Compile each .c to assembly, assemble that to a .o object file, then link all the objects plus the C runtime into one executable.

* Each source file travels its own compile → assemble path to a .o; the linker fuses all objects plus the C runtime into the final executable. *

The compilation pipeline:

Key insight: Each .c file is compiled independently to its own .o file. The linker combines all .o files plus the C runtime library (CRT) into the final executable.

# View the full compilation process
$ gcc -v -O2 -Wall -g -o prog main.c swap.c

Tip: GCC is actually a "compiler driver" - it orchestrates calls to the preprocessor, compiler, assembler, and linker.

Go deeper:

• GCC — the compiler driver (Wikipedia) — how one gcc command chains preprocessor, compiler, assembler and linker.
• Ian Lance Taylor — Linkers, part 1 — start of a linker author's classic 20-part deep dive into what happens after compilation.

It loads the executable and its shared libraries into memory, then resolves every symbol and relocation before main runs.

* What the dynamic linker builds: code and read-only data map low, writable data and heap above, shared libraries in the middle, and the stack at the top. *

The kernel actually launches the dynamic linker first (its path is recorded in the ELF header); the linker then maps in the program and its .so dependencies and patches everything up so the code can find the functions and data it calls.

The dynamic linker handles:

1. Load the executable into memory
2. Find required shared libraries (.so files)
3. Load shared libraries into the process address space
4. Resolve symbols - connect function calls to their implementations
5. Perform relocations for position-independent code

Process memory layout after dynamic linking:

Tip: The dynamic linker itself is specified in the ELF header and loaded by the kernel before the program starts.

Go deeper:

• ld.so(8) — dynamic linker/loader man page — the authoritative reference for how ld-linux.so finds, loads and binds shared objects.
• LWN — How programs get run: ELF binaries — what the kernel does on execve, and how it hands off to the dynamic linker.
• Dynamic linker (Wikipedia) — load-time linking across ELF, Windows and macOS.