kconfig: support user-defined function and recursively expanded variable

[carl9170fw.git] / config / preprocess.c

diff --git a/config/preprocess.c b/config/preprocess.c
index 528be594e1d01f6d03b729e43fdc0fccf20b0001..46487fe6b36cd99e9ea04cc0bc2cbe7708b98121 100644 (file)
--- a/config/preprocess.c
+++ b/config/preprocess.c
@@ -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 @@ free:
        for (i = 0; i < new_argc; i++)
                free(new_argv[i]);
        free(name);
+free_tmp:
        free(tmp);
 
        return res;