Use stub bfd for dynobj
A series of patches refactors binutils' dynamic object handling, introducing a stub BFD for dynobj and improving various ELF linking routines.
This patch series, a follow-up to a previous discussion, aims to refactor binutils’ handling of dynamic objects. It introduces a stub BFD intended for use as a dynamic object and makes several improvements to ELF linking, including input object compatibility checks, splitting functions for clarity, and adding sanity checks for dynamic relocation sections. The changes touch upon numerous architecture-specific ELF BFD implementations.
- proposer
Introduces a series of patches to improve dynamic object handling in binutils, including using a stub BFD and refining ELF linking logic.
“This series is a followup to https://sourceware.org/pipermail/binutils/2026-May/149276.html being the first patch mentioned there, split into nine.”
- proposer
Explains a specific change to move GOT section creation functions outside of dynamic object tests for better code clarity.
“It isn't obvious that it is correct to call the various create got section functions inside a !dynobj test, ie. somebody reading the code is left wondering whether the got might not be be created.”
- proposer
Details a change to avoid duplicate dynobj assignments in elfnn-kvx.c and elfnn-loongarch.c.
“bfd/elfnn-kvx.c (kvx_elf_create_got_section): Don't set dynobj. bfd/elfnn-loongarch.c (loongarch_elf_check_relocs): Don't repeat dynobj assignment already done.”
- proposer
Describes the extraction of input object compatibility checks into a new function in elflink.c.
“A number of places in elflink.c need to check that the input object relocs are compatible with the output. Extract those checks into a new function.”
- proposer
Explains the splitting of `_bfd_elf_link_create_dynstrtab` into two functions to improve modularity.
“_bfd_elf_link_create_dynstrtab doesn't just create dynstrtab, it also sets dynobj. This patch splits it into two separate functions, _bfd_elf_link_dynobj and _bfd_elf_link_dynstr.”
In Details
This patch series refactors binutils' ELF linker, specifically focusing on dynamic object (dynobj) handling. It introduces a "stub BFD" to represent dynamic objects more cleanly and reorganizes several functions within elflink.c and architecture-specific ELF BFD code. The goal is to improve code clarity, reduce redundancy, and enhance robustness by performing better input object compatibility checks and refining how dynamic sections like GOT and dynstrtab are managed.
- BFD
- The Binary File Descriptor library, a low-level interface used by GNU binutils to manipulate object file formats.
- dynobj
- Abbreviation for dynamic object, referring to shared libraries or dynamically linked executables.
- ELF
- Executable and Linkable Format, a common standard file format for executable, object code, shared libraries, and core dumps on Unix-like systems.
- GOT
- Global Offset Table, a table used in position-independent executable code to store addresses of global and static variables.
- dynstrtab
- Dynamic string table, part of the ELF format, containing strings used in the dynamic linking section.
- relocation
- Information in an object file that describes how to modify code or data addresses when the object is linked with other modules or loaded into memory.