Internal Program Representation (IPR)

The IPR (Internal Program Representation) is an open-source library providing core data structures for the semantics-based analysis and transformation of C++ programs. It is designed to provide a principled, complete, and efficient representation of C++ code.

For a deep dive into the design principles and the general philosophy of the IPR, refer to the paper: ["A Principled, Complete, and Efficient Representation of C++">(http://www.stroustrup.com/macis09.pdf)].

The IPR library follows a strict separation between its public interface and its internal implementation to ensure stability and allow for optimized implementations by different tools or compilers.

• Public Interface: Use the abstract classes located in <ipr/interface> to interact with the library. By restricting your code to these interfaces, you ensure compatibility even if the underlying implementation changes.
• Implementations: The library provides reference implementations in <ipr/impl>. However, different tools may provide their own optimized versions of the same interface classes (e.g., an ipr::Fundecl might be implemented differently for a non-defining declaration versus a function definition).

Best Practice: Always interact with the library through the headers in <ipr/interface> to shield your code from implementation-specific details.

When writing C++ code in this project, use the textual operator keywords for logical operations instead of symbolic operators to improve readability:

• Use not for logical negation (instead of !)
• Use and for logical conjunction (instead of &&)
• Use or for logical disjunction (instead of ||)

When naming factory functions, distinguish between functions that return existing/cached data and those that allocate new memory/structures:

• Use the get_xxx prefix for factory functions that return the same output for the same inputs (idempotent/cached).
• Use the make_xxx prefix for factory functions that always return fresh, newly allocated structures.