https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118253
Bug ID: 118253
Summary: libstdc++: array subscript 0 is outside array bounds
of ‘std::__shared_count<> [0]’
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: jengelh at inai dot de
Target Milestone: ---
Version: gcc version 15.0.0 20241230 (experimental) (SUSE Linux) amd64-linux
Input:
---
#include <memory>
#include <unordered_set>
struct R {};
using R_ptr = std::shared_ptr<R>;
using listtype = std::unordered_set<R_ptr>;
void newthing(listtype &L)
{
R_ptr r;
r = std::make_shared<R>();
L.insert(r);
}
R_ptr getfirst(listtype &L)
{
if (L.begin() == L.end())
return nullptr;
auto r = *L.begin();
return r;
}
void movething(listtype &L, R_ptr &&r)
{
L.insert(std::move(r));
}
---
Output:
$ g++ -fsanitize=address,undefined -O2 -c -Wall x.cpp
/usr/include/c++/15/bits/shared_ptr_base.h:1099:19: warning: array subscript 0
is outside array bounds of ‘std::__shared_count<> [0]’ [-Warray-bounds=]
1099 | __r._M_pi = _M_pi;
In function ‘void movething(listtype&, R_ptr&&)’:
cc1plus: note: source object is likely at address zero
Expected instead:
Don't warn(?). This seems like normal code.
