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digitalmars.D.bugs - [Issue 1306] New: extern (Windows) should work like extern (C) for variables

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1306

           Summary: extern (Windows) should work like extern (C) for
                    variables
           Product: D
           Version: 1.017
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: link-failure
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: torhu yahoo.com


In some cases, extern (Windows) causes ' 0' to get added to the end of symbols
that represent variables.  This causes linking errors.  I wasn't able to create
a simple test case, but the problem should be clear.

Scenario:
I have a few hundred function pointers in a C library.  To link with those, I
have to use extern (C).  But to actually call the functions, I need the
function pointers to have type extern (Windows).  Since extern (Windows)
changes the mangling of the pointers, I can't link both link with the C
library, and call the functions successfully.  So I'm stuck, and probably need
some ugly workaround.

I compiled 'int __stdcall x;' with msvc 6, which it accepted with a warning. 
Looking at the object file, the symbol was not affected by __stdcall.  So DMD's
behavior is probably wrong.


--
Jul 02 2007
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1306






Please include a set of reproduction steps, including source code.


--
Jul 02 2007
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1306






I nailed, it's another problem with the export keyword.


stdcall.d:
---
export extern (Windows) void (*funcptr)(int);

void main()
{
    funcptr(5);
}
---

Just to show how funcptr gets mangled:

c:\prog\test\D>dmd stdcall
c:\prog\dmd\bin\..\..\dm\bin\link.exe stdcall,,,user32+kernel32/noi;
OPTLINK (R) for Win32  Release 7.50B1
Copyright (C) Digital Mars 1989 - 2001  All Rights Reserved

c:\prog\dmd\bin\..\lib\phobos.lib(dmain2)
 Error 42: Symbol Undefined _funcptr 0
--- errorlevel 1


funcptr is mangled as _funcptr 0, which I believe is a stdcall function of zero
arguments.  This is clearly wrong, and won't link with the corresponding C
definition of the function pointer.


--
Jul 02 2007
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=1306


bugzilla digitalmars.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED





Fixed DMD 1.019 and 2.003


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Jul 30 2007