From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Mon, 28 May 2018 09:21:50 +0000 (+0900)
Subject: kconfig: support simply expanded variable
X-Git-Url: https://jxself.org/git/?p=carl9170fw.git;a=commitdiff_plain;h=dd88a7e5b482637a26c67ffa1cdf7ebed204161d

kconfig: support simply expanded variable

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>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
---

diff --git a/config/lkc_proto.h b/config/lkc_proto.h
index 2b16d6e..6303193 100644
--- a/config/lkc_proto.h
+++ b/config/lkc_proto.h
@@ -49,8 +49,13 @@ const char * sym_get_string_value(struct symbol *sym);
 const char * prop_get_type_name(enum prop_type type);
 
 /* preprocess.c */
+enum variable_flavor {
+	VAR_SIMPLE,
+	VAR_RECURSIVE,
+};
 void env_write_dep(FILE *f, const char *auto_conf_name);
-void variable_add(const char *name, const char *value);
+void variable_add(const char *name, const char *value,
+		  enum variable_flavor flavor);
 void variable_all_del(void);
 char *expand_string(const char *in);
 char *expand_dollar(const char **str);
diff --git a/config/preprocess.c b/config/preprocess.c
index 46487fe..d103683 100644
--- a/config/preprocess.c
+++ b/config/preprocess.c
@@ -185,6 +185,7 @@ static LIST_HEAD(variable_list);
 struct variable {
 	char *name;
 	char *value;
+	enum variable_flavor flavor;
 	struct list_head node;
 };
 
@@ -203,15 +204,22 @@ static struct variable *variable_lookup(const char *name)
 static char *variable_expand(const char *name, int argc, char *argv[])
 {
 	struct variable *v;
+	char *res;
 
 	v = variable_lookup(name);
 	if (!v)
 		return NULL;
 
-	return expand_string_with_args(v->value, argc, argv);
+	if (v->flavor == VAR_RECURSIVE)
+		res = expand_string_with_args(v->value, argc, argv);
+	else
+		res = xstrdup(v->value);
+
+	return res;
 }
 
-void variable_add(const char *name, const char *value)
+void variable_add(const char *name, const char *value,
+		  enum variable_flavor flavor)
 {
 	struct variable *v;
 
@@ -224,7 +232,12 @@ void variable_add(const char *name, const char *value)
 		list_add_tail(&v->node, &variable_list);
 	}
 
-	v->value = xstrdup(value);
+	v->flavor = flavor;
+
+	if (flavor == VAR_SIMPLE)
+		v->value = expand_string(value);
+	else
+		v->value = xstrdup(value);
 }
 
 static void variable_del(struct variable *v)
diff --git a/config/zconf.l b/config/zconf.l
index f1add95..d0f5b13 100644
--- a/config/zconf.l
+++ b/config/zconf.l
@@ -114,7 +114,8 @@ n	[A-Za-z0-9_-]
 		yylval.string = text;
 		return T_VARIABLE;
 	}
-	"="	{ BEGIN(ASSIGN_VAL); return T_ASSIGN; }
+	"="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_RECURSIVE; return T_ASSIGN; }
+	":="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_SIMPLE; return T_ASSIGN; }
 	[[:blank:]]+
 	.	warn_ignored_character(*yytext);
 	\n	{
diff --git a/config/zconf.y b/config/zconf.y
index addd4a6..a4b1775 100644
--- a/config/zconf.y
+++ b/config/zconf.y
@@ -41,6 +41,7 @@ static struct menu *current_menu, *current_entry;
 	struct expr *expr;
 	struct menu *menu;
 	const struct kconf_id *id;
+	enum variable_flavor flavor;
 }
 
 %token <id>T_MAINMENU
@@ -78,7 +79,7 @@ static struct menu *current_menu, *current_entry;
 %token T_OPEN_PAREN
 %token T_EOL
 %token <string> T_VARIABLE
-%token T_ASSIGN
+%token <flavor> T_ASSIGN
 %token <string> T_ASSIGN_VAL
 
 %left T_OR
@@ -517,7 +518,7 @@ word_opt: /* empty */			{ $$ = NULL; }
 
 /* assignment statement */
 
-assignment_stmt:  T_VARIABLE T_ASSIGN assign_val T_EOL	{ variable_add($1, $3); free($1); free($3); }
+assignment_stmt:  T_VARIABLE T_ASSIGN assign_val T_EOL	{ variable_add($1, $3, $2); free($1); free($3); }
 
 assign_val:
 	/* empty */		{ $$ = xstrdup(""); };