[Issue 1629] New: Link error: Previous Definition Different: blablah__initZ

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=1629

           Summary: Link error: Previous Definition Different:
                    blablah__initZ
           Product: D
           Version: 1.022
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: wbaxter at gmail.com


The error seems to require a sort of a diamond pattern of imports.  So it takes
several files to get it to happen.  Here's the minimal I've been able to get so
far:
---link_main.d---
module link_main;
import link_a;
import link_b;
link_a.Thing thinga;
link_b.Thing thingb;
void main()
{
}
---link_a.d---
module link_a;
import link_common;
alias link_common.CommonThing!() Thing;
---link_b.d---
module link_b;
import link_common;
alias link_common.CommonThing!() Thing;
---link_common.d---
module link_common;
import link_default;

struct CommonThing(T = DefaultT)
{
    struct InnerT {
        alias DefaultT.Type Type;
    }
    const ConstValue = DefaultT.ConstValue;
}
---link_default.d--
module link_default;
struct DefaultT
{
    alias float Type ;
    const uint ConstValue = 0;
}
---

Here's the exact compilation error:

rebuild -oqobjs link_main
f:\usr\pkg\d\dmd\bin\..\..\dm\bin\link.exe
objs\_link_main+objs\_link_a+objs\_link_common+objs\_link_default+objs\_link_b,link_main.exe,,user32+kernel32/noi;

OPTLINK (R) for Win32  Release 7.50B1
Copyright (C) Digital Mars 1989 - 2001  All Rights Reserved

objs\_link_b.obj(_link_b)  Offset 001ADH Record Type 0091 
 Error 1: Previous Definition Different :
_D11link_common17__T11CommonThingZ11CommonThing6InnerT6__initZ
--- errorlevel 1



At least in my actual case where this came up I found I could make the problem
go away if I created yet another module that link_a and link_b import that
looks like:

    public import link_common;
    alias link_common.CommonThing!() Thing;

This seems to clue the linker in that the two aliases are really instantiations
of the same template.


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