PowerAda Freezing Rules

Chapter 8

• Notice
• Chapter 1. Overview
• Chapter 2. Getting Started
• Chapter 3. Basic PowerAda Concepts
• Chapter 4. The PowerAda Development Environment
• Chapter 5. Project Management with PowerAda
• Chapter 6. The PowerAda Debugger: adbg
• Chapter 7. Interface to Other Languages
• Chapter 8. Implementation Details
• Chapter 9. Optimization
• APPENDIX A - Glossary
• APPENDIX B - Support Packages
• APPENDIX C - Implementation Characteristics
• APPENDIX D - Demos and Tutorials
• APPENDIX E - Tools Reference
• APPENDIX F - Debugger Command Reference
• Index

Contents |  Installation Guide | Release Notes

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The compiler checks the freezing rules (described in RM95 section 13.14). The compiler detects the following as a semantic error:

type T is (A, B, C);
OBJ : T;
for T use (A => 0, B => 3, C => 5);

The error in this code occurs when an object, OBJ, is declared to be of type T before the representation of type T is determined. To correct this code, move the declaration of the object to follow the representation clause for type T, as shown below:

type T is (A, B, C);
for T use (A => 0, B => 3, C => 5);
OBJ : T;