Tommy Thorn wrote:
> Christopher Li wrote:
>> So here is what I got. A patch address both of our need. It gives warning
>> of using sizeof(void) explicitly. void* + offset will continue to work without
>> warnings. It will also make is_byte_type() continue to work as it was
>> before.
>>
>> Here is my test script:
>>
>> void *p;
>>
>> int i = sizeof(void);
>> int j = sizeof(*p);
>>
> I can't test it right now, but does it give a warning for both sizeof's
> above? If just first results in a warning, then I think that quite
> reasonable.
Both trigger the warning. I'm not sure this is a problem, as there are
no such usage cases in the kernel.
I added (hopefully the right way) handling of (sizeof(function)) to the
patch. function++ was already prohibited.
Running the test on the kernel right now.
--
From: Christopher Li <sparse@xxxxxxxxxxx>
sizeof(void) and sizeof(function) still evaluate as 1
after the warning. void_ctype.bit_size remain zero so
is_byte_type() will continue to work.
Signed-Off-By: Christopher Li <sparse@xxxxxxxxxxx>
[sizeof(function) added by Alexey Zaytsev]
Signed-off-by: Alexey Zaytsev <alexey.zaytsev@xxxxxxxxx>
---
evaluate.c | 13 ++++++++++++-
symbol.c | 2 +-
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/evaluate.c b/evaluate.c
index f976645..e82be53 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -579,7 +579,7 @@ static struct symbol *evaluate_ptr_add(struct expression *expr, struct symbol *i
}
/* Get the size of whatever the pointer points to */
- multiply = bits_to_bytes(base->bit_size);
+ multiply = (base == &void_ctype) ? 1 : bits_to_bytes(base->bit_size);
if (ctype == &null_ctype)
ctype = &ptr_ctype;
@@ -2044,8 +2044,19 @@ static struct symbol *evaluate_sizeof(struct expression *expr)
return NULL;
size = type->bit_size;
+
+ if (type->ctype.base_type == &void_ctype) {
+ warning(expr->pos, "expression using sizeof(void)");
+ 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 ((size < 0) || (size & (bits_in_char - 1)))
expression_error(expr, "cannot size expression");
+
expr->type = EXPR_VALUE;
expr->value = bits_to_bytes(size);
expr->taint = 0;
diff --git a/symbol.c b/symbol.c
index 02844cf..4da253b 100644
--- a/symbol.c
+++ b/symbol.c
@@ -834,7 +834,7 @@ static const struct ctype_declare {
struct symbol *base_type;
} ctype_declaration[] = {
{ &bool_ctype, SYM_BASETYPE, MOD_UNSIGNED, &bits_in_bool, &max_int_alignment, &int_type },
- { &void_ctype, SYM_BASETYPE, 0, &bits_in_char, NULL, NULL },
+ { &void_ctype, SYM_BASETYPE, 0, NULL, NULL, NULL },
{ &type_ctype, SYM_BASETYPE, MOD_TYPE, NULL, NULL, NULL },
{ &incomplete_ctype,SYM_BASETYPE, 0, NULL, NULL, NULL },
{ &bad_ctype, SYM_BASETYPE, 0, NULL, NULL, NULL },
--
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