• IchorDev (21/21) Jul 12 2023 While writing some mixins I accidentally used `alias` instead of
• Dennis (7/9) Jul 12 2023 Do you have a test case that reproduces it? I tried:
• IchorDev (7/17) Jul 12 2023 No, I simply don’t have the time for that. Compiler oddities tend
• Dennis (4/7) Jul 13 2023 That gives a parse error inside the mixin, since a string literal
• IchorDev (5/8) Jul 13 2023 Not that version of it. Some of the code was meh, so I've already
• Stefan Koch (7/17) Jul 14 2023 Do you know how to use the dustmite tool?
• IchorDev (32/38) Jul 17 2023 Never used it before.

IchorDev <zxinsworld gmail.com> writes:

While writing some mixins I accidentally used `alias` instead of 
`enum` for a string manifest constant.
Compiling with GDC helped me locate the issue, as it gave an 
appropriate error message:
```
error: alias ‘bgfx.Attachment._init1094248_mangleof’ cannot alias 
an expression 
‘"_ZN4bgfx10Attachment4initENS_13TextureHandleENS_6Access4EnumEttth"’
[...]
```

DMD and LDC2, however, decided that the real problem was an 
unmarked lambda placed within a mixin statement at module-scope:
```
../bindbc-bgfx/source/bgfx/package.d:1906:17: error: array 
literal in ‘ nogc’ function ‘bgfx.Resolution.__lambda18’ may 
cause a GC allocation
[...]
```

and switching the `alias` declaration for `enum` made it work.

Highly informative as always...

Dennis <dkorpel gmail.com> writes:

On Wednesday, 12 July 2023 at 15:53:39 UTC, IchorDev wrote:
 DMD and LDC2, however, decided that the real problem was an 
 unmarked lambda placed within a mixin statement at module-scope:


Do you have a test case that reproduces it? I tried:

```D
alias y = mixin("``");
```

But that gives the "alias `y` cannot alias an expression `""`" 
error.

IchorDev <zxinsworld gmail.com> writes:

On Wednesday, 12 July 2023 at 16:00:34 UTC, Dennis wrote:
 On Wednesday, 12 July 2023 at 15:53:39 UTC, IchorDev wrote:
 DMD and LDC2, however, decided that the real problem was an 
 unmarked lambda placed within a mixin statement at 
 module-scope:


 Do you have a test case that reproduces it? I tried:

 ```D
 alias y = mixin("``");
 ```

 But that gives the "alias `y` cannot alias an expression `""`" 
 error.

No, I simply don’t have the time for that. Compiler oddities tend 
to be very painful to narrow down.
The code is more like…
mixin(“alias y = `”~someFn.mangleof~”`;”);
mixin(“someOtherFn(…, y);”);

But I doubt that’s enough to recreate it either.

Dennis <dkorpel gmail.com> writes:

On Wednesday, 12 July 2023 at 21:52:08 UTC, IchorDev wrote:
 No, I simply don’t have the time for that.

Is the code base public by any chance?

 The code is more like…
 mixin(“alias y = `”~someFn.mangleof~”`;”);

That gives a parse error inside the mixin, since a string literal 
is not allowed in that position.

IchorDev <zxinsworld gmail.com> writes:

On Thursday, 13 July 2023 at 10:41:06 UTC, Dennis wrote:
 On Wednesday, 12 July 2023 at 21:52:08 UTC, IchorDev wrote:
 No, I simply don’t have the time for that.

 Is the code base public by any chance?

Not that version of it. Some of the code was meh, so I've already 
replaced a lot of it now. There's several layers of possible 
causes for such a strange error, I don't think anyone could 
repro. it very easily.

Stefan Koch <uplink.coder googlemail.com> writes:

On Thursday, 13 July 2023 at 10:54:30 UTC, IchorDev wrote:
 On Thursday, 13 July 2023 at 10:41:06 UTC, Dennis wrote:
 On Wednesday, 12 July 2023 at 21:52:08 UTC, IchorDev wrote:
 No, I simply don’t have the time for that.

 Is the code base public by any chance?

 Not that version of it. Some of the code was meh, so I've 
 already replaced a lot of it now. There's several layers of 
 possible causes for such a strange error, I don't think anyone 
 could repro. it very easily.

Do you know how to use the dustmite tool?
[https://github.com/CyberShadow/DustMite]
If not please get familiar with it and reduce the bug in your 
codebase.

Cheers,
Stefan

IchorDev <zxinsworld gmail.com> writes:

On Friday, 14 July 2023 at 07:58:36 UTC, Stefan Koch wrote:
 Do you know how to use the dustmite tool?
 [https://github.com/CyberShadow/DustMite]
 If not please get familiar with it and reduce the bug in your 
 codebase.

 Cheers,
 Stefan

Never used it before.
I had an issue yesterday where an alias from a mixin was not 
being found by a module that was being used by an import of the 
module where the alias was declared. Like this:

A:
```d
import B;
mixin("
import foreign.code;
alias x = foreign.code.y!false;
");
```
B:
```d
import C;

C.Type blabla;
```
C:
```d
import A;

struct Type{}

A.x(); //ERROR! Undefined identifier!
```

Perhaps DustMite would be good for reducing this kind of error to 
its components as well. I’ll look into it if I find any more 
weird ones. :)

I think we need a dedicated thread for sharing obtuse compiler 
messages, alongside what the *actual* error ended up being. Often 
the compilers really just doesn’t understand how to tell us what 
we did wrong. Especially if the error is a bit weird, like a 
missing quote.