https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99714
Bug ID: 99714
Summary: warn about alloca/dealloc mismatches based on calls
with same object in different functions
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
Deallocating an object in one function through a pointer that's assigned the
result of a mismatched allocation in another function is almost certainly a
bug. Diagnosing such mismatched calls would help detect at compile time
problems like pr99687 that are currently only detected by dynamic analysis
tools.
#if __cplusplus
struct A {
int *p;
A (int);
~A ();
};
A::A (int n): p (new int[n]{ }) { }
A::~A ()
{
delete p; // missing -Wmismatched-new-delete
}
#else
struct A { int *p; };
void dealloc (void*);
__attribute__ ((malloc (dealloc))) void* alloc (int);
void init (struct A *p, int n) { p = alloc (n * sizeof *p); }
void fini (struct A *p)
{
__builtin_free (p); // missing -Wmismatched-dealloc
}
#endif
