kconfig: support append assignment operator

[carl9170fw.git] / config / preprocess.c

diff --git a/config/preprocess.c b/config/preprocess.c
index d103683b386edc551ffc526d28bf74434856d7b1..56aa1f0bad0422eab2d1f1f2eb1f8d79f99b769c 100644 (file)
--- 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)