Sleigh Library

Sleigh is a language used to describe the semantics of instruction sets of general-purpose microprocessors, with enough detail to facilitate the reverse engineering of software compiled for these architectures. It is part of the Ghidra reverse engineering platform and underpins two of its major components: its disassembly and decompilation engines.

This repository provides a CMake-based build project for Sleigh so that it can be built and packaged as a standalone library and be reused in projects other than Ghidra.

Supported Platforms

Name	Support
Linux	Yes
macOS	Yes
Windows	Yes

Dependencies and Prerequisites

Required

Name	Version	Linux Package to Install	macOS Homebrew Package to Install
(HEAD builds) zlib	Recent	zlib1g-dev	zlib
Git	Latest	git	N/A
CMake	3.18+	cmake	cmake

NOTE: This CMake project pulls the Ghidra source code from the internet during configuration. See the note on Ghidra source code section for more details.

Optional

For building documentation:

Name	Version	Linux Package to Install	macOS Homebrew Package to Install
Doxygen	Latest	doxygen	doxygen
GraphViz	Latest	graphviz	graphviz

Build and Install the Sleigh Library

# Clone this repository (CMake project for sleigh)
git clone https://github.com/lifting-bits/sleigh.git
cd sleigh

# Configure CMake
cmake -B build -S .

# Build Sleigh
cmake --build build --parallel 8

# Install Sleigh
cmake --install build --prefix ./install

Note on Ghidra source code

The Ghidra source code is not actually included in this git repo, and by default, CMake will automatically pull a stable version from the internet for you.

Please see src/README.md for more information on how to customize which Ghidra source code commit will be used/compiled, including specifying your own local copy of the Ghidra source.

Packaging

The CMake configuration also supports building packages for Sleigh.

For example:

# Package Sleigh
cmake --build build --target package

API Usage

An example program called sleigh-lift has been included to demonstrate how to use the Sleigh API. It takes a hexadecimal string of bytes and can disassemble it or lift it to p-code. The program can be invoked as follows, where the action argument must be either disassemble or pcode:

sleigh-lift [action] [sla_file] [bytes] [-a address] [-p root_sla_dir] [-s pspec_file]

For example, to disassemble the following byte string:

$ sleigh-lift disassemble x86-64.sla 4881ecc00f0000
0x00000000: SUB RSP,0xfc0

And to lift it to p-code:

$ sleigh-lift pcode x86-64.sla 4881ecc00f0000
(register,0x200,1) = INT_LESS (register,0x20,8) (const,0xfc0,8)
(register,0x20b,1) = INT_SBORROW (register,0x20,8) (const,0xfc0,8)
(register,0x20,8) = INT_SUB (register,0x20,8) (const,0xfc0,8)
(register,0x207,1) = INT_SLESS (register,0x20,8) (const,0x0,8)
(register,0x206,1) = INT_EQUAL (register,0x20,8) (const,0x0,8)
(unique,0x12c00,8) = INT_AND (register,0x20,8) (const,0xff,8)
(unique,0x12c80,1) = POPCOUNT (unique,0x12c00,8)
(unique,0x12d00,1) = INT_AND (unique,0x12c80,1) (const,0x1,1)
(register,0x202,1) = INT_EQUAL (unique,0x12d00,1) (const,0x0,1)

If you do not want to build sleigh-lift, you must set the CMake variable sleigh_BUILD_EXTRATOOLS option to OFF during CMake configuration.

Helpers

This repository contains a helper not part of Sleigh/Ghidra, which you can find in the support directory. It has the following signature and can help the user find the location of a given spec file on the system:

std::optional<std::filesystem::path>
FindSpecFile(std::string_view file_name,
             const std::vector<std::filesystem::path> &search_paths =
                 gDefaultSearchPaths);

The sleigh::FindSpecFile function will search the paths provided by the user via the search_paths argument for a spec file with the name file_name. The default argument for search_paths is sleigh::gDefaultSearchPaths which contains the install/build directories generated during CMake configuration and a set of common installation locations.

If you do not want to build the helpers, you must set the CMake variable sleigh_BUILD_SUPPORT option to OFF during CMake configuration.

Integration as a Dependency

An installation of Sleigh provides a CMake interface that you can use when building your project.

You can find an example of how to use the CMake package config file in the find_package example.

We also provide a CMake helper function sleigh_compile to compile your .slaspec files using a sleigh compiler.

You can find a more complex CMake example with compiling Sleigh specifications in the example directory, which uses the upstream-provided sleigh example source code.

Lastly, you can locate the installed compiled sleigh files through the CMake variable sleigh_INSTALL_SPECDIR, which is an absolute path to the root directory for the compiled sleigh files---you should manually inspect this to know what to expect.

Referencing the CMake config file and specfiles CMake file is also suggested for learning more about the exposed CMake variables and modules.

License

See the LICENSE file.