fonttools/Lib/fontTools/ttLib/tables/ttProgram.py

"""ttLib.tables.ttProgram.py -- Assembler/disassembler for TrueType bytecode programs."""
from __future__ import annotations

from fontTools.misc.textTools import num2binary, binary2num, readHex, strjoin
import array
from io import StringIO
from typing import List
import re
import logging


log = logging.getLogger(__name__)

# first, the list of instructions that eat bytes or words from the instruction stream

streamInstructions = [
    #
    # 	opcode  mnemonic     argBits    descriptive name      pops pushes         eats from instruction stream          pushes
    #
    (
        0x40,
        "NPUSHB",
        0,
        "PushNBytes",
        0,
        -1,
    ),  #                      n, b1, b2,...bn      b1,b2...bn
    (
        0x41,
        "NPUSHW",
        0,
        "PushNWords",
        0,
        -1,
    ),  #                       n, w1, w2,...w      w1,w2...wn
    (
        0xB0,
        "PUSHB",
        3,
        "PushBytes",
        0,
        -1,
    ),  #                          b0, b1,..bn  b0, b1, ...,bn
    (
        0xB8,
        "PUSHW",
        3,
        "PushWords",
        0,
        -1,
    ),  #                           w0,w1,..wn   w0 ,w1, ...wn
]


# next,	the list of "normal" instructions

instructions = [
    #
    # ,	opcode  mnemonic     argBits    descriptive name      pops pushes         eats from instruction stream          pushes
    #
    (
        0x7F,
        "AA",
        0,
        "AdjustAngle",
        1,
        0,
    ),  #                                    p               -
    (
        0x64,
        "ABS",
        0,
        "Absolute",
        1,
        1,
    ),  #                                    n             |n|
    (
        0x60,
        "ADD",
        0,
        "Add",
        2,
        1,
    ),  #                               n2, n1       (n1 + n2)
    (
        0x27,
        "ALIGNPTS",
        0,
        "AlignPts",
        2,
        0,
    ),  #                               p2, p1               -
    (
        0x3C,
        "ALIGNRP",
        0,
        "AlignRelativePt",
        -1,
        0,
    ),  #             p1, p2, ... , ploopvalue               -
    (
        0x5A,
        "AND",
        0,
        "LogicalAnd",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x2B,
        "CALL",
        0,
        "CallFunction",
        1,
        0,
    ),  #                                    f               -
    (
        0x67,
        "CEILING",
        0,
        "Ceiling",
        1,
        1,
    ),  #                                    n         ceil(n)
    (
        0x25,
        "CINDEX",
        0,
        "CopyXToTopStack",
        1,
        1,
    ),  #                                    k              ek
    (
        0x22,
        "CLEAR",
        0,
        "ClearStack",
        -1,
        0,
    ),  #               all items on the stack               -
    (
        0x4F,
        "DEBUG",
        0,
        "DebugCall",
        1,
        0,
    ),  #                                    n               -
    (
        0x73,
        "DELTAC1",
        0,
        "DeltaExceptionC1",
        -1,
        0,
    ),  #    argn, cn, argn-1,cn-1, , arg1, c1               -
    (
        0x74,
        "DELTAC2",
        0,
        "DeltaExceptionC2",
        -1,
        0,
    ),  #    argn, cn, argn-1,cn-1, , arg1, c1               -
    (
        0x75,
        "DELTAC3",
        0,
        "DeltaExceptionC3",
        -1,
        0,
    ),  #    argn, cn, argn-1,cn-1, , arg1, c1               -
    (
        0x5D,
        "DELTAP1",
        0,
        "DeltaExceptionP1",
        -1,
        0,
    ),  #   argn, pn, argn-1, pn-1, , arg1, p1               -
    (
        0x71,
        "DELTAP2",
        0,
        "DeltaExceptionP2",
        -1,
        0,
    ),  #   argn, pn, argn-1, pn-1, , arg1, p1               -
    (
        0x72,
        "DELTAP3",
        0,
        "DeltaExceptionP3",
        -1,
        0,
    ),  #   argn, pn, argn-1, pn-1, , arg1, p1               -
    (
        0x24,
        "DEPTH",
        0,
        "GetDepthStack",
        0,
        1,
    ),  #                                    -               n
    (
        0x62,
        "DIV",
        0,
        "Divide",
        2,
        1,
    ),  #                               n2, n1   (n1 * 64)/ n2
    (
        0x20,
        "DUP",
        0,
        "DuplicateTopStack",
        1,
        2,
    ),  #                                    e            e, e
    (
        0x59,
        "EIF",
        0,
        "EndIf",
        0,
        0,
    ),  #                                    -               -
    (
        0x1B,
        "ELSE",
        0,
        "Else",
        0,
        0,
    ),  #                                    -               -
    (
        0x2D,
        "ENDF",
        0,
        "EndFunctionDefinition",
        0,
        0,
    ),  #                                    -               -
    (
        0x54,
        "EQ",
        0,
        "Equal",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x57,
        "EVEN",
        0,
        "Even",
        1,
        1,
    ),  #                                    e               b
    (
        0x2C,
        "FDEF",
        0,
        "FunctionDefinition",
        1,
        0,
    ),  #                                    f               -
    (
        0x4E,
        "FLIPOFF",
        0,
        "SetAutoFlipOff",
        0,
        0,
    ),  #                                    -               -
    (
        0x4D,
        "FLIPON",
        0,
        "SetAutoFlipOn",
        0,
        0,
    ),  #                                    -               -
    (
        0x80,
        "FLIPPT",
        0,
        "FlipPoint",
        -1,
        0,
    ),  #              p1, p2, ..., ploopvalue               -
    (
        0x82,
        "FLIPRGOFF",
        0,
        "FlipRangeOff",
        2,
        0,
    ),  #                                 h, l               -
    (
        0x81,
        "FLIPRGON",
        0,
        "FlipRangeOn",
        2,
        0,
    ),  #                                 h, l               -
    (
        0x66,
        "FLOOR",
        0,
        "Floor",
        1,
        1,
    ),  #                                    n        floor(n)
    (
        0x46,
        "GC",
        1,
        "GetCoordOnPVector",
        1,
        1,
    ),  #                                    p               c
    (
        0x88,
        "GETINFO",
        0,
        "GetInfo",
        1,
        1,
    ),  #                             selector          result
    (
        0x91,
        "GETVARIATION",
        0,
        "GetVariation",
        0,
        -1,
    ),  #                                    -        a1,..,an
    (
        0x0D,
        "GFV",
        0,
        "GetFVector",
        0,
        2,
    ),  #                                    -          px, py
    (
        0x0C,
        "GPV",
        0,
        "GetPVector",
        0,
        2,
    ),  #                                    -          px, py
    (
        0x52,
        "GT",
        0,
        "GreaterThan",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x53,
        "GTEQ",
        0,
        "GreaterThanOrEqual",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x89,
        "IDEF",
        0,
        "InstructionDefinition",
        1,
        0,
    ),  #                                    f               -
    (0x58, "IF", 0, "If", 1, 0),  #                                    e               -
    (
        0x8E,
        "INSTCTRL",
        0,
        "SetInstrExecControl",
        2,
        0,
    ),  #                                 s, v               -
    (
        0x39,
        "IP",
        0,
        "InterpolatePts",
        -1,
        0,
    ),  #             p1, p2, ... , ploopvalue               -
    (
        0x0F,
        "ISECT",
        0,
        "MovePtToIntersect",
        5,
        0,
    ),  #                    a1, a0, b1, b0, p               -
    (
        0x30,
        "IUP",
        1,
        "InterpolateUntPts",
        0,
        0,
    ),  #                                    -               -
    (
        0x1C,
        "JMPR",
        0,
        "Jump",
        1,
        0,
    ),  #                               offset               -
    (
        0x79,
        "JROF",
        0,
        "JumpRelativeOnFalse",
        2,
        0,
    ),  #                            e, offset               -
    (
        0x78,
        "JROT",
        0,
        "JumpRelativeOnTrue",
        2,
        0,
    ),  #                            e, offset               -
    (
        0x2A,
        "LOOPCALL",
        0,
        "LoopAndCallFunction",
        2,
        0,
    ),  #                             f, count               -
    (
        0x50,
        "LT",
        0,
        "LessThan",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x51,
        "LTEQ",
        0,
        "LessThenOrEqual",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x8B,
        "MAX",
        0,
        "Maximum",
        2,
        1,
    ),  #                               e2, e1     max(e1, e2)
    (
        0x49,
        "MD",
        1,
        "MeasureDistance",
        2,
        1,
    ),  #                                p2,p1               d
    (
        0x2E,
        "MDAP",
        1,
        "MoveDirectAbsPt",
        1,
        0,
    ),  #                                    p               -
    (
        0xC0,
        "MDRP",
        5,
        "MoveDirectRelPt",
        1,
        0,
    ),  #                                    p               -
    (
        0x3E,
        "MIAP",
        1,
        "MoveIndirectAbsPt",
        2,
        0,
    ),  #                                 n, p               -
    (
        0x8C,
        "MIN",
        0,
        "Minimum",
        2,
        1,
    ),  #                               e2, e1     min(e1, e2)
    (
        0x26,
        "MINDEX",
        0,
        "MoveXToTopStack",
        1,
        1,
    ),  #                                    k              ek
    (
        0xE0,
        "MIRP",
        5,
        "MoveIndirectRelPt",
        2,
        0,
    ),  #                                 n, p               -
    (
        0x4B,
        "MPPEM",
        0,
        "MeasurePixelPerEm",
        0,
        1,
    ),  #                                    -            ppem
    (
        0x4C,
        "MPS",
        0,
        "MeasurePointSize",
        0,
        1,
    ),  #                                    -       pointSize
    (
        0x3A,
        "MSIRP",
        1,
        "MoveStackIndirRelPt",
        2,
        0,
    ),  #                                 d, p               -
    (
        0x63,
        "MUL",
        0,
        "Multiply",
        2,
        1,
    ),  #                               n2, n1    (n1 * n2)/64
    (
        0x65,
        "NEG",
        0,
        "Negate",
        1,
        1,
    ),  #                                    n              -n
    (
        0x55,
        "NEQ",
        0,
        "NotEqual",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x5C,
        "NOT",
        0,
        "LogicalNot",
        1,
        1,
    ),  #                                    e       ( not e )
    (
        0x6C,
        "NROUND",
        2,
        "NoRound",
        1,
        1,
    ),  #                                   n1              n2
    (
        0x56,
        "ODD",
        0,
        "Odd",
        1,
        1,
    ),  #                                    e               b
    (
        0x5B,
        "OR",
        0,
        "LogicalOr",
        2,
        1,
    ),  #                               e2, e1               b
    (
        0x21,
        "POP",
        0,
        "PopTopStack",
        1,
        0,
    ),  #                                    e               -
    (
        0x45,
        "RCVT",
        0,
        "ReadCVT",
        1,
        1,
    ),  #                             location           value
    (
        0x7D,
        "RDTG",
        0,
        "RoundDownToGrid",
        0,
        0,
    ),  #                                    -               -
    (
        0x7A,
        "ROFF",
        0,
        "RoundOff",
        0,
        0,
    ),  #                                    -               -
    (
        0x8A,
        "ROLL",
        0,
        "RollTopThreeStack",
        3,
        3,
    ),  #                                a,b,c           b,a,c
    (
        0x68,
        "ROUND",
        2,
        "Round",
        1,
        1,
    ),  #                                   n1              n2
    (
        0x43,
        "RS",
        0,
        "ReadStore",
        1,
        1,
    ),  #                                    n               v
    (
        0x3D,
        "RTDG",
        0,
        "RoundToDoubleGrid",
        0,
        0,
    ),  #                                    -               -
    (
        0x18,
        "RTG",
        0,
        "RoundToGrid",
        0,
        0,
    ),  #                                    -               -
    (
        0x19,
        "RTHG",
        0,
        "RoundToHalfGrid",
        0,
        0,
    ),  #                                    -               -
    (
        0x7C,
        "RUTG",
        0,
        "RoundUpToGrid",
        0,
        0,
    ),  #                                    -               -
    (
        0x77,
        "S45ROUND",
        0,
        "SuperRound45Degrees",
        1,
        0,
    ),  #                                    n               -
    (
        0x7E,
        "SANGW",
        0,
        "SetAngleWeight",
        1,
        0,
    ),  #                               weight               -
    (
        0x85,
        "SCANCTRL",
        0,
        "ScanConversionControl",
        1,
        0,
    ),  #                                    n               -
    (
        0x8D,
        "SCANTYPE",
        0,
        "ScanType",
        1,
        0,
    ),  #                                    n               -
    (
        0x48,
        "SCFS",
        0,
        "SetCoordFromStackFP",
        2,
        0,
    ),  #                                 c, p               -
    (
        0x1D,
        "SCVTCI",
        0,
        "SetCVTCutIn",
        1,
        0,
    ),  #                                    n               -
    (
        0x5E,
        "SDB",
        0,
        "SetDeltaBaseInGState",
        1,
        0,
    ),  #                                    n               -
    (
        0x86,
        "SDPVTL",
        1,
        "SetDualPVectorToLine",
        2,
        0,
    ),  #                               p2, p1               -
    (
        0x5F,
        "SDS",
        0,
        "SetDeltaShiftInGState",
        1,
        0,
    ),  #                                    n               -
    (
        0x0B,
        "SFVFS",
        0,
        "SetFVectorFromStack",
        2,
        0,
    ),  #                                 y, x               -
    (
        0x04,
        "SFVTCA",
        1,
        "SetFVectorToAxis",
        0,
        0,
    ),  #                                    -               -
    (
        0x08,
        "SFVTL",
        1,
        "SetFVectorToLine",
        2,
        0,
    ),  #                               p2, p1               -
    (
        0x0E,
        "SFVTPV",
        0,
        "SetFVectorToPVector",
        0,
        0,
    ),  #                                    -               -
    (
        0x34,
        "SHC",
        1,
        "ShiftContourByLastPt",
        1,
        0,
    ),  #                                    c               -
    (
        0x32,
        "SHP",
        1,
        "ShiftPointByLastPoint",
        -1,
        0,
    ),  #              p1, p2, ..., ploopvalue               -
    (
        0x38,
        "SHPIX",
        0,
        "ShiftZoneByPixel",
        -1,
        0,
    ),  #           d, p1, p2, ..., ploopvalue               -
    (
        0x36,
        "SHZ",
        1,
        "ShiftZoneByLastPoint",
        1,
        0,
    ),  #                                    e               -
    (
        0x17,
        "SLOOP",
        0,
        "SetLoopVariable",
        1,
        0,
    ),  #                                    n               -
    (
        0x1A,
        "SMD",
        0,
        "SetMinimumDistance",
        1,
        0,
    ),  #                             distance               -
    (
        0x0A,
        "SPVFS",
        0,
        "SetPVectorFromStack",
        2,
        0,
    ),  #                                 y, x               -
    (
        0x02,
        "SPVTCA",
        1,
        "SetPVectorToAxis",
        0,
        0,
    ),  #                                    -               -
    (
        0x06,
        "SPVTL",
        1,
        "SetPVectorToLine",
        2,
        0,
    ),  #                               p2, p1               -
    (
        0x76,
        "SROUND",
        0,
        "SuperRound",
        1,
        0,
    ),  #                                    n               -
    (
        0x10,
        "SRP0",
        0,
        "SetRefPoint0",
        1,
        0,
    ),  #                                    p               -
    (
        0x11,
        "SRP1",
        0,
        "SetRefPoint1",
        1,
        0,
    ),  #                                    p               -
    (
        0x12,
        "SRP2",
        0,
        "SetRefPoint2",
        1,
        0,
    ),  #                                    p               -
    (
        0x1F,
        "SSW",
        0,
        "SetSingleWidth",
        1,
        0,
    ),  #                                    n               -
    (
        0x1E,
        "SSWCI",
        0,
        "SetSingleWidthCutIn",
        1,
        0,
    ),  #                                    n               -
    (
        0x61,
        "SUB",
        0,
        "Subtract",
        2,
        1,
    ),  #                               n2, n1       (n1 - n2)
    (
        0x00,
        "SVTCA",
        1,
        "SetFPVectorToAxis",
        0,
        0,
    ),  #                                    -               -
    (
        0x23,
        "SWAP",
        0,
        "SwapTopStack",
        2,
        2,
    ),  #                               e2, e1          e1, e2
    (
        0x13,
        "SZP0",
        0,
        "SetZonePointer0",
        1,
        0,
    ),  #                                    n               -
    (
        0x14,
        "SZP1",
        0,
        "SetZonePointer1",
        1,
        0,
    ),  #                                    n               -
    (
        0x15,
        "SZP2",
        0,
        "SetZonePointer2",
        1,
        0,
    ),  #                                    n               -
    (
        0x16,
        "SZPS",
        0,
        "SetZonePointerS",
        1,
        0,
    ),  #                                    n               -
    (
        0x29,
        "UTP",
        0,
        "UnTouchPt",
        1,
        0,
    ),  #                                    p               -
    (
        0x70,
        "WCVTF",
        0,
        "WriteCVTInFUnits",
        2,
        0,
    ),  #                                 n, l               -
    (
        0x44,
        "WCVTP",
        0,
        "WriteCVTInPixels",
        2,
        0,
    ),  #                                 v, l               -
    (
        0x42,
        "WS",
        0,
        "WriteStore",
        2,
        0,
    ),  #                                 v, l               -
]


def bitRepr(value, bits):
    s = ""
    for i in range(bits):
        s = "01"[value & 0x1] + s
        value = value >> 1
    return s


_mnemonicPat = re.compile(r"[A-Z][A-Z0-9]*$")


def _makeDict(instructionList):
    opcodeDict = {}
    mnemonicDict = {}
    for op, mnemonic, argBits, name, pops, pushes in instructionList:
        assert _mnemonicPat.match(mnemonic)
        mnemonicDict[mnemonic] = op, argBits, name
        if argBits:
            argoffset = op
            for i in range(1 << argBits):
                opcodeDict[op + i] = mnemonic, argBits, argoffset, name
        else:
            opcodeDict[op] = mnemonic, 0, 0, name
    return opcodeDict, mnemonicDict


streamOpcodeDict, streamMnemonicDict = _makeDict(streamInstructions)
opcodeDict, mnemonicDict = _makeDict(instructions)


class tt_instructions_error(Exception):
    def __init__(self, error):
        self.error = error

    def __str__(self):
        return "TT instructions error: %s" % repr(self.error)


_comment = r"/\*.*?\*/"
_instruction = r"([A-Z][A-Z0-9]*)\s*\[(.*?)\]"
_number = r"-?[0-9]+"
_token = "(%s)|(%s)|(%s)" % (_instruction, _number, _comment)

_tokenRE = re.compile(_token)
_whiteRE = re.compile(r"\s*")

_pushCountPat = re.compile(r"[A-Z][A-Z0-9]*\s*\[.*?\]\s*/\* ([0-9]+).*?\*/")

_indentRE = re.compile(r"^FDEF|IF|ELSE\[ \]\t.+")
_unindentRE = re.compile(r"^ELSE|ENDF|EIF\[ \]\t.+")


def _skipWhite(data, pos):
    m = _whiteRE.match(data, pos)
    newPos = m.regs[0][1]
    assert newPos >= pos
    return newPos


class Program(object):
    def __init__(self) -> None:
        pass

    def fromBytecode(self, bytecode: bytes) -> None:
        self.bytecode = array.array("B", bytecode)
        if hasattr(self, "assembly"):
            del self.assembly

    def fromAssembly(self, assembly: List[str] | str) -> None:
        if isinstance(assembly, list):
            self.assembly = assembly
        elif isinstance(assembly, str):
            self.assembly = assembly.splitlines()
        else:
            raise TypeError(f"expected str or List[str], got {type(assembly).__name__}")
        if hasattr(self, "bytecode"):
            del self.bytecode

    def getBytecode(self) -> bytes:
        if not hasattr(self, "bytecode"):
            self._assemble()
        return self.bytecode.tobytes()

    def getAssembly(self, preserve=True) -> List[str]:
        if not hasattr(self, "assembly"):
            self._disassemble(preserve=preserve)
        return self.assembly

    def toXML(self, writer, ttFont) -> None:
        if (
            not hasattr(ttFont, "disassembleInstructions")
            or ttFont.disassembleInstructions
        ):
            try:
                assembly = self.getAssembly()
            except:
                import traceback

                tmp = StringIO()
                traceback.print_exc(file=tmp)
                msg = "An exception occurred during the decompilation of glyph program:\n\n"
                msg += tmp.getvalue()
                log.error(msg)
                writer.begintag("bytecode")
                writer.newline()
                writer.comment(msg.strip())
                writer.newline()
                writer.dumphex(self.getBytecode())
                writer.endtag("bytecode")
                writer.newline()
            else:
                if not assembly:
                    return
                writer.begintag("assembly")
                writer.newline()
                i = 0
                indent = 0
                nInstr = len(assembly)
                while i < nInstr:
                    instr = assembly[i]
                    if _unindentRE.match(instr):
                        indent -= 1
                    writer.write(writer.indentwhite * indent)
                    writer.write(instr)
                    writer.newline()
                    m = _pushCountPat.match(instr)
                    i = i + 1
                    if m:
                        nValues = int(m.group(1))
                        line: List[str] = []
                        j = 0
                        for j in range(nValues):
                            if j and not (j % 25):
                                writer.write(writer.indentwhite * indent)
                                writer.write(" ".join(line))
                                writer.newline()
                                line = []
                            line.append(assembly[i + j])
                        writer.write(writer.indentwhite * indent)
                        writer.write(" ".join(line))
                        writer.newline()
                        i = i + j + 1
                    if _indentRE.match(instr):
                        indent += 1
                writer.endtag("assembly")
                writer.newline()
        else:
            bytecode = self.getBytecode()
            if not bytecode:
                return
            writer.begintag("bytecode")
            writer.newline()
            writer.dumphex(bytecode)
            writer.endtag("bytecode")
            writer.newline()

    def fromXML(self, name, attrs, content, ttFont) -> None:
        if name == "assembly":
            self.fromAssembly(strjoin(content))
            self._assemble()
            del self.assembly
        else:
            assert name == "bytecode"
            self.fromBytecode(readHex(content))

    def _assemble(self) -> None:
        assembly = " ".join(getattr(self, "assembly", []))
        bytecode: List[int] = []
        push = bytecode.append
        lenAssembly = len(assembly)
        pos = _skipWhite(assembly, 0)
        while pos < lenAssembly:
            m = _tokenRE.match(assembly, pos)
            if m is None:
                raise tt_instructions_error(
                    "Syntax error in TT program (%s)" % assembly[pos - 5 : pos + 15]
                )
            dummy, mnemonic, arg, number, comment = m.groups()
            pos = m.regs[0][1]
            if comment:
                pos = _skipWhite(assembly, pos)
                continue

            arg = arg.strip()
            if mnemonic.startswith("INSTR"):
                # Unknown instruction
                op = int(mnemonic[5:])
                push(op)
            elif mnemonic not in ("PUSH", "NPUSHB", "NPUSHW", "PUSHB", "PUSHW"):
                op, argBits, name = mnemonicDict[mnemonic]
                if len(arg) != argBits:
                    raise tt_instructions_error(
                        "Incorrect number of argument bits (%s[%s])" % (mnemonic, arg)
                    )
                if arg:
                    arg = binary2num(arg)
                    push(op + arg)
                else:
                    push(op)
            else:
                args = []
                pos = _skipWhite(assembly, pos)
                while pos < lenAssembly:
                    m = _tokenRE.match(assembly, pos)
                    if m is None:
                        raise tt_instructions_error(
                            "Syntax error in TT program (%s)" % assembly[pos : pos + 15]
                        )
                    dummy, _mnemonic, arg, number, comment = m.groups()
                    if number is None and comment is None:
                        break
                    pos = m.regs[0][1]
                    pos = _skipWhite(assembly, pos)
                    if comment is not None:
                        continue
                    args.append(int(number))
                nArgs = len(args)
                if mnemonic == "PUSH":
                    # Automatically choose the most compact representation
                    nWords = 0
                    while nArgs:
                        while (
                            nWords < nArgs
                            and nWords < 255
                            and not (0 <= args[nWords] <= 255)
                        ):
                            nWords += 1
                        nBytes = 0
                        while (
                            nWords + nBytes < nArgs
                            and nBytes < 255
                            and 0 <= args[nWords + nBytes] <= 255
                        ):
                            nBytes += 1
                        if (
                            nBytes < 2
                            and nWords + nBytes < 255
                            and nWords + nBytes != nArgs
                        ):
                            # Will write bytes as words
                            nWords += nBytes
                            continue

                        # Write words
                        if nWords:
                            if nWords <= 8:
                                op, argBits, name = streamMnemonicDict["PUSHW"]
                                op = op + nWords - 1
                                push(op)
                            else:
                                op, argBits, name = streamMnemonicDict["NPUSHW"]
                                push(op)
                                push(nWords)
                            for value in args[:nWords]:
                                assert -32768 <= value < 32768, (
                                    "PUSH value out of range %d" % value
                                )
                                push((value >> 8) & 0xFF)
                                push(value & 0xFF)

                        # Write bytes
                        if nBytes:
                            pass
                            if nBytes <= 8:
                                op, argBits, name = streamMnemonicDict["PUSHB"]
                                op = op + nBytes - 1
                                push(op)
                            else:
                                op, argBits, name = streamMnemonicDict["NPUSHB"]
                                push(op)
                                push(nBytes)
                            for value in args[nWords : nWords + nBytes]:
                                push(value)

                        nTotal = nWords + nBytes
                        args = args[nTotal:]
                        nArgs -= nTotal
                        nWords = 0
                else:
                    # Write exactly what we've been asked to
                    words = mnemonic[-1] == "W"
                    op, argBits, name = streamMnemonicDict[mnemonic]
                    if mnemonic[0] != "N":
                        assert nArgs <= 8, nArgs
                        op = op + nArgs - 1
                        push(op)
                    else:
                        assert nArgs < 256
                        push(op)
                        push(nArgs)
                    if words:
                        for value in args:
                            assert -32768 <= value < 32768, (
                                "PUSHW value out of range %d" % value
                            )
                            push((value >> 8) & 0xFF)
                            push(value & 0xFF)
                    else:
                        for value in args:
                            assert 0 <= value < 256, (
                                "PUSHB value out of range %d" % value
                            )
                            push(value)

            pos = _skipWhite(assembly, pos)

        if bytecode:
            assert max(bytecode) < 256 and min(bytecode) >= 0
        self.bytecode = array.array("B", bytecode)

    def _disassemble(self, preserve=False) -> None:
        assembly = []
        i = 0
        bytecode = getattr(self, "bytecode", [])
        numBytecode = len(bytecode)
        while i < numBytecode:
            op = bytecode[i]
            try:
                mnemonic, argBits, argoffset, name = opcodeDict[op]
            except KeyError:
                if op in streamOpcodeDict:
                    values = []

                    # Merge consecutive PUSH operations
                    while bytecode[i] in streamOpcodeDict:
                        op = bytecode[i]
                        mnemonic, argBits, argoffset, name = streamOpcodeDict[op]
                        words = mnemonic[-1] == "W"
                        if argBits:
                            nValues = op - argoffset + 1
                        else:
                            i = i + 1
                            nValues = bytecode[i]
                        i = i + 1
                        assert nValues > 0
                        if not words:
                            for j in range(nValues):
                                value = bytecode[i]
                                values.append(repr(value))
                                i = i + 1
                        else:
                            for j in range(nValues):
                                # cast to signed int16
                                value = (bytecode[i] << 8) | bytecode[i + 1]
                                if value >= 0x8000:
                                    value = value - 0x10000
                                values.append(repr(value))
                                i = i + 2
                        if preserve:
                            break

                    if not preserve:
                        mnemonic = "PUSH"
                    nValues = len(values)
                    if nValues == 1:
                        assembly.append("%s[ ]	/* 1 value pushed */" % mnemonic)
                    else:
                        assembly.append(
                            "%s[ ]	/* %s values pushed */" % (mnemonic, nValues)
                        )
                    assembly.extend(values)
                else:
                    assembly.append("INSTR%d[ ]" % op)
                    i = i + 1
            else:
                if argBits:
                    assembly.append(
                        mnemonic
                        + "[%s]	/* %s */" % (num2binary(op - argoffset, argBits), name)
                    )
                else:
                    assembly.append(mnemonic + "[ ]	/* %s */" % name)
                i = i + 1
        self.assembly = assembly

    def __bool__(self) -> bool:
        """
        >>> p = Program()
        >>> bool(p)
        False
        >>> bc = array.array("B", [0])
        >>> p.fromBytecode(bc)
        >>> bool(p)
        True
        >>> p.bytecode.pop()
        0
        >>> bool(p)
        False

        >>> p = Program()
        >>> asm = ['SVTCA[0]']
        >>> p.fromAssembly(asm)
        >>> bool(p)
        True
        >>> p.assembly.pop()
        'SVTCA[0]'
        >>> bool(p)
        False
        """
        return (hasattr(self, "assembly") and len(self.assembly) > 0) or (
            hasattr(self, "bytecode") and len(self.bytecode) > 0
        )

    __nonzero__ = __bool__

    def __eq__(self, other) -> bool:
        if type(self) != type(other):
            return NotImplemented
        return self.__dict__ == other.__dict__

    def __ne__(self, other) -> bool:
        result = self.__eq__(other)
        return result if result is NotImplemented else not result


def _test():
    """
    >>> _test()
    True
    """

    bc = b"""@;:9876543210/.-,+*)(\'&%$#"! \037\036\035\034\033\032\031\030\027\026\025\024\023\022\021\020\017\016\015\014\013\012\011\010\007\006\005\004\003\002\001\000,\001\260\030CXEj\260\031C`\260F#D#\020 \260FN\360M/\260\000\022\033!#\0213Y-,\001\260\030CX\260\005+\260\000\023K\260\024PX\261\000@8Y\260\006+\033!#\0213Y-,\001\260\030CXN\260\003%\020\362!\260\000\022M\033 E\260\004%\260\004%#Jad\260(RX!#\020\326\033\260\003%\020\362!\260\000\022YY-,\260\032CX!!\033\260\002%\260\002%I\260\003%\260\003%Ja d\260\020PX!!!\033\260\003%\260\003%I\260\000PX\260\000PX\270\377\3428!\033\260\0208!Y\033\260\000RX\260\0368!\033\270\377\3608!YYYY-,\001\260\030CX\260\005+\260\000\023K\260\024PX\271\000\000\377\3008Y\260\006+\033!#\0213Y-,N\001\212\020\261F\031CD\260\000\024\261\000F\342\260\000\025\271\000\000\377\3608\000\260\000<\260(+\260\002%\020\260\000<-,\001\030\260\000/\260\001\024\362\260\001\023\260\001\025M\260\000\022-,\001\260\030CX\260\005+\260\000\023\271\000\000\377\3408\260\006+\033!#\0213Y-,\001\260\030CXEdj#Edi\260\031Cd``\260F#D#\020 \260F\360/\260\000\022\033!! \212 \212RX\0213\033!!YY-,\001\261\013\012C#Ce\012-,\000\261\012\013C#C\013-,\000\260F#p\261\001F>\001\260F#p\261\002FE:\261\002\000\010\015-,\260\022+\260\002%E\260\002%Ej\260@\213`\260\002%#D!!!-,\260\023+\260\002%E\260\002%Ej\270\377\300\214`\260\002%#D!!!-,\260\000\260\022+!!!-,\260\000\260\023+!!!-,\001\260\006C\260\007Ce\012-, i\260@a\260\000\213 \261,\300\212\214\270\020\000b`+\014d#da\\X\260\003aY-,\261\000\003%EhT\260\034KPZX\260\003%E\260\003%E`h \260\004%#D\260\004%#D\033\260\003% Eh \212#D\260\003%Eh`\260\003%#DY-,\260\003% Eh \212#D\260\003%Edhe`\260\004%\260\001`#D-,\260\011CX\207!\300\033\260\022CX\207E\260\021+\260G#D\260Gz\344\033\003\212E\030i \260G#D\212\212\207 \260\240QX\260\021+\260G#D\260Gz\344\033!\260Gz\344YYY\030-, \212E#Eh`D-,EjB-,\001\030/-,\001\260\030CX\260\004%\260\004%Id#Edi\260@\213a \260\200bj\260\002%\260\002%a\214\260\031C`\260F#D!\212\020\260F\366!\033!!!!Y-,\001\260\030CX\260\002%E\260\002%Ed`j\260\003%Eja \260\004%Ej \212\213e\260\004%#D\214\260\003%#D!!\033 EjD EjDY-,\001 E\260\000U\260\030CZXEh#Ei\260@\213a \260\200bj \212#a \260\003%\213e\260\004%#D\214\260\003%#D!!\033!!\260\031+Y-,\001\212\212Ed#EdadB-,\260\004%\260\004%\260\031+\260\030CX\260\004%\260\004%\260\003%\260\033+\001\260\002%C\260@T\260\002%C\260\000TZX\260\003% E\260@aDY\260\002%C\260\000T\260\002%C\260@TZX\260\004% E\260@`DYY!!!!-,\001KRXC\260\002%E#aD\033!!Y-,\001KRXC\260\002%E#`D\033!!Y-,KRXED\033!!Y-,\001 \260\003%#I\260@`\260 c \260\000RX#\260\002%8#\260\002%e8\000\212c8\033!!!!!Y\001-,KPXED\033!!Y-,\001\260\005%\020# \212\365\000\260\001`#\355\354-,\001\260\005%\020# \212\365\000\260\001a#\355\354-,\001\260\006%\020\365\000\355\354-,F#F`\212\212F# F\212`\212a\270\377\200b# \020#\212\261KK\212pE` \260\000PX\260\001a\270\377\272\213\033\260F\214Y\260\020`h\001:-, E\260\003%FRX\260\002%F ha\260\003%\260\003%?#!8\033!\021Y-, E\260\003%FPX\260\002%F ha\260\003%\260\003%?#!8\033!\021Y-,\000\260\007C\260\006C\013-,\212\020\354-,\260\014CX!\033 F\260\000RX\270\377\3608\033\260\0208YY-, \260\000UX\270\020\000c\260\003%Ed\260\003%Eda\260\000SX\260\002\033\260@a\260\003Y%EiSXED\033!!Y\033!\260\002%E\260\002%Ead\260(QXED\033!!YY-,!!\014d#d\213\270@\000b-,!\260\200QX\014d#d\213\270 \000b\033\262\000@/+Y\260\002`-,!\260\300QX\014d#d\213\270\025Ub\033\262\000\200/+Y\260\002`-,\014d#d\213\270@\000b`#!-,KSX\260\004%\260\004%Id#Edi\260@\213a \260\200bj\260\002%\260\002%a\214\260F#D!\212\020\260F\366!\033!\212\021#\022 9/Y-,\260\002%\260\002%Id\260\300TX\270\377\3708\260\0108\033!!Y-,\260\023CX\003\033\002Y-,\260\023CX\002\033\003Y-,\260\012+#\020 <\260\027+-,\260\002%\270\377\3608\260(+\212\020# \320#\260\020+\260\005CX\300\033<Y \020\021\260\000\022\001-,KS#KQZX8\033!!Y-,\001\260\002%\020\320#\311\001\260\001\023\260\000\024\020\260\001<\260\001\026-,\001\260\000\023\260\001\260\003%I\260\003\0278\260\001\023-,KS#KQZX E\212`D\033!!Y-, 9/-"""

    p = Program()
    p.fromBytecode(bc)
    asm = p.getAssembly(preserve=True)
    p.fromAssembly(asm)
    print(bc == p.getBytecode())


if __name__ == "__main__":
    import sys
    import doctest

    sys.exit(doctest.testmod().failed)