Hello, I am trying to compile a 1 year old project of mine which uses htmld and vibed. But I get this weird linker error which does not make any sense to me atleast. I am using Windows 7 and dub.

htmld 0.3.6: target for configuration "library" is up to date.
taggedalgebraic 0.10.12: target for configuration "library" is up to date.
eventcore 0.8.40: target for configuration "winapi" is up to date.
stdx-allocator 2.77.5: target for configuration "library" is up to date.
vibe-core 1.5.0: target for configuration "winapi" is up to date.
vibe-d:utils 0.8.4: target for configuration "library" is up to date.
vibe-d:data 0.8.4: target for configuration "library" is up to date.
mir-linux-kernel 1.0.1: target for configuration "library" is up to date.
vibe-d:crypto 0.8.4: target for configuration "library" is up to date.
diet-ng 1.5.0: target for configuration "library" is up to date.
vibe-d:stream 0.8.4: target for configuration "library" is up to date.
vibe-d:textfilter 0.8.4: target for configuration "library" is up to date.
vibe-d:inet 0.8.4: target for configuration "library" is up to date.
vibe-d:tls 0.8.4: target for configuration "openssl-mscoff" is up to date.
vibe-d:http 0.8.4: target for configuration "library" is up to date.
vibe-d:mail 0.8.4: target for configuration "library" is up to date.
vibe-d:mongodb 0.8.4: target for configuration "library" is up to date.
vibe-d:redis 0.8.4: target for configuration "library" is up to date.
vibe-d:web 0.8.4: target for configuration "library" is up to date.
vibe-d 0.8.4: target for configuration "vibe-core" is up to date.
my_stuff ~master: building configuration "updater-local"...
Linking...
vibe-d_web.lib(common.obj) : warning LNK4255: library contain multiple objects of the same name; lin
king object as if no debug info
eventcore.lib(driver.obj) : warning LNK4255: library contain multiple objects of the same name; link
ing object as if no debug info
eventcore.lib(driver.obj) : warning LNK4255: library contain multiple objects of the same name; link
ing object as if no debug info
eventcore.lib(core.obj) : warning LNK4255: library contain multiple objects of the same name; linkin
g object as if no debug info
my_stuff.obj : error LNK2019: unresolved external symbol _D60TypeInfo_xS4html3dom__T15ChildrenForwar
dTCQBfQBd4NodeVnnZQBi6__initZ referenced in function _D8typecons__T11ThrowOnNullTS4html3dom__T15Chil
drenForwardTCQBfQBd4NodeVnnZQBiZQCn9__xtoHashFNbNeKxSQDu__TQDoTQDeZQDwZm
.dub\build\updater-local-debug-windows-x86_64-dmd_2083-F0ADCB72FF986B7D6354817AF1E3A045\my_stuff.exe
 : fatal error LNK1120: 1 unresolved externals
Error: linker exited with status 1120
dmd failed with exit code 1.

I tried to find the typecons.ThrowOnNull thing in the standard library but that one does not exist. So I am pretty confused about what is going on here.

Thank you.

On 1/21/19 3:37 PM, Jerry wrote:
> Hello, I am trying to compile a 1 year old project of mine which uses htmld and vibed. But I get this weird linker error which does not make any sense to me atleast. I am using Windows 7 and dub.
> 
> htmld 0.3.6: target for configuration "library" is up to date.
> taggedalgebraic 0.10.12: target for configuration "library" is up to date.
> eventcore 0.8.40: target for configuration "winapi" is up to date.
> stdx-allocator 2.77.5: target for configuration "library" is up to date.
> vibe-core 1.5.0: target for configuration "winapi" is up to date.
> vibe-d:utils 0.8.4: target for configuration "library" is up to date.
> vibe-d:data 0.8.4: target for configuration "library" is up to date.
> mir-linux-kernel 1.0.1: target for configuration "library" is up to date.
> vibe-d:crypto 0.8.4: target for configuration "library" is up to date.
> diet-ng 1.5.0: target for configuration "library" is up to date.
> vibe-d:stream 0.8.4: target for configuration "library" is up to date.
> vibe-d:textfilter 0.8.4: target for configuration "library" is up to date.
> vibe-d:inet 0.8.4: target for configuration "library" is up to date.
> vibe-d:tls 0.8.4: target for configuration "openssl-mscoff" is up to date.
> vibe-d:http 0.8.4: target for configuration "library" is up to date.
> vibe-d:mail 0.8.4: target for configuration "library" is up to date.
> vibe-d:mongodb 0.8.4: target for configuration "library" is up to date.
> vibe-d:redis 0.8.4: target for configuration "library" is up to date.
> vibe-d:web 0.8.4: target for configuration "library" is up to date.
> vibe-d 0.8.4: target for configuration "vibe-core" is up to date.
> my_stuff ~master: building configuration "updater-local"...
> Linking...
> vibe-d_web.lib(common.obj) : warning LNK4255: library contain multiple objects of the same name; lin
> king object as if no debug info
> eventcore.lib(driver.obj) : warning LNK4255: library contain multiple objects of the same name; link
> ing object as if no debug info
> eventcore.lib(driver.obj) : warning LNK4255: library contain multiple objects of the same name; link
> ing object as if no debug info
> eventcore.lib(core.obj) : warning LNK4255: library contain multiple objects of the same name; linkin
> g object as if no debug info
> my_stuff.obj : error LNK2019: unresolved external symbol _D60TypeInfo_xS4html3dom__T15ChildrenForwar
> dTCQBfQBd4NodeVnnZQBi6__initZ referenced in function _D8typecons__T11ThrowOnNullTS4html3dom__T15Chil
> drenForwardTCQBfQBd4NodeVnnZQBiZQCn9__xtoHashFNbNeKxSQDu__TQDoTQDeZQDwZm
> ..dub\build\updater-local-debug-windows-x86_64-dmd_2083-F0ADCB72FF986B7D6354817AF1E3A045\my_stuff.exe 
> 
>   : fatal error LNK1120: 1 unresolved externals
> Error: linker exited with status 1120
> dmd failed with exit code 1.
> 
> I tried to find the typecons.ThrowOnNull thing in the standard library but that one does not exist. So I am pretty confused about what is going on here.
> 
> Thank you.

I had a similar problem that I fixed myself actually last dconf:

https://issues.dlang.org/show_bug.cgi?id=17968

This looks almost identical as the issue was in the generated xtoHash function.

What version of the compiler are you using? My issue was fixed in 2.080.1, and then a followup fix in 2.081.1.

-Steve

On Monday, 21 January 2019 at 21:02:23 UTC, Steven Schveighoffer wrote:
> What version of the compiler are you using? My issue was fixed in 2.080.1, and then a followup fix in 2.081.1.
>
> -Steve


Hello!
I am using 2.084.
Interestingly it works with LDC 1.9 (frontend 2.79) and that just works fine.

Bisecting dmd versions.

- Jerry

On Mon, Jan 21, 2019 at 04:02:23PM -0500, Steven Schveighoffer via Digitalmars-d-learn wrote:
> On 1/21/19 3:37 PM, Jerry wrote:
> > Hello, I am trying to compile a 1 year old project of mine which uses htmld and vibed. But I get this weird linker error which does not make any sense to me atleast. I am using Windows 7 and dub.
[...]
> > my_stuff.obj : error LNK2019: unresolved external symbol
> > _D60TypeInfo_xS4html3dom__T15ChildrenForwar
> > dTCQBfQBd4NodeVnnZQBi6__initZ referenced in function
> > _D8typecons__T11ThrowOnNullTS4html3dom__T15Chil
> > drenForwardTCQBfQBd4NodeVnnZQBiZQCn9__xtoHashFNbNeKxSQDu__TQDoTQDeZQDwZm
> > ..dub\build\updater-local-debug-windows-x86_64-dmd_2083-F0ADCB72FF986B7D6354817AF1E3A045\my_stuff.exe
> > 
> >   : fatal error LNK1120: 1 unresolved externals
> > Error: linker exited with status 1120
> > dmd failed with exit code 1.
[...]

Looks like a problem with stale cached object files.  Try:

	rm dub.selections.json
	dub build --force

(Be sure to back up dub.selections.json before doing this, if you have
customized it by hand.)


T

-- 
Music critic: "That's an imitation fugue!"

On Monday, 21 January 2019 at 21:37:22 UTC, H. S. Teoh wrote:
> On Mon, Jan 21, 2019 at 04:02:23PM -0500, Steven Schveighoffer via Digitalmars-d-learn wrote:
>> On 1/21/19 3:37 PM, Jerry wrote:
>> > [...]
> [...]
>> > [...]
> [...]
>
> Looks like a problem with stale cached object files.  Try:
>
> 	rm dub.selections.json
> 	dub build --force
>
> (Be sure to back up dub.selections.json before doing this, if you have
> customized it by hand.)
>
>
> T

Still same error, on both 2.78 and 2.84.

On Monday, 21 January 2019 at 21:02:23 UTC, Steven Schveighoffer wrote:
> On 1/21/19 3:37 PM, Jerry wrote:
>> [...]
>
> I had a similar problem that I fixed myself actually last dconf:
>
> https://issues.dlang.org/show_bug.cgi?id=17968
>
> This looks almost identical as the issue was in the generated xtoHash function.
>
> What version of the compiler are you using? My issue was fixed in 2.080.1, and then a followup fix in 2.081.1.
>
> -Steve

Ok, I get the same linker error down to version 2.74. Below that my eventcore version does not compile. Atleast LDC can compile so I can move forward. I will try to dustmite this tomorrow.

On Mon, Jan 21, 2019 at 10:19:00PM +0000, Jerry via Digitalmars-d-learn wrote:
> On Monday, 21 January 2019 at 21:37:22 UTC, H. S. Teoh wrote:
[...]
> > Looks like a problem with stale cached object files.  Try:
> > 
> > 	rm dub.selections.json
> > 	dub build --force
> > 
> > (Be sure to back up dub.selections.json before doing this, if you
> > have customized it by hand.)
[...]
> Still same error, on both 2.78 and 2.84.

Hmm.  OK, then I've no idea what's wrong, sorry.


T

-- 
Dogs have owners ... cats have staff. -- Krista Casada

On Monday, 21 January 2019 at 22:31:15 UTC, H. S. Teoh wrote:
> On Mon, Jan 21, 2019 at 10:19:00PM +0000, Jerry via Digitalmars-d-learn wrote:
>> On Monday, 21 January 2019 at 21:37:22 UTC, H. S. Teoh wrote:
> [...]
>> > Looks like a problem with stale cached object files.  Try:
>> > 
>> > 	rm dub.selections.json
>> > 	dub build --force
>> > 
>> > (Be sure to back up dub.selections.json before doing this, if you
>> > have customized it by hand.)
> [...]
>> Still same error, on both 2.78 and 2.84.
>
> Hmm.  OK, then I've no idea what's wrong, sorry.
>
>
> T

Thank you for all the effort!

On 1/21/19 5:28 PM, Jerry wrote:
> On Monday, 21 January 2019 at 21:02:23 UTC, Steven Schveighoffer wrote:
>> On 1/21/19 3:37 PM, Jerry wrote:
>>> [...]
>>
>> I had a similar problem that I fixed myself actually last dconf:
>>
>> https://issues.dlang.org/show_bug.cgi?id=17968
>>
>> This looks almost identical as the issue was in the generated xtoHash function.
>>
>> What version of the compiler are you using? My issue was fixed in 2.080.1, and then a followup fix in 2.081.1.
>>
> 
> Ok, I get the same linker error down to version 2.74. Below that my eventcore version does not compile. Atleast LDC can compile so I can move forward. I will try to dustmite this tomorrow.

This was a PITA for me when it happened (I used dustmite to go down to a pretty small version). I was essentially blocked on my work in iopipe until this was fixed.

The issue I ran starts with dmd generating a function xtoHash for structs where you don't define toHash. In certain cases (and these can be very weird indeed), dmd generates a function which, for each of its members, calls essentially typeid(x).toHash(&x).

In the case of a struct that contains a class reference, this all goes fine, but the compiler doesn't generate the TypeInfo for the class when it should in these certain cases (in particular, the TypeInfo_Const for that class reference).

The reason I feel like your error is very very similar, is because you show the missing symbol as being the InitZ, which is the TypeInfo initializer of something, and you see the symbol that requires it as being an xtoHash symbol.

Not knowing your code base, it's hard to know what exact situation you're in. But hopefully this helps you get an understanding as to why it might happen.

I think in my case, it was a template class in an auto function, within an import (hard now to remember the details). In fact, the root cause is still there, I just added a workaround in the xtoHash generation (that cheats and uses typeid(Object) instead of the real typeid, since it's a virtual function call anyway).

See the related bug report with the root cause: https://issues.dlang.org/show_bug.cgi?id=18833, maybe it helps you relate to what is happening.

-Steve