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>
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index d103683..56aa1f0 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/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)