# ollvm

**Repository Path**: r6/ollvm

## Basic Information

- **Project Name**: ollvm
- **Description**: 原始代码来自于 https://github.com/obfuscator-llvm/obfuscator 移植到了最新的 LLVM 上。并在此基础上持续增强相关功能
- **Primary Language**: C++
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 7
- **Forks**: 6
- **Created**: 2020-12-01
- **Last Updated**: 2024-06-16

## Categories & Tags

**Categories**: ci

**Tags**: None

## README

# The LLVM Compiler Infrastructure

This directory and its subdirectories contain source code for LLVM,
a toolkit for the construction of highly optimized compilers,
optimizers, and runtime environments.

## Getting Started with the LLVM System

Taken from https://llvm.org/docs/GettingStarted.html.

### Overview

Welcome to the LLVM project!

The LLVM project has multiple components. The core of the project is
itself called "LLVM". This contains all of the tools, libraries, and header
files needed to process intermediate representations and converts it into
object files.  Tools include an assembler, disassembler, bitcode analyzer, and
bitcode optimizer.  It also contains basic regression tests.

C-like languages use the [Clang](http://clang.llvm.org/) front end.  This
component compiles C, C++, Objective C, and Objective C++ code into LLVM bitcode
-- and from there into object files, using LLVM.

Other components include:
the [libc++ C++ standard library](https://libcxx.llvm.org),
the [LLD linker](https://lld.llvm.org), and more.

### Getting the Source Code and Building LLVM

The LLVM Getting Started documentation may be out of date.  The [Clang
Getting Started](http://clang.llvm.org/get_started.html) page might have more
accurate information.

This is an example workflow and configuration to get and build the LLVM source:

1. Checkout LLVM (including related subprojects like Clang):

     * ``git clone https://github.com/llvm/llvm-project.git``

     * Or, on windows, ``git clone --config core.autocrlf=false
    https://github.com/llvm/llvm-project.git``

2. Configure and build LLVM and Clang:

     * ``cd llvm-project``

     * ``mkdir build``

     * ``cd build``

     * ``cmake -G <generator> [options] ../llvm``

        Some common generators are:

        * ``Ninja`` --- for generating [Ninja](https://ninja-build.org)
          build files. Most llvm developers use Ninja.
        * ``Unix Makefiles`` --- for generating make-compatible parallel makefiles.
        * ``Visual Studio`` --- for generating Visual Studio projects and
          solutions.
        * ``Xcode`` --- for generating Xcode projects.

        Some Common options:

        * ``-DLLVM_ENABLE_PROJECTS='...'`` --- semicolon-separated list of the LLVM
          subprojects you'd like to additionally build. Can include any of: clang,
          clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld,
          polly, or debuginfo-tests.

          For example, to build LLVM, Clang, libcxx, and libcxxabi, use
          ``-DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi"``.

        * ``-DCMAKE_INSTALL_PREFIX=directory`` --- Specify for *directory* the full
          pathname of where you want the LLVM tools and libraries to be installed
          (default ``/usr/local``).

        * ``-DCMAKE_BUILD_TYPE=type`` --- Valid options for *type* are Debug,
          Release, RelWithDebInfo, and MinSizeRel. Default is Debug.

        * ``-DLLVM_ENABLE_ASSERTIONS=On`` --- Compile with assertion checks enabled
          (default is Yes for Debug builds, No for all other build types).

      * Run your build tool of choice!

        * The default target (i.e. ``ninja`` or ``make``) will build all of LLVM.

        * The ``check-all`` target (i.e. ``ninja check-all``) will run the
          regression tests to ensure everything is in working order.

        * CMake will generate build targets for each tool and library, and most
          LLVM sub-projects generate their own ``check-<project>`` target.

        * Running a serial build will be *slow*.  To improve speed, try running a
          parallel build. That's done by default in Ninja; for ``make``, use
          ``make -j NNN`` (NNN is the number of parallel jobs, use e.g. number of
          CPUs you have.)

      * For more information see [CMake](https://llvm.org/docs/CMake.html)

Consult the
[Getting Started with LLVM](https://llvm.org/docs/GettingStarted.html#getting-started-with-llvm)
page for detailed information on configuring and compiling LLVM. You can visit
[Directory Layout](https://llvm.org/docs/GettingStarted.html#directory-layout)
to learn about the layout of the source code tree.

# credits

本仓库的porting的原始代码，commit来自llvm官方

commit 79b773fe7fffbea3bee2b34ace8f8ca5bae8526d 移植自 [AllocAndInit/ollvm5.0.1](https://github.com/AllocAndInit/ollvm5.0.1) （该项目中stringobfuscation部分代码和 [GoSSIP-SJTU/Armariris](https://github.com/GoSSIP-SJTU/Armariris)比较接近）

感谢AllocAndInit，GoSSIP-SJTU等开源的贡献！

# 使用方式
	
[控制流平展功能](https://gitee.com/r6/ollvm/wikis/%E6%8E%A7%E5%88%B6%E6%B5%81%E6%89%81%E5%B9%B3%E5%8C%96?sort_id=3162350)
* -mllvm -fla: activates control flow flattening
* -mllvm -split: activates basic block splitting. Improve the flattening when applied together.
* -mllvm -split_num=3: if the pass is activated, applies it 3 times on each basic block. Default: 1

[混淆控制流](https://gitee.com/r6/ollvm/wikis/%E6%B7%B7%E6%B7%86%E6%8E%A7%E5%88%B6%E6%B5%81?sort_id=3162423)
* -mllvm -bcf: activates the bogus control flow pass
* -mllvm -bcf_loop=3: if the pass is activated, applies it 3 times on a function. Default: 1
* -mllvm -bcf_prob=40: if the pass is activated, a basic bloc will be obfuscated with a probability of 40%. Default: 30

[指令替换](https://gitee.com/r6/ollvm/wikis/%E6%8C%87%E4%BB%A4%E6%9B%BF%E6%8D%A2?sort_id=3162358)
* -mllvm -sub: activate instructions substitution
* -mllvm -sub_loop=3: if the pass is activated, applies it 3 times on a function