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@xxxxxxxxxxxxx> --- Changes in v5: - Remove lazy expansion support and simplify the code again Changes in v4: None Changes in v3: - Re-implement the parse logic - Use = operator to define a user-defined function Changes in v2: - Use 'macro' directly instead of inside the string type symbol. scripts/kconfig/lkc_proto.h | 2 ++ scripts/kconfig/preprocess.c | 86 +++++++++++++++++++++++++++++++++++++++++++- scripts/kconfig/zconf.l | 17 +++++++-- scripts/kconfig/zconf.y | 19 +++++++++- 4 files changed, 120 insertions(+), 4 deletions(-) diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h index c46929f..2b16d6e 100644 --- a/scripts/kconfig/lkc_proto.h +++ b/scripts/kconfig/lkc_proto.h @@ -50,6 +50,8 @@ const char * prop_get_type_name(enum prop_type type); /* preprocess.c */ void env_write_dep(FILE *f, const char *auto_conf_name); +void variable_add(const char *name, const char *value); +void variable_all_del(void); char *expand_string(const char *in); char *expand_dollar(const char **str); char *expand_one_token(const char **str); diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c index 528be59..46487fe 100644 --- a/scripts/kconfig/preprocess.c +++ b/scripts/kconfig/preprocess.c @@ -178,6 +178,72 @@ static char *function_expand(const char *name, int argc, char *argv[]) } /* + * Variables (and user-defined functions) + */ +static LIST_HEAD(variable_list); + +struct variable { + char *name; + char *value; + struct list_head node; +}; + +static struct variable *variable_lookup(const char *name) +{ + struct variable *v; + + list_for_each_entry(v, &variable_list, node) { + if (!strcmp(name, v->name)) + return v; + } + + return NULL; +} + +static char *variable_expand(const char *name, int argc, char *argv[]) +{ + struct variable *v; + + v = variable_lookup(name); + if (!v) + return NULL; + + return expand_string_with_args(v->value, argc, argv); +} + +void variable_add(const char *name, const char *value) +{ + struct variable *v; + + v = variable_lookup(name); + if (v) { + free(v->value); + } else { + v = xmalloc(sizeof(*v)); + v->name = xstrdup(name); + list_add_tail(&v->node, &variable_list); + } + + v->value = xstrdup(value); +} + +static void variable_del(struct variable *v) +{ + list_del(&v->node); + free(v->name); + free(v->value); + free(v); +} + +void variable_all_del(void) +{ + struct variable *v, *tmp; + + list_for_each_entry_safe(v, tmp, &variable_list, node) + variable_del(v); +} + +/* * Evaluate a clause with arguments. argc/argv are arguments from the upper * function call. * @@ -185,14 +251,26 @@ static char *function_expand(const char *name, int argc, char *argv[]) */ static char *eval_clause(const char *str, size_t len, int argc, char *argv[]) { - char *tmp, *name, *res, *prev, *p; + char *tmp, *name, *res, *endptr, *prev, *p; int new_argc = 0; char *new_argv[FUNCTION_MAX_ARGS]; int nest = 0; int i; + unsigned long n; tmp = xstrndup(str, len); + /* + * If variable name is '1', '2', etc. It is generally an argument + * from a user-function call (i.e. local-scope variable). If not + * available, then look-up global-scope variables. + */ + n = strtoul(tmp, &endptr, 10); + if (!*endptr && n > 0 && n <= argc) { + res = xstrdup(argv[n - 1]); + goto free_tmp; + } + prev = p = tmp; /* @@ -238,6 +316,11 @@ static char *eval_clause(const char *str, size_t len, int argc, char *argv[]) new_argv[i] = expand_string_with_args(new_argv[i + 1], argc, argv); + /* Search for variables */ + res = variable_expand(name, new_argc, new_argv); + if (res) + goto free; + /* Look for built-in functions */ res = function_expand(name, new_argc, new_argv); if (res) @@ -255,6 +338,7 @@ static char *eval_clause(const char *str, size_t len, int argc, char *argv[]) for (i = 0; i < new_argc; i++) free(new_argv[i]); free(name); +free_tmp: free(tmp); return res; diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l index 9a14797..dd08f7a 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 <zippel@xxxxxxxxxxxxxx> * Released under the terms of the GNU GPL v2.0. */ +#include <assert.h> #include <limits.h> #include <stdio.h> #include <stdlib.h> @@ -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_-] } } +<ASSIGN_VAL>{ + [^[:blank:]\n]+.* { + alloc_string(yytext, yyleng); + yylval.string = text; + return T_ASSIGN_VAL; + } + \n { BEGIN(INITIAL); return T_EOL; } + . +} + <PARAM>{ "&&" return T_AND; "||" return T_OR; diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y index 8a82aaf..e15e8c7 100644 --- a/scripts/kconfig/zconf.y +++ b/scripts/kconfig/zconf.y @@ -77,6 +77,9 @@ static struct menu *current_menu, *current_entry; %token T_CLOSE_PAREN %token T_OPEN_PAREN %token T_EOL +%token <string> T_VARIABLE +%token T_ASSIGN +%token <string> T_ASSIGN_VAL %left T_OR %left T_AND @@ -92,7 +95,7 @@ static struct menu *current_menu, *current_entry; %type <id> end %type <id> option_name %type <menu> if_entry menu_entry choice_entry -%type <string> symbol_option_arg word_opt +%type <string> symbol_option_arg word_opt assign_val %destructor { fprintf(stderr, "%s:%d: missing end statement for this entry\n", @@ -143,6 +146,7 @@ common_stmt: | config_stmt | menuconfig_stmt | source_stmt + | assignment_stmt ; option_error: @@ -511,6 +515,15 @@ symbol: nonconst_symbol word_opt: /* empty */ { $$ = NULL; } | T_WORD +/* assignment statement */ + +assignment_stmt: T_VARIABLE T_ASSIGN assign_val T_EOL { variable_add($1, $3); free($1); free($3); } + +assign_val: + /* empty */ { $$ = xstrdup(""); }; + | T_ASSIGN_VAL +; + %% void conf_parse(const char *name) @@ -525,6 +538,10 @@ void conf_parse(const char *name) if (getenv("ZCONF_DEBUG")) yydebug = 1; yyparse(); + + /* Variables are expanded in the parse phase. We can free them here. */ + variable_all_del(); + if (yynerrs) exit(1); if (!modules_sym) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html