goldeneye_src/tools/ido5.3_recomp

ido5.3_recomp

This directory builds a native x86-64 Linux copy of the original SGI IRIX 5.3 IDO compiler toolchain (cc, cfe, uopt, ugen, as1, acpp, copt, ujoin, uld, umerge, usplit, plus the err.english.cc message table cc reads at runtime). This is what the root Makefile invokes when building with IDO_RECOMP=YES (the default) — see docs/SetupGuide.md for how that fits into the overall build.

Where this comes from

The original IDO 5.3 binaries only ever ran on real IRIX (MIPS) hardware or under an emulator like qemu-irix. decompals/ido-static-recomp is a static recompiler: a tool (recomp.cpp in this directory) that disassembles one of those original MIPS ELF binaries and emits equivalent C source, which is then compiled normally with a host C compiler (gcc). The result is a program that behaves like the original IRIX binary but runs natively, without any emulation overhead — much faster to compile GoldenEye's C source with than running the real thing under qemu-irix.

decompals/ido-static-recomp is itself a fork of Emill/ido-static-recomp (the original author's repo) that has become the actively maintained version. This directory's source is a vendored copy of decompals/ido-static-recomp, not a submodule — the relevant files (recomp.cpp, libc_impl.c, libc_impl.h, header.h, helpers.h, elf.h, version_info.c) are copied in directly rather than referenced as a git submodule or fetched at build time, so this repo can be built offline/reproducibly without depending on that repo staying available.

What's tracked here vs. generated

Only source files and this Makefile/README.md are committed to git:

• recomp.cpp, libc_impl.c, libc_impl.h, header.h, helpers.h, elf.h, version_info.c — the recompiler and the IRIX-syscall runtime shim (libc_impl.*) the recompiled binaries link against
• rabbitizer/ — vendored dependency, see below
• Makefile, .gitignore, this README.md

Everything else in this directory when you look at it locally (recomp, cc, cfe, uopt, ugen, as1, acpp, copt, ujoin, uld, umerge, usplit, err.english.cc, the intermediate *_c.c files, *.o) is build output, covered by .gitignore, and gets regenerated from scratch by make.

Building

Automatically (normal case)

A plain make from the repo root builds this toolchain automatically if tools/ido5.3_recomp/cc doesn't exist yet — wired up via tools/Makefile ($(MAKE) -C ido5.3_recomp runs as a dependency whenever cc is missing) and scripts/make/build_tools.sh, which the root Makefile's prerequisites target calls. You don't need to do anything extra for this in the common case.

Manually

cd tools/ido5.3_recomp
make

This requires the original SGI IRIX 5.3 IDO binaries to be present at ../irix/root/usr/{bin,lib}/* (checked into this repo — cc is under usr/bin, everything else recompiled is under usr/lib). The recipe (per binary): run ./recomp <irix binary> > <name>_c.c, then compile that generated C against libc_impl.o (the IRIX syscall/runtime shim) and version_info.o with gcc.

ugen needs recomp --conservative specifically — the original ugen binary relies on undefined-behavior stack reads, and --conservative makes recomp emit C that reproduces that behavior safely instead of leaving it to chance under a different compiler/optimization level.

make clean removes all generated binaries/intermediate files and also runs make -C rabbitizer distclean.

Rabbitizer (the vendored dependency)

recomp needs a MIPS instruction disassembler to make sense of the original IRIX binaries' machine code before it can emit equivalent C. Older versions of this tool used the general-purpose libcapstone library for that (a system package, libcapstone-dev). As of decompals' rewrite in October 2022, upstream replaced Capstone with rabbitizer — a small, purpose-built MIPS/RSP/R5900 disassembly library maintained by the same decompilation-tooling group, with better support for the instruction quirks recomp actually cares about.

"Vendored in" means the rabbitizer/ subdirectory here is a plain copy of rabbitizer's source, not a git submodule/subrepo and not a system package — there's nothing to apt install for it. Upstream decompals/ido-static-recomp tracks rabbitizer as a git subrepo (see their tools/rabbitizer/.gitrepo) pinned at commit 72bf240f468d30286888212b5fb773fae94340f6; the copy here was taken from that same commit, with the Python bindings directory and standalone test programs stripped out (recomp only needs the C/C++ static library, not rabbitizer's Python module or its own test suite).

It's built automatically as a dependency of recomp — the Makefile here runs make -C rabbitizer static first, which produces rabbitizer/build/librabbitizer.a and librabbitizerpp.a (both gitignored build output), and recomp links against the C++ one.

To refresh rabbitizer to a newer version: check what commit current decompals/ido-static-recomp pins in tools/rabbitizer/.gitrepo, fetch Decompollaborate/rabbitizer at that commit, and replace this rabbitizer/ directory with it (again trimming the Python bindings/tests if you want to keep the vendored copy minimal — they aren't required for make static).

Version pinning / updating to a newer decompals release

The recompiler source here is currently pinned to decompals/ido-static-recomp @ commit d5aec59 (origin/main HEAD at the time it was last updated, 17 commits past tag v1.2). This is recorded in two places: a comment at the top of this Makefile, and the RECOMP_PACKAGE_VERSION variable baked into every built binary — check it with ./cc --version (or any other built binary) after building.

To pick up a newer version:

1. Clone or update a local checkout of decompals/ido-static-recomp and check out whatever commit/tag you want to move to.
2. Copy recomp.cpp, libc_impl.c, libc_impl.h, header.h, helpers.h, elf.h, and version_info.c from that checkout over the copies in this directory. Diff first — upstream's main root Makefile is much bigger than this one (it builds IDO 7.1 too, multiple binary sets, universal macOS builds, etc.); this Makefile only needs to keep pace with whatever those individual source files require to compile.
3. If rabbitizer's pinned commit changed upstream, refresh rabbitizer/ per the section above.
4. Update the pinned-commit comment at the top of this Makefile and the RECOMP_PACKAGE_VERSION variable.
5. make clean && make here, then — this is the important part — do a full clean rebuild of the ROM for all three regions from the repo root (make clean && make VERSION=US && make VERSION=EU && make VERSION=JP) and confirm scripts/make/checksum.sh still reports MATCH! for each. This project's entire premise is a byte-identical ROM; a recomp version bump that changes how any of these programs behaves when compiling GoldenEye's actual source is a real regression even if everything "builds successfully." If a mismatch shows up, bisect by swapping individual binaries (cc, cfe, uopt, ugen, as1, uld, umerge, ujoin, usplit, acpp, copt) between old and new builds to isolate which one changed behavior.