[Issue 922] New: export keyword causes undefined references on linux

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=922

           Summary: export keyword causes undefined references on linux
           Product: D
           Version: 1.00
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Keywords: link-failure
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: torhu at yahoo.com


Let's say you have a C lib that you want to link with your D app.  You'd have a
D 'header' like this:

// need access to global_var defined in the C lib
export extern extern (C) {
    int global_var;
}

The export keyword is there to facilitate dynamic linking on Windows.  On
linux, it causes link failure, both with static and dynamic linking. 
"undefined reference to `_imp__global_var'".  This is not a actual error
message, since I don't have access to a linux box.  But similar errors have
been reported by others.

Supposedly, 'export' is not needed with ELF, as all symbols are visible by
default.  So I suppose dmd should ignore export on linux?

The workaround we're using is to have a script remove 'export' from the files
before compiling on linux.  Pretty ugly.  Littering code with version
statements, or reorganizing it so we can put 'version (Windows) export:'
somewhere wasn't very attractive either.


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