https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101983
Bug ID: 101983
Summary: analyzer leak false positives building singly linked
list
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: dmalcolm at gcc dot gnu.org
Target Milestone: ---
-fanalyzer reports various "leak" false positives on the following code:
*******************************************************************
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
struct list {
struct list* next;
void *a;
};
void func(struct list **res)
{
struct list *cur = NULL;
do {
struct list *n = malloc(sizeof(struct list));
void *a = malloc(1);
if (n == NULL || a == NULL) {
if (n != NULL) free(n);
if (a != NULL) free(a);
break;
}
if (cur == NULL) {
*res = cur = n;
} else {
cur->next = n;
cur = n;
}
n->a = a;
} while (true);
}
int main()
{
struct list *res;
func(&res);
}
*******************************************************************
trunk shows 5 "leak" false positives: https://godbolt.org/z/W4T88579q
gcc 11.2 shows 1 "leak" false positive: https://godbolt.org/z/YEa94PcaK
Reported downstream as https://bugzilla.redhat.com/show_bug.cgi?id=1995208
