The Linker
Hacker News
February 8, 2026
AI-Generated Deep Dive Summary
The article delves into the critical role of the linker in the compilation process, particularly in Go programming. After the compiler transforms optimized code into object files, the linker steps in to combine these files into a single executable. This involves four key tasks: symbol resolution, relocation, dead code elimination, and generating the final executable format.
Symbol resolution ensures that all function calls and references across different object files are correctly mapped. For instance, when your program imports packages like `fmt`, the linker identifies where `fmt.Println` is defined and links it to your main function, even if they reside in separate files. This step is crucial for ensuring that every function call resolves properly, allowing the program to run smoothly.
Relocation addresses the placeholders (relocations) left by the compiler, which indicate where specific data or functions will be placed in memory. The linker replaces these placeholders with actual memory addresses once it knows the final layout of the executable. This process is essential for ensuring that all parts of the program can communicate correctly and efficiently.
Dead code elimination helps keep executables lean by removing unused functions and variables from imported packages. For example, if your program only uses one function from a large library, the linker strips away the unnecessary code, reducing the size of the final binary without affecting functionality.
Finally, the linker generates the executable file in a format compatible with the target operating system (like ELF for Linux or Mach-O for macOS). This ensures that the compiled program can be executed properly on its intended platform. Understanding these processes is vital for developers aiming to optimize their code and troubleshoot linking issues effectively.
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Originally published on Hacker News on 2/8/2026