H-Series Application Migration Guide (H06.03+)

The TNS/E Native Development Environment
H-Series Application Migration Guide—429855-006
2-8
TNS/E Native Linker and Loader
eld has some additional functionality compared to ld. One significant difference is that
eld has the combined functionality of ld and the TNS/R native non-PIC linker nld. For
example, eld can create relinkable object files (linkfiles) as well as loadfiles, whereas ld
can create only loadfiles. See the eld Manual for details.
The TNS/E run-time loader rld is identical to the TNS/R run-time loader rld.
Comparing ndl and eld
eld provides the same functionality and most of the same command line options as nld.
The main difference between eld and nld is that eld supports DLLs but not SRLs. nld,
by contrast, supports SRLs but not DLLs. To understand the differences between eld
and nld, you need to understand how DLLs are created and used. The recommended
sources of information are the DLL Programmer’s Guide for TNS/E Systems and the
eld Manual.
The nld options related to the building and linking of SRLs are either not supported by
eld or have a different behavior when used with DLLs in eld. eld provides several new
options related to the creation and linking of DLLs.
eld accepts PIC object files and produces PIC executable object files, whereas nld
accepts non-PIC object files and produces non-PIC executable object files. Like nld, eld
can be used to produce both linkfiles and loadfiles. (A linkfile can be linked to other
linkfiles to produce a loadfile but cannot be loaded for execution. A loadfile cannot be
linked but can be loaded for execution.)
eld provides the same command options as nld, with the following exceptions:
Additionally, eld provides many enhancements over nld. Some of the more significant
enhancements are:
•
An option to use all linkfiles in archives, rather than using only those that provide
needed symbols.
•
Three options for searching archives and libraries: search only archives, search
only libraries (DLLs), and search both archives and DLLs. nld provides only two
options: search only archives and search both archives and SRLs.
•
An option to export all symbols that might normally be exported. nld provides only
the option to export a specified symbol.
•
The ability to specify a directory or subvolume for eld to search for archives and
DLLs before searching public libraries.
-NS_extent_size This nld option is not meaningful in the TNS/E native environment
-NS_max_extents This nld option is not meaningful in the TNS/E native environment
-import This nld option is intended for use in constructing SRLs. SRLs are
not supported on TNS/E systems. eld provides similar options for
use in building DLLs. See the eld Manual for details.