https://bugs.kde.org/show_bug.cgi?id=485276
Bug ID: 485276
Summary: std::optional use: "Conditional jump or move depends
on uninitialised value(s)" (clang)
Classification: Developer tools
Product: valgrind
Version: unspecified
Platform: Other
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: memcheck
Assignee: jsew...@acm.org
Reporter: kde.si...@dralias.com
Target Milestone: ---
Similar to https://bugs.kde.org/show_bug.cgi?id=472329
Steps to reproduce with clang-18:
# batcat main.cpp dummy.* && clang++-18 -std=c++17 -g -O2 -I. main.cpp
dummy.cpp -o /tmp/exe && valgrind /tmp/exe
│ File: main.cpp
1 │ #include <dummy.h>
2 │
3 │ #include <optional>
4 │ #include <set>
5 │
6 │ static std::set<int> empty_set;
7 │
8 │ std::optional<dummy> static none()
9 │ {
10 │ std::optional<dummy> maybe;
11 │ {
12 │ for (const auto& a : empty_set) {
13 │ if (empty_set.size() > 10) {
14 │ maybe.emplace(dummy{});
15 │ }
16 │ }
17 │ }
18 │ return maybe;
19 │ }
20 │
21 │ dummy dummy_or_default()
22 │ {
23 │ return none().value_or(dummy{});
24 │ }
25 │
26 │ int main()
27 │ {
28 │ dummy_or_default();
29 │ }
│ File: dummy.cpp
1 │ #include <dummy.h>
2 │
3 │ dummy::dummy() = default;
│ File: dummy.h
1 │ #include <cstdlib>
2 │
3 │ struct dummy {
4 │ char* ptr{};
5 │
6 │ unsigned zero = 0;
7 │ bool hp() const { return zero > 0; }
8 │
9 │ dummy();
10 │
11 │ ~dummy()
12 │ {
13 │ if (hp()) std::free(ptr);
14 │ }
15 │ };
==73841== Memcheck, a memory error detector
==73841== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==73841== Using Valgrind-3.22.0 and LibVEX; rerun with -h for copyright info
==73841== Command: /tmp/exe
==73841==
==73841== Conditional jump or move depends on uninitialised value(s)
==73841== at 0x108BB8: _M_reset (optional:317)
==73841== by 0x108BB8: ~_Optional_payload (optional:441)
==73841== by 0x108BB8: ~_Optional_base (optional:512)
==73841== by 0x108BB8: dummy_or_default() (???:23)
==73841== by 0x108C27: main (main.cpp:28)
==73841==
==73841==
==73841== HEAP SUMMARY:
==73841== in use at exit: 0 bytes in 0 blocks
==73841== total heap usage: 1 allocs, 1 frees, 73,728 bytes allocated
==73841==
==73841== All heap blocks were freed -- no leaks are possible
==73841==
==73841== Use --track-origins=yes to see where uninitialised values come from
==73841== For lists of detected and suppressed errors, rerun with: -s
==73841== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
--
You are receiving this mail because:
You are watching all bug changes.
