This code
--- 8< ---------------
import core.stdc.stdio;
struct DestroyMe
{
~this() { printf("~this() called\n"); }
int opApply(in int delegate(int item) dg)
{
throw new Exception("Here we go!");
}
}
void main()
{
printf("Version with no dtor call:\n");
try {
foreach (item; DestroyMe()) {}
} catch {}
printf("Version with dtor call:\n");
try {
auto lvalue = DestroyMe();
foreach (item; lvalue) {}
} catch {}
}
--- >8 --------------
prints:
Version with no dtor call:
Version with dtor call:
~this() called
So the dtor call gets missed when the struct's scope is inside the foreach header. There is another open bug about struct destructors not being called on out parameters:
http://d.puremagic.com/issues/show_bug.cgi?id=6186
Comment #1 by k.hara.pg — 2013-07-07T23:13:36Z
I couldn't reproduce the issue on Windows7, by using release-dmd versions from 2.058 to 2.063.2. What version do you use?
Comment #2 by Marco.Leise — 2013-07-08T02:54:27Z
(In reply to comment #1)
> I couldn't reproduce the issue on Windows7, by using release-dmd versions from
> 2.058 to 2.063.2. What version do you use?
I was using GDC and LDC. It really doesn't happen with DMD. I'll mark this as invalid and open new reports for the other compilers. Thanks for looking into this anyway!
Comment #3 by ibuclaw — 2013-07-08T11:34:09Z
From the backend's perspective, the frontend represents the code in this way:
try
{
DestroyMe __sl5;
DestroyMe.opApply (&__sl5, {.object=0B, .func=__foreachbody6});
apply.DestroyMe.~this (&__sl5);
}
catch (struct Throwable &)
{
}
try
{
struct DestroyMe lvalue;
try
{
DestroyMe.opApply (&lvalue, {.object=0B, .func=__foreachbody8});
}
finally
{
apply.DestroyMe.~this (&lvalue);
}
}
catch (struct Throwable &)
{
}
In this instance, you could either say that it is the job of the backend to wrap ExpDtorStatement's in try{} finally{} blocks, or fix the frontend to generate a matching representation.
Comment #4 by ibuclaw — 2013-07-08T12:15:06Z
(In reply to comment #3)
> In this instance, you could either say that it is the job of the backend to
> wrap ExpDtorStatement's in try{} finally{} blocks, or fix the frontend to
> generate a matching representation.
Hmmm... I meant Expression::toElemDtor. :)
Comment #5 by robert.schadek — 2024-12-13T18:08:25Z