What are the key considerations in linker design?

Key considerations in linker design include handling symbol resolution, relocation, library linking, and performance optimisation.

Linker design is a complex process that requires careful consideration of several factors. One of the primary considerations is symbol resolution. The linker must be able to correctly identify and resolve symbols, which are essentially names used in the source code. This involves mapping each symbol to the correct memory location. Incorrect symbol resolution can lead to errors in the final executable program, so it's crucial that the linker handles this process accurately.

Relocation is another important aspect of linker design. The linker must be able to adjust the addresses of symbols and references in the object code so that they correspond to the correct locations in the final executable. This is particularly important in systems where memory is dynamically allocated, as the exact location of a symbol in memory may not be known until runtime.

Library linking is also a key consideration. The linker must be able to correctly link the object code with any required libraries. This involves identifying the correct versions of the libraries, resolving any dependencies, and ensuring that the libraries are correctly integrated into the final executable. This can be a complex process, particularly when dealing with large libraries or systems with many dependencies.

Performance optimisation is another crucial aspect of linker design. The linker must be able to generate efficient executable code that runs as quickly and smoothly as possible. This involves optimising the layout of the code in memory, minimising the number of external references, and reducing the size of the final executable. The linker may also need to support various optimisation options, allowing developers to choose the best balance between performance and other factors such as code size or debugging capabilities.

In conclusion, designing a linker involves careful consideration of several complex factors. The linker must be able to accurately resolve symbols, handle relocation, link with libraries, and optimise performance. Each of these aspects requires careful design and thorough testing to ensure that the linker produces correct and efficient executable code.