On Wed, May 4, 2011 at 4:39 PM, Ben Pfaff <blp@xxxxxxxxxx> wrote:
> Without this commit, sizeof(_Bool) provokes an error with "cannot size
> expression" because _Bool is a 1-bit type and thus not a multiple of a full
> byte in size. But sizeof(_Bool) is valid C that should evaluate to 1, so
> this commit fixes the problem and adds a regression test.
Thanks for the patch.
The sizeof _Bool is implementation define. Gcc make sizeof(_Bool) as 1.
I modify your patch to issue an warning. Applied and pushed.
The incremental change follows. Please check that works for you or not.
Chris
diff --git a/evaluate.c b/evaluate.c
index f196dbc..1309001 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -2028,14 +2028,18 @@ static struct symbol *evaluate_sizeof(struct
expression *expr)
size = bits_in_char;
}
+ if (size == 1 && is_bool_type(type)) {
+ warning(expr->pos, "expression using sizeof bool");
+ size = bits_in_char;
+ }
+
if (is_function(type->ctype.base_type)) {
warning(expr->pos, "expression using sizeof on a function");
size = bits_in_char;
}
- if (is_bool_type(type))
- size = bits_in_char;
- else if ((size < 0) || (size & (bits_in_char - 1)))
+
+ if ((size < 0) || (size & (bits_in_char - 1)))
expression_error(expr, "cannot size expression");
expr->type = EXPR_VALUE;
diff --git a/validation/sizeof-bool.c b/validation/sizeof-bool.c
index dfcb12a..6c68748 100644
--- a/validation/sizeof-bool.c
+++ b/validation/sizeof-bool.c
@@ -6,4 +6,7 @@ static int a(void)
* check-name: sizeof(_Bool) is valid
* check-description: sizeof(_Bool) was rejected because _Bool is not an even
* number of bytes
+ * check-error-start
+sizeof-bool.c:3:16: warning: expression using sizeof bool
+ * check-error-end
*/
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
