@samitouri / QOSamiQemu / commits / 2a58162a1e

tests: Clean up double comparisons to avoid compiler warning

To enable -Wformat-overflow=2, we need to clean up a couple of false positives: [2/5] Compiling C object tests/unit/test-qobject-output-visitor.p/test-qobject-output-visitor.c.o ../tests/unit/test-qobject-output-visitor.c: In function ‘test_visitor_out_list_struct’: ../tests/unit/test-qobject-output-visitor.c:577:28: error: ‘%.6f’ directive writing between 3 and 317 bytes into a region of size 32 [-Werror=format-overflow=] 577 | sprintf(expected, "%.6f", (double)i / 3); | ^~~~ ../tests/unit/test-qobject-output-visitor.c:577:27: note: assuming directive output of 8 bytes 577 | sprintf(expected, "%.6f", (double)i / 3); | ^~~~~~ In file included from /usr/include/stdio.h:970, from /home/me/q/var/qemu/include/qemu/osdep.h:114, from ../tests/unit/test-qobject-output-visitor.c:13: In function ‘sprintf’, inlined from ‘test_visitor_out_list_struct’ at ../tests/unit/test-qobject-output-visitor.c:577:9: /usr/include/bits/stdio2.h:30:10: note: ‘__builtin___sprintf_chk’ output between 4 and 318 bytes into a destination of size 32 30 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 31 | __glibc_objsize (__s), __fmt, | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 32 | __va_arg_pack ()); | ~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors FAILED: tests/unit/test-qobject-output-visitor.p/test-qobject-output-visitor.c.o These buffers cannot actually overflow because the doubles are between 0 and 31.0/3 inclusive. However, formatting doubles just to compare them is silly. Compare them directly instead. To avoid potential rounding trouble, change the numbers tested to be representable exactly in double. Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-ID: <20260305-nvme-v4-3-b65b9de1839f@rsg.ci.i.u-tokyo.ac.jp> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Akihiko Odaki committed Mar 5, 2026 at 15:16 UTC 2a58162a1e4545cf26e77c139c46d7a644b2318b

2 files changed +4 -11

tests/unit/test-qobject-input-visitor.c

+2 -6

@@ -500,7 +500,7 @@ static void test_visitor_in_list_struct(TestInputVisitorData *data,

500 g_string_append_printf(json, "'number': [");

501 sep = "";

502 for (i = 0; i < 32; i++) {

503 - g_string_append_printf(json, "%s%f", sep, (double)i / 3);

503 + g_string_append_printf(json, "%s%f", sep, (double)i / FLT_RADIX);

504 sep = ", ";

505 }

506 g_string_append_printf(json, "], ");

@@ -583,11 +583,7 @@ static void test_visitor_in_list_struct(TestInputVisitorData *data,

583

584 i = 0;

585 for (num_list = arrs->number; num_list; num_list = num_list->next) {

586 - char expected[32], actual[32];

587 -

588 - sprintf(expected, "%.6f", (double)i / 3);

589 - sprintf(actual, "%.6f", num_list->value);

590 - g_assert_cmpstr(expected, ==, actual);

586 + g_assert_cmpfloat(num_list->value, ==, (double)i / FLT_RADIX);

587 i++;

588 }

589

tests/unit/test-qobject-output-visitor.c

+2 -5

@@ -538,7 +538,7 @@ static void test_visitor_out_list_struct(TestOutputVisitorData *data,

538 }

539

540 for (i = 31; i >= 0; i--) {

541 - QAPI_LIST_PREPEND(arrs->number, (double)i / 3);

541 + QAPI_LIST_PREPEND(arrs->number, (double)i / FLT_RADIX);

542 }

543

544 for (i = 31; i >= 0; i--) {

@@ -571,12 +571,9 @@ static void test_visitor_out_list_struct(TestOutputVisitorData *data,

571 i = 0;

572 QLIST_FOREACH_ENTRY(qlist, e) {

573 QNum *qvalue = qobject_to(QNum, qlist_entry_obj(e));

574 - char expected[32], actual[32];

574

575 g_assert(qvalue);

577 - sprintf(expected, "%.6f", (double)i / 3);

578 - sprintf(actual, "%.6f", qnum_get_double(qvalue));

579 - g_assert_cmpstr(actual, ==, expected);

576 + g_assert_cmpfloat(qnum_get_double(qvalue), ==, (double)i / FLT_RADIX);

577 i++;

578 }

579