https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98989
Bug ID: 98989
Summary: missing -Wfree-nonheap-object freeing std::strings
over 15 bytes long
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: ---
Given the test case below, -Wfree-nonheap-object detects the invalid attempt to
free the std::string buffer provided the string constant it's initialized with
is no more than 15 characters long (plus the terminating nul). But the option
fails to diagnose the invalid call once the string length is 16 or more.
#include <string>
void f ()
{
std::string str (STR);
char *p = &str[0];
free (p);
}
$ g++ -DSTR='"abcdefghijklmno"' -O2 -S -Wall t.C
t.C: In function ‘void f()’:
t.C:7:8: warning: ‘void free(void*)’ called on unallocated object ‘str’
[-Wfree-nonheap-object]
7 | free (p);
| ~~~~~^~~
t.C:5:15: note: declared here
5 | std::string str (STR);
| ^~~
