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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Missing returned object destructor call after exception throw"
href="https://bugs.llvm.org/show_bug.cgi?id=51523">51523</a>
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<th>Summary</th>
<td>Missing returned object destructor call after exception throw
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>mbtrash@yandex.ru
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>14.3.2 Exception handling:Constructors and destructors:2
(<a href="https://eel.is/c++draft/except.ctor#2">https://eel.is/c++draft/except.ctor#2</a>)
says
"If an exception is thrown during the destruction of temporaries or local
variables for a return statement ([stmt.return]), the destructor for the
returned object (if any) is also invoked"
And it contains example (<a href="https://eel.is/c++draft/except.ctor#example-1">https://eel.is/c++draft/except.ctor#example-1</a>) with
description
"...the local variable y is destroyed, causing stack unwinding, resulting in
the destruction of the returned object, ..."
Trying to recreate this example with following code
#include <iostream>
using namespace std;
struct S{
int i = 123;
S(int i) :i(i) {cout<<"S("<<i<<")"<<endl;}
~S() {cout<<"~S("<<i<<")"<<endl;}
};
struct T {
T() {cout<<"T()"<<endl;}
~T() noexcept(false) {
cout<<"~T()"<<endl;
throw 0;
}
};
S foo() {
try {
T t;
return {3};
} catch (...){}
return {4};
}
int main() {
foo();
}
Output doesn't have S{3}'s (returned object) destruction line:
T()
S(3)
~T()
S(4)
~S(4)
while should be
T()
S(3)
~T()
~S(3) <-----!
S(4)
~S(4)
Link to godbolt:
<a href="https://godbolt.org/z/YrasqsvMe">https://godbolt.org/z/YrasqsvMe</a></pre>
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