kconfig: add a symbol string expansion helper

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Michal Marek <mmarek@suse.cz>

diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 9a948c9ce44edd4732d6beb579266b23b9049cb0..4531badb3fe19ec9f2f0237c5f833c7e4b98ff59 100644 (file)
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -28,6 +28,7 @@ P(symbol_hash,struct symbol *,[SYMBOL_HASHSIZE]);
 
 P(sym_lookup,struct symbol *,(const char *name, int flags));
 P(sym_find,struct symbol *,(const char *name));
+P(sym_expand_string_value,const char *,(const char *in));
 P(sym_re_search,struct symbol **,(const char *pattern));
 P(sym_type_name,const char *,(enum symbol_type type));
 P(sym_calc_value,void,(struct symbol *sym));

diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 943712ca6c0a6a0eb5bbf97dbba2a2d20e495b47..dc5dcf2189a01c33807b1593be13ff4c22c9745f 100644 (file)
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -840,6 +840,55 @@ struct symbol *sym_find(const char *name)
        return symbol;
 }
 
+/*
+ * Expand symbol's names embedded in the string given in argument. Symbols'
+ * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
+ * the empty string.
+ */
+const char *sym_expand_string_value(const char *in)
+{
+       const char *src;
+       char *res;
+       size_t reslen;
+
+       reslen = strlen(in) + 1;
+       res = malloc(reslen);
+       res[0] = '\0';
+
+       while ((src = strchr(in, '$'))) {
+               char *p, name[SYMBOL_MAXLENGTH];
+               const char *symval = "";
+               struct symbol *sym;
+               size_t newlen;
+
+               strncat(res, in, src - in);
+               src++;
+
+               p = name;
+               while (isalnum(*src) || *src == '_')
+                       *p++ = *src++;
+               *p = '\0';
+
+               sym = sym_find(name);
+               if (sym != NULL) {
+                       sym_calc_value(sym);
+                       symval = sym_get_string_value(sym);
+               }
+
+               newlen = strlen(res) + strlen(symval) + strlen(src);
+               if (newlen > reslen) {
+                       reslen = newlen;
+                       realloc(res, reslen);
+               }
+
+               strcat(res, symval);
+               in = src;
+       }
+       strcat(res, in);
+
+       return res;
+}
+
 struct symbol **sym_re_search(const char *pattern)
 {
        struct symbol *sym, **sym_arr = NULL;