tests/qtest/ast2700-gpio-test: Use g_strdup_printf() instead of char arrays

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/ast2700-gpio-test.c: In function ‘test_input_pins’:
../tests/qtest/ast2700-gpio-test.c:54:36: 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/ast2700-gpio-test.c:54:13: 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>
Tested-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20260310153334.3063224-2-peter.maydell@linaro.org

diff --git a/tests/qtest/ast2700-gpio-test.c b/tests/qtest/ast2700-gpio-test.c
index eeae9bf11fc27fa08b3c2085e4ae3a30d9f82930..533feea7da241f802f42f5b9b86d861bc0e57eb7 100644 (file)
--- a/tests/qtest/ast2700-gpio-test.c
+++ b/tests/qtest/ast2700-gpio-test.c
@@ -44,14 +44,13 @@ static void test_output_pins(const char *machine, const uint32_t base)
 static void test_input_pins(const char *machine, const uint32_t base)
 {
     QTestState *s = qtest_init(machine);
-    char name[16];
     uint32_t offset = 0;
     uint32_t value = 0;
     uint32_t pin = 0;
 
     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);
             offset = base + (pin * 4);
             /* input direction */
             qtest_writel(s, offset, 0);