Older versions of gcc with -Wformat-overflow=2 don't like the usage of
fixed size char arrays in this test; gcc 7.5.0 (SUSE Linux) says:

../tests/qtest/aspeed_gpio-test.c: In function ‘test_set_input_pins’:
../tests/qtest/aspeed_gpio-test.c:149:36: error: ‘sprintf’ may write a terminating nul past the end of the destination [-Werror=format-overflow=]
             sprintf(name, "gpio%c%d", c, i);
                                    ^
../tests/qtest/aspeed_gpio-test.c:149:13: note: ‘sprintf’ output between 7 and 17 bytes into a destination of size 16
             sprintf(name, "gpio%c%d", c, i);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This can't actually happen because of the limited size of the values
being substituted in.  However rather than require readers to check
whether the arrays really have been declared large enough, we prefer
to use g_strdup_printf() for this kind of string work.

Reported-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 tests/qtest/aspeed_gpio-test.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/qtest/aspeed_gpio-test.c b/tests/qtest/aspeed_gpio-test.c
index decbba23c8..029b3731d1 100644
--- a/tests/qtest/aspeed_gpio-test.c
+++ b/tests/qtest/aspeed_gpio-test.c
@@ -140,13 +140,13 @@ static void test_set_colocated_pins(const void *data)
 static void test_set_input_pins(const void *data)
 {
     QTestState *s = (QTestState *)data;
-    char name[16];
     uint32_t value;
 
     qtest_writel(s, AST2600_GPIO_BASE + GPIO_ABCD_DIRECTION, 0x00000000);
     for (char c = 'A'; c <= 'D'; c++) {
         for (int i = 0; i < 8; i++) {
-            sprintf(name, "gpio%c%d", c, i);
+            g_autofree const char *name = g_strdup_printf("gpio%c%d", c, i);
+
             qtest_qom_set_bool(s, "/machine/soc/gpio", name, true);
         }
     }
-- 
2.43.0

On 10/3/26 16:33, Peter Maydell wrote:
> Older versions of gcc with -Wformat-overflow=2 don't like the usage of
> fixed size char arrays in this test; gcc 7.5.0 (SUSE Linux) says:
> 
> ../tests/qtest/aspeed_gpio-test.c: In function ‘test_set_input_pins’:
> ../tests/qtest/aspeed_gpio-test.c:149:36: error: ‘sprintf’ may write a terminating nul past the end of the destination [-Werror=format-overflow=]
>               sprintf(name, "gpio%c%d", c, i);
>                                      ^
> ../tests/qtest/aspeed_gpio-test.c:149:13: note: ‘sprintf’ output between 7 and 17 bytes into a destination of size 16
>               sprintf(name, "gpio%c%d", c, i);
>               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> This can't actually happen because of the limited size of the values
> being substituted in.  However rather than require readers to check
> whether the arrays really have been declared large enough, we prefer
> to use g_strdup_printf() for this kind of string work.
> 
> Reported-by: Fabiano Rosas <farosas@suse.de>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   tests/qtest/aspeed_gpio-test.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>