eld Manual

Binding of References
eld Manual—527255-009
3-23
The Public Library Registry
Each set of public libraries is installed in a separate subvolume, separate from the
SYSnn subvolume and separate from any other set of public DLLs. This subvolume is
on the same disk as the SYSnn subvolume.
The SYSnn subvolume also contains the imp-imp file, named zimpimp. This is the
import file usable for resolving external references to the explicit libraries. The imp-imp
file can be copied to the public-DLL subvolume. This renders the public-DLL
subvolume portable. A portable public-DLL subvolume contains everything the linker
needs to link files to use these particular public libraries. A portable subvolume can be
copied for use by the linker (eld) on another system or another platform, such as a PC.
The Public Library Registry
The public-DLL registry file (ZREG) serves as an interface between DSM/SCM (that
you use), the public-library installation tool (that HP uses), the preloader and the linker.
DSM/SCM creates an initial registry file, listing all the public DLLs by name. This is an
edit file (filecode 101). Use DSM/SCM to add your public DLLs to those provided by
HP.
Entries to the file consist of a series of statements. The dll statement describes a public
DLL. In its simplest form, it is just a name, for example:
dll file ztestdll;
Here is another example; it contains the license attribute. A licensed DLL is one that
contains priviliged code. Unless you use this attribute along with the value “1”, the
default is “0”, which means the DLL is unlicensed.
dll license 1, file privdll;
There are other attributes which are created automatically, for example the timestamps
that you and the tools can use for version control. Here are two examples, the
link_timestamp (from when the linker first created the DLL), and the update_timestamp
(from when the linker last updated the DLL, or when another tool rebases or presets it):
dll file zredll,
link_timestamp 2004-08-01 16:34:41.213592,
update_timestamp 2004-08-01 17:15:17.119634;
From these examples you can see that attributes can be in any order, attributes are
separated by commas, and statements are terminated by semicolons.
Finding and Reading The Public DLL Registry (ZREG) File
The linker always tries to find the public DLL registry file whenever it is creating a
loadfile. There are three ways that the linker may find the public DLL registry file:
1. If the -public_registry option is specified, that tells the name of the public DLL
registry file. (This option could also be used to override another location of the zreg
file.) If the file does not exist, or the linker cannot open the specified file for
reading, eld reports an error.