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An AOT (ahead-of-time) compiler for WebAssembly that creates C compatible binaries, either as sandboxed plugins you can dynamically load, or as stand-alone executables that interface directly with the operating system. This allows webassembly modules to participate in C linking and the build process, either statically, dynamically, or with access to the host operating system. The runtime can be installed standalone on a user's machine, or it can be embedded inside your program. It's highly customizable, letting you choose the features, isolation level, and optimization amount you need for your use-case. If you find a bug, or your program can't compile on inNative until we implement a specific feature, file an issue on GitHub so we can track the needs of developers.


The primary source of documentation for inNative is the GitHub Wiki, which lists all the externally accessible functions and how to use them. This wiki should be kept up to date, but always double-check the source code comments if something seems amiss. Feel free to file an issue if there is misleading or missing documentation.


Precompiled binaries for Windows are provided in releases for those who do not want to build from source. The SDK is portable and can be unzipped to any directory, but can also be installed and registered on the target system. The provided installers will register the SDK with the system, which enables dynamic loaders to find the runtime, and register it as a .wasm, .wat and .wast file extension handler on windows. Even if you did not use an installer, you can always install a portable version by running innative-cmd.exe -i on windows or ./innative-cmd -i on linux. Read the wiki articles for the SDK and the Redistributable for more information.

For those building from source, prebuilt binaries for inNative's LLVM fork are provided here. Once installed, your folder structure should look like bin/llvm/bin, bin/llvm/lib, and bin/llvm/include. However, these prebuilt binaries may not work for some Linux distros, which will require you to rebuild from source using inNative's custom fork of LLVM.

Command Line Utility

The inNative SDK comes with a command line utility with many useful features for webassembly developers.

Usage: innative-cmd [-r] [-f <FLAG>] [-l <FILE> ... ] [-shared-lib <FILE> ... ] [-o <FILE>] [-serialize [<FILE>]] [-generate-loader] [-v] [-build-sourcemap] [-w <[MODULE:]FUNCTION> ... ] [-sys <MODULE>] [-linker] [-i [lite]] [-u] [-sdk <DIR>] [-obj <DIR>] [-compile-llvm]
  -r -run: Run the compiled result immediately and display output. Requires a start function.
  -f -flag -flags <FLAG>: Set a supported flag to true. Flags:

  -l -lib -libs -library <FILE> ... : Links the input files against <FILE>, which must be a static library.
  -shared-lib -shared-libs -shared-library <FILE> ... : Links the input files against <FILE>, which must be an ELF shared library.
  -o -out -output <FILE>: Sets the output path for the resulting executable or library.
  -serialize [<FILE>]: Serializes all modules to .wat files in addition to compiling them. <FILE> can specify the output if only one module is present.
  -generate-loader: Instead of compiling immediately, creates a loader embedded with all the modules, environments, and settings, which compiles the modules on-demand when run.
  -v -verbose: Turns on verbose logging.
  -build-sourcemap: Assumes input files are ELF object files or binaries that contain DWARF debugging information, and creates a source map from them.
  -w -whitelist <[MODULE:]FUNCTION> ... : whitelists a given C import, does name-mangling if the module is specified.
  -sys -system <MODULE>: Sets the environment/system module name. Any functions with the module name will have the module name stripped when linking with C functions
  -linker: Specifies an alternative linker executable to use instead of LLD.
  -i -install [lite]: Installs this SDK to the host operating system. On Windows, also updates file associations unless 'lite' is specified.
  -u -uninstall: Uninstalls and deregisters this SDK from the host operating system.
  -sdk -library-dir <DIR>: Sets the directory that contains the SDK library and data files.
  -obj -obj-dir -object-dir -intermediate-dir <DIR>: Sets the directory for temporary object files and intermediate compilation results.

Example usage:

innative-cmd your-module.wasm
innative-cmd -r your-module.wasm
innative-cmd yourfile.wat -flag debug o3 -run
innative-cmd your-library.wasm -f library


If you're on linux, or you really want to build LLVM from source, use the provided build-llvm script (.ps1 for windows and .sh for linux). You cannot build only LLD - you will have to recompile all of LLVM for it to work with inNative. If you are building LLVM on Linux, ensure that you have cmake and python installed, as the script cannot do this for you.

If you aren't building LLVM, but you'd like to run the test suite, you will need to get the webassembly spec submodule by running git submodule update --init spec. This will only check out the spec submodule, which allows you to skip checking out the entire llvm-project monorepo. If you get errors when running the tests, be sure to double check that you have acquired spec and spec/document/core/util/katex.

inNative does not yet have a working CMake configuration, so build instructions are still provided on a per-platform basis.


inNative currently requires C++17 to build, and only supports Visual Studio 2019. After installing the LLVM/LLD binaries or building it from source, open innative.sln in Visual Studio and build the project, or run msbuild innative.sln.


Since inNative requires C++17 to build, the minimum supported compiler is gcc-7 or clang-5. Once you've installed the LLVM/LLD binaries or built it from source, run cmake to create makefiles or a Ninja configuration that you can then use to build the project. It is suggested to create a new folder called build and then run cmake .. to isolate the generated project files. The existing makefiles are deprecated and will be removed in a future release.

Any Linux system configured with flatpak can build a standalone SDK bundle and install it to their system for development inside containers:

cd flatpak
flatpak --user --assumeyes install org.freedesktop.Sdk.Extension.innative.flatpak
flatpak run --command=sh --devel $APP
. /usr/lib/sdk/innative/

Build benchmarks

The benchmarks are already compiled to webassembly, but if you want to recompile them yourself, you can run make benchmarks from the root directory, assuming you have a webassembly-enabled compiler available. If you are on windows, it is recommended you simply use WSL to build the benchmarks.

Build Docker Image

A Dockerfile is included in the source that uses a two-stage build process to create an alpine docker image. When assembling a docker image, it is recommended you make a shallow clone of the repository (without any submodules) and then run docker build . from the root directory, without building anything. Docker will copy the repository and clone the submodules itself, before building both LLVM and inNative, which can take quite some time. Once compiled, inNative will be copied into a fresh alpine image and installed so it is usable from the command line, while the LLVM compilation result will be discarded.

Targeting inNative

To build a shared library that does not rely on WASI, you can use wasm_malloc.c and clang:

clang your_program.c wasm_malloc.c -o your_program.wasm --target=wasm32-unknown-unknown-wasm -nostdlib --optimize=3 -Xlinker --no-entry -Xlinker --export-dynamic

inNative supports sourcemaps and, if present, will generate debug info for the original language that was compiled to WebAssembly. With C++, inNative can automatically extract the debug information generated by clang: simply add -g (and remove optimizations), and the resulting wasm module will have the necessary debug information embedded inside of it. Compile this webassembly module with the DEBUG flag enabled and inNative will automatically generate debugging information from it.

clang your_program.c wasm_malloc.c -g -o your_program.wasm --target=wasm32-unknown-unknown-wasm -nostdlib --optimize=0 -Xlinker --no-entry -Xlinker --export-dynamic

No compiler fully supports inNative, because current WebAssembly compilers target web embeddings and make assumptions about which functions are available. For now, try building webassembly modules that have no dependencies, as these can always be run on any webassembly implementation. True C interop is provided via two special compiler functions, _innative_to_c and _innative_from_c. These can be used to acquire C pointers to WebAssembly memory to pass to other functions, and to convert C pointers into a form that can be manipulated by WebAssembly. However, it is not possible to safely manipulate outside memory pointers, so using these intrinsics can invalidate the sandbox, and by default you must enable them explicitly using the C Import whitelist. inNative also provides a custom cref extension that automatically converts WebAssembly indexes into C pointers for external C functions.

The WebIDL bindings proposal will make it easier to target native C environments, and hopefully compilers will make it easier to target non-web embeddings of WebAssembly.

Embedding inNative

inNative is compiled as either a dynamic or static library, and can be integrated into any project as a scripting or plugin engine. While the caveats of C interop still apply, you can still use inNative to run simple webassembly scripts inside your program. How much you trust those webassembly scripts is up to you - if you want proper sandboxing, use the whitelist functionality to limit what C functions they can call. After linking the inNative library to your project, use the steps below to compile and call a webassembly module.

// Create the environment, setting the dynamic library flag
INExports exports;
Environment* env = (*exports.CreateEnvironment)(1, 0, (!argc ? 0 : argv[0]));
env->flags |= ENV_LIBRARY; // Add ENV_NO_INIT if you want to manually initialize and cleanup the DLL.

// Add the script you want to compile
int err;
(*exports.AddModule)(env, "your_script.wasm", 0, "your_script", &err);

// Add the default static library and any additional libraries you want to expose to the script
err = (*exports.AddEmbedding)(env, 0, (void*)INNATIVE_DEFAULT_ENVIRONMENT, 0);

err = (*exports.FinalizeEnvironment)(env);

// Compile and dynamically load the result
err = (*exports.Compile)(env, "your_script.out");
void* assembly = (*exports.LoadAssembly)("your_script.out");

// Destroy environment (no longer needed after compilation, but will be needed if using JIT)

// Load functions and execute
void (*update_entity)(int) = (void (*)(int))(*exports.LoadFunction)(assembly, "your_module", "update_entity");


// Free assembly once finished