HP-UX 11i December 2004 Release Notes

Programming
Miscellaneous
Chapter 15
325
Details of Linker Changes
Incremental linking: Incremental linking provides significant linktime improvements
for compile-link-debug development cycles by processing only those input files that are
actually modified between cycles. Files that are not modified do not need to be
reprocessed. For large application, incremental linking may provide up to 10x (and
sometimes greater) improvements in linktime.
Unix 98: Support for the APIs dlopen, dlsym, dlerror and dlclose has been added for
32-bit programs.
Filtered Libraries: Filtered shared libraries divide up a large library into one filter
and several implementation libraries. The user links against the filter library, but the
real definitions of data and functions actually resides in the implementation libraries. At
run time, only those implementation libraries that are actually used are loaded. Filtered
libraries can be nested; an implementation library can itself be a filtered library
containing other implementation libraries.
GProf 32-bit support: GProf, an enhanced version of prof, produces call graph profile
data (along with the data generated by prof). While the profiling of shared libraries was
not supported in earlier releases, this release will now support profiling of shared
libraries using the environmental variable LD_PROFILE. No recompilation is required for
profiling shared libraries.
PLabel cache: +plabel_cache is added to 32-bit linker and dld.sl to control the
global symbol hash mechanism.
Compatibility
Various serious and critical defects were repaired.
Forward and backward compatibility are maintained. However, use of new features in
this release may break backward compatibility.
Invoking chatr on some binaries built with an older linker may emit the following
message:
chatr(error): dl_header_ext.size != sizeof(dl_header_ext). Please update your version of
the linker/chatr.
This message should be regarded as a warning rather than an error. The operation of
chatr will be successful despite the warning.
Changes to the linker/dld Interface
updated for
March 2002
The linker/dld interface support for CXperf no longer applies, as the CXperf product
has been discontinued. For further details, see
http://www.software.hp.com/RELEASES-MEDIA/proginfo/mail176/5971-4689.htm.
new at 11i
original release
Patches to the linker/dld interface include the following enhancements:
• Added support for the CXperf performance measuring tool in both 32-bit and 64-bit
versions of the ld command. Both versions now recognize the +tools option, which
enables CXperf information to be propagated to an executable program.
• Added support for huge data (.bss > 4GB)
• A defect was repaired whereby +Oprocelim removed more than it should have
causing a runtime error.