readelf: move some code around
Refactors readelf.c to improve code organization and reduce forward declarations.
This patch series for the readelf utility reorganizes functions within readelf.c to enhance code structure and minimize the need for forward declarations. Specifically, bitness-dependent helper functions are now placed immediately before their respective main functions (get_program_headers, get_dynamic_section, get_section_headers, get_elf_symbols), grouping related code. This change also eliminates the forward declaration for validate_section_info by defining it alongside its helper.
- proposer
Proposes to reorganize functions in `readelf.c` to group related code and reduce forward declarations.
“Avoid the need to forward-declare get_program_headers() and get_dynamic_section(); put them right after their bitness-dependent helpers (i.e. after the readelf-nn.c inclusion point). Then, to keep related things together, move get_section_headers() and get_elf_symbols() as well.”
- proposer
Notes that using function pointers for `get_elf_symbols` might be an alternative but would not extend well to other functions, making the current reorganization a more practical approach.
“One aspect I noticed: Instead of the trivial get_elf_symbols() wrapper we could use a function pointer. That, however, already wouldn't quite extend to get_section_headers() and get_dynamic_section(), let alone get_program_headers(), so would - overall - be of little help.”
Technical Tradeoffs
- Improves code readability and maintainability by reducing forward declarations and grouping related functions.
- May require careful review to ensure no functional changes are introduced by the code rearrangement.
In Details
This patch series refactors binutils/readelf.c by rearranging function definitions. The goal is to improve code locality and reduce the number of forward declarations. Bitness-specific helper functions are now placed directly before the main functions they support (e.g., get_program_headers), and related functions like get_section_headers and get_elf_symbols are also moved to keep related code together. The validate_section_info function and its helper are also relocated to avoid forward declarations.
- readelf
- A utility that displays information about ELF (Executable and Linkable Format) files.
- ELF
- Executable and Linkable Format, a common standard file format for object files used in Unix-like systems.
- forward declaration
- A declaration of an identifier (like a function or variable) before it is fully defined, allowing it to be used in the interim.
- bitness-dependent
- Code that behaves differently or is specifically implemented for different data sizes, such as 32-bit or 64-bit.
- section headers
- Data structures within an ELF file that describe each section (e.g., code, data, symbols).
- program headers
- Data structures within an ELF file that describe segments, which are mappings of sections into memory for execution.
- dynamic section
- An ELF section containing information needed for dynamic linking and runtime execution.