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digitalmars.D.learn - Linker error with one particular function

reply "Gary Willoughby" <dev nomad.so> writes:
I have defined the following module:

/**
  * Module containing unit test helper functions for date time 
operations.
  */
module common.test.unit.datetime;

/**
  * Imports.
  */
import std.conv;
import std.datetime;

/**
  * Return a unix timestamp.
  *
  * Params:
  *     T = The return type of the unix timestamp.
  *     A = Variadic argument type for args parameter.
  *     args = Time arguments as specified by the DateTime struct.
  *
  * Reference:

  */
T getUnixTime(T, A...)(A args)
{
	return to!T(SysTime(DateTime(args)).toUnixTime());
}

But when i import it and use the getUnixTime function i get the 
following linker error:

Undefined symbols for architecture x86_64:
   "_D6common4test4unit8datetime12__ModuleInfoZ", referenced from:
       _D5logic25generalstatisticprocessor12__ModuleInfoZ in main.o
       _D5logic14eventprocessor12__ModuleInfoZ in main.o
       _D5logic24devicestatisticprocessor12__ModuleInfoZ in main.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Any idea why this is? If i comment out the getUnixTime function 
and put in other code it seems to import and work ok. Is it 
anything to do with the way i've written the function?
Aug 14 2013
next sibling parent reply Jacob Carlborg <doob me.com> writes:
On 2013-08-14 15:21, Gary Willoughby wrote:

 I have defined the following module:

 /**
   * Module containing unit test helper functions for date time operations.
   */
 module common.test.unit.datetime;

 /**
   * Imports.
   */
 import std.conv;
 import std.datetime;

 /**
   * Return a unix timestamp.
   *
   * Params:
   *     T = The return type of the unix timestamp.
   *     A = Variadic argument type for args parameter.
   *     args = Time arguments as specified by the DateTime struct.
   *
   * Reference:

   */
 T getUnixTime(T, A...)(A args)
 {
      return to!T(SysTime(DateTime(args)).toUnixTime());
 }

 But when i import it and use the getUnixTime function i get the
 following linker error:

 Undefined symbols for architecture x86_64:
    "_D6common4test4unit8datetime12__ModuleInfoZ", referenced from:
        _D5logic25generalstatisticprocessor12__ModuleInfoZ in main.o
        _D5logic14eventprocessor12__ModuleInfoZ in main.o
        _D5logic24devicestatisticprocessor12__ModuleInfoZ in main.o
 ld: symbol(s) not found for architecture x86_64
 collect2: ld returned 1 exit status

 Any idea why this is? If i comment out the getUnixTime function and put
 in other code it seems to import and work ok. Is it anything to do with
 the way i've written the function?


Have you compiled all the files? Show us the command you use to compile 
your code. Usually this is enough "rdmd main.d", where "main.d" is the 
file containing the main function.

-- 
/Jacob Carlborg
Aug 14 2013
parent reply "Gary Willoughby" <dev nomad.so> writes:
On Wednesday, 14 August 2013 at 14:05:07 UTC, Jacob Carlborg 
wrote:

 Have you compiled all the files? Show us the command you use to 
 compile your code. Usually this is enough "rdmd main.d", where 
 "main.d" is the file containing the main function.


I'm sure all source files are compiled during the build and this 
is the only import giving me problems. Like i said before if i 
comment out that function everything seems to work. If i import 
the above module into another project i get the same issue. It's 
weird.

Compiler command:

rdmd --force -D -Dd../docs -de -debug -I~/Projects/shared/d -m64 
-property -unittest -w main.d
Aug 14 2013
parent "Dicebot" <public dicebot.lv> writes:
On Wednesday, 14 August 2013 at 16:11:38 UTC, Gary Willoughby 
wrote:

 ...


Hm, I remember I had similar issue once which faded away once I 
have stopped naming main module as `main`. Was not able to track 
exact conditions to trigger it - this may be something similar.
Aug 14 2013
prev sibling parent reply "Jesse Phillips" <Jesse.K.Phillips+D gmail.com> writes:
I don't have an answer, but in case you are not familiar with 
cryptic linker:

On Wednesday, 14 August 2013 at 13:21:49 UTC, Gary Willoughby 
wrote:

 But when i import it and use the getUnixTime function i get the 
 following linker error:

 Undefined symbols for architecture x86_64:


The linker is complaining specifically about 64bit, this likely 
means it found this symbol in 32bit.


   "_D6common4test4unit8datetime12__ModuleInfoZ", referenced 
 from:


It is looking for a unit test within datetime.


       _D5logic25generalstatisticprocessor12__ModuleInfoZ in 
 main.o
       _D5logic14eventprocessor12__ModuleInfoZ in main.o
       _D5logic24devicestatisticprocessor12__ModuleInfoZ in 
 main.o
 ld: symbol(s) not found for architecture x86_64
 collect2: ld returned 1 exit status


Repeating original complaint.

I would expect removing -unittest from the command line will fix 
this error. But I don't know why it is trying to pull in Phobos 
unittests.
Aug 15 2013
next sibling parent reply Jacob Carlborg <doob me.com> writes:
On 2013-08-15 20:54, Jesse Phillips wrote:

 I don't have an answer, but in case you are not familiar with cryptic
 linker:

 On Wednesday, 14 August 2013 at 13:21:49 UTC, Gary Willoughby wrote:

 But when i import it and use the getUnixTime function i get the
 following linker error:

 Undefined symbols for architecture x86_64:


 The linker is complaining specifically about 64bit, this likely means it
 found this symbol in 32bit.


No, I don't think so. At least on Mac OS X it always tell you the 
architecture:

void foo();

void main ()
{
     foo();
}

Undefined symbols for architecture x86_64:
   "_D4main3fooFZv", referenced from:
       __Dmain in main.d.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

-- 
/Jacob Carlborg
Aug 15 2013
parent "Jesse Phillips" <Jesse.K.Phillips+D gmail.com> writes:
On Friday, 16 August 2013 at 06:39:42 UTC, Jacob Carlborg wrote:

 No, I don't think so. At least on Mac OS X it always tell you 
 the architecture:

 void foo();

 void main ()
 {
     foo();
 }

 Undefined symbols for architecture x86_64:
   "_D4main3fooFZv", referenced from:
       __Dmain in main.d.o
 ld: symbol(s) not found for architecture x86_64
 collect2: ld returned 1 exit status


Well, I've only seen the architecture mentioned when it couldn't 
find a library with the of the matching arch, guess I applied 
that wrong.
Aug 16 2013
prev sibling parent reply "Gary Willoughby" <dev nomad.so> writes:
On Thursday, 15 August 2013 at 18:54:40 UTC, Jesse Phillips wrote:

 I don't have an answer, but in case you are not familiar with 
 cryptic linker:

 On Wednesday, 14 August 2013 at 13:21:49 UTC, Gary Willoughby 
 wrote:

 But when i import it and use the getUnixTime function i get 
 the following linker error:

 Undefined symbols for architecture x86_64:


 The linker is complaining specifically about 64bit, this likely 
 means it found this symbol in 32bit.


  "_D6common4test4unit8datetime12__ModuleInfoZ", referenced 
 from:


 It is looking for a unit test within datetime.


      _D5logic25generalstatisticprocessor12__ModuleInfoZ in 
 main.o
      _D5logic14eventprocessor12__ModuleInfoZ in main.o
      _D5logic24devicestatisticprocessor12__ModuleInfoZ in 
 main.o
 ld: symbol(s) not found for architecture x86_64
 collect2: ld returned 1 exit status


 Repeating original complaint.

 I would expect removing -unittest from the command line will 
 fix this error. But I don't know why it is trying to pull in 
 Phobos unittests.


You might be onto something here as i only import this module 
into unit tests. When i get time i'll investigate a little 
further.
Aug 16 2013
parent reply "Gary Willoughby" <dev nomad.so> writes:
On Friday, 16 August 2013 at 09:52:53 UTC, Gary Willoughby wrote:

 You might be onto something here as i only import this module 
 into unit tests. When i get time i'll investigate a little 
 further.


If i take the import out of the unit test and place it at the top 
of my source file everything works as expected. This is really 
odd. It only fails if the import is placed inside a unit test.
Sep 10 2013
parent "Gary Willoughby" <dev nomad.so> writes:
On Tuesday, 10 September 2013 at 10:42:44 UTC, Gary Willoughby 
wrote:

 On Friday, 16 August 2013 at 09:52:53 UTC, Gary Willoughby 
 wrote:

 You might be onto something here as i only import this module 
 into unit tests. When i get time i'll investigate a little 
 further.


 If i take the import out of the unit test and place it at the 
 top of my source file everything works as expected. This is 
 really odd. It only fails if the import is placed inside a unit 
 test.


I can't narrow it down anymore so probably not enough information 
for a bug report. But as i mentioned before it only occurred if i 
imported the module into a unit test not the module itself.

I've since renamed the function *and* renamed the file (renaming 
the file alone had no effect) and it now imports with no error at 
all when imported within a unit test. Very strange.
Sep 10 2013