[Bug c++/105794] New: Spurious "control reaches end of non-void function" warning with a combination of destructor, try/catch and if (true)
kamil.sliwak at codepoets dot it
gcc-bugzilla@gcc.gnu.org
Tue May 31 15:42:07 GMT 2022
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105794
Bug ID: 105794
Summary: Spurious "control reaches end of non-void function"
warning with a combination of destructor, try/catch
and if (true)
Product: gcc
Version: 12.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: kamil.sliwak at codepoets dot it
Target Milestone: ---
After switching to GCC 12 I noticed that in several places in the C++ project
I'm working on I'm now getting the `control reaches end of non-void function`
warning. This seems like a regression since it's not happening with earlier GCC
versions or with latest Clang.
I managed to distill the problematic code into a small repro (see below) and
it's reproducible via https://godbolt.org so it does not seem dependent on my
specific environment.
The original code is more complicated but in the end a combination of three
things seems to be causing this:
1. A variable of a custom class type that has an explicitly defined destructor
(which can be empty though).
2. A try/catch block with a return.
3. A `throw` wrapped in a condition that's a compile-time constant.
Removing any of the above makes the warning go away.
### Environment
- GCC version: 12.1.0
- System: Arch Linux
### Repro
#### Command
```
g++ test.cpp
```
#### `test.cpp`
```
#include <exception>
class C {
public:
~C() {}
};
int foo()
{
C c;
try
{
return 1;
}
catch (std::exception const&)
{
}
if (true)
throw std::exception();
}
int main() {
return 0;
}
```
#### Output
```
test.cpp: In function ‘int foo()’:
test.cpp:22:1: warning: control reaches end of non-void function
[-Wreturn-type]
22 | }
| ^
```
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