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digitalmars.D - dmd segmentation fault with duplicate class definition

reply number <putimalitze gmx.de> writes:
I'm learning, so no idea if this is known or what causes the 
segfault.

Linux
DMD64 D Compiler v2.078.3

```
void main()
{
	import std.stdio;
	
	{
		class C
		{
			int i;
		}
	}
	{
		class C
		{
			int i;
		}
		C c1 = new C();
		c1.i++;          // no segfault without this line
		C c2 = c1;
	}
}
```

dmd -run test.d
test.d(12): Error: declaration C is already defined in another 
scope in main
test.d(16): Error: class C no size because of forward reference
test.d(12): Error: class C is forward referenced when looking for 
'i'
test.d(12): Error: class C is forward referenced when looking for 
'i'
test.d(12): Error: class C is forward referenced when looking for 
'opDot'
test.d(12): Error: class C is forward referenced when looking for 
'opDispatch'
Segmentation fault (core dumped)
Mar 29 2018
next sibling parent Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Thursday, March 29, 2018 20:48:47 number via Digitalmars-d wrote:

 I'm learning, so no idea if this is known or what causes the
 segfault.


If you cannot find the issue https://issues.dlang.org, then report it. Worst
case, if there was a matching report that you missed, then the new issue
will be closed as a duplicate. Either way, the compiler should never
segfault.

- Jonathan M Davis
Mar 29 2018
prev sibling parent reply Seb <seb wilzba.ch> writes:
On Thursday, 29 March 2018 at 20:48:47 UTC, number wrote:

 I'm learning, so no idea if this is known or what causes the 
 segfault.

 [...]


Always try the latest release when you run into an ICE - chances 
are very good that it already has been fixed:

https://run.dlang.io/is/OySBGO
Mar 29 2018
next sibling parent number <putimalitze gmx.de> writes:
On Thursday, 29 March 2018 at 21:18:02 UTC, Seb wrote:

 On Thursday, 29 March 2018 at 20:48:47 UTC, number wrote:

 I'm learning, so no idea if this is known or what causes the 
 segfault.

 [...]


 Always try the latest release when you run into an ICE - 
 chances are very good that it already has been fixed:

 https://run.dlang.io/is/OySBGO


the provoking line is commented out in that snippet. when 
commented in, all compilers give the segfault, including ldc 
ones. except for 'all dmd compilers..' with version <= 2.066.0
Mar 30 2018
prev sibling parent LiNbO3 <nosp m.please> writes:
On Thursday, 29 March 2018 at 21:18:02 UTC, Seb wrote:

 On Thursday, 29 March 2018 at 20:48:47 UTC, number wrote:

 I'm learning, so no idea if this is known or what causes the 
 segfault.

 [...]


 Always try the latest release when you run into an ICE - 
 chances are very good that it already has been fixed:

 https://run.dlang.io/is/OySBGO


There are a couple of bugs here:

---
void main()
{
     { class C { } }
     class C { }
     // C x; x.x=1;
     // static assert (!__traits(compiles, C.x));
}
---

The first bug can be shown by de-commenting the first line and 
can be easily solved by modifying hdrgen.d by adding a check on 
t.sym.parent being non-null to the visit(TypeClass) method.
Once that's fixed de-comment the second line to have the compiler 
crash and burn somewhere else.
Mar 30 2018