From 9ced3bddec080e974e910bf887715540a8d9d96b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:21:49 +0900 Subject: kconfig: support user-defined function and recursively expanded variable 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 --- scripts/kconfig/zconf.l | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'scripts/kconfig/zconf.l') diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l index 9a147977dc3f..dd08f7a38ccd 100644 --- a/scripts/kconfig/zconf.l +++ b/scripts/kconfig/zconf.l @@ -1,12 +1,13 @@ %option nostdinit noyywrap never-interactive full ecs %option 8bit nodefault yylineno -%x COMMAND HELP STRING PARAM +%x COMMAND HELP STRING PARAM ASSIGN_VAL %{ /* * Copyright (C) 2002 Roman Zippel * Released under the terms of the GNU GPL v2.0. */ +#include #include #include #include @@ -111,8 +112,10 @@ n [A-Za-z0-9_-] } alloc_string(yytext, yyleng); yylval.string = text; - return T_WORD; + return T_VARIABLE; } + "=" { BEGIN(ASSIGN_VAL); return T_ASSIGN; } + [[:blank:]]+ . warn_ignored_character(*yytext); \n { BEGIN(INITIAL); @@ -120,6 +123,16 @@ n [A-Za-z0-9_-] } } +{ + [^[:blank:]\n]+.* { + alloc_string(yytext, yyleng); + yylval.string = text; + return T_ASSIGN_VAL; + } + \n { BEGIN(INITIAL); return T_EOL; } + . +} + { "&&" return T_AND; "||" return T_OR; -- cgit v1.2.3-59-g8ed1b