ld: pep: Stop emitting reference to the pseudo-relocator function
Patch to stop the PE linker from emitting a reference to the _pei386_runtime_relocator function, simplifying Cygwin runtime and preparing for future architectu…
Jon Turney proposes to stop the PE linker (ld) from emitting a reference to the _pei386_runtime_relocator function. This function currently exists as a non-functional stub in the Cygwin runtime solely to satisfy this linker-synthesized reference. While the MinGW runtime has actual content for this function, it’s already called explicitly at CRT startup. The patch aims to remove the confusing stub from the Cygwin runtime, especially as GCC prepares for future architectures like aarch64 where backwards compatibility concerns are less pressing. For PE+ targets, the reference will no longer be emitted, although it will be retained for i386 targets that might still require it for compatibility with older runtimes.
- proposer
Proposes to stop the PE linker from emitting a reference to `_pei386_runtime_relocator` to simplify the Cygwin runtime and prepare for future architectures.
In Details
This patch targets the PE linker (ld) and its handling of runtime relocation mechanisms, specifically concerning the _pei386_runtime_relocator function. Currently, ld synthesizes a reference to this function for PE targets. In the Cygwin environment, this function is a mere stub, serving only to satisfy the linker's reference. The MinGW environment has a functional version, but it's invoked directly. This change removes the synthesized reference from ld for Cygwin, clarifying the runtime's role and preparing for the linker's evolution on architectures beyond x86.
- PE
- Portable Executable, a file format for executables, object code, DLLs and others used in 32-bit and 64-bit versions of Windows operating systems.
- ld
- The GNU linker, responsible for combining object files and libraries into an executable or library.
- Runtime relocator
- A function or mechanism that resolves certain symbolic references or adjusts addresses in an executable at runtime, often used in dynamic linking or for Position-Independent Code (PIC).
- Stub
- A small piece of code that acts as a placeholder or interface, often used to satisfy a reference or to forward calls to another function.
- CRT
- C Runtime, the startup code for C programs that initializes the execution environment before main() is called.