DLL Programmer's Guide for TNS/E Systems

Essential DLL Facility Controls

DLL Programmer’s Guide for TNS/E Systems—527252-006

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Things to Consider about the Loader

Because the search order for the linker and loader comes to D before Y (See Finding

Symbol Definitions on page 4-1), D’s Gamma masks Y’s. So without any change to the

users, all of those that formerly used old D’s Gamma will now get new D’s Gamma.

Things to Consider about the Loader

Many of the loader’s operations are automatic and driven by adequate defaults. This

subsection discusses a few of which you must be aware. For more precise control of

the loader, see Load-Time Operation on page 5-13.

The Link-Time-Defined Search Path of the Loader

The linker can run on an auxiliary system while the loader must run on the execution

target, so their search paths might necessarily be different. For example, the directory

and subvolume names are unlikely to be the same on the auxiliary and execution-

target systems. This subsection discusses how, when executing the link, you can direct

the load-time search to appropriate paths on the target system.

While the loader’s search path is similar to the linker’s, the search-path information the

linker gets from -first_L, -libvol, or -L options is not passed on to the loader.

Instead, the loader’s search path is controlled at link time by -RLD_first_L or

-RLD_L options. These are repeatable options.

The loader’s search path can also be modified at load time, as discussed in Controlling

the Loader’s Search Path at Load Time on page 5-13; however, when not augmented

at load time, the loader’s search path is:

1. The directories or subvolumes specified in a -RLD_first_L <parameter>

option in the linker’s command stream, where <parameter> is a path or paths

to a specified directory or subvolume. The -RLD_first_L option is not

required, but when used, is repeatable with different path strings.

Figure 2-3. the New Symbol, Gamma, With New Function (Shaded), Replaces the

Old Gamma.

DLL A

Alpha

Beta

Gamma

DLL D

(new)

Gamma

VST023.vsd

DLL Y

(old D)

Alpha

Beta

Gamma