Skip to content

feat(core): add lv_check_arg to public functions in lv_observer #10203

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
axos88 wants to merge 3 commits into
base: master
Choose a base branch
from
+13 −4
Open

feat(core): add lv_check_arg to public functions in lv_observer #10203

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
0377278
feat(core): add lv_check_arg to public functions in lv_observer
axos88 May 28, 2026
cfbe214
feat(core): add lv_check_arg to all public functions in lv_observer
axos88 May 29, 2026
0af4f5e
Fix pr
axos88 Jun 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 13 additions & 4 deletions src/core/lv_observer.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,7 @@ static void subject_set_string_free_user_data_event_cb(lv_event_t * e);
#if LV_USE_EXT_DATA
void lv_subject_set_external_data(lv_subject_t * subject, void * data, void (* free_cb)(void * data))
{
LV_CHECK_ARG(subject != NULL, return, "Can't attach external user data and destructor callback to a NULL subject");
LV_CHECK_ARG(subject != NULL, return);

subject->ext_data.data = data;
subject->ext_data.free_cb = free_cb;
Expand Down Expand Up @@ -222,6 +222,9 @@ void lv_subject_set_max_value_float(lv_subject_t * subject, float max_value)
void lv_subject_init_string(lv_subject_t * subject, char * buf, char * prev_buf, size_t size, const char * value)
{
LV_CHECK_ARG(subject != NULL, return);
LV_CHECK_ARG(buf != NULL, return);
LV_CHECK_ARG(size > 0, return);
LV_CHECK_ARG(value != NULL, return);

lv_memzero(subject, sizeof(lv_subject_t));
lv_strlcpy(buf, value, size);
Expand All @@ -239,6 +242,7 @@ void lv_subject_copy_string(lv_subject_t * subject, const char * buf)
{
LV_CHECK_ARG(subject != NULL, return);
LV_CHECK_ARG(subject->type == LV_SUBJECT_TYPE_STRING, return);
LV_CHECK_ARG(buf != NULL, return);

if(subject->size == 0) return;
if(subject->prev_value.pointer) {
Expand All @@ -254,6 +258,7 @@ void lv_subject_snprintf(lv_subject_t * subject, const char * format, ...)
{
LV_CHECK_ARG(subject != NULL, return);
LV_CHECK_ARG(subject->type == LV_SUBJECT_TYPE_STRING, return);
LV_CHECK_ARG(format != NULL, return);

if(subject->size < 1U) return;

Expand Down Expand Up @@ -381,6 +386,8 @@ void lv_subject_init_group(lv_subject_t * group_subject, lv_subject_t * list[],

lv_subject_t * lv_subject_get_group_element(lv_subject_t * subject, int32_t index)
{
LV_CHECK_ARG(subject != NULL, return NULL);

if(subject->type != LV_SUBJECT_TYPE_GROUP) {
LV_LOG_WARN("Subject type is not LV_SUBJECT_TYPE_GROUP");
return NULL;
Expand All @@ -394,7 +401,7 @@ lv_subject_t * lv_subject_get_group_element(lv_subject_t * subject, int32_t inde

void lv_subject_deinit(lv_subject_t * subject)
{
if(!subject) return;
LV_CHECK_ARG(subject != NULL, return);

lv_observer_t * observer = lv_ll_get_head(&subject->subs_ll);
while(observer) {
Expand Down Expand Up @@ -475,7 +482,7 @@ lv_observer_t * lv_subject_add_observer_with_target(lv_subject_t * subject, lv_o

void lv_observer_remove(lv_observer_t * observer)
{
LV_CHECK_ARG(observer != NULL, return);
if(observer == NULL) return;

if(observer->for_obj && observer->target) {
lv_obj_remove_event_cb_with_user_data(observer->target, unsubscribe_on_delete_cb, observer);
Expand All @@ -502,7 +509,8 @@ void lv_observer_remove(lv_observer_t * observer)
void lv_obj_remove_from_subject(lv_obj_t * obj, lv_subject_t * subject)
{
LV_CHECK_ARG(obj != NULL, return);
LV_CHECK_ARG(subject != NULL, return);
/* subject == NULL is documented as valid: remove from ALL subjects */
Copy link
Copy Markdown
Contributor

@cubic-dev-ai cubic-dev-ai Bot Jun 3, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

P2: Allowing subject == NULL here opens a path where lv_obj_remove_event_cb_with_user_data(obj, NULL, subject) becomes ...user_data == NULL, which can remove unrelated callbacks from the widget.

(Based on your team's feedback about documented NULL semantics for lv_obj_remove_from_subject.)

Prompt for AI agents 
Check if this issue is valid — if so, understand the root cause and fix it. At src/core/lv_observer.c, line 512:

<comment>Allowing `subject == NULL` here opens a path where `lv_obj_remove_event_cb_with_user_data(obj, NULL, subject)` becomes `...user_data == NULL`, which can remove unrelated callbacks from the widget.

(Based on your team's feedback about documented NULL semantics for `lv_obj_remove_from_subject`.) </comment>

<file context>
@@ -502,7 +509,8 @@ void lv_observer_remove(lv_observer_t * observer)
 {
     LV_CHECK_ARG(obj != NULL, return);
-    LV_CHECK_ARG(subject != NULL, return);
+    /* subject == NULL is documented as valid: remove from ALL subjects */
+
     /*
</file context>


/*
* Look for the `observer` that connects `obj` and `subject`
* Since the obj is associated with the subject,
Expand Down Expand Up @@ -687,6 +695,7 @@ void lv_obj_add_subject_set_string_event(lv_obj_t * obj, lv_subject_t * subject,
LV_CHECK_ARG(obj != NULL, return);
LV_CHECK_ARG(subject != NULL, return);
LV_CHECK_ARG(subject->type == LV_SUBJECT_TYPE_STRING, return);
LV_CHECK_ARG(value != NULL, return);

subject_set_string_user_data_t * user_data = lv_malloc(sizeof(subject_set_string_user_data_t));
if(user_data == NULL) {
Expand Down
Loading