ref: be7c5f83d4655f77d592b626a702dd2da07c3fb8
parent: ee42812835eb35735b73cc2f4588a8c25326355b
author: Roberto E. Vargas Caballero <[email protected]>
date: Thu Jul 17 14:05:07 EDT 2014
Add support for labels in cc2 Labels are the base for all the loops and jumps, so they are strictly necessary.
--- a/cc2/parser.c
+++ b/cc2/parser.c
@@ -11,8 +11,15 @@
#define NR_SYMBOLS 1024
typedef struct {- char vartype;
- char storage;
+ union {+ struct {+ char type;
+ char storage;
+ } v;
+ struct {+ short addr;
+ } l;
+ } u;
} Symbol;
typedef struct node {@@ -96,7 +103,7 @@
np->op = op;
np->u.id = id;
- np->type = symtbl[id].vartype;
+ np->type = symtbl[id].u.v.type;
np->left = np->right = NULL;
push(np);
}
@@ -125,6 +132,16 @@
push(np);
}
+static void
+label(char op)
+{+ Node *np = newnode();
+
+ np->left = np->right = NULL;
+ np->op = 'L';
+ push(np);
+}
+
static Node *
getroot(void)
{@@ -142,6 +159,7 @@
['A'] = variable,
['T'] = variable,
['G'] = variable,
+ ['L'] = label,
['#'] = immediate,
['\177'] = NULL
};
@@ -171,12 +189,20 @@
Symbol *sym = &symtbl[getid()];
getchar(); /* skip tab */
- sym->storage = sclass;
- sym->vartype = gettype();
+ sym->u.v.storage = sclass;
+ sym->u.v.type = gettype();
if (getchar() != '\n')
esyntax();
}
+static void
+deflabel(void)
+{+ Symbol *sym = &symtbl[getid()];
+
+ sym->u.l.addr = listp - listexp;
+}
+
int
parse(void)
{@@ -188,7 +214,7 @@
expression();
break;
case 'L':
- /* label */
+ deflabel();
break;
case 'S':
/* struct */