https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118763
Bug ID: 118763
Summary: [12/13/14/15 regression] memory leak involving early
return from statement expressions
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: valentin at tolmer dot fr
Target Milestone: ---
A "new" with a statement expression returning out of the function still
allocates, but it shouldn't.
source.cpp:
```
int* f() {
return new int(
({
return nullptr;
1;
})
);
}
int main() { delete f(); }
```
$ g++ -fsanitize=address source.cpp
$ ./a.out
=================================================================
==1==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 4 byte(s) in 1 object(s) allocated from:
#0 0x7b2e355b2feb in operator new(unsigned long)
(/opt/compiler-explorer/gcc-snapshot/lib64/libasan.so.8+0x126feb) (BuildId:
038c66d3bc17819b861997d7d471707338d4d599)
#1 0x000000401163 in f() source.cpp:7
#2 0x000000401173 in main source.cpp:10
#3 0x7b2e34e29d8f (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId:
490fef8403240c91833978d494d39e537409b92e)
Note that it's not a matter of calling the constructor:
```
#include <iostream>
struct P {
P(int i) { std::cout << "construction: " << i << "\n"; }
};
P f() {
return P(({
return P(0);
1;
}));
}
int main() { f(); }
```
This one will print `construction: 0`.
AFAIU the memory is allocated but never written to (and never freed).
It started with gcc 12.1 (doesn't reproduce with 11.4) and is still happening
on trunk.
https://godbolt.org/z/c7so753z7
