scc

commit cae714c448ebdea4a6de048b012927b96be9b628
parent c1768b2e370906fc8418bc26cd69d88529c8c96b
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Mon, 14 Apr 2014 10:38:09 +0200

Check against assigns to const variables

It is implementation defined what happens in that cases, and
I choose report an error.

Diffstat:
M
expr.c
 | 
8
+++++++-
M
types.c
 | 
2
+-

2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/expr.c b/expr.c
@@ -511,9 +511,10 @@ ternary(void)
 static Node *
 assign(void)
 {
-	register Node *np1 = ternary(), *np2;
+	register Node *np1, *np2;
 	char *err;
 
+	np1 = ternary();
 	for (;;) {
 		register char op;
 
@@ -535,6 +536,8 @@ assign(void)
 		np2 = assign();
 		if (!np1->b.lvalue)
 			goto nolvalue;
+		if (isconst(np1->type->op))
+			goto const_mod;
 		/* TODO: if it necessary a 0 comparision? */
 		if ((np2 = convert(np2, np1->type)) == NULL)
 			goto incompatibles;
@@ -543,6 +546,9 @@ assign(void)
 return_np:
 	return np1;
 
+const_mod:
+	err = "const value modified";
+	goto error;
 nolvalue:
 	err = "lvalue required as left operand of assignment";
 	goto error;
diff --git a/types.c b/types.c
@@ -144,7 +144,7 @@ mktype(Type *tp, uint8_t op,
 	case ARY:    letter = 'V'; break;
 	case ENUM:   letter = 'E'; break;
 	case STRUCT: letter = 'S'; break;
-	default:     abort();
+	default: letter = tp->letter;
 	}
 	bp = xmalloc(sizeof(*bp));
 	bp->next = *tbl;