topic Re: Symbol resolution on I64 VMS in Operating System - OpenVMS

Symbol resolution on I64 VMS

Douglas Rupp — Sun, 11 Mar 2007 15:03:07 GMT

Given a program that references decc$main and C$_EXIT1. Decc$main is resolved in decc$shr.exe, but C$_EXIT1 is resolved in module c$errno.obj out of starlet.olb. Linking in c$errno.obj after decc$shr.exe should cause lots of multiple definitions of symbols, like C$_EPERM, which are defined in both decc$shr.exe and c$errno.obj but doesn't. Why? I can't find anything in the VMS ELf spec regarding the symbol binding or visibility attributes that would allow for this.

Re: Symbol resolution on I64 VMS

Hoff — Sun, 11 Mar 2007 15:17:09 GMT

As this whole area is entirely transparent to a C program, I have to inquire some background.

It might appear that the application design or build is up to something here that's a little, um, unusual.

Can you post up a short example of or a description of the implementation, and how the application might be built?

Or are you building a compiler?

Re: Symbol resolution on I64 VMS

Douglas Rupp — Sun, 11 Mar 2007 15:28:54 GMT

Hoff is right to say the question is independent of my "C" example.

I'm just trying to better understand how the VMS linker resolves symbols.

Re: Symbol resolution on I64 VMS

Hoff — Sun, 11 Mar 2007 17:45:26 GMT

I'll assume you've seen:

http://h71000.www7.hp.com/doc/83final/4548/4548pro_003.html#itn_symb_res_ch

I haven't looked to see if the selective search is set on the c$errno.obj in the library, but that's what I'd check.

Re: Symbol resolution on I64 VMS

Douglas Rupp — Sun, 11 Mar 2007 18:02:06 GMT

Thanks, that was it.

$ lib/list/only=C$ERRNO sys$library:starlet.olb/full
Directory of ELF OBJECT library SYS$COMMON:[SYSLIB]STARLET.OLB;2

C$ERRNO Ident 0 Inserted 27-JUN-2005 10:48:09 381 symbols
***Selectively searched***