has /opt/mypackage/lib in it, which will then be able to handle both 32-bit and 64-bit binaries that have linked against libmystuff.so.

Example 3-1: Directory Structure

/opt/mypackage/

include/

mystuff.h

lib/

i686/

libmystuff.a

libmystuff.so x86_64/

libmystuff.a

libmystuff.so

If you have an existing paradigm using different names, HP recommends introducing links with the above names. An example of this is shown in Example 3-2.

Example 3-2: Recommended Directory Structure

/opt/mypackage/

include/

mystuff.h

lib/

32/

libmystuff.a

libmystuff.so

64/

libmystuff.a

libmystuff.so

....... i686 -> 32

....... x86_64 -> 64

Linking an application using the library (dynamic or archive) requires you to specify the appropriate subdirectory, depending on whether the application is 32-bit or 64-bit.

For example, to build a 32-bit application, you might enter:

<linkcommand> <32-bit>-L/opt/mypackage/lib/i686-lmystuffTo build a 64-bit application, you might enter:

<linkcommand> <64-bit>-L/opt/mypackage/lib/x86_64-lmystuffNote that there is no shortcut as there is for the dynamic loader.

3.9 Advanced Topics

This section discusses topics of an advanced nature pertaining to developing applications in the HP XC environment.

3.9.1 Using the GNU Parallel Make Capability

By default, the make command invokes the GNU make program. GNU make has the ability to make independent targets concurrently. For example, if building a program requires compiling 10 source files, and the compilations can be done independently, make can manage multiple compilations at once — the number of jobs is user selectable. More precisely, each target’s rules are run normally (sequentially within the rule). Typically the rules for an object file target is a

3-10Developing Applications