New Features

This section gives an overview of new features and/or updates that have been added to this document and to which release they were added:

Solaris 8 release:

• The secure directory from which files can be preloaded is now /usr/lib/secure for 32-bit objects and /usr/lib/secure/sparcv9 for 64-bit SPARC objects. See "Security".

• Greater flexibility in modifying the runtime linkers search paths can be achieved with the link-editors -z nodefaultlib option, and runtime configuration files created by the new utility crle(1). See "Directories Searched by the Runtime Linker" and "Configuring the Default Search Paths".

• The new extern mapfile directive provides for -z defs usage with externally defined symbols. See "Defining Additional Symbols".

• Greater flexibility in establishing instruction set specific, and system specific dependencies is provided with the new $ISALIST, $OSNAME and $OSREL dynamic string tokens. See "Dynamic String Tokens".

• Some cautionary notes on the use of the link-editors -Bsymbolic option are provided in "The Use of -Bsymbolic".

• Additional means of invoking runtime link auditing libraries is provided by the link-editor options -p and -P. See "Recording Local Auditors". Additional runtime link auditing interfaces la_activity() and la_objsearch(), have been added. See "Audit Interface Functions".

• Coordination of ELF files with core images is possible with a new dynamic section tag, DT_CHECKSUM. See Table 7-41.

Solaris 7 release:

• The 64-bit ELF object format is now supported. See "File Format" for details. Link-editor extensions and differences for 64-bit processing include: the use of /usr/lib/sparcv9 (see "Directories Searched by the Link-Editor", "Directories Searched by the Runtime Linker" and "Naming Conventions"), the environment variable LD_LIBRARY_PATH_64 (see "Using an Environment Variable" and "Directories Searched by the Runtime Linker"), and the runtime linker /usr/lib/sparcv9/ld.so.1 (see "Overview").

• Shared objects can be built with optimized relocation sections by using the link-editor -z combreloc option. See "Combined Relocation Sections".

• Greater flexibility in establishing dependencies within unbundled software is provided with the new $ORIGIN dynamic string token. See "Dynamic String Tokens".

• The loading of a shared object can now be deferred until the object is actually referenced by the running program. See "Lazy Loading of Dynamic Dependencies".

• The SHT_SUNW_COMDAT section has been added to allow for the elimination of multiply defined symbols. See "Comdat Section".

• The SHT_SUNW_move section has been added to allow for partially initialized symbols. See "Move Section".

• Additional runtime link auditing interfaces la_symbind64(), la_sparcv9_pltenter() and la_pltexit64(), together with a new link-auditing flag LA_SYMB_ALTVALUE, have been added. See "Audit Interface Functions".

Solaris 2.6 release:

• Weak symbol references can trigger archive member extraction by using the link-editor -z weakextract option. Extracting all archive members can be achieved using the -z allextract option. See "Archive Processing".

• Shared objects specified as part of a link-edit that are not referenced by the object being built can be ignored, and hence their dependency recording suppressed, using the -z ignore option. See "Shared Object Processing".

• The link-editor generates the reserved symbols _START_ and _END_ to provide a means of establishing an objects address range. See "Generating the Output Image".

• Changes have been made to the runtime ordering of initialization and finalization code to better accommodate dependency requirements. See "Debugging Aids".

• Symbol resolution semantics have been expanded for dlopen(3DL). See "Symbol Lookup", RTLD_GROUP in "Isolating a Group", and RTLD_PARENT in "Object Hierarchies".

• Symbol lookup semantics have been expanded with a new dlsym(3DL) handle RTLD_DEFAULT. See "Default Symbol Lookup Model".

• Extensions have been made to filter processing that allow more than one filtee to be defined, and provide for forcibly loading filtees. An example of creating a platform specific filter is also provided. See "Shared Objects as Filters".

• Recording additional version dependencies can be achieved using the mapfile file control directive $ADDVERS. See "Binding to Additional Version Definitions".

• A runtime linker audit interface provides support for monitoring and modifying a dynamically linked application from within the process. See "Runtime Linker Auditing Interface".

• A runtime linker debugger interface provides support for monitoring and modifying a dynamically linked application from an external process. See "Runtime Linker Debugger Interface".

• Additional section types are supported. See Table 7-11 for SHN_BEFORE and SHN_AFTER, and see Table 7-14 for SHF_ORDERED and SHF_EXCLUDE.

• A new dynamic section tag, DT_1_FLAGS, is supported. See Table 7-42 for the various flag values.

• A package of demonstration ELF programs is provided. See Chapter 7, Object Files.

• The link-editors now support internationalized messages. All system errors are reported using strerror(3C).