kconfig: expand lefthand side of assignment statement

Make expands the lefthand side of assignment statements.  In fact,
Kbuild relies on it since kernel makefiles mostly look like this:

  obj-$(CONFIG_FOO) += foo.o

Do likewise in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index a6cbe2d06d014d6edb793dbbf3dd919b73516bcd..25bd2b89fe3f3b8d588cad2c72b3cc9b3ebae2cb 100644 (file)
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -114,6 +114,13 @@ n  [A-Za-z0-9_-]
                yylval.string = text;
                return T_VARIABLE;
        }
+       ({n}|$)+        {
+               /* this token includes at least one '$' */
+               yylval.string = expand_token(yytext, yyleng);
+               if (strlen(yylval.string))
+                       return T_VARIABLE;
+               free(yylval.string);
+       }
        "="     { 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; }