README.md

WIP

This project is a work in progress. The implementation is incomplete and subject to change. The documentation can be inaccurate.

ll2go

ll2go is a tool which decompiles LLVM IR assembly files to Go source code (e.g. *.ll -> *.go).

Please note that ll2go is meant to be used in combination with go-post which post-processes the Go source code to make it more idiomatic.

Installation

• Install the dependencies before running go-get.

go get decomp.org/x/cmd/ll2go

Usage

Usage: ll2go [OPTION]... FILE...

Flags:
  -f  Force overwrite existing Go source code.
  -funcs string
      Comma separated list of functions to decompile (e.g. "foo,bar").
  -pkgname string
      Package name.
  -q  Suppress non-error messages.
  -v  Enable verbose output.

Examples

$ ll2go foo.ll

INPUT: foo.ll

define i32 @main(i32 %argc, i8** %argv) {
  br label %1

; <label>:1                                       ; preds = %9, %0
  %i.0 = phi i32 [ 0, %0 ], [ %10, %9 ]
  %x.0 = phi i32 [ 0, %0 ], [ %x.1, %9 ]
  %2 = icmp slt i32 %i.0, 10
  br i1 %2, label %3, label %11

; <label>:3                                       ; preds = %1
  %4 = icmp slt i32 %x.0, 100
  br i1 %4, label %5, label %8

; <label>:5                                       ; preds = %3
  %6 = mul nsw i32 3, %i.0
  %7 = add nsw i32 %x.0, %6
  br label %8

; <label>:8                                       ; preds = %5, %3
  %x.1 = phi i32 [ %7, %5 ], [ %x.0, %3 ]
  br label %9

; <label>:9                                       ; preds = %8
  %10 = add nsw i32 %i.0, 1
  br label %1

; <label>:11                                      ; preds = %1
  ret i32 %x.0
}

OUTPUT: foo.go

Unpolished Go output; polish using go-post.

package main

func main() {
    i = 0
    x = 0
    for i < 10 {
        _4 := x < 100
        x = x
        if _4 {
            _6 := 3 * i
            _7 := x + _6
            x = _7
        }
        _10 := i + 1
        i = _10
        x = x
    }
    return x
}

Dependencies

• llvm.org/llvm/bindings/go/llvm with unnamed.patch
• llvm-as from LLVM
• dot from Graphviz
• ll2dot

Public domain

The source code and any original content of this repository is hereby released into the public domain.