Re: Weak globals

Joe:
See the ILE Concepts manual, around page 76, for a detailed explanation of "weak exports."


What are you hoping to achieve by using this feature? 


 (So, "ILE" really does mean "It's a Linkage Editor!") ;-)


Hope that helps,

Mark S. Waterbury



On Tuesday, April 2, 2019, 10:12:42 AM EDT, Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx> wrote:

Nope - still getting CPD5D03.

On 4/2/2019 9:08 AM, Joe Pluta wrote:

Thanks Jon, that's the way I'll go if I can't figure anything else
out. As you probably guess, I don't like DUPPROC, especially since as
I read the documentation, weak should work.

The EXPORT(*ALL) is simply for testing, but I'm not sure how the
binder source would help.  I'm not very versed in binder source, but
as far as I can tell all binder source does is order the exported
modules.  How would it help when resolving duplicate symbols?

Oh wait.  Maybe that's the problem! Maybe it's trying to export both
the weak and the strong.  Ah, let me try that.  If I add binder source
to only export main maybe that will work.


On 4/2/2019 8:53 AM, Jon Paris wrote:

Joe - I think dup proc is the only way to go. As to your comment "and
even then the order isn't _guaranteed_" that should be dealt with by
binder language/source instead of doing Export *All.  That guarantees
the slot sequence.


Jon Paris

www.partner400.com
www.SystemiDeveloper.com

On Apr 2, 2019, at 8:43 AM, Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>
wrote:

Has anybody successfully used the weak #pragma for a function?  I'm
trying to create a service program with three modules: one that
references a function, one with that function defined weakly, and
one with the function defined strongly.  In that scenario, I should
be able to combine the following:

Reference, weak: calls weak
Reference, strong: calls strong
Reference, weak, strong: calls strong
Reference only: won't compile

The best example code I found was in the AIX reference:

https://www.ibm.com/support/knowledgecenter/SSGH3R_13.1.0/com.ibm.xlcpp131.aix.doc/compiler_ref/prag_weak.html


 From what I can tell, that same syntax should work in the ILE
compiler, so I created the following:

|// TFOO1.CPP #include <stdio.h> void foo(); int main() { foo(); }
// TFOO2.CPP #include <stdio.h> #pragma weak foo__Fv void foo() {
printf("Foo called from compilation unit 2\n"); } // TFOO3.CPP
#include <stdio.h> void foo() { printf("Foo called from compilation
unit 3\n"); } |


CRTSRVPGM TFOO MODULES(TFOO1 TFOO2 TFOO3) EXPORT(*ALL) fails with
CPD5D03, Definition supplied multiple times for symbol 'foo__Fv'.

I can get around it with OPTION(*DUPPROC) but then I have to be very
careful of the order of my modules in the MODULES keyword of
CRTSRVPGM (and even then the order isn't _guaranteed_).  That also
would hide any cases of unintentional procedure duplication, so I'd
really like to get #pragma weak working.


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