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digitalmars.D.learn - Real simple unresolved external symbols question...

reply WhatMeWorry <kheaser gmail.com> writes:
I'm trying to create a super simple dynamic library consisting of 
two files:


  ------------ file2.d ----------------------
extern(D):
     double addEight(double d) { return (d + 8.0); }
	
------------ fileB.d ----------------------
extern(D)
{
     string concatSuffix(string s) { return (s ~ ".ext"); }
}



dmd -m64 -c file2.d
dmd -m64 -c fileB.d


creates file2.obj and fileB.obj files

link.exe /DLL /NOENTRY file2.obj fileB.obj msvcrt.lib

fileB.obj : error LNK2019: unresolved external symbol 
_D12TypeInfo_Aya6__initZ referenced in function 
_D5fileB12concatPrefixFAyaZQe
fileB.obj : error LNK2019: unresolved external symbol 
_d_arraycatT referenced in function _D5fileB12concatPrefixFAyaZQe

Ok. I find _d_arraycatT in the D website at:

https://dlang.org/library/rt/lifetime/_d_arraycat_t.html

So I thought, this symbol will be in phobos64.lib.  But when I 
add it to the command, all hell breaks loose:



link.exe /DLL /NOENTRY file2.obj fileB.obj msvcrt.lib 
phobos64.lib


phobos64.lib(bits_23fa_21c.obj) : error LNK2001: unresolved 
external symbol memcpy
  o  o  o
file2.dll : fatal error LNK1120: 57 unresolved externals


So I'm stuck and don't have a clue as to how to continue.

I thought Phobos64.lib was self-contained.  Do I need to add 
other libraries?  And how do I know which ones?
Feb 09 2021
next sibling parent Kagamin <spam here.lot> writes:
Add libraries that provide missing symbols.
Feb 10 2021
prev sibling next sibling parent Rumbu <rumbu rumbu.ro> writes:
On Tuesday, 9 February 2021 at 19:37:17 UTC, WhatMeWorry wrote:

 I'm trying to create a super simple dynamic library consisting 
 of two files:


  ------------ file2.d ----------------------
 extern(D):
     double addEight(double d) { return (d + 8.0); }
 	
 ------------ fileB.d ----------------------
 extern(D)
 {
     string concatSuffix(string s) { return (s ~ ".ext"); }
 }



dmd -m64 -c file2.d
dmd -m64 -c fileB.d


 creates file2.obj and fileB.obj files

 link.exe /DLL /NOENTRY file2.obj fileB.obj msvcrt.lib

 fileB.obj : error LNK2019: unresolved external symbol 
 _D12TypeInfo_Aya6__initZ referenced in function 
 _D5fileB12concatPrefixFAyaZQe
 fileB.obj : error LNK2019: unresolved external symbol 
 _d_arraycatT referenced in function 
 _D5fileB12concatPrefixFAyaZQe

 Ok. I find _d_arraycatT in the D website at:

 https://dlang.org/library/rt/lifetime/_d_arraycat_t.html

 So I thought, this symbol will be in phobos64.lib.  But when I 
 add it to the command, all hell breaks loose:



link.exe /DLL /NOENTRY file2.obj fileB.obj msvcrt.lib 
phobos64.lib


 phobos64.lib(bits_23fa_21c.obj) : error LNK2001: unresolved 
 external symbol memcpy
  o  o  o
 file2.dll : fatal error LNK1120: 57 unresolved externals


 So I'm stuck and don't have a clue as to how to continue.

 I thought Phobos64.lib was self-contained.  Do I need to add 
 other libraries?  And how do I know which ones?


You have 2 obj files, and you link them. Where do you want the 
"self contained" to be present?

The missing symbols in your case are in druntime.lib, not in 
phobos.
Feb 10 2021
prev sibling next sibling parent reply Ferhat =?UTF-8?B?S3VydHVsbXXFnw==?= <aferust gmail.com> writes:
On Tuesday, 9 February 2021 at 19:37:17 UTC, WhatMeWorry wrote:

 I'm trying to create a super simple dynamic library consisting 
 of two files:

 [...]


remove /NOENTRY, and include "mixin SimpleDllMain;" in one of the 
sources. And link with druntime.

link /DLL file2.obj fileB.obj druntime-ldc.lib msvcrt.lib
Feb 10 2021
parent reply WhatMeWorry <kheaser gmail.com> writes:
On Wednesday, 10 February 2021 at 11:38:00 UTC, Ferhat Kurtulmuş 
wrote:

 On Tuesday, 9 February 2021 at 19:37:17 UTC, WhatMeWorry wrote:

 I'm trying to create a super simple dynamic library consisting 
 of two files:

 [...]


 remove /NOENTRY, and include "mixin SimpleDllMain;" in one of 
 the sources. And link with druntime.

 link /DLL file2.obj fileB.obj druntime-ldc.lib msvcrt.lib



Okay, thanks. Then why does the README.md at

https://github.com/dlang/druntime

say "Runtime is typically linked together with Phobos in a 
release such that the compiler only has to link to a single 
library to provide the user with the runtime and the standard 
library."
Feb 10 2021
parent reply "H. S. Teoh" <hsteoh quickfur.ath.cx> writes:
On Wed, Feb 10, 2021 at 11:35:27PM +0000, WhatMeWorry via Digitalmars-d-learn
wrote:
[...]

 Okay, thanks. Then why does the README.md at
 
 https://github.com/dlang/druntime
 
 say "Runtime is typically linked together with Phobos in a release
 such that the compiler only has to link to a single library to provide
 the user with the runtime and the standard library."


Probably outdated information.  Somebody should submit a PR for it. ;-)


T

-- 
Let X be the set not defined by this sentence...
Feb 10 2021
next sibling parent kinke <noone nowhere.com> writes:
On Thursday, 11 February 2021 at 00:18:23 UTC, H. S. Teoh wrote:

 On Wed, Feb 10, 2021 at 11:35:27PM +0000, WhatMeWorry via 
 Digitalmars-d-learn wrote: [...]

 Okay, thanks. Then why does the README.md at
 
 https://github.com/dlang/druntime
 
 say "Runtime is typically linked together with Phobos in a 
 release such that the compiler only has to link to a single 
 library to provide the user with the runtime and the standard 
 library."


 Probably outdated information.  Somebody should submit a PR for 
 it. ;-)


It basically says there's no separate libdruntime with DMD, it's 
included in libphobos2 (unlike LDC). So 'runtime' in the context 
of the druntime repo is 'druntime', not 'C runtime and other 
platform libs' libphobos/druntime depend on.
Feb 10 2021
prev sibling parent Imperatorn <johan_forsberg_86 hotmail.com> writes:
On Thursday, 11 February 2021 at 00:18:23 UTC, H. S. Teoh wrote:

 On Wed, Feb 10, 2021 at 11:35:27PM +0000, WhatMeWorry via 
 Digitalmars-d-learn wrote: [...]

 Okay, thanks. Then why does the README.md at
 
 https://github.com/dlang/druntime
 
 say "Runtime is typically linked together with Phobos in a 
 release such that the compiler only has to link to a single 
 library to provide the user with the runtime and the standard 
 library."


 Probably outdated information.  Somebody should submit a PR for 
 it. ;-)


 T


Can someone in here update the docs?
Feb 11 2021
prev sibling parent kinke <noone nowhere.com> writes:
On Tuesday, 9 February 2021 at 19:37:17 UTC, WhatMeWorry wrote:

 I'm trying to create a super simple dynamic library consisting 
 of two files:


  ------------ file2.d ----------------------
 extern(D):
     double addEight(double d) { return (d + 8.0); }
 	
 ------------ fileB.d ----------------------
 extern(D)
 {
     string concatSuffix(string s) { return (s ~ ".ext"); }
 }



dmd -m64 -c file2.d
dmd -m64 -c fileB.d


 creates file2.obj and fileB.obj files

 link.exe /DLL /NOENTRY file2.obj fileB.obj msvcrt.lib


If you go the easy route and use LDC, everything works:

ldc2 -shared file1.d file2.d
=> file1.dll

Or, if you really prefer separate compile + link:

ldc2 -c file1.d
ldc2 -c file2.d
ldc2 -shared file1.obj file2.obj

Use `-v` to see what the actual link.exe cmdline is, and notice 
the MSVC and Windows libs that are implicitly added. - IIRC, DMD 
only embeds these system libs into the object file containing 
main/DllMain (and you have none), whereas LDC adds them to the 
linker cmdline.
Feb 10 2021