goto skipping declarations

[Steven Schveighoffer]

On Friday, 19 September 2025 at 00:02:53 UTC, Walter Bright wrote:
> gcc does not produce an error:
>
> ```c
> int foo(int x)
> {
>         goto END;
>         int what;
>     END: return what;
> }
> ```
>
> so D is still doing better! D gives an error. (ImportC does not 
> give an error, on purpose!)


```c
int foo(int x) {
       goto END;
       int what = 0;
     END:
       return what;
     }
```

Does yield an error:

```
<source>: In function 'int foo(int)':
<source>:5:5: error: jump to label 'END'
     5 |     END:
       |     ^~~
<source>:3:12: note:   from here
     3 |       goto END;
       |            ^~~
<source>:4:11: note:   crosses initialization of 'int what'
     4 |       int what = 0;
       |           ^~~~
Compiler returned: 1
```

So the skipping of initialization is technically caught, it's 
just that D default initializes and C does not.

Let's try D code that doesn't initialize:

```d
int foo(int x) {
       goto END;
       int what = void;
     END:
       return what;
     }
```

Same error. I still like the D mechanism better, as it's very 
likely you didn't mean to do this, and it's generally better to 
avoid this problem.

-Steve