-- lips.lua local assembler = { _DESCRIPTION = 'Assembles MIPS assembly files for the R4300i CPU.', _URL = 'https://github.com/notwa/lips/', _LICENSE = [[ Copyright (C) 2015 Connor Olding This program is licensed under the terms of the MIT License, and is distributed without any warranty. You should have received a copy of the license along with this program; see the file LICENSE. ]], } local byte = string.byte local char = string.char local find = string.find local format = string.format local floor = math.floor local insert = table.insert local Class = function(inherit) local class = {} local mt_obj = {__index = class} local mt_class = { __call = function(self, ...) local obj = setmetatable({}, mt_obj) obj:init(...) return obj end, __index = inherit, } return setmetatable(class, mt_class) end local function bitrange(x, lower, upper) return floor(x/2^lower) % 2^(upper - lower + 1) end local function readfile(fn) local f = io.open(fn, 'r') if not f then error('could not open assembly file for reading: '..tostring(fn), 2) end local asm = f:read('*a') f:close() return asm end local registers = { [0]= 'R0', 'AT', 'V0', 'V1', 'A0', 'A1', 'A2', 'A3', 'T0', 'T1', 'T2', 'T3', 'T4', 'T5', 'T6', 'T7', 'S0', 'S1', 'S2', 'S3', 'S4', 'S5', 'S6', 'S7', 'T8', 'T9', 'K0', 'K1', 'GP', 'SP', 'FP', 'RA', } local sys_registers = { [0]= "INDEX", "RANDOM", "ENTRYLO0", "ENTRYLO1", "CONTEXT", "PAGEMASK", "WIRED", "RESERVED0", "BADVADDR", "COUNT", "ENTRYHI", "COMPARE", "STATUS", "CAUSE", "EPC", "PREVID", "CONFIG", "LLADDR", "WATCHLO", "WATCHHI", "XCONTEXT", "RESERVED1", "RESERVED2", "RESERVED3", "RESERVED4", "RESERVED5", "PERR", "CACHEERR", "TAGLO", "TAGHI", "ERROREPC", "RESERVED6", } local fpu_registers = { [0]= 'F0', 'F1', 'F2', 'F3', 'F4', 'F5', 'F6', 'F7', 'F8', 'F9', 'F10', 'F11', 'F12', 'F13', 'F14', 'F15', 'F16', 'F17', 'F18', 'F19', 'F20', 'F21', 'F22', 'F23', 'F24', 'F25', 'F26', 'F27', 'F28', 'F29', 'F30', 'F31', } local all_directives = { 'ALIGN', 'SKIP', 'ASCII', 'ASCIIZ', 'BYTE', 'HALFWORD', 'WORD', 'FLOAT', --'HEX', -- excluded here due to different syntax 'INC', 'INCASM', 'INCLUDE', 'INCBIN', 'ORG', } local all_registers = {} for k, v in pairs(registers) do all_registers[k] = v end for k, v in pairs(sys_registers) do all_registers[k + 32] = v end for k, v in pairs(fpu_registers) do all_registers[k + 64] = v end -- set up reverse table lookups local function revtable(t) for k, v in pairs(t) do t[v] = k end end revtable(registers) revtable(sys_registers) revtable(fpu_registers) revtable(all_registers) revtable(all_directives) registers['ZERO'] = 0 all_registers['ZERO'] = 0 registers['S8'] = 30 all_registers['S8'] = 30 for i=0, 31 do local r = 'REG'..tostring(i) registers[r] = i all_registers[r] = i end local fmt_single = 16 local fmt_double = 17 local fmt_word = 20 local fmt_long = 21 local instructions = { --[[ data guide: --INSTRUCTION_NAME = {opcode, infmt, outfmt, const, fmtconst}, underscores are translated to dots later. opcode: the first 6 bits of the instruction. infmt: the input format; one character per argument. outfmt: the output format: R-, I-, and J-types are inferred by length. const: (optional) the number to replace 'C' with in outfmt. fmtconst: (optional) the number to replace 'F' with in outfmt. input format guide: such and such: expects a... d: register for rd s: register for rs t: register for rt D: floating point register for fd S: floating point register for fs T: floating point register for ft X: system register for rd Y: system register for rs (unused) Z: system register for rt (unused) o: constant for offset b: register to dereference for base r: relative constant or label for offset I: constant or label for index (long jump) i: immediate (must fit in a halfword; cannot be a label) k: immediate to negate (must fit in a halfword; cannot be a label) K: signed immediate (-0x8000 <= immediate < 0x10000; cannot be a label) output format guide: such and such: writes ... at this position 0: zero (sometimes used to refer to R0) d: rd s: rs t: rt D: fd S: fs T: ft o: offset b: base i: immediate (infmt 'i' and 'k' both write to here) I: index C: constant (given in argument immediately after) F: format constant (given in argument after constant) --]] J = {2, 'I', 'I'}, JAL = {3, 'I', 'I'}, JALR = {0, 'ds', 's0d0C', 9}, MTHI = {0, 's', 's000C', 17}, MTLO = {0, 's', 's000C', 19}, JR = {0, 's', 's000C', 8}, BREAK = {0, '', '0000C', 13}, SYSCALL = {0, '', '0000C', 12}, SYNC = {0, '', '0000C', 15}, LB = {32, 'tob', 'bto'}, LBU = {36, 'tob', 'bto'}, LD = {55, 'tob', 'bto'}, LDL = {26, 'tob', 'bto'}, LDR = {27, 'tob', 'bto'}, LH = {33, 'tob', 'bto'}, LHU = {37, 'tob', 'bto'}, LL = {48, 'tob', 'bto'}, LLD = {52, 'tob', 'bto'}, LW = {35, 'tob', 'bto'}, LWL = {34, 'tob', 'bto'}, LWR = {38, 'tob', 'bto'}, LWU = {39, 'tob', 'bto'}, SB = {40, 'tob', 'bto'}, SC = {56, 'tob', 'bto'}, SCD = {60, 'tob', 'bto'}, SD = {63, 'tob', 'bto'}, SDL = {44, 'tob', 'bto'}, SDR = {45, 'tob', 'bto'}, SH = {41, 'tob', 'bto'}, SW = {43, 'tob', 'bto'}, SWL = {42, 'tob', 'bto'}, SWR = {46, 'tob', 'bto'}, LUI = {15, 'ti', '0ti'}, MFHI = {0, 'd', '00d0C', 16}, MFLO = {0, 'd', '00d0C', 18}, ADDI = { 8, 'tsK', 'sti'}, ADDIU = { 9, 'tsK', 'sti'}, ANDI = {12, 'tsK', 'sti'}, DADDI = {24, 'tsK', 'sti'}, DADDIU = {25, 'tsK', 'sti'}, ORI = {13, 'tsi', 'sti'}, SLTI = {10, 'tsi', 'sti'}, SLTIU = {11, 'tsi', 'sti'}, XORI = {14, 'tsi', 'sti'}, ADD = {0, 'dst', 'std0C', 32}, ADDU = {0, 'dst', 'std0C', 33}, AND = {0, 'dst', 'std0C', 36}, DADD = {0, 'dst', 'std0C', 44}, DADDU = {0, 'dst', 'std0C', 45}, DSLLV = {0, 'dst', 'std0C', 20}, DSUB = {0, 'dst', 'std0C', 46}, DSUBU = {0, 'dst', 'std0C', 47}, NOR = {0, 'dst', 'std0C', 39}, OR = {0, 'dst', 'std0C', 37}, SLLV = {0, 'dst', 'std0C', 4}, SLT = {0, 'dst', 'std0C', 42}, SLTU = {0, 'dst', 'std0C', 43}, SRAV = {0, 'dst', 'std0C', 7}, SRLV = {0, 'dst', 'std0C', 6}, SUB = {0, 'dst', 'std0C', 34}, SUBU = {0, 'dst', 'std0C', 35}, XOR = {0, 'dst', 'std0C', 38}, DDIV = {0, 'st', 'st00C', 30}, DDIVU = {0, 'st', 'st00C', 31}, DIV = {0, 'st', 'st00C', 26}, DIVU = {0, 'st', 'st00C', 27}, DMULT = {0, 'st', 'st00C', 28}, DMULTU = {0, 'st', 'st00C', 29}, MULT = {0, 'st', 'st00C', 24}, MULTU = {0, 'st', 'st00C', 25}, DSLL = {0, 'dti', '0tdiC', 56}, DSLL32 = {0, 'dti', '0tdiC', 60}, DSRA = {0, 'dti', '0tdiC', 59}, DSRA32 = {0, 'dti', '0tdiC', 63}, DSRAV = {0, 'dts', '0tdsC', 23}, DSRL = {0, 'dti', '0tdiC', 58}, DSRL32 = {0, 'dti', '0tdiC', 62}, DSRLV = {0, 'dts', '0tdsC', 22}, SLL = {0, 'dti', '0tdiC', 0}, SRA = {0, 'dti', '0tdiC', 3}, SRL = {0, 'dti', '0tdiC', 2}, BEQ = { 4, 'str', 'sto'}, BEQL = {20, 'str', 'sto'}, BNE = { 5, 'str', 'sto'}, BNEL = {21, 'str', 'sto'}, BGEZ = { 1, 'sr', 'sCo', 1}, BGEZAL = { 1, 'sr', 'sCo', 17}, BGEZALL = { 1, 'sr', 'sCo', 19}, BGEZL = { 1, 'sr', 'sCo', 3}, BGTZ = { 7, 'sr', 'sCo', 0}, BGTZL = {23, 'sr', 'sCo', 0}, BLEZ = { 6, 'sr', 'sCo', 0}, BLEZL = {22, 'sr', 'sCo', 0}, BLTZ = { 1, 'sr', 'sCo', 0}, BLTZAL = { 1, 'sr', 'sCo', 16}, BLTZALL = { 1, 'sr', 'sCo', 18}, BLTZL = { 1, 'sr', 'sCo', 2}, TEQ = {0, 'st', 'st00C', 52}, TGE = {0, 'st', 'st00C', 48}, TGEU = {0, 'st', 'st00C', 49}, TLT = {0, 'st', 'st00C', 50}, TLTU = {0, 'st', 'st00C', 51}, TNE = {0, 'st', 'st00C', 54}, ADD_D = {17, 'DST', 'FTSDC', 0, fmt_double}, ADD_S = {17, 'DST', 'FTSDC', 0, fmt_single}, DIV_D = {17, 'DST', 'FTSDC', 3, fmt_double}, DIV_S = {17, 'DST', 'FTSDC', 3, fmt_single}, MUL_D = {17, 'DST', 'FTSDC', 2, fmt_double}, MUL_S = {17, 'DST', 'FTSDC', 2, fmt_single}, SUB_D = {17, 'DST', 'FTSDC', 1, fmt_double}, SUB_S = {17, 'DST', 'FTSDC', 1, fmt_single}, CFC1 = {17, 'tS', 'CtS00', 2}, CTC1 = {17, 'tS', 'CtS00', 6}, DMFC1 = {17, 'tS', 'CtS00', 1}, DMTC1 = {17, 'tS', 'CtS00', 5}, MFC0 = {16, 'tX', 'Ctd00', 0}, MFC1 = {17, 'tS', 'CtS00', 0}, MTC0 = {16, 'tX', 'Ctd00', 4}, MTC1 = {17, 'tS', 'CtS00', 4}, LDC1 = {53, 'Tob', 'bTo'}, LWC1 = {49, 'Tob', 'bTo'}, SDC1 = {61, 'Tob', 'bTo'}, SWC1 = {57, 'Tob', 'bTo'}, C_EQ_D = {17, 'ST', 'FTS0C', 50, fmt_double}, C_EQ_S = {17, 'ST', 'FTS0C', 50, fmt_single}, C_F_D = {17, 'ST', 'FTS0C', 48, fmt_double}, C_F_S = {17, 'ST', 'FTS0C', 48, fmt_single}, C_LE_D = {17, 'ST', 'FTS0C', 62, fmt_double}, C_LE_S = {17, 'ST', 'FTS0C', 62, fmt_single}, C_LT_D = {17, 'ST', 'FTS0C', 60, fmt_double}, C_LT_S = {17, 'ST', 'FTS0C', 60, fmt_single}, C_NGE_D = {17, 'ST', 'FTS0C', 61, fmt_double}, C_NGE_S = {17, 'ST', 'FTS0C', 61, fmt_single}, C_NGL_D = {17, 'ST', 'FTS0C', 59, fmt_double}, C_NGL_S = {17, 'ST', 'FTS0C', 59, fmt_single}, C_NGLE_D= {17, 'ST', 'FTS0C', 57, fmt_double}, C_NGLE_S= {17, 'ST', 'FTS0C', 57, fmt_single}, C_NGT_D = {17, 'ST', 'FTS0C', 63, fmt_double}, C_NGT_S = {17, 'ST', 'FTS0C', 63, fmt_single}, C_OLE_D = {17, 'ST', 'FTS0C', 54, fmt_double}, C_OLE_S = {17, 'ST', 'FTS0C', 54, fmt_single}, C_OLT_D = {17, 'ST', 'FTS0C', 52, fmt_double}, C_OLT_S = {17, 'ST', 'FTS0C', 52, fmt_single}, C_SEQ_D = {17, 'ST', 'FTS0C', 58, fmt_double}, C_SEQ_S = {17, 'ST', 'FTS0C', 58, fmt_single}, C_SF_D = {17, 'ST', 'FTS0C', 56, fmt_double}, C_SF_S = {17, 'ST', 'FTS0C', 56, fmt_single}, C_UEQ_D = {17, 'ST', 'FTS0C', 51, fmt_double}, C_UEQ_S = {17, 'ST', 'FTS0C', 51, fmt_single}, C_ULE_D = {17, 'ST', 'FTS0C', 55, fmt_double}, C_ULE_S = {17, 'ST', 'FTS0C', 55, fmt_single}, C_ULT_D = {17, 'ST', 'FTS0C', 53, fmt_double}, C_ULT_S = {17, 'ST', 'FTS0C', 53, fmt_single}, C_UN_D = {17, 'ST', 'FTS0C', 49, fmt_double}, C_UN_S = {17, 'ST', 'FTS0C', 49, fmt_single}, CVT_D_L = {17, 'DS', 'F0SDC', 33, fmt_long}, CVT_D_S = {17, 'DS', 'F0SDC', 33, fmt_single}, CVT_D_W = {17, 'DS', 'F0SDC', 33, fmt_word}, CVT_L_D = {17, 'DS', 'F0SDC', 37, fmt_double}, CVT_L_S = {17, 'DS', 'F0SDC', 37, fmt_single}, CVT_S_D = {17, 'DS', 'F0SDC', 32, fmt_double}, CVT_S_L = {17, 'DS', 'F0SDC', 32, fmt_long}, CVT_S_W = {17, 'DS', 'F0SDC', 32, fmt_word}, CVT_W_D = {17, 'DS', 'F0SDC', 36, fmt_double}, CVT_W_S = {17, 'DS', 'F0SDC', 36, fmt_single}, ABS_D = {17, 'DS', 'F0SDC', 5, fmt_double}, ABS_S = {17, 'DS', 'F0SDC', 5, fmt_single}, CEIL_L_D= {17, 'DS', 'F0SDC', 10, fmt_double}, CEIL_L_S= {17, 'DS', 'F0SDC', 10, fmt_single}, CEIL_W_D= {17, 'DS', 'F0SDC', 14, fmt_double}, CEIL_W_S= {17, 'DS', 'F0SDC', 14, fmt_single}, FLOOR_L_D={17, 'DS', 'F0SDC', 11, fmt_double}, FLOOR_L_S={17, 'DS', 'F0SDC', 11, fmt_single}, FLOOR_W_D={17, 'DS', 'F0SDC', 15, fmt_double}, FLOOR_W_S={17, 'DS', 'F0SDC', 15, fmt_single}, MOV_D = {17, 'DS', 'F0SDC', 6, fmt_double}, MOV_S = {17, 'DS', 'F0SDC', 6, fmt_single}, NEG_D = {17, 'DS', 'F0SDC', 7, fmt_double}, NEG_S = {17, 'DS', 'F0SDC', 7, fmt_single}, ROUND_L_D={17, 'DS', 'F0SDC', 8, fmt_double}, ROUND_L_S={17, 'DS', 'F0SDC', 8, fmt_single}, ROUND_W_D={17, 'DS', 'F0SDC', 12, fmt_double}, ROUND_W_S={17, 'DS', 'F0SDC', 12, fmt_single}, SQRT_D = {17, 'DS', 'F0SDC', 4, fmt_double}, SQRT_S = {17, 'DS', 'F0SDC', 4, fmt_single}, TRUNC_L_D={17, 'DS', 'F0SDC', 9, fmt_double}, TRUNC_L_S={17, 'DS', 'F0SDC', 9, fmt_single}, TRUNC_W_D={17, 'DS', 'F0SDC', 13, fmt_double}, TRUNC_W_S={17, 'DS', 'F0SDC', 13, fmt_double}, TEQI = {1, 'si', 'sCi', 12}, TGEI = {1, 'si', 'sCi', 8}, TGEIU = {1, 'si', 'sCi', 9}, TLTI = {1, 'si', 'sCi', 10}, TLTIU = {1, 'si', 'sCi', 11}, TNEI = {1, 'si', 'sCi', 14}, -- immediate limited to 3 bits? CACHE = {47, 'iob', 'bio'}, -- misuses 'F' to write the initial bit ERET = {16, '', 'F000C', 24, 16}, TLBP = {16, '', 'F000C', 8, 16}, TLBR = {16, '', 'F000C', 1, 16}, TLBWI = {16, '', 'F000C', 2, 16}, TLBWR = {16, '', 'F000C', 6, 16}, -- only one condition code on the R4300i? BC1F = {17, 'r', 'FCo', 0, 8}, BC1FL = {17, 'r', 'FCo', 2, 8}, BC1T = {17, 'r', 'FCo', 1, 8}, BC1TL = {17, 'r', 'FCo', 3, 8}, -- pseudo-instructions B = {4, 'r', '00o'}, -- BEQ R0, R0, offset BAL = {1, 'r', '0Co', 17}, -- BGEZAL R0, offset BEQZ = {4, 'sr', 's0o'}, -- BEQ RS, R0, offset BNEZ = {5, 'sr', 's0o'}, -- BNE RS, R0, offset CL = {0, 'd', '00d0C', 37}, -- OR RD, R0, R0 MOV = {0, 'ds', 's0d0C', 37}, -- OR RD, RS, R0 NEG = {0, 'dt', '0td0C', 34}, -- SUB RD, R0, RT NOP = {0, '', '0'}, -- SLL R0, R0, 0 NOT = {0, 'ds', 's0d0C', 39}, -- NOR RD, RS, R0 SUBI = {8, 'tsk', 'sti'}, -- ADDI RT, RS, -immediate SUBIU = {9, 'tsk', 'sti'}, -- ADDIU RT, RS, -immediate -- ...that expand to multiple instructions LI = {}, -- only one instruction for values < 0x10000 LA = {}, -- variable arguments PUSH = {}, POP = {}, JPOP = {}, ABS = {}, -- BGEZ NOP SUBU? MUL = {}, -- MULT MFLO --DIV = {}, -- 3 arguments REM = {}, -- 3 arguments NAND = {}, -- AND, NOT NANDI = {}, -- ANDI, NOT NORI = {}, -- ORI, NOT ROL = {}, -- SLL, SRL, OR ROR = {}, -- SRL, SLL, OR SEQ = {}, SEQI = {}, SEQIU = {}, SEQU = {}, SGE = {}, SGEI = {}, SGEIU = {}, SGEU = {}, SGT = {}, SGTI = {}, SGTIU = {}, SGTU = {}, SLE = {}, SLEI = {}, SLEIU = {}, SLEU = {}, SNE = {}, SNEI = {}, SNEIU = {}, SNEU = {}, BEQI = {}, BNEI = {}, BGE = {}, BGEI = {}, BLE = {}, BLEI = {}, BLT = {}, BLTI = {}, BGT = {}, BGTI = {}, } local all_instructions = {} local i = 1 for k, v in pairs(instructions) do all_instructions[k:gsub('_', '.')] = i i = i + 1 end revtable(all_instructions) local Lexer = Class() function Lexer:init(asm, fn, options) self.asm = asm self.fn = fn or '(string)' self.options = options or {} self.pos = 1 self.line = 1 self.EOF = -1 self:nextc() end local Dumper = Class() function Dumper:init(writer, fn, options) self.writer = writer self.fn = fn or '(string)' self.options = options or {} self.labels = {} self.commands = {} self.pos = options.offset or 0 self.lastcommand = nil end local Parser = Class() function Parser:init(writer, fn, options) self.fn = fn or '(string)' self.main_fn = self.fn self.options = options or {} self.dumper = Dumper(writer, fn, options) self.defines = {} end function Lexer:error(msg) error(format('%s:%d: Error: %s', self.fn, self.line, msg), 2) end function Lexer:nextc() if self.pos > #self.asm then self.ord = self.EOF self.ord2 = self.EOF self.chr = '' self.chr2 = '' self.chrchr = '' return end if self.chr == '\n' then self.line = self.line + 1 end self.ord = byte(self.asm, self.pos) self.pos = self.pos + 1 -- handle newlines; translate CRLF to LF if self.ord == 13 then if self.pos <= #self.asm and byte(self.asm, self.pos) == 10 then self.pos = self.pos + 1 end self.ord = 10 end self.chr = char(self.ord) if self.pos <= #self.asm then self.ord2 = byte(self.asm, self.pos) self.chr2 = char(self.ord2) self.chrchr = char(self.ord, self.ord2) else self.ord2 = self.EOF self.chr2 = '' self.chrchr = self.chr end end function Lexer:skip_to_EOL() while self.chr ~= '\n' and self.ord ~= self.EOF do self:nextc() end end function Lexer:read_chars(pattern) local buff = '' while find(self.chr, pattern) do buff = buff..self.chr self:nextc() end return buff end function Lexer:read_decimal() local buff = self:read_chars('%d') local num = tonumber(buff) if not num then self:error('invalid decimal number') end return num end function Lexer:read_hex() local buff = self:read_chars('%x') local num = tonumber(buff, 16) if not num then self:error('invalid hex number') end return num end function Lexer:read_octal() local buff = self:read_chars('[0-7]') local num = tonumber(buff, 8) if not num then self:error('invalid octal number') end return num end function Lexer:read_binary() local buff = self:read_chars('[01]') local num = tonumber(buff, 2) if not num then self:error('invalid binary number') end return num end function Lexer:read_number() if self.chr == '%' then self:nextc() return self:read_binary() elseif self.chr == '$' then self:nextc() return self:read_hex() elseif self.chr:find('%d') then if self.chr2 == 'x' or self.chr2 == 'X' then self:nextc() self:nextc() return self:read_hex() elseif self.chr == '0' and self.chr2:find('%d') then self:nextc() return self:read_octal() else return self:read_decimal() end elseif self.chr == '#' then self:nextc() return self:read_decimal() end end function Lexer:lex_hex(yield) local hexmatch = '[0-9A-Fa-f]' local entered = false while true do if self.chr == '\n' then self:nextc() yield('EOL', '\n') elseif self.ord == self.EOF then self:error('unexpected EOF; incomplete hex directive') elseif self.chr == ';' then self:skip_to_EOL() elseif self.chrchr == '//' then self:skip_to_EOL() elseif self.chrchr == '/*' then self:nextc() self:nextc() self:lex_block_comment(yield) elseif self.chr:find('%s') then self:nextc() elseif self.chr == '{' then if entered then self:error('unexpected opening brace') end self:nextc() entered = true elseif self.chr == '}' then if not entered then self:error('expected opening brace') end self:nextc() break elseif self.chr == ',' then self:error('commas are not allowed in HEX directives') elseif self.chr:find(hexmatch) and self.chr2:find(hexmatch) then local num = tonumber(self.chrchr, 16) self:nextc() self:nextc() if self.chr:find(hexmatch) then self:error('too many hex digits to be a single byte') end yield('DIR', 'BYTE') yield('NUM', num) elseif self.chr:find(hexmatch) then self:error('expected two hex digits to make a byte') else if entered then self:error('expected bytes given in hex or closing brace') else self:error('expected opening brace') end end end end function Lexer:lex_block_comment(yield) while true do if self.chr == '\n' then self:nextc() yield('EOL', '\n') elseif self.ord == self.EOF then self:error('unexpected EOF; incomplete block comment') elseif self.chrchr == '*/' then self:nextc() self:nextc() break else self:nextc() end end end function Lexer:lex_string(yield) -- TODO: support escaping if self.chr ~= '"' then self:error("expected opening double quote") end self:nextc() local buff = self:read_chars('[^"\n]') if self.chr ~= '"' then self:error("expected closing double quote") end self:nextc() yield('STRING', buff) end function Lexer:lex_include(_yield) self:read_chars('%s') local fn self:lex_string(function(tt, tok) fn = tok end) if self.options.path then fn = self.options.path..fn end local sublexer = Lexer(readfile(fn), fn, self.options) sublexer:lex(_yield) end function Lexer:lex(_yield) local function yield(tt, tok) return _yield(tt, tok, self.fn, self.line) end while true do if self.chr == '\n' then self:nextc() yield('EOL', '\n') elseif self.ord == self.EOF then yield('EOF', self.EOF) break elseif self.chr == ';' then self:skip_to_EOL() elseif self.chrchr == '//' then self:skip_to_EOL() elseif self.chrchr == '/*' then self:nextc() self:nextc() self:lex_block_comment(yield) elseif self.chr:find('%s') then self:nextc() elseif self.chr == ',' then self:nextc() yield('SEP', ',') elseif self.chr == '[' then self:nextc() local buff = self:read_chars('[%w_]') if self.chr ~= ']' then self:error('invalid define name') end self:nextc() if self.chr ~= ':' then self:error('define requires a colon') end self:nextc() yield('DEF', buff) elseif self.chr == '(' then self:nextc() local buff = self:read_chars('[%w_]') if self.chr ~= ')' then self:error('invalid register name') end self:nextc() local up = buff:upper() if not all_registers[up] then self:error('not a register') end yield('DEREF', up) elseif self.chr == '.' then self:nextc() local buff = self:read_chars('[%w]') local up = buff:upper() if not all_directives[up] then self:error('not a directive') end if up == 'INC' or up == 'INCASM' or up == 'INCLUDE' then yield('DIR', 'INC') self:lex_include(_yield) else yield('DIR', up) end elseif self.chr == '@' then self:nextc() local buff = self:read_chars('[%w_]') yield('DEFSYM', buff) elseif self.chr:find('[%a_]') then local buff = self:read_chars('[%w_.]') local up = buff:upper() if self.chr == ':' then if buff:find('%.') then self:error('labels cannot contain dots') end self:nextc() yield('LABEL', buff) elseif up == 'HEX' then self:lex_hex(yield) elseif all_registers[up] then yield('REG', up) elseif all_instructions[up] then yield('INSTR', up:gsub('%.', '_')) else if buff:find('%.') then self:error('labels cannot contain dots') end yield('LABELSYM', buff) end elseif self.chr == ']' then self:error('unmatched closing bracket') elseif self.chr == ')' then self:error('unmatched closing parenthesis') elseif self.chr == '+' or self.chr == '-' then local sign_chr = self.chr local sign = sign_chr == '+' and 1 or -1 local buff = self:read_chars('%'..self.chr) if #buff == 1 and self.chr == ':' then self:nextc() yield('RELLABEL', sign_chr) else local n = self:read_number() if n then yield('NUM', sign*n) else yield('RELLABELSYM', sign*#buff) end end else local n = self:read_number() if n then yield('NUM', n) else self:error('unknown character or control character') end end end end function Parser:error(msg) error(format('%s:%d: Error: %s', self.fn, self.line, msg), 2) end function Parser:advance() self.i = self.i + 1 local t = self.tokens[self.i] self.tt = t.tt self.tok = t.tok self.fn = t.fn self.line = t.line return t.tt, t.tok end function Parser:is_EOL() return self.tt == 'EOL' or self.tt == 'EOF' end function Parser:expect_EOL() if self:is_EOL() then self:advance() return end self:error('expected end of line') end function Parser:optional_comma() if self.tt == 'SEP' and self.tok == ',' then self:advance() return true end end function Parser:number() if self.tt ~= 'NUM' then self:error('expected number') end local value = self.tok self:advance() return value end function Parser:directive() local name = self.tok self:advance() local line = self.line if name == 'ORG' then self.dumper:add_directive(line, name, self:number()) elseif name == 'ALIGN' or name == 'SKIP' then if self:is_EOL() and name == 'ALIGN' then self.dumper:add_directive(line, name, 0) else local size = self:number() if self:is_EOL() then self.dumper:add_directive(line, name, size) else self:optional_comma() self.dumper:add_directive(line, name, size, self:number()) end self:expect_EOL() end elseif name == 'BYTE' or name == 'HALFWORD' or name == 'WORD' then self.dumper:add_directive(line, name, self:number()) while not self:is_EOL() do self:advance() self:optional_comma() self.dumper:add_directive(line, name, self:number()) end self:expect_EOL() elseif name == 'HEX' then self:error('unimplemented') elseif name == 'INC' then -- noop elseif name == 'INCBIN' then self:error('unimplemented') elseif name == 'FLOAT' or name == 'ASCII' or name == 'ASCIIZ' then self:error('unimplemented') else self:error('unknown directive') end end function Parser:register(t) t = t or registers if self.tt ~= 'REG' then self:error('expected register') end local reg = self.tok if not t[reg] then self:error('wrong type of register') end self:advance() return reg end function Parser:deref() if self.tt ~= 'DEREF' then self:error('expected register to dereference') end local reg = self.tok self:advance() return reg end function Parser:const(relative, no_label) if self.tt ~= 'NUM' and self.tt ~= 'LABELSYM' then self:error('expected constant') end if no_label and self.tt == 'LABELSYM' then self:error('labels are not allowed here') end if relative and self.tt == 'LABELSYM' then self.tt = 'LABELREL' end local t = {self.tt, self.tok} self:advance() return t end function Parser:format_in(informat) local args = {} for i=1,#informat do local c = informat:sub(i, i) local c2 = informat:sub(i + 1, i + 1) if c == 'd' and not args.rd then args.rd = self:register() elseif c == 's' and not args.rs then args.rs = self:register() elseif c == 't' and not args.rt then args.rt = self:register() elseif c == 'D' and not args.fd then args.fd = self:register(fpu_registers) elseif c == 'S' and not args.fs then args.fs = self:register(fpu_registers) elseif c == 'T' and not args.ft then args.ft = self:register(fpu_registers) elseif c == 'X' and not args.rd then args.rd = self:register(sys_registers) elseif c == 'Y' and not args.rs then args.rs = self:register(sys_registers) elseif c == 'Z' and not args.rt then args.rt = self:register(sys_registers) elseif c == 'o' and not args.offset then args.offset = {'SIGNED', self:const()} elseif c == 'r' and not args.offset then args.offset = {'SIGNED', self:const('relative')} elseif c == 'i' and not args.immediate then args.immediate = self:const(nil, 'no label') elseif c == 'I' and not args.index then args.index = {'INDEX', self:const()} elseif c == 'k' and not args.immediate then args.immediate = {'NEGATE', self:const(nil, 'no label')} elseif c == 'K' and not args.immediate then args.immediate = {'SIGNED', self:const(nil, 'no label')} elseif c == 'b' and not args.base then args.base = self:deref() else error('Internal Error: invalid input formatting string', 1) end if c2:find('[dstDSTorIikKXYZ]') then self:optional_comma() end end return args end function Parser:format_out_raw(outformat, first, args, const, formatconst) local lookup = { [1]=self.dumper.add_instruction_j, [3]=self.dumper.add_instruction_i, [5]=self.dumper.add_instruction_r, } out = {} for i=1,#outformat do local c = outformat:sub(i, i) if c == 'd' then out[#out+1] = args.rd elseif c == 's' then out[#out+1] = args.rs elseif c == 't' then out[#out+1] = args.rt elseif c == 'D' then out[#out+1] = args.fd elseif c == 'S' then out[#out+1] = args.fs elseif c == 'T' then out[#out+1] = args.ft elseif c == 'o' then out[#out+1] = args.offset elseif c == 'i' then out[#out+1] = args.immediate elseif c == 'I' then out[#out+1] = args.index elseif c == 'b' then out[#out+1] = args.base elseif c == '0' then out[#out+1] = 0 elseif c == 'C' then out[#out+1] = const elseif c == 'F' then out[#out+1] = formatconst end end local f = lookup[#outformat] if f == nil then error('Internal Error: invalid output formatting string', 1) end f(self.dumper, self.line, first, out[1], out[2], out[3], out[4], out[5]) end function Parser:format_out(t, args) self:format_out_raw(t[3], t[1], args, t[4], t[5]) end local overrides = {} function overrides.LI(self, name) local lui = instructions['LUI'] local ori = instructions['ORI'] local addiu = instructions['ADDIU'] local args = {} args.rt = self:register() self:optional_comma() local im = self:const() -- for us, this is just semantics. for a "real" assembler, -- LA could add appropriate RELO LUI/ADDIU directives. if im[1] == 'LABELSYM' then self:error('use LA for labels') end im[2] = im[2] % 0x100000000 if im[2] >= 0x10000 and im[2] <= 0xFFFF8000 then args.rs = args.rt args.immediate = {'UPPER', im} self:format_out(lui, args) if im[2] % 0x10000 ~= 0 then args.immediate = {'LOWER', im} self:format_out(ori, args) end elseif im[2] >= 0x8000 and im[2] < 0x10000 then args.rs = 'R0' args.immediate = {'LOWER', im} self:format_out(ori, args) else args.rs = 'R0' args.immediate = {'LOWER', im} self:format_out(addiu, args) end end function overrides.LA(self, name) local lui = instructions['LUI'] local addiu = instructions['ADDIU'] local args = {} args.rt = self:register() self:optional_comma() local im = self:const() args.rs = args.rt args.immediate = {'UPPEROFF', im} self:format_out(lui, args) args.immediate = {'LOWER', im} self:format_out(addiu, args) end function overrides.PUSH(self, name) local addi = instructions['ADDI'] local w = instructions[name == 'PUSH' and 'SW' or 'LW'] local jr = instructions['JR'] local stack = {} while not self:is_EOL() do if self.tt == 'NUM' then if self.tok < 0 then self:error("can't push a negative number of spaces") end for i=1,self.tok do insert(stack, '') end self:advance() else insert(stack, self:register()) end if not self:is_EOL() then self:optional_comma() end end if #stack == 0 then self:error(name..' requires at least one argument') end local args = {} if name == 'PUSH' then args.rt = 'SP' args.rs = 'SP' args.immediate = {'NEGATE', {'NUM', #stack*4}} self:format_out(addi, args) end args.base = 'SP' for i, r in ipairs(stack) do args.rt = r if r ~= '' then args.offset = {'NUM', (i - 1)*4} self:format_out(w, args) end end if name == 'JPOP' then args.rs = 'RA' self:format_out(jr, args) end if name == 'POP' or name == 'JPOP' then args.rt = 'SP' args.rs = 'SP' args.immediate = {'NUM', #stack*4} self:format_out(addi, args) end end overrides.POP = overrides.PUSH overrides.JPOP = overrides.PUSH function overrides.NAND(self, name) local and_ = instructions['AND'] local nor = instructions['NOR'] local args = {} args.rd = self:register() self:optional_comma() args.rs = self:register() self:optional_comma() args.rt = self:register() self:format_out(and_, args) args.rs = args.rd args.rt = 'R0' self:format_out(nor, args) end function overrides.NANDI(self, name) local andi = instructions['ANDI'] local nor = instructions['NOR'] local args = {} args.rt = self:register() self:optional_comma() args.rs = self:register() self:optional_comma() args.immediate = self:const() self:format_out(andi[3], andi[1], args, andi[4], andi[5]) args.rd = args.rt args.rs = args.rt args.rt = 'R0' self:format_out(nor[3], nor[1], args, nor[4], nor[5]) end function overrides.NORI(self, name) local ori = instructions['ORI'] local nor = instructions['NOR'] local args = {} args.rt = self:register() self:optional_comma() args.rs = self:register() self:optional_comma() args.immediate = self:const() self:format_out(ori, args) args.rd = args.rt args.rs = args.rt args.rt = 'R0' self:format_out(nor, args) end function overrides.ROL(self, name) local sll = instructions['SLL'] local srl = instructions['SRL'] local or_ = instructions['OR'] local args = {} local left = self:register() self:optional_comma() args.rt = self:register() self:optional_comma() args.immediate = self:const() args.rd = left if args.rd == 'AT' or args.rt == 'AT' then self:error('registers cannot be AT in this pseudo-instruction') end if args.rd == args.rt and args.rd ~= 'R0' then self:error('registers cannot be the same') end self:format_out(sll, args) args.rd = 'AT' args.immediate = {'NUM', 32 - args.immediate[2]} self:format_out(srl, args) args.rd = left args.rs = left args.rt = 'AT' self:format_out(or_, args) end function overrides.ROR(self, name) local sll = instructions['SLL'] local srl = instructions['SRL'] local or_ = instructions['OR'] local args = {} local right = self:register() self:optional_comma() args.rt = self:register() self:optional_comma() args.immediate = self:const() args.rd = right if args.rt == 'AT' or args.rd == 'AT' then self:error('registers cannot be AT in a pseudo-instruction that uses AT') end if args.rd == args.rt and args.rd ~= 'R0' then self:error('registers cannot be the same') end self:format_out(srl, args) args.rd = 'AT' args.immediate = {'NUM', 32 - args.immediate[2]} self:format_out(sll, args) args.rd = right args.rs = right args.rt = 'AT' self:format_out(or_, args) end function overrides.JR(self, name) local jr = instructions['JR'] local args = {} if self:is_EOL() then args.rs = 'RA' else args.rs = self:register() end self:format_out(jr, args) end local branch_basics = { BEQI = "BEQ", BGEI = "BEQ", BGTI = "BEQ", BLEI = "BNE", BLTI = "BNE", BNEI = "BNE", } function overrides.BEQI(self, name) local addiu = instructions['ADDIU'] local branch = instructions[branch_basics[name]] local args = {} local reg = self:register() self:optional_comma() args.immediate = self:const() self:optional_comma() args.offset = {'SIGNED', self:const('relative')} if reg == 'AT' then self:error('register cannot be AT in this pseudo-instruction') end args.rt = 'AT' args.rs = 'R0' self:format_out(addiu, args) args.rs = reg self:format_out(branch, args) end overrides.BNEI = overrides.BEQI function overrides.BLTI(self, name) local slti = instructions['SLTI'] local branch = instructions[branch_basics[name]] local args = {} args.rs = self:register() self:optional_comma() args.immediate = self:const() self:optional_comma() args.offset = {'SIGNED', self:const('relative')} if reg == 'AT' then self:error('register cannot be AT in this pseudo-instruction') end args.rt = 'AT' self:format_out(slti, args) args.rs = 'AT' args.rt = 'R0' self:format_out(branch, args) end overrides.BGEI = overrides.BLTI function overrides.BLEI(self, name) -- TODO: this can probably be optimized local addiu = instructions['ADDIU'] local slt = instructions['SLT'] local branch = instructions[branch_basics[name]] local beq = instructions['BEQ'] local args = {} local reg = self:register() self:optional_comma() args.immediate = self:const() self:optional_comma() local offset = {'SIGNED', self:const('relative')} if reg == 'AT' then self:error('register cannot be AT in this pseudo-instruction') end args.rt = 'AT' args.rs = 'R0' self:format_out(addiu, args) if name == 'BLEI' then args.offset = offset else args.offset = 2 -- branch to delay slot of the next branch end args.rs = reg self:format_out(beq, args) args.rd = 'AT' self:format_out(slt, args) args.rs = 'AT' args.rt = 'R0' args.offset = offset self:format_out(branch, args) end overrides.BGTI = overrides.BLEI function Parser:instruction() local name = self.tok local h = instructions[name] self:advance() -- FIXME: errors thrown here probably have the wrong line number (+1) if h == nil then self:error('undefined instruction') elseif overrides[name] then overrides[name](self, name) elseif h[2] == 'tob' then -- or h[2] == 'Tob' then local lui = instructions['LUI'] local args = {} args.rt = self:register() self:optional_comma() local o = self:const() local is_label = o[1] == 'LABELSYM' if self:is_EOL() then local lui_args = {} lui_args.immediate = {'UPPEROFF', o} lui_args.rt = 'AT' self:format_out(lui, lui_args) args.offset = {'LOWER', o} args.base = 'AT' else if is_label then self:error('labels cannot be used as offsets') end args.offset = {'SIGNED', o} self:optional_comma() args.base = self:deref() end self:format_out(h, args) elseif h[2] ~= nil then args = self:format_in(h[2]) self:format_out(h, args) else self:error('unimplemented instruction') end self:expect_EOL() end function Parser:tokenize(asm) self.tokens = {} self.i = 0 local routine = coroutine.create(function() local lexer = Lexer(asm, self.main_fn, self.options) lexer:lex(coroutine.yield) end) local function lex() local t = {} local ok, a, b, c, d = coroutine.resume(routine) if not ok then a = a or 'Internal Error: lexer coroutine has stopped' error(a) end t.tt = a t.tok = b t.fn = c t.line = d insert(self.tokens, t) return t.tt, t.tok, t.fn, t.line end -- first pass: collect tokens, constants, and relative labels. -- can't do more because instruction size can depend on a constant's size -- and labels depend on instruction size. -- note however, instruction size does not depend on label size. -- this would cause a recursive problem to solve, -- which is too much for our simple assembler. local plus_labels = {} -- constructed forwards local minus_labels = {} -- constructed backwards while true do local tt, tok, fn, line = lex() self.fn = fn self.line = line if tt == 'DEF' then local tt2, tok2 = lex() if tt2 ~= 'NUM' then self:error('expected number for define') end self.defines[tok] = tok2 elseif tt == 'RELLABEL' then if tok == '+' then insert(plus_labels, #self.tokens) elseif tok == '-' then insert(minus_labels, 1, #self.tokens) else error('Internal Error: unexpected token for relative label', 1) end elseif tt == 'EOL' then -- noop elseif tt == 'EOF' then if fn == self.main_fn then break end elseif tt == nil then error('Internal Error: missing token', 1) end end -- resolve defines and relative labels for i, t in ipairs(self.tokens) do self.fn = t.fn self.line = t.line if t.tt == 'DEFSYM' then t.tt = 'NUM' t.tok = self.defines[t.tok] if t.tok == nil then self:error('undefined define') -- uhhh nice wording end elseif t.tt == 'RELLABEL' then t.tt = 'LABEL' -- exploits the fact that user labels can't begin with a number t.tok = tostring(i) elseif t.tt == 'RELLABELSYM' then t.tt = 'LABELSYM' local rel = t.tok local seen = 0 -- TODO: don't iterate over *every* label, just the ones nearby if rel > 0 then for _, label_i in ipairs(plus_labels) do if label_i > i then seen = seen + 1 if seen == rel then t.tok = tostring(label_i) break end end end else for _, label_i in ipairs(minus_labels) do if label_i < i then seen = seen - 1 if seen == rel then t.tok = tostring(label_i) break end end end end if seen ~= rel then self:error('could not find appropriate relative label') end end end end function Parser:parse(asm) self:tokenize(asm) self:advance() while true do if self.tt == 'EOF' then if self.fn == self.main_fn then break end self:advance() elseif self.tt == 'EOL' then -- empty line self:advance() elseif self.tt == 'DEF' then self:advance() self:advance() elseif self.tt == 'DIR' then self:directive() elseif self.tt == 'LABEL' then self.dumper:add_label(self.tok) self:advance() elseif self.tt == 'INSTR' then self:instruction() else self:error('unexpected token (unknown instruction?)') end end return self.dumper:dump() end function Dumper:error(msg) error(format('%s:%d: Error: %s', self.fn, self.line, msg), 2) end function Dumper:advance(by) self.pos = self.pos + by end function Dumper:push_instruction(t) t.kind = 'instruction' insert(self.commands, t) self:advance(4) end function Dumper:add_instruction_j(line, o, T) self:push_instruction{line=line, o, T} end function Dumper:add_instruction_i(line, o, s, t, i) self:push_instruction{line=line, o, s, t, i} end function Dumper:add_instruction_r(line, o, s, t, d, f, c) self:push_instruction{line=line, o, s, t, d, f, c} end function Dumper:add_label(name) self.labels[name] = self.pos end function Dumper:add_bytes(line, ...) local bs = {...} local t local use_last = self.lastcommand and self.lastcommand.kind == 'bytes' if use_last then t = self.lastcommand else t = {} t.kind = 'bytes' t.size = 0 end t.line = line for _, b in ipairs(bs) do t.size = t.size + 1 t[t.size] = b end if not use_last then insert(self.commands, t) end self:advance(t.size) end function Dumper:add_directive(line, name, a, b) local t = {} t.line = line if name == 'BYTE' then self:add_bytes(line, a % 0x100) elseif name == 'HALFWORD' then local b0 = bitrange(a, 0, 7) local b1 = bitrange(a, 8, 15) self:add_bytes(line, b1, b0) elseif name == 'WORD' then local b0 = bitrange(a, 0, 7) local b1 = bitrange(a, 8, 15) local b2 = bitrange(a, 16, 23) local b3 = bitrange(a, 24, 31) self:add_bytes(line, b3, b2, b1, b0) elseif name == 'ORG' then t.kind = 'goto' t.addr = a insert(self.commands, t) self.pos = a % 0x80000000 self:advance(0) elseif name == 'ALIGN' then t.kind = 'ahead' local align = a*2 if align == 0 then align = 4 elseif align < 0 then self:error('negative alignment') end local temp = self.pos + align - 1 t.skip = temp - (temp % align) - self.pos t.fill = t.fill or 0 insert(self.commands, t) self:advance(t.skip) elseif name == 'SKIP' then t.kind = 'ahead' t.skip = a t.fill = b insert(self.commands, t) self:advance(t.skip) else self:error('unimplemented directive') end end function Dumper:desym(tok) -- FIXME: errors can give wrong filename, also off by one if type(tok[2]) == 'number' then return tok[2] elseif tok[1] == 'LABELSYM' then local label = self.labels[tok[2]] if label == nil then self:error('undefined label') end return label elseif tok[1] == 'LABELREL' then local label = self.labels[tok[2]] if label == nil then self:error('undefined label') end label = label % 0x80000000 local pos = self.pos % 0x80000000 local rel = floor(label/4) - 1 - floor(pos/4) if rel > 0x8000 or rel <= -0x8000 then self:error('branch too far') end return rel % 0x10000 end self:error('failed to desym') end function Dumper:toval(tok) if tok == nil then self:error('nil value') elseif type(tok) == 'number' then return tok elseif all_registers[tok] then return registers[tok] or fpu_registers[tok] or sys_registers[tok] end if type(tok) == 'table' then if #tok ~= 2 then self:error('invalid token') end if tok[1] == 'UPPER' then local val = self:desym(tok[2]) return bitrange(val, 16, 31) elseif tok[1] == 'LOWER' then local val = self:desym(tok[2]) return bitrange(val, 0, 15) elseif tok[1] == 'UPPEROFF' then local val = self:desym(tok[2]) local upper = bitrange(val, 16, 31) local lower = bitrange(val, 0, 15) if lower >= 0x8000 then -- accommodate for offsets being signed upper = (upper + 1) % 0x10000 end return upper elseif tok[1] == 'SIGNED' then local val = self:desym(tok[2]) if val >= 0x10000 or val < -0x8000 then self:error('value out of range') end return val % 0x10000 elseif tok[1] == 'NEGATE' then local val = -self:desym(tok[2]) if val >= 0x10000 or val < -0x8000 then self:error('value out of range') end return val % 0x10000 elseif tok[1] == 'INDEX' then local val = self:desym(tok[2]) % 0x80000000 val = floor(val/4) return val else return self:desym(tok) end end self:error('invalid value') end function Dumper:validate(n, bits) local max = 2^bits if n == nil then self:error('value is nil') end if n > max or n < 0 then self:error('value out of range') end end function Dumper:valvar(tok, bits) local val = self:toval(tok) self:validate(val, bits) return val end function Dumper:write(t) for _, b in ipairs(t) do local s = ('%02X'):format(b) self.writer(self.pos, s) self.pos = self.pos + 1 end end function Dumper:dump_instruction(t) local uw = 0 local lw = 0 local o = t[1] uw = uw + o*0x400 if #t == 2 then local val = self:valvar(t[2], 26) uw = uw + bitrange(val, 16, 25) lw = lw + bitrange(val, 0, 15) elseif #t == 4 then uw = uw + self:valvar(t[2], 5)*0x20 uw = uw + self:valvar(t[3], 5) lw = lw + self:valvar(t[4], 16) elseif #t == 6 then uw = uw + self:valvar(t[2], 5)*0x20 uw = uw + self:valvar(t[3], 5) lw = lw + self:valvar(t[4], 5)*0x800 lw = lw + self:valvar(t[5], 5)*0x40 lw = lw + self:valvar(t[6], 6) else error('Internal Error: unknown n-size', 1) end return uw, lw end function Dumper:dump() self.pos = self.options.offset or 0 for i, t in ipairs(self.commands) do if t.line == nil then error('Internal Error: no line number available') end self.line = t.line if t.kind == 'instruction' then uw, lw = self:dump_instruction(t) local b0 = bitrange(lw, 0, 7) local b1 = bitrange(lw, 8, 15) local b2 = bitrange(uw, 0, 7) local b3 = bitrange(uw, 8, 15) self:write{b3, b2, b1, b0} elseif t.kind == 'bytes' then self:write(t) elseif t.kind == 'goto' then self.pos = t.addr elseif t.kind == 'ahead' then if t.fill then for i=1, t.skip do self:write{t.fill} end else self.pos = self.pos + t.skip end else error('Internal Error: unknown command', 1) end end end function assembler.word_writer() local buff = {} local max = -1 return function(pos, b) if pos then buff[pos] = b if pos > max then max = pos end else if max == -1 then return end for i=0, max, 4 do local a = buff[i+0] or '00' local b = buff[i+1] or '00' local c = buff[i+2] or '00' local d = buff[i+3] or '00' print(a..b..c..d) end end end end function assembler.assemble(fn_or_asm, writer, options) -- assemble MIPS R4300i assembly code. -- if fn_or_asm contains a newline; treat as assembly, otherwise load file. -- returns error message on error, or nil on success. fn_or_asm = tostring(fn_or_asm) local default_writer = not writer writer = writer or assembler.word_writer() options = options or {} function main() local fn = nil local asm if fn_or_asm:find('[\r\n]') then asm = fn_or_asm else fn = fn_or_asm asm = readfile(fn) options.path = fn:match(".*/") end local parser = Parser(writer, fn, options) parser:parse(asm) if default_writer then writer() end end if options.unsafe then return main() else local ok, err = pcall(main) return err end end return setmetatable(assembler, { __call = function(self, ...) return self.assemble(...) end, })