| Issue |
91761
|
| Summary |
Double-destruction (& double-construction) when statement-_expression_ returns
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
higher-performance
|
It seems #85398 hasn't been quite fixed. In some sense, I think commit 89ba7e183e6e2c64370ed1b963e54c06352211db actually made things worse, because we now get a double-destruction (which is more likely to cause a security issue) instead of neglecting to run a destructor (which would've been more likely to cause a leak instead).
[Repro](https://godbolt.org/z/obP9dxE4a):
```
#include <stdio.h>
struct D {
~D() { printf("[%p] D::~D()\n" , this); }
D() { printf("[%p] D::D()\n" , this); }
D(int x) { printf("[%p] D::D(int %d)\n" , this, x); }
D(D const &other) { printf("[%p] D::D(D const & %p)\n", this, &other); }
};
struct S { D d; int i; };
static S f() { return S{ D(1), ({ return S(); 0; }) }; }
int main() { return f().i; }
```
Clang (trunk):
```
[0x7ffdfbc4df68] D::D(int 1)
[0x7ffdfbc4df68] D::D()
[0x7ffdfbc4df68] D::~D()
[0x7ffdfbc4df68] D::~D()
```
Clang 18.1.0:
```
[0x7fffa42f9e60] D::D(int 1)
[0x7fffa42f9e60] D::D()
[0x7fffa42f9e60] D::~D()
```
Expected behavior: The `D(1)` subobject should be destroyed before `S()` constructs an object on top of it.
Actual behavior: The object is constructed twice at the same location, _then_ destroyed twice at the same location.
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