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Commit 9ced3bdd authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

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: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
parent 9de07153

scripts/kconfig/lkc_proto.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

scripts/kconfig/preprocess.c

+85 −1
Original line number Diff line number Diff line
@@ -177,6 +177,72 @@ static char *function_expand(const char *name, int argc, char *argv[]) 
	return NULL;

}



/*

 * 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;

scripts/kconfig/zconf.l

+15 −2
Original line number Diff line number Diff line 
%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@linux-m68k.org>

 * 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;

scripts/kconfig/zconf.y

+18 −1
Original line number Diff line number Diff line
@@ -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)