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-rw-r--r--conf/cf-lex.l3
-rw-r--r--conf/conf.h2
-rw-r--r--conf/confbase.Y31
3 files changed, 35 insertions, 1 deletions
diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index f653bca..66f3038 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -101,7 +101,7 @@ WHITE [ \t]
return SYM;
}
-[{}:;,] {
+[={}:;,()+*/%-] {
return yytext[0];
}
@@ -177,6 +177,7 @@ cf_find_sym(byte *c, unsigned int h0)
sym_hash[h] = s;
s->class = SYM_VOID;
s->def = NULL;
+ s->aux = 0;
strcpy(s->name, c);
return s;
}
diff --git a/conf/conf.h b/conf/conf.h
index 0853ae8..6a0a328 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -21,12 +21,14 @@ extern int (*cf_read_hook)(byte *buf, unsigned int max);
struct symbol {
struct symbol *next;
int class;
+ int aux;
void *def;
char name[1];
};
#define SYM_VOID 0
#define SYM_PROTO 1
+#define SYM_NUMBER 2
void cf_lex_init_tables(void);
int cf_lex(void);
diff --git a/conf/confbase.Y b/conf/confbase.Y
index b20986a..db6d021 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -30,8 +30,17 @@ CF_DECLS
%token <s> SYM
%token <t> TEXT
+%type <i> expr
+
+%left '+' '-'
+%left '*' '/' '%'
+
+CF_KEYWORDS(DEFINE)
+
CF_GRAMMAR
+/* Basic config file structure */
+
config: conf_entries END {
return 0;
}
@@ -44,6 +53,28 @@ conf_entries:
CF_ADDTO(conf, /* EMPTY */)
+/* Expressions */
+
+expr:
+ NUM
+ | expr '+' expr { $$ = $1 + $3; }
+ | expr '-' expr { $$ = $1 - $3; }
+ | expr '*' expr { $$ = $1 * $3; }
+ | expr '/' expr { if ($3) $$ = $1 / $3; else cf_error("Division by zero"); }
+ | expr '%' expr { if ($3) $$ = $1 % $3; else cf_error("Division by zero"); }
+ | '(' expr ')' { $$ = $2; }
+ | SYM { if ($1->class != SYM_NUMBER) cf_error("Number expected"); else $$ = $1->aux; }
+ ;
+
+CF_ADDTO(conf, definition)
+definition:
+ DEFINE SYM '=' expr {
+ if ($2->class != SYM_VOID) cf_error("Symbol already defined");
+ $2->class = SYM_NUMBER;
+ $2->aux = $4;
+ }
+ ;
+
CF_CODE
CF_END