From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Mon, 28 May 2018 09:21:51 +0000 (+0900)
Subject: kconfig: support append assignment operator
X-Git-Url: https://jxself.org/git/?a=commitdiff_plain;h=c9645e9489aac917a4883ddecc857b1c6fcc2c38;p=carl9170fw.git

kconfig: support append assignment operator

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 <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 6303193..a8b7a33 100644
--- a/config/lkc_proto.h
+++ b/config/lkc_proto.h
@@ -52,6 +52,7 @@ const char * prop_get_type_name(enum prop_type type);
 enum variable_flavor {
 	VAR_SIMPLE,
 	VAR_RECURSIVE,
+	VAR_APPEND,
 };
 void env_write_dep(FILE *f, const char *auto_conf_name);
 void variable_add(const char *name, const char *value,
diff --git a/config/preprocess.c b/config/preprocess.c
index d103683..56aa1f0 100644
--- a/config/preprocess.c
+++ b/config/preprocess.c
@@ -222,11 +222,23 @@ void variable_add(const char *name, const char *value,
 		  enum variable_flavor flavor)
 {
 	struct variable *v;
+	char *new_value;
+	bool append = false;
 
 	v = variable_lookup(name);
 	if (v) {
-		free(v->value);
+		/* For defined variables, += inherits the existing flavor */
+		if (flavor == VAR_APPEND) {
+			flavor = v->flavor;
+			append = true;
+		} else {
+			free(v->value);
+		}
 	} else {
+		/* For undefined variables, += assumes the recursive flavor */
+		if (flavor == VAR_APPEND)
+			flavor = VAR_RECURSIVE;
+
 		v = xmalloc(sizeof(*v));
 		v->name = xstrdup(name);
 		list_add_tail(&v->node, &variable_list);
@@ -235,9 +247,19 @@ void variable_add(const char *name, const char *value,
 	v->flavor = flavor;
 
 	if (flavor == VAR_SIMPLE)
-		v->value = expand_string(value);
+		new_value = expand_string(value);
 	else
-		v->value = xstrdup(value);
+		new_value = xstrdup(value);
+
+	if (append) {
+		v->value = xrealloc(v->value,
+				    strlen(v->value) + strlen(new_value) + 2);
+		strcat(v->value, " ");
+		strcat(v->value, new_value);
+		free(new_value);
+	} else {
+		v->value = new_value;
+	}
 }
 
 static void variable_del(struct variable *v)
diff --git a/config/zconf.l b/config/zconf.l
index d0f5b13..62a0973 100644
--- a/config/zconf.l
+++ b/config/zconf.l
@@ -116,6 +116,7 @@ n	[A-Za-z0-9_-]
 	}
 	"="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_RECURSIVE; return T_ASSIGN; }
 	":="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_SIMPLE; return T_ASSIGN; }
+	"+="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_APPEND; return T_ASSIGN; }
 	[[:blank:]]+
 	.	warn_ignored_character(*yytext);
 	\n	{