tests/unit: fix a -Wformat-trunction warning

[PATCH] tests/unit: fix a -Wformat-trunction warning

Posted by marcandre.lureau@redhat.com 3 years, 6 months ago

From: Marc-André Lureau <marcandre.lureau@redhat.com>

../tests/test-qobject-input-visitor.c: In function ‘test_visitor_in_list’:
../tests/test-qobject-input-visitor.c:454:49: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 6 [-Wformat-truncation=]
  454 |         snprintf(string, sizeof(string), "string%d", i);
      |                                                 ^~
../tests/test-qobject-input-visitor.c:454:42: note: directive argument in the range [0, 2147483606]
  454 |         snprintf(string, sizeof(string), "string%d", i);
      |                                          ^~~~~~~~~~
../tests/test-qobject-input-visitor.c:454:9: note: ‘snprintf’ output between 8 and 17 bytes into a destination of size 12
  454 |         snprintf(string, sizeof(string), "string%d", i);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Not trying to be clever, this is called 3 times during tests,
let simply use g_strdup_printf().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 tests/unit/test-qobject-input-visitor.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/unit/test-qobject-input-visitor.c b/tests/unit/test-qobject-input-visitor.c
index 14329dabcf..5f614afdbf 100644
--- a/tests/unit/test-qobject-input-visitor.c
+++ b/tests/unit/test-qobject-input-visitor.c
@@ -447,9 +447,8 @@ static void test_visitor_in_list(TestInputVisitorData *data,
     g_assert(head != NULL);
 
     for (i = 0, item = head; item; item = item->next, i++) {
-        char string[12];
+        g_autofree char *string = g_strdup_printf("string%d", i);
 
-        snprintf(string, sizeof(string), "string%d", i);
         g_assert_cmpstr(item->value->string, ==, string);
         g_assert_cmpint(item->value->integer, ==, 42 + i);
     }
-- 
2.37.1

Re: [PATCH] tests/unit: fix a -Wformat-trunction warning

Posted by Peter Maydell 3 years, 6 months ago

On Wed, 10 Aug 2022 at 13:20, <marcandre.lureau@redhat.com> wrote:
>
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> ../tests/test-qobject-input-visitor.c: In function ‘test_visitor_in_list’:
> ../tests/test-qobject-input-visitor.c:454:49: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 6 [-Wformat-truncation=]
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |                                                 ^~
> ../tests/test-qobject-input-visitor.c:454:42: note: directive argument in the range [0, 2147483606]
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |                                          ^~~~~~~~~~
> ../tests/test-qobject-input-visitor.c:454:9: note: ‘snprintf’ output between 8 and 17 bytes into a destination of size 12
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Not trying to be clever, this is called 3 times during tests,
> let simply use g_strdup_printf().
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

This is a pretty safe fix and compiler warnings seem like they're
worth fixing for rc3. Since I need to do a target-arm pullreq
anyway I'll take this via that, unless anybody objects.

(I've fixed up the commit message typo in my tree.)

thanks
-- PMM

Re: [PATCH] tests/unit: fix a -Wformat-trunction warning

Posted by Markus Armbruster 3 years, 6 months ago

Typo in subject, it's -Wformat-truncation

marcandre.lureau@redhat.com writes:

> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> ../tests/test-qobject-input-visitor.c: In function ‘test_visitor_in_list’:
> ../tests/test-qobject-input-visitor.c:454:49: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 6 [-Wformat-truncation=]
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |                                                 ^~
> ../tests/test-qobject-input-visitor.c:454:42: note: directive argument in the range [0, 2147483606]
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |                                          ^~~~~~~~~~
> ../tests/test-qobject-input-visitor.c:454:9: note: ‘snprintf’ output between 8 and 17 bytes into a destination of size 12
>   454 |         snprintf(string, sizeof(string), "string%d", i);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Not trying to be clever, this is called 3 times during tests,
> let simply use g_strdup_printf().
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  tests/unit/test-qobject-input-visitor.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/tests/unit/test-qobject-input-visitor.c b/tests/unit/test-qobject-input-visitor.c
> index 14329dabcf..5f614afdbf 100644
> --- a/tests/unit/test-qobject-input-visitor.c
> +++ b/tests/unit/test-qobject-input-visitor.c
> @@ -447,9 +447,8 @@ static void test_visitor_in_list(TestInputVisitorData *data,
>      g_assert(head != NULL);
>  
>      for (i = 0, item = head; item; item = item->next, i++) {
> -        char string[12];
> +        g_autofree char *string = g_strdup_printf("string%d", i);
>  
> -        snprintf(string, sizeof(string), "string%d", i);
>          g_assert_cmpstr(item->value->string, ==, string);
>          g_assert_cmpint(item->value->integer, ==, 42 + i);
>      }

Even less clever would be char string[32].

Anyway, with the typo corrected:
Reviewed-by: Markus Armbruster <armbru@redhat.com>

Re: [PATCH] tests/unit: fix a -Wformat-trunction warning

Posted by Philippe Mathieu-Daudé via 3 years, 6 months ago

On 10/8/22 14:24, Markus Armbruster wrote:
> Typo in subject, it's -Wformat-truncation
> 
> marcandre.lureau@redhat.com writes:
> 
>> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>>
>> ../tests/test-qobject-input-visitor.c: In function ‘test_visitor_in_list’:
>> ../tests/test-qobject-input-visitor.c:454:49: warning: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 6 [-Wformat-truncation=]
>>    454 |         snprintf(string, sizeof(string), "string%d", i);
>>        |                                                 ^~
>> ../tests/test-qobject-input-visitor.c:454:42: note: directive argument in the range [0, 2147483606]
>>    454 |         snprintf(string, sizeof(string), "string%d", i);
>>        |                                          ^~~~~~~~~~
>> ../tests/test-qobject-input-visitor.c:454:9: note: ‘snprintf’ output between 8 and 17 bytes into a destination of size 12
>>    454 |         snprintf(string, sizeof(string), "string%d", i);
>>        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Not trying to be clever, this is called 3 times during tests,
>> let simply use g_strdup_printf().
>>
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>>   tests/unit/test-qobject-input-visitor.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/tests/unit/test-qobject-input-visitor.c b/tests/unit/test-qobject-input-visitor.c
>> index 14329dabcf..5f614afdbf 100644
>> --- a/tests/unit/test-qobject-input-visitor.c
>> +++ b/tests/unit/test-qobject-input-visitor.c
>> @@ -447,9 +447,8 @@ static void test_visitor_in_list(TestInputVisitorData *data,
>>       g_assert(head != NULL);
>>   
>>       for (i = 0, item = head; item; item = item->next, i++) {
>> -        char string[12];
>> +        g_autofree char *string = g_strdup_printf("string%d", i);
>>   
>> -        snprintf(string, sizeof(string), "string%d", i);
>>           g_assert_cmpstr(item->value->string, ==, string);
>>           g_assert_cmpint(item->value->integer, ==, 42 + i);
>>       }
> 
> Even less clever would be char string[32].

Or assert(i < 10) before calling snprintf (the test data only contains 3 
strings).

> 
> Anyway, with the typo corrected:
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> 
>