objcopy

Active contributors: andrewrk

Purpose

lib/compiler/objcopy.zig (~31 KB) is the Zig implementation of objcopy. It backs the zig objcopy sub-command and provides a single binary that handles ELF, Mach-O, and COFF for the cases the toolchain needs — strip sections, extract debug info, convert formats, set/clear symbols.

Features

The flag set in lib/compiler/objcopy.zig mirrors the GNU objcopy features the Zig toolchain depends on, including:

• --strip-debug / --strip-all / --only-keep-debug — debug info separation.
• -O <format> / -I <format> — output/input format conversion (where supported).
• --add-gnu-debuglink — link a stripped binary to an external symbol file.
• --set-section-flags, --rename-section — section editing.
• --extract-to <file> — extract debug info into its own file.

How it is used

• Stand-alone: zig objcopy .... Uses the same CLI shape as GNU objcopy.
• From the build system: std.Build.Step.ObjCopy in lib/std/Build/Step/ObjCopy.zig invokes it as a step.
• From Compilation: when split debug info is requested, src/Compilation.zig runs an objcopy pass over the linker output.

Implementation

The implementation reads the input file via lib/std/elf.zig, lib/std/macho.zig, or lib/std/coff.zig, applies the requested transformations in memory, and writes the result. Supporting helpers come from lib/std/Build/Cache.zig (paths) and lib/std/Io.zig (I/O).

Key source files

File	Purpose
lib/compiler/objcopy.zig	Implementation.
lib/std/Build/Step/ObjCopy.zig	Build-step wrapper.
lib/std/elf.zig, lib/std/macho.zig, lib/std/coff.zig	File-format support.

See Linkers for the upstream stage that produces the binary objcopy operates on.