ Upstream commit 77c1c0fa8b1477c5799bdad65026ea5ff676da44 ] Currently, warn_ignore_character() displays invalid file name and line number. The lexer should use current_file->name and yylineno, while the parser should use zconf_curname() and zconf_lineno(). This difference comes from that the lexer is always going ahead of the parser. The parser needs to look ahead one token to make a shift/reduce decision, so the lexer is requested to scan more text from the input file. This commit fixes the warning message from warn_ignored_character(). [Test Code] ----(Kconfig begin)---- / -----(Kconfig end)----- [Output] Before the fix: :0:warning: ignoring unsupported character '/' After the fix: Kconfig:1:warning: ignoring unsupported character '/' Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kconfig: expand lefthand side of assignment statement

2018-05-28T18:31:19+00:00

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: Masahiro Yamada

kconfig: support append assignment operator

2018-05-28T18:31:19+00:00

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

kconfig: support simply expanded variable

2018-05-28T18:31:19+00:00

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

kconfig: support user-defined function and recursively expanded variable

2018-05-28T18:31:19+00:00

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

kconfig: begin PARAM state only when seeing a command keyword

2018-05-28T18:31:19+00:00

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: Masahiro Yamada

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

2018-05-28T18:28:58+00:00

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: use yylineno option instead of manual lineno increments

2018-03-25T17:04:07+00:00

Tracking the line number by hand is error-prone since you need to increment it in every \n matching pattern. If '%option yylineno' is set, flex defines 'yylineno' to contain the current line number and automatically updates it each time it reads a \n character. This is much more convenient although the lexer does not initializes yylineno, so you need to set it to 1 each time you start reading a new file, and restore it you go back to the previous file. I tested this with DEBUG_PARSE, and confirmed the same dump message was produced. I removed the perf-report option. Otherwise, I see the following message: %option yylineno entails a performance penalty ONLY on rules that can match newline characters Signed-off-by: Masahiro Yamada

kconfig: detect recursive inclusion earlier

2018-03-25T17:04:07+00:00

Currently, the recursive inclusion is not detected when the offending file is about to be included; it is detected the offending file is about to include the *next* file. This is because the detection loop does not involve the file being included. Do this check against the file that is about to be included so that the recursive inclusion is detected before unneeded parsing happens. Signed-off-by: Masahiro Yamada