ecmascript/interpreter

Bytecode interpreter that executes ArkCompiler ABC instructions through a register-based virtual machine. Primary Language: C++

Design

The interpreter provides execution of ark bytecode with C++ implementation:

  ABC bytecode (.abc file)
       │
       ▼
  EcmaInterpreter::Execute()
       │
       └──▶ C++ interpreter (interpreter-inl.cpp)
             ├── switch/case dispatch
             ├── Bytecode handler functions
             ├── Type checks and guards
             └── Runtime calls (fast_runtime_stub/slow_runtime_stub)

Key abstractions:

• EcmaInterpreter — Main interpreter entry point and execution control
• FrameHandler — Stack frame management, argument passing, and return value handling
• EcmaRuntimeCallInfo — Execution context containing VM, arguments, and return slot
• FastRuntimeStub — Fast-path runtime call declarations
• SlowRuntimeStub — Slow-path runtime call implementations

Assembly interpreter integration:

• interpreter_assembly.cpp provides assembly interpreter call entry points and debugging utilities
• Actual assembly interpreter implementation is located in ecmascript/compiler/interpreter_stub.cpp
• templates/ contains assembly template files for bytecode handler generation

Reference Source

• arkcompiler/ets_runtime/ecmascript/interpreter/interpreter.h (1-90行) - Interpreter interface
• arkcompiler/ets_runtime/ecmascript/interpreter/interpreter-inl.h - C++ interpreter implementation

Key Files

File	Role
interpreter.h/.cpp	Main interpreter entry point
interpreter-inl.h/.cpp	C++ interpreter implementation with switch/case dispatch
interpreter_assembly.h/.cpp	Assembly interpreter call entry and debugging utilities
frame_handler.h/.cpp	Stack frame and call management
fast_runtime_stub.h	Fast runtime call declarations
slow_runtime_stub.h/.cpp	Slow runtime call implementations
templates/	Assembly template files for bytecode handler generation

Building

Standalone repo (from repo root ../../):

python ark.py x64.debug

Full OHOS tree:

./build.sh --product-name <product-name> --build-target ark_js_host_linux_tools_packages

Tests

Standalone repo (from repo root ../../):

python ark.py x64.debug unittest   # includes interpreter tests

Full OHOS tree:

./build.sh --product-name <product-name> --build-target ecmascript/tests:host_unittest

Boundaries

• Assembly interpreter code is in ecmascript/compiler/interpreter_stub.cpp; this directory only provides call entry points.
• C++ interpreter and assembly interpreter must maintain consistent semantics.
• Hotness counter updates trigger JIT compilation; ensure correct threshold management.