ECEn 424 Review Topics: Chapter 7

Can you explain what each of the tools invoked by a compiler driver does, including the pre-processor, the compiler itself, the assembler, and the linker? (What kinds of files does each read and write?)
What are the main tasks that any linker must perform?
What are the three types of object files?
ELF relocatable object files:
- What types of information are stored in an ELF relocatable object file?
- What sections are included in the file and why? (Why separate parts of a program in this way?)
- What information exists specifically to allow relocation? (What information is contained within a relocation entry and which sections are affected by relocation?)
- What kind of symbol information is present?
- How are variables and functions with the "static" attribute handled differently?
What are the possible outcomes when duplicate symbol names are defined?
How are static libraries organized and how much of each is included by the linker?
What algorithm is used by the linker to resolve symbols for a list of relocatable object files and archives? (What "baffling link-time errors" can result?)
What steps are taken when the linker performs relocation, and why is relocation required?
What kinds of information is present in an ELF executable object file? (What are key differences with relocatable object files?)
What are the actions taken by a loader with an executable object file?
What are the important differences between static and dynamic linking?
What are the important differences between static and shared libraries?
What functionality is provided to application programs under Linux to load and link shared libraries at run (not load) time?
What are the key characteristics of position-independent code, and why is the global offset table important?
What is library interpositioning, when can it occur, and what role does the linker play in supporting it?
Self test: Can you complete all practice problems in Chapter 7?

Updated for 3rd Edition of CS:APP