SSVM 0.5.0

0.5.0 (2020-04-01)

Features:

• Ethereum environment interface
  • Implemented all EEI functions.
  • For more details, please refer to Ewasm functions design document
• Validation
  • Completed validations for wasm sections.
  • Completed checkings in const expressions.
• Runtime Wasm module registering
  • WASM modules can be registered into Store for importing.
  • Host modules, which may contain host functions and globals, can be registered into Store.
• (Experimental) New VM APIs
  • New VM is refactoring from legacy’s VM and provides a rapidly running process for WASM.
  • Export Store for external access.
• Node.js addon
  • Integrate SSVM with Node.js Addon API.
  • SSVM Node.js addon is separated from this project as an independent repository.

Refactor:

• Code structure layout
  • Create common namespace for cross-component data structures and type definitions.
  • Extract AST structures from ast to common.
  • Extract duplicate enumerations to common.
  • Collects all error code classes into common.
• Internal error handling mechanism
  • Apply C++ p0323r9 expected features
  • Add several helper functions for wrapping return values with error code.
• Wasm loader
  • Simplify workflow.
  • Take a wasm input and return an AST object directly.
• Wasm validator
  • Simplify workflow.
  • Take an AST object and return the results.
  • Rename validator/vm to formchecker.
• Refine runtime data structure
  • Extract instances, host functions, stack manager, and store manager classes to runtime folder.
  • Extract frame, label, and value entry classes into stack manager.
  • Delete redundant checks in stack manager. All of these checks are verified in the validation stage.
  • Add ImportObj class for handling the host modules registration.
• Interpreter
  • Create interpreter namespace.
  • Extract executor class to interpreter.
  • Add instantiation methods for registering host modules.
• Host functions
  • Create host namespace.
  • Extract EEI, Wasi-core, and ONNC host functions to host.
  • Make host functions construction in host modules.
  • Extract host environments from environment manager to respective host modules.
• Refactoring from legacy VM.
  • Simplify workflow. Provide two approaches for invoking a wasm function.
    • All-in-one way: Calling runWasmFile can instantiate and invoke a wasm function directly.
    • Step-by-step way: Calling loadWasm, validate, instantiate, execute sequentially can make developers control the workflow manually.
  • External access APIs
    • Access exported wasm functions.
    • Export Store.
    • Export measurement data class including instruction counter, timer, and cost meter.
  • Provide registration API for wasm modules and host modules.
  • Extract host environments of EEI and Wasi-core into respective host modules.
  • Apply experimental VM to ssvm-proxy and ssvm-evmc tools.

Tools:

• Remove unused ssvm-evm
  • ssvm-evm is replaced by ssvm-evmc.
• (Experimental) Add sub-project ssvm-aot
  • ssvm-aot provides ahead-of-time(AOT) compilation mechanism for general wasm applications.

Tests:

• Remove redundant ssvm-evm tests.
• (Experimental) Add integration tests for ssvm-aot.
• (Experimental) Add unit tests for C++ expected feature.
• Move AST tests to the test top folder.

Fixed issues:

• Ethereum Environment Interface
  • Fix function signatures.
  • Return fail instead of revert when the execution state is out of gas.
  • Handle memory edge case when loading and storing from memory instance.
  • Add missing check for evmc flags.
  • Set running code to evmc environment.
• Complete import matching when instantiation in the interpreter.
• Fix lost of validation when importing globals.