Coverage for wasmtime/_ffi.py: 77%

1from ctypes import * 

2from pathlib import Path 

3import ctypes 

4import sys 

5import platform 

6import typing 

7 

8if sys.maxsize <= 2**32: 

9 raise RuntimeError("wasmtime only works on 64-bit platforms right now") 

10 

11if sys.platform == 'linux': 

12 libname = '_libwasmtime.so' 

13elif sys.platform == 'win32': 

14 libname = '_wasmtime.dll' 

15elif sys.platform == 'darwin': 

16 libname = '_libwasmtime.dylib' 

17else: 

18 raise RuntimeError("unsupported platform `{}` for wasmtime".format(sys.platform)) 

19 

20machine = platform.machine() 

21if machine == 'AMD64': 

22 machine = 'x86_64' 

23if machine == 'arm64' or machine == 'ARM64': 

24 machine = 'aarch64' 

25if machine != 'x86_64' and machine != 'aarch64': 

26 raise RuntimeError("unsupported architecture for wasmtime: {}".format(machine)) 

27 

28filename = Path(__file__).parent / (sys.platform + '-' + machine) / libname 

29if not filename.exists(): 

30 raise RuntimeError("precompiled wasmtime binary not found at `{}`".format(filename)) 

31dll = cdll.LoadLibrary(str(filename)) 

32 

33WASM_I32 = c_uint8(0) 

34WASM_I64 = c_uint8(1) 

35WASM_F32 = c_uint8(2) 

36WASM_F64 = c_uint8(3) 

37WASM_ANYREF = c_uint8(128) 

38WASM_FUNCREF = c_uint8(129) 

39# WASM_V128 = c_uint8(4) 

40 

41WASMTIME_I32 = c_uint8(0) 

42WASMTIME_I64 = c_uint8(1) 

43WASMTIME_F32 = c_uint8(2) 

44WASMTIME_F64 = c_uint8(3) 

45WASMTIME_V128 = c_uint8(4) 

46WASMTIME_FUNCREF = c_uint8(5) 

47WASMTIME_EXTERNREF = c_uint8(6) 

48 

49WASM_CONST = c_uint8(0) 

50WASM_VAR = c_uint8(1) 

51 

52WASMTIME_EXTERN_FUNC = c_uint8(0) 

53WASMTIME_EXTERN_GLOBAL = c_uint8(1) 

54WASMTIME_EXTERN_TABLE = c_uint8(2) 

55WASMTIME_EXTERN_MEMORY = c_uint8(3) 

56WASMTIME_EXTERN_SHAREDMEMORY = c_uint8(4) 

57WASMTIME_EXTERN_INSTANCE = c_uint8(4) 

58WASMTIME_EXTERN_MODULE = c_uint8(5) 

59 

60WASMTIME_FUNCREF_NULL = (1 << 64) - 1 

61 

62 

63class wasm_ref_t(Structure): 

64 pass 

65 

66 

67class wasm_val_union(Union): 

68 _fields_ = [ 

69 ("i32", c_int32), 

70 ("i64", c_int64), 

71 ("f32", c_float), 

72 ("f64", c_double), 

73 ("ref", POINTER(wasm_ref_t)), 

74 ] 

75 

76 i32: int 

77 i64: int 

78 f32: float 

79 f64: float 

80 ref: "typing.Union[ctypes._Pointer[wasm_ref_t], None]" 

81 

82 

83class wasm_val_t(Structure): 

84 _fields_ = [("kind", c_uint8), ("of", wasm_val_union)] 

85 

86 kind: int 

87 of: wasm_val_union 

88 

89 

90from ._bindings import * # noqa 

91 

92 

93def to_bytes(vec: wasm_byte_vec_t) -> bytearray: 

94 ty = c_uint8 * vec.size 

95 return bytearray(ty.from_address(addressof(vec.data.contents))) 

96 

97 

98def to_str(vec: wasm_byte_vec_t) -> str: 

99 return to_bytes(vec).decode("utf-8") 

100 

101 

102def to_str_raw(ptr: "ctypes._Pointer", size: int) -> str: 

103 return string_at(ptr, size).decode("utf-8") 

104 

105 

106def str_to_name(s: str, trailing_nul: bool = False) -> wasm_byte_vec_t: 

107 if not isinstance(s, str): 

108 raise TypeError("expected a string") 

109 s_bytes = s.encode('utf8') 

110 buf = cast(create_string_buffer(s_bytes), POINTER(c_uint8)) 

111 if trailing_nul: 

112 extra = 1 

113 else: 

114 extra = 0 

115 return wasm_byte_vec_t(len(s_bytes) + extra, buf)