vm

package
v0.2.0 Latest Latest
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 Go to latest Published: Jun 8, 2023 License: BSD-3-Clause Imports: 5 Imported by: 13

Documentation

Overview

Evaluate opcodes

Opcodes from opcodes.h

Python virtual machine

Index

Constants

View Source 
const (
	PyCmp_LT = iota
	PyCmp_LE
	PyCmp_EQ
	PyCmp_NE
	PyCmp_GT
	PyCmp_GE
	PyCmp_IN
	PyCmp_NOT_IN
	PyCmp_IS
	PyCmp_IS_NOT
	PyCmp_EXC_MATCH
	PyCmp_BAD
)

Rich comparison opcodes

Variables

View Source 
var PrintExpr = func(out string) {
	_, _ = os.Stdout.WriteString(out + "\n")
}

PrintExpr controls where the output of PRINT_EXPR goes which is used in the REPL

Functions

func EvalCode 

func EvalCode(ctx py.Context, co *py.Code, globals, locals py.StringDict, args []py.Object, kws py.StringDict, defs []py.Object, kwdefs py.StringDict, closure py.Tuple) (retval py.Object, err error)

EvalCode runs a new virtual machine on a Code object.

Any parameters are expected to have been decoded into locals

Returns an Object and an error. The error will be a py.ExceptionInfo

This is the equivalent of PyEval_EvalCode with closure support

func EvalGetFuncDesc 

func EvalGetFuncDesc(fn py.Object) string

EvalGetFuncDesc returns a description of the arguments for the function object

func EvalGetFuncName 

func EvalGetFuncName(fn py.Object) string

EvalGetFuncName returns the name of the function object passed in

func RunFrame 

func RunFrame(frame *py.Frame) (res py.Object, err error)

Run the virtual machine on a Frame object

FIXME figure out how we are going to signal exceptions!

Returns an Object and an error. The error will be a py.ExceptionInfo

This is the equivalent of PyEval_EvalFrame

Types

type OpCode 

type OpCode byte

Type for OpCodes 

const (
	POP_TOP     OpCode = 1
	ROT_TWO     OpCode = 2
	ROT_THREE   OpCode = 3
	DUP_TOP     OpCode = 4
	DUP_TOP_TWO OpCode = 5
	NOP         OpCode = 9

	UNARY_POSITIVE OpCode = 10
	UNARY_NEGATIVE OpCode = 11
	UNARY_NOT      OpCode = 12

	UNARY_INVERT OpCode = 15

	BINARY_POWER OpCode = 19

	BINARY_MULTIPLY OpCode = 20

	BINARY_MODULO        OpCode = 22
	BINARY_ADD           OpCode = 23
	BINARY_SUBTRACT      OpCode = 24
	BINARY_SUBSCR        OpCode = 25
	BINARY_FLOOR_DIVIDE  OpCode = 26
	BINARY_TRUE_DIVIDE   OpCode = 27
	INPLACE_FLOOR_DIVIDE OpCode = 28
	INPLACE_TRUE_DIVIDE  OpCode = 29

	STORE_MAP        OpCode = 54
	INPLACE_ADD      OpCode = 55
	INPLACE_SUBTRACT OpCode = 56
	INPLACE_MULTIPLY OpCode = 57

	INPLACE_MODULO OpCode = 59
	STORE_SUBSCR   OpCode = 60
	DELETE_SUBSCR  OpCode = 61

	BINARY_LSHIFT    OpCode = 62
	BINARY_RSHIFT    OpCode = 63
	BINARY_AND       OpCode = 64
	BINARY_XOR       OpCode = 65
	BINARY_OR        OpCode = 66
	INPLACE_POWER    OpCode = 67
	GET_ITER         OpCode = 68
	PRINT_EXPR       OpCode = 70
	LOAD_BUILD_CLASS OpCode = 71
	YIELD_FROM       OpCode = 72

	INPLACE_LSHIFT OpCode = 75
	INPLACE_RSHIFT OpCode = 76
	INPLACE_AND    OpCode = 77
	INPLACE_XOR    OpCode = 78
	INPLACE_OR     OpCode = 79
	BREAK_LOOP     OpCode = 80
	WITH_CLEANUP   OpCode = 81

	RETURN_VALUE OpCode = 83
	IMPORT_STAR  OpCode = 84

	YIELD_VALUE OpCode = 86
	POP_BLOCK   OpCode = 87
	END_FINALLY OpCode = 88
	POP_EXCEPT  OpCode = 89

	HAVE_ARGUMENT OpCode = 90 // OpCodes from here have an argument:

	STORE_NAME      OpCode = 90 // Index in name list
	DELETE_NAME     OpCode = 91 // ""
	UNPACK_SEQUENCE OpCode = 92 // Number of sequence items
	FOR_ITER        OpCode = 93
	UNPACK_EX       OpCode = 94 // Num items before variable part + (Num items after variable part << 8)

	STORE_ATTR    OpCode = 95 // Index in name list
	DELETE_ATTR   OpCode = 96 // ""
	STORE_GLOBAL  OpCode = 97 // ""
	DELETE_GLOBAL OpCode = 98 // ""

	LOAD_CONST  OpCode = 100 // Index in const list
	LOAD_NAME   OpCode = 101 // Index in name list
	BUILD_TUPLE OpCode = 102 // Number of tuple items
	BUILD_LIST  OpCode = 103 // Number of list items
	BUILD_SET   OpCode = 104 // Number of set items
	BUILD_MAP   OpCode = 105 // Always zero for now
	LOAD_ATTR   OpCode = 106 // Index in name list
	COMPARE_OP  OpCode = 107 // Comparison operator
	IMPORT_NAME OpCode = 108 // Index in name list
	IMPORT_FROM OpCode = 109 // Index in name list

	JUMP_FORWARD         OpCode = 110 // Number of bytes to skip
	JUMP_IF_FALSE_OR_POP OpCode = 111 // Target byte offset from beginning of code
	JUMP_IF_TRUE_OR_POP  OpCode = 112 // ""
	JUMP_ABSOLUTE        OpCode = 113 // ""
	POP_JUMP_IF_FALSE    OpCode = 114 // ""
	POP_JUMP_IF_TRUE     OpCode = 115 // ""

	LOAD_GLOBAL OpCode = 116 // Index in name list

	CONTINUE_LOOP OpCode = 119 // Start of loop (absolute)
	SETUP_LOOP    OpCode = 120 // Target address (relative)
	SETUP_EXCEPT  OpCode = 121 // ""
	SETUP_FINALLY OpCode = 122 // ""

	LOAD_FAST   OpCode = 124 // Local variable number
	STORE_FAST  OpCode = 125 // Local variable number
	DELETE_FAST OpCode = 126 // Local variable number

	RAISE_VARARGS OpCode = 130 // Number of raise arguments (1, 2 or 3)
	// CALL_FUNCTION_XXX opcodes defined below depend on this definition
	CALL_FUNCTION OpCode = 131 // #args + (#kwargs<<8)
	MAKE_FUNCTION OpCode = 132 // #defaults + #kwdefaults<<8 + #annotations<<16
	BUILD_SLICE   OpCode = 133 // Number of items

	MAKE_CLOSURE OpCode = 134 // same as MAKE_FUNCTION
	LOAD_CLOSURE OpCode = 135 // Load free variable from closure
	LOAD_DEREF   OpCode = 136 // Load and dereference from closure cell
	STORE_DEREF  OpCode = 137 // Store into cell
	DELETE_DEREF OpCode = 138 // Delete closure cell

	// The next 3 opcodes must be contiguous and satisfy
	// (CALL_FUNCTION_VAR - CALL_FUNCTION) & 3 == 1
	CALL_FUNCTION_VAR    OpCode = 140 // #args + (#kwargs<<8)
	CALL_FUNCTION_KW     OpCode = 141 // #args + (#kwargs<<8)
	CALL_FUNCTION_VAR_KW OpCode = 142 // #args + (#kwargs<<8)

	SETUP_WITH OpCode = 143

	// Support for opargs more than 16 bits long
	EXTENDED_ARG OpCode = 144

	LIST_APPEND OpCode = 145
	SET_ADD     OpCode = 146
	MAP_ADD     OpCode = 147

	LOAD_CLASSDEREF OpCode = 148 // New in Python 3.4
)

func (OpCode) HAS_ARG 

func (op OpCode) HAS_ARG() bool

If op has an argument

func (OpCode) String 

func (i OpCode) String() string

type Vm 

type Vm struct {
	// contains filtered or unexported fields
}

Virtual machine state

func (*Vm) AddTraceback 

func (vm *Vm) AddTraceback(exc *py.ExceptionInfo)

Adds a traceback to the exc passed in for the current vm state

func (*Vm) Call 

func (vm *Vm) Call(argc int32, starArgs py.Object, starKwargs py.Object) error

Implements a function call - see CALL_FUNCTION for a description of how the arguments are arranged.

Optionally pass in args and kwargs

The result is put on the stack

func (*Vm) CheckException 

func (vm *Vm) CheckException()

Check for an exception (panic)

Must be called as a defer function

func (*Vm) CheckExceptionRecover 

func (vm *Vm) CheckExceptionRecover(r interface{})

Check for an exception (panic)

Should be called with the result of recover

func (*Vm) DROP 

func (vm *Vm) DROP()

func (*Vm) DROPN 

func (vm *Vm) DROPN(n int)

func (*Vm) EXTEND 

func (vm *Vm) EXTEND(items py.Tuple)

Push items to top of vm stack

func (*Vm) EXTEND_REVERSED 

func (vm *Vm) EXTEND_REVERSED(items py.Tuple)

Push items to top of vm stack in reverse order

func (*Vm) FOURTH 

func (vm *Vm) FOURTH() py.Object

func (*Vm) PEEK 

func (vm *Vm) PEEK(n int) py.Object

func (*Vm) POP 

func (vm *Vm) POP() py.Object

Pop from top of vm stack

func (*Vm) PUSH 

func (vm *Vm) PUSH(obj py.Object)

Push to top of vm stack

func (*Vm) SECOND 

func (vm *Vm) SECOND() py.Object

func (*Vm) SET_FOURTH 

func (vm *Vm) SET_FOURTH(v py.Object)

func (*Vm) SET_SECOND 

func (vm *Vm) SET_SECOND(v py.Object)

func (*Vm) SET_THIRD 

func (vm *Vm) SET_THIRD(v py.Object)

func (*Vm) SET_TOP 

func (vm *Vm) SET_TOP(v py.Object)

func (*Vm) SET_VALUE 

func (vm *Vm) SET_VALUE(n int, v py.Object)

func (*Vm) STACK_LEVEL 

func (vm *Vm) STACK_LEVEL() int

Stack operations

func (*Vm) SetException 

func (vm *Vm) SetException(exception py.Object)

Set an exception in the VM

The exception must be a valid exception instance (eg as returned by py.MakeException)

It sets vm.curexc.* and sets vm.why to whyException

func (*Vm) THIRD 

func (vm *Vm) THIRD() py.Object

func (*Vm) TOP 

func (vm *Vm) TOP() py.Object

func (*Vm) UnwindBlock 

func (vm *Vm) UnwindBlock(frame *py.Frame, block *py.TryBlock)

Unwinds the stack for a block

func (*Vm) UnwindExceptHandler 

func (vm *Vm) UnwindExceptHandler(frame *py.Frame, block *py.TryBlock)

Unwinds the stack in the presence of an exception

Source Files

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