Exploring the WAVM source
April 2, 2026 ยท View on GitHub
Directory Structure
- Lib/ - Core library implementations (compiled into libWAVM)
- Include/WAVM/ - Public header files organized by component
- Programs/wavm/ - Implementation of the wavm program
- Test/ - Test suites and benchmarks
- Examples/ - Example WebAssembly modules and embedder code
- Build/ - Build system and scripts
- Doc/ - Documentation
- ThirdParty/ - External dependencies
Core Library Components (Lib/)
Each component has a corresponding header directory in Include/WAVM/.
| Component | Purpose |
|---|---|
| IR | WebAssembly module structure, type system, and validation |
| LLVMJIT | Compiles WebAssembly IR to native machine code using LLVM |
| Runtime | Execution engine, memory management, module instantiation |
| WASM | Binary WebAssembly format (.wasm) parsing and serialization |
| WASTParse | Text format (.wast/.wat) parsing |
| WASTPrint | IR to text format conversion (disassembly) |
| Platform | OS-specific implementations (POSIX/, Windows/) |
| WASI | WebAssembly System Interface implementation |
| VFS | Virtual filesystem abstraction for WASI |
| ObjectCache | JIT code caching using LMDB |
| Logging | Logging infrastructure |
| NFA/RegExp | Lexer support for WASTParse |
| wavm-c | Standard WebAssembly C API bindings |
"Inline" Header-Only Library Component (Include/WAVM/Inline/)
Header-only library component including hash containers (HashMap.h, HashSet.h), assertions, error handling, serialization, and 128-bit integer support.
Test Organization (Test/)
| Directory | Contents |
|---|---|
| wavm/ | WAVM-specific feature tests |
| WebAssembly/spec/ | Official spec compliance tests |
| WebAssembly/memory64/ | Memory64 proposal tests |
| WebAssembly/threads/ | Threading/atomics tests |
| WebAssembly/multi-memory/ | Multi-memory proposal tests |
| wasi/ | WASI interface tests |
| fuzz/ | Fuzzing targets |
| benchmark/ | Performance benchmarks |
Key API References
- Runtime API:
Include/WAVM/Runtime/Runtime.h - IR Module:
Include/WAVM/IR/Module.h - IR Types:
Include/WAVM/IR/Types.h - IR Operators:
Include/WAVM/IR/Operators.h - WASI:
Include/WAVM/WASI/WASI.h - C API:
Include/WAVM/wavm-c/wavm-c.h
Key Implementation References
- Translation to LLVM IR:
Lib/LLVMJIT/Emit*.cpp - Module instantiation:
Lib/Runtime/Instance.cpp - WASM parsing:
Lib/WASM/WASMSerialization.cpp - WAST parsing:
Lib/WASTParse/Parse*.cpp - IR validation:
Lib/IR/Validate.cpp - WASI implementation:
Lib/WASI/WASI*.cpp