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Compaq C

Compaq C
Migration Guide for OpenVMS VAX Systems

Contents (summary)
Preface	Preface
Chapter 1	Migrating to the Compaq C Run-Time Library
Chapter 2	Migrating to the Compaq C Compiler
	Tables

Contents

Preface

Preface Preface

Chapter 1

1 Migrating to the Compaq C Run-Time Library

     1.1     Why Migrate to the Compaq C RTL

     1.2     How to Migrate to the Compaq C RTL

         1.2.1         Migrating Using the Compaq C Compiler

             1.2.1.1             Linking with the Compaq C RTL Shareable Images

             1.2.1.2             Linking with the Compaq C RTL Object Libraries

         1.2.2         Migrating VAX C Code Using Shareable Images

         1.2.3         Migrating VAX C Code Using Object Libraries

     1.3     Potential Migration Concerns and Solutions

         1.3.1         Linking /NOSYSSHR with the Compaq C RTL Object Libraries

         1.3.2         Behavior Differences Between the VAX C RTL and Compaq C RTL

         1.3.3         Compaq C RTL Obsolete Features

             1.3.3.1             VAXC$MALLOC_OPT and Related Routines

             1.3.3.2             sys_nerr and sys_nerrlist Global Symbols

         1.3.4         Debugging and the Compaq C RTL Object Library

     1.4     C RTL Interoperability Concerns

         1.4.1         Problems with Images that Export C RTL Context

             1.4.1.1             Becoming Encapsulated---Solutions to the General Problem

             1.4.1.2             Issues for File I/O

             1.4.1.3             Considerations for errno

             1.4.1.4             Child Process Context

             1.4.1.5             Random Number Seed

             1.4.1.6             Signal Context

             1.4.1.7             VAXC$CRTL_INIT and Context Initialization for main Program

         1.4.2         Resolving Link-Time Conflicts with Multiple C RTLs

             1.4.2.1             Using VAXC$LCL.OPT

             1.4.2.2             Using VAXC$EMPTY.EXE

             1.4.2.3             Using DECC$EMPTY.EXE

         1.4.3         Distributing Programs to Other Systems---Version Dependency

             1.4.3.1             Using the Compaq C/C++ Run-Time Components Kit

             1.4.3.2             Supplying an Alternative Version of SYS$LIBRARY

Chapter 2

2 Migrating to the Compaq C Compiler

     2.1     General Porting Approach

     2.2     Coexistence of VAX C & Compaq C

     2.3     Compiler Mode and Message Control

         2.3.1         Choosing the Compilation Mode---The /STANDARD Qualifier

         2.3.2         Using Compiler Message Control---/WARNINGS, #pragma message

             2.3.2.1             The /WARNINGS Qualifier

             2.3.2.2             The #pragma message Preprocessor Directive

     2.4     Using Compiler Modes and Message Control to Port your Program

     2.5     New Mechanism for Controlling External Objects

         2.5.1         Extern Model Defaults Have Changed

     2.6     Mixing VAX C and Compaq C Object Files

     2.7     Using Predefined Macros to Aid Coexistence of VAX C and Compaq C code

     2.8     Additional Information

Tables

1 Conventions Used in this Guide

1-1 Changes in printf Behavior Required by ANSI

1-2 Linking Conflicts

2-1 Compaq C Compiler Modes

2-2 /WARNINGS Qualifier Options

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