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Linker and Libraries Guide

Preface

SolarisTM provides an environment in which application developers can build applications and libraries using the link-editor ld(1), and execute these utilities with the aid of the runtime linker ld.so.1(1). For many application developers, the fact that the link-editor is called via the compilation system, and that the runtime linker might play a part in the execution of their application, is mildly interesting. This manual is for those who want to understand more fully the concepts involved.

About This Manual

This manual describes the operations of the Solaris link-editor and runtime linker. Special emphasis is placed on the generation and use of shared objects because of their importance in a dynamic runtime environment.

Intended Audience

This manual is intended for a range of programmers who are interested in the Solaris linkers, from the curious beginner to the advanced user:

Not many programmers should find it necessary to read this manual from cover to cover.

Organization

Chapter 1, Introduction gives an overview of the linking processes under Solaris, together with an introduction of new features added with this release. This chapter is intended for all programmers.

Chapter 2, Link-Editor describes the functions of the link-editor, its two modes of linking (static and dynamic), scope and forms of input, and forms of output. This chapter is intended for all programmers.

Chapter 3, Runtime Linker describes the execution environment and program-controlled runtime binding of code and data. This chapter is intended for all programmers.

Chapter 4, Shared Objects gives definitions of shared objects, describes their mechanisms, and explains how to build and use them. This chapter is intended for all programmers.

Chapter 5, Versioning describes how to manage the evolution of an interface provided by a dynamic object. This chapter is intended for all programmers.

Chapter 6, Support Interfaces describes interfaces for monitoring, and in some cases modifying, link-editor and runtime linker processing. This chapter is intended for advanced programmers.

Chapter 7, Object Files is a reference chapter on ELF files. This chapter is intended for advanced programmers.

Chapter 8, Mapfile Option describes the mapfile directives to the link-editor, which specify the layout of the output file. This chapter is intended for advanced programmers.

Appendix A, Link-Editor Quick Reference gives an overview of the most commonly used link-editor options, and is intended for all programmers.

Appendix B, Versioning Quick Reference gives naming conventions and guidelines for versioning shared objects, and is intended for all programmers.

Appendix C, Recording Dependencies with $ORIGIN gives examples of how to use the $ORIGIN token to load dynamic dependencies, and is intended for all programmers.

Throughout this document, all command-line examples use sh(1) syntax, and all programming examples are written in the C language.

Note -

The term "x86" refers to the Intel 8086 family of microprocessor chips, including the Pentium and Pentium Pro processors and compatible microprocessor chips made by AMD and Cyrix. In this document, the term "x86" refers to the overall platform architecture, whereas "Intel Platform Edition" appears in the product name.

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For a list of documents and how to order them, see the catalog section of the SunExpressTM Internet site at http://www.sun.com/sunexpress.