[llvm-bugs] [Bug 52416] New: Can't jump into scope of a variable with a nontrivial destructor in C++20
via llvm-bugs
llvm-bugs at lists.llvm.org
Thu Nov 4 23:32:01 PDT 2021
https://bugs.llvm.org/show_bug.cgi?id=52416
Bug ID: 52416
Summary: Can't jump into scope of a variable with a nontrivial
destructor in C++20
Product: clang
Version: 13.0
Hardware: PC
OS: All
Status: NEW
Keywords: compile-fail
Severity: normal
Priority: P
Component: C++2a
Assignee: unassignedclangbugs at nondot.org
Reporter: josephcsible at gmail.com
CC: blitzrakete at gmail.com, erik.pilkington at gmail.com,
llvm-bugs at lists.llvm.org, richard-llvm at metafoo.co.uk
The C++17 standard says "A program that jumps from a point where a variable
with automatic storage duration is not in scope to a point where it is in scope
is ill-formed unless the variable has scalar type, class type with a trivial
default constructor and a trivial destructor, a cv-qualified version of one of
these types, or an array of one of the preceding types and is declared without
an initializer (11.6)."
The C++20 standard says "A program that jumps from a point where a variable
with automatic storage duration is not in scope to a point where it is in scope
is ill-formed unless the variable has vacuous initialization (6.7.3)." and "A
variable is said to have vacuous initialization if it is default-initialized
and, if it is of class type or a (possibly multi-dimensional) array thereof,
that class type has a trivial default constructor."
Note that the C++17 standard mentions a trivial destructor here, but the C++20
standard does not. Now consider this code:
struct MyStruct {
~MyStruct() {}
};
void foo() {
goto x;
MyStruct s;
x:
return;
}
It's ill-formed in C++17, but fine in C++20. However, we currently reject this
program even with -std=c++20.
--
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20211105/9a56a3b4/attachment.html>
More information about the llvm-bugs
mailing list