nld Manual

nld Utility

nld Manual—528272-001

2-20

Linking Archive Files

The nld utility supports archive files for selecting input object files when building a new

object file. An archive file is created by the ar utility and contains a collection of object

files. Any type of file can be put into an archive, but nld uses only the relinkable

TNS/R native object files in an archive file.

To create an archive file, use the ar utility in either the Guardian environment, the OSS

environment, or on platforms running Windows. The nld utility supports archive files

existing in the Guardian and OSS environments, regardless of where the archives

were created. The ar utility is described in the noft Manual.

In the OSS environment, archive files often have filenames that start with lib and end

with the filename suffix .a, such as libc.a.

You can specify archive files on the nld command line directly and with the options -l

or -lib on page 3-7. Specifying archive files with options is usually easier than

specifying archive files on the command line.

nld resolves references using archive files in the order they are specified, either on

the command line directly or with -l or -lib options.

nld searches an archive file to resolve references. When nld finds object files that

satisfy references, it copies them from the archive file to the target object file. Unlike

Binder, nld copies the entire object file, not only the individual procedure.

For example, given object files obja, objb, and objc and archive files arc1 and

arc2 and this nld command line:

nld obja objb -lib arc1 objc arc2 -o myexec

nld performs these steps:

1. Copies obja and objb.

2. Searches arc1 for unresolved references in obja and objb. For those references

satisfied in arc1, nld copies the object file satisfying the reference.

3. Copies objc.

4. Searches arc2 for unresolved references in obja, objb, and objc. nld also

searches arc2 for unresolved references in object files copied from arc1.

A duplicate reference in an object file or an archive file generates an error.