From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [87.239.111.99] (localhost [127.0.0.1]) by dev.tarantool.org (Postfix) with ESMTP id 79CFD6ECFB; Wed, 27 May 2026 15:39:00 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org 79CFD6ECFB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tarantool.org; s=dev; t=1779885540; bh=UzFQvOzw/alDGX70zRSx49VGRw1fgUUkjWItgc3u6HM=; h=Date:To:Cc:References:In-Reply-To:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=PDevWm7IGKHGACZIEaPagP7nNMewj+Yqb1FoZLtBITf8T0yRv8a3/AdD8YfOEmfAB qpKUbTs+3HavmqW18cB0pE0ubqEx6W89DghK/oj6ghjjLUOQS/bfxFMb2rtNCMWk0H /eCw/SM1UrHP//wW2A23J+cdKgOM7aJMkK//sUfE= Received: from send103.i.mail.ru (send103.i.mail.ru [89.221.237.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 4DAE56ECFB for ; Wed, 27 May 2026 15:38:59 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org 4DAE56ECFB Received: by exim-smtp-5b85998476-4ggj7 with esmtpa (envelope-from ) id 1wSDXF-000000006CM-27Bu; Wed, 27 May 2026 15:38:58 +0300 Content-Type: multipart/alternative; boundary="------------rttd6sOXBrWyY67CsL0Fw8fj" Message-ID: <2f29ca87-ac11-4459-8717-b62f077afdfa@tarantool.org> Date: Wed, 27 May 2026 15:38:56 +0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: Sergey Kaplun , Mikhail Elhimov , Evgeniy Temirgaleev Cc: tarantool-patches@dev.tarantool.org References: <20260519123913.178775-1-skaplun@tarantool.org> <20260519123913.178775-6-skaplun@tarantool.org> In-Reply-To: <20260519123913.178775-6-skaplun@tarantool.org> X-Mailru-Src: smtp X-4EC0790: 10 X-618D5548: 32BB9F9F8D97ECFC2EB5D77EF37489D1C0AC7CF4C6E0148A93074CABA4FCAB4C00495D08ECA0478E X-7564579A: 646B95376F6C166E X-77F55803: 4F1203BC0FB41BD98DC58EE55F2C5C37235345BD62AE6C9C712A59D0E6C829EB00894C459B0CD1B932BB9F9F8D97ECFC2EB5D77EF37489D1763DC9628AF222CF93074CABA4FCAB4C35485DF4C51D0362 X-7FA49CB5: FF5795518A3D127A4AD6D5ED66289B5278DA827A17800CE73CA91848DF1CD634EA1F7E6F0F101C67BD4B6F7A4D31EC0BCC500DACC3FED6E28638F802B75D45FF8AA50765F7900637FE9EFE935CD7C6AE8638F802B75D45FF914D58D5BE9E6BC1A93B80C6DEB9DEE97C6FB206A91F05B27F5FE4692623DCAD2E070BE324C7D3C42010D5FFC561CD42F6B57BC7E64490618DEB871D839B73339E8FC8737B5C2249D52CD31C43BF465FCC7F00164DA146DAFE8445B8C89999729449624AB7ADAF37F6B57BC7E64490611E7FA7ABCAF51C92176DF2183F8FC7C0B27420F9988F54058941B15DA834481F9449624AB7ADAF372E808ACE2090B5E14AD6D5ED66289B5259CC434672EE63711DD303D21008E298D5E8D9A59859A8B6B372FE9A2E580EFC725E5C173C3A84C3CD42BCEBB57B85E635872C767BF85DA2F004C90652538430E4A6367B16DE6309 X-C1DE0DAB: 0D63561A33F958A543E0CA52B4F8588F5002B1117B3ED69683F253EB99F5532FC81EEE05487B0209823CB91A9FED034534781492E4B8EEAD3A7DBC15E4F9C80F X-C8649E89: 1C3962B70DF3F0ADB58128AB1E6D661A716CD42B3DD1D34CAB70F9BE574AE9C625B6776AC983F447FC0B9F89525902EE6F57B2FD27647F25E66C117BDB76D6598FF9636F29202E9BA805E28EA8933AB734EBFE87FA8397F3B031246014BBA24A3BEB424515052EA8B8341EE9D5BE9A0ACEAA919432CCAFD9A5637553CC8469DEB85991564092BF1BC7CEAA0681F5848F4C41F94D744909CE2512F26BEC029E55448553D2254B8D95CD72808BE417F3B9E0E7457915DAA85F X-D57D3AED: 3ZO7eAau8CL7WIMRKs4sN3D3tLDjz0dLbV79QFUyzQ2Ujvy7cMT6pYYqY16iZVKkSc3dCLJ7zSJH7+u4VD18S7Vl4ZUrpaVfd2+vE6kuoey4m4VkSEu53w8ahmwBjZKM/YPHZyZHvz5uv+WouB9+ObcCpyrx6l7KImUglyhkEat/+ysWwi0gdhEs0JGjl6ggRWTy1haxBpVdbIX1nthFXMZebaIdHP2ghjoIc/363UZI6Kf1ptIMVax5M0mESuWm0j/fKcOpngg= X-DA7885C5: B980652842335BCBF255D290C0D534F9392A70228371BB4294C142E245C8E06F86CF35857DAB9ACB5B1A4C17EAA7BC4BEF2421ABFA55128DAF83EF9164C44C7E X-Mailru-Sender: 689FA8AB762F7393520AF17B8A65FDE2B00773E8CF88FC0EDB82EE0A5485BEAE1D058DC26B53E687EF86D5F70DA33880E41E8EF7A07863ECB274557F927329BE2DDF8182D28ACDB545BD1C3CC395C826B4A721A3011E896F X-Mras: Ok Subject: Re: [Tarantool-patches] [PATCH v2 luajit 5/6] dbg: generalize extension X-BeenThere: tarantool-patches@dev.tarantool.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Sergey Bronnikov via Tarantool-patches Reply-To: Sergey Bronnikov Errors-To: tarantool-patches-bounces@dev.tarantool.org Sender: "Tarantool-patches" This is a multi-part message in MIME format. --------------rttd6sOXBrWyY67CsL0Fw8fj Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi, Sergey, thanks for the patch! LGTM with a minor comment. Sergey On 5/19/26 15:39, Sergey Kaplun wrote: > This patch joins the LLDB and GDB LuaJIT debugging extensions > into one, so now the extension logic can be debugger-agnostic. > > To do that, an adapter class is introduced, and all of the > debugger-specific behavior is encapsulated there and in its child > debugger classes with the specific implementations of required methods. > The extension auto-detects the debugger it was loaded into and selects > the correct low-level logic implementation. > > The F821 ignore is removed from <.flake8rc> since there is no more need > for it. > --- > .flake8rc | 5 - > src/luajit-gdb.py | 884 ------------ > src/luajit_dbg.py | 1281 +++++++++++++++++ > src/luajit_lldb.py | 1015 ------------- > .../debug-extension-tests.py | 4 +- > 5 files changed, 1283 insertions(+), 1906 deletions(-) > delete mode 100644 src/luajit-gdb.py > create mode 100644 src/luajit_dbg.py "autopep8 -i" generates the following patch: --- a/src/luajit_dbg.py +++ b/src/luajit_dbg.py @@ -651,7 +651,7 @@ def frame_ftsz(framelink):  def frame_pc(framelink):      return dbg.cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \ -                    else mref('BCIns *', framelink['fr']['tp']['pcr']) +        else mref('BCIns *', framelink['fr']['tp']['pcr'])  def frame_prevl(framelink): Feel free to ignore, but I propose following PEP8 style from the beginning. > delete mode 100644 src/luajit_lldb.py > > diff --git a/.flake8rc b/.flake8rc > index 13e6178f..e69de29b 100644 > --- a/.flake8rc > +++ b/.flake8rc > @@ -1,5 +0,0 @@ > -[flake8] > -extend-ignore = > - # XXX: Suppress F821, since we have autogenerated names for > - # 'ptr' type complements in luajit_lldb.py. > - F821 > diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py > deleted file mode 100644 > index be67bf18..00000000 > --- a/src/luajit-gdb.py > +++ /dev/null > @@ -1,884 +0,0 @@ > -# GDB extension for LuaJIT post-mortem analysis. > -# To use, just put 'source /src/luajit-gdb.py' in gdb. > - > -import re > -import gdb > -import sys > - > -# make script compatible with the ancient Python {{{ > - > - > -LEGACY = re.match(r'^2\.', sys.version) > - > -if LEGACY: > - CONNECTED = False > - int = long > - range = xrange > - > - > -# }}} > - > - > -gtype_cache = {} > - > - > -def gtype(typestr): > - if typestr in gtype_cache: > - return gtype_cache[typestr] > - > - m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr) > - > - gtype = gdb.lookup_type(typestr) if m is None \ > - else gdb.lookup_type(m.group(1)).pointer() > - > - gtype_cache[typestr] = gtype > - return gtype > - > - > -def cast(typestr, val): > - return gdb.Value(val).cast(gtype(typestr)) > - > - > -def lookup(symbol): > - variable, _ = gdb.lookup_symbol(symbol) > - return variable.value() if variable else None > - > - > -def parse_arg(arg): > - if not arg: > - return None > - > - ret = gdb.parse_and_eval(arg) > - > - if not ret: > - raise gdb.GdbError('table argument empty') > - > - return ret > - > - > -def tou64(val): > - return cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF > - > - > -def tou32(val): > - return cast('uint32_t', val) & 0xFFFFFFFF > - > - > -def i2notu32(val): > - return ~int(val) & 0xFFFFFFFF > - > - > -def strx64(val): > - return re.sub('L?$', '', > - hex(int(cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF))) > - > - > -# Types {{{ > - > - > -LJ_T = { > - 'NIL': i2notu32(0), > - 'FALSE': i2notu32(1), > - 'TRUE': i2notu32(2), > - 'LIGHTUD': i2notu32(3), > - 'STR': i2notu32(4), > - 'UPVAL': i2notu32(5), > - 'THREAD': i2notu32(6), > - 'PROTO': i2notu32(7), > - 'FUNC': i2notu32(8), > - 'TRACE': i2notu32(9), > - 'CDATA': i2notu32(10), > - 'TAB': i2notu32(11), > - 'UDATA': i2notu32(12), > - 'NUMX': i2notu32(13), > -} > - > - > -def typenames(value): > - return { > - LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys() > - }.get(int(value), 'LJ_TINVALID') > - > - > -# }}} > - > -# Frames {{{ > - > - > -FRAME_TYPE = 0x3 > -FRAME_P = 0x4 > -FRAME_TYPEP = FRAME_TYPE | FRAME_P > - > -FRAME = { > - 'LUA': 0x0, > - 'C': 0x1, > - 'CONT': 0x2, > - 'VARG': 0x3, > - 'LUAP': 0x4, > - 'CP': 0x5, > - 'PCALL': 0x6, > - 'PCALLH': 0x7, > -} > - > - > -def frametypes(ft): > - return { > - FRAME['LUA']: 'L', > - FRAME['C']: 'C', > - FRAME['CONT']: 'M', > - FRAME['VARG']: 'V', > - }.get(ft, '?') > - > - > -def bc_a(ins): > - return (ins >> 8) & 0xff > - > - > -def frame_ftsz(framelink): > - return cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2 > - else framelink['fr']['tp']['ftsz']) > - > - > -def frame_pc(framelink): > - return cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \ > - else mref('BCIns *', framelink['fr']['tp']['pcr']) > - > - > -def frame_prevl(framelink): > - return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1])) > - > - > -def frame_ispcall(framelink): > - return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL'] > - > - > -def frame_sized(framelink): > - return (frame_ftsz(framelink) & ~FRAME_TYPEP) > - > - > -def frame_prevd(framelink): > - return cast('TValue *', cast('char *', framelink) - frame_sized(framelink)) > - > - > -def frame_type(framelink): > - return frame_ftsz(framelink) & FRAME_TYPE > - > - > -def frame_typep(framelink): > - return frame_ftsz(framelink) & FRAME_TYPEP > - > - > -def frame_islua(framelink): > - return frametypes(int(frame_type(framelink))) == 'L' \ > - and int(frame_ftsz(framelink)) > 0 > - > - > -def frame_prev(framelink): > - return frame_prevl(framelink) if frame_islua(framelink) \ > - else frame_prevd(framelink) > - > - > -def frame_sentinel(L): > - return mref('TValue *', L['stack']) + LJ_FR2 > - > - > -# }}} > - > -# Const {{{ > - > - > -LJ_64 = None > -LJ_GC64 = None > -LJ_FR2 = None > -LJ_DUALNUM = None > - > -LJ_GCVMASK = ((1 << 47) - 1) > -LJ_TISNUM = None > -PADDING = None > - > -# These constants are meaningful only for 'LJ_64' mode. > -LJ_LIGHTUD_BITS_SEG = 8 > -LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG > -LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1 > -LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1 > - > - > -# }}} > - > - > -def itype(o): > - return cast('uint32_t', o['it64'] >> 47) if LJ_GC64 else o['it'] > - > - > -def mref(typename, obj): > - return cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32']) > - > - > -def gcref(obj): > - return cast('GCobj *', obj['gcptr64'] if LJ_GC64 > - else cast('uintptr_t', obj['gcptr32'])) > - > - > -def gcval(obj): > - return cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64 > - else cast('uintptr_t', obj['gcptr32'])) > - > - > -def gcnext(obj): > - return gcref(obj)['gch']['nextgc'] > - > - > -def L(L=None): > - # lookup a symbol for the main coroutine considering the host app > - # XXX Fragile: though the loop initialization looks like a crap but it > - # respects both Python 2 and Python 3. > - for lstate in [L] + list(map(lambda main: lookup(main), ( > - # LuaJIT main coro (see luajit/src/luajit.c) > - 'globalL', > - # Tarantool main coro (see tarantool/src/lua/init.h) > - 'tarantool_L', > - # TODO: Add more > - ))): > - if lstate: > - return cast('lua_State *', lstate) > - > - > -def G(L): > - return mref('global_State *', L['glref']) > - > - > -def J(g): > - typeGG = gtype('GG_State') > - > - return cast('jit_State *', int(cast('char *', g)) > - - int(typeGG['g'].bitpos / 8) > - + int(typeGG['J'].bitpos / 8)) > - > - > -def vm_state(g): > - return { > - i2notu32(0): 'INTERP', > - i2notu32(1): 'LFUNC', > - i2notu32(2): 'FFUNC', > - i2notu32(3): 'CFUNC', > - i2notu32(4): 'GC', > - i2notu32(5): 'EXIT', > - i2notu32(6): 'RECORD', > - i2notu32(7): 'OPT', > - i2notu32(8): 'ASM', > - }.get(int(tou32(g['vmstate'])), 'TRACE') > - > - > -def gc_state(g): > - return { > - 0: 'PAUSE', > - 1: 'PROPAGATE', > - 2: 'ATOMIC', > - 3: 'SWEEPSTRING', > - 4: 'SWEEP', > - 5: 'FINALIZE', > - 6: 'LAST', > - }.get(int(g['gc']['state']), 'INVALID') > - > - > -def jit_state(g): > - return { > - 0: 'IDLE', > - 0x10: 'ACTIVE', > - 0x11: 'RECORD', > - 0x12: 'START', > - 0x13: 'END', > - 0x14: 'ASM', > - 0x15: 'ERR', > - }.get(int(J(g)['state']), 'INVALID') > - > - > -def tvisint(o): > - return LJ_DUALNUM and itype(o) == LJ_TISNUM > - > - > -def tvisnumber(o): > - return itype(o) <= LJ_TISNUM > - > - > -def tvislightud(o): > - if LJ_64 and not LJ_GC64: > - return (cast('int32_t', itype(o)) >> 15) == -2 > - else: > - return itype(o) == LJ_T['LIGHTUD'] > - > - > -def strdata(obj): > - # String is printed with pointer to it, thanks to gdb. Just strip it. > - try: > - return str(cast('char *', cast('GCstr *', obj) + 1))[len(PADDING):] > - except UnicodeEncodeError: > - return "" > - > - > -def itypemap(o): > - if LJ_64 and not LJ_GC64: > - return LJ_T['NUMX'] if tvisnumber(o) \ > - else LJ_T['LIGHTUD'] if tvislightud(o) \ > - else itype(o) > - else: > - return LJ_T['NUMX'] if tvisnumber(o) else itype(o) > - > - > -def funcproto(func): > - assert func['ffid'] == 0 > - > - return cast('GCproto *', > - mref('char *', func['pc']) - gdb.lookup_type('GCproto').sizeof) > - > - > -def gclistlen(root, end=0x0): > - count = 0 > - while (gcref(root) != end): > - count += 1 > - root = gcnext(root) > - return count > - > - > -def gcringlen(root): > - if not gcref(root): > - return 0 > - elif gcref(root) == gcref(gcnext(root)): > - return 1 > - else: > - return 1 + gclistlen(gcnext(root), gcref(root)) > - > - > -gclen = { > - 'root': gclistlen, > - 'gray': gclistlen, > - 'grayagain': gclistlen, > - 'weak': gclistlen, > - # XXX: gc.mmudata is a ring-list. > - 'mmudata': gcringlen, > -} > - > - > -# The generator that implements frame iterator. > -# Every frame is represented as a tuple of framelink and frametop. > -def frames(L): > - frametop = L['top'] > - framelink = L['base'] - 1 > - framelink_sentinel = frame_sentinel(L) > - while True: > - yield framelink, frametop > - frametop = framelink - (1 + LJ_FR2) > - if framelink <= framelink_sentinel: > - break > - framelink = frame_prev(framelink) > - > - > -def lightudV(tv): > - if LJ_64: > - u = int(tv['u64']) > - # lightudseg macro expanded. > - seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK > - segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg']) > - # lightudlo macro expanded. > - return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK) > - else: > - return gcval(tv['gcr']) > - > - > -# Dumpers {{{ > - > - > -def dump_lj_tnil(tv): > - return 'nil' > - > - > -def dump_lj_tfalse(tv): > - return 'false' > - > - > -def dump_lj_ttrue(tv): > - return 'true' > - > - > -def dump_lj_tlightud(tv): > - return 'light userdata @ {}'.format(strx64(lightudV(tv))) > - > - > -def dump_lj_tstr(tv): > - return 'string {body} @ {address}'.format( > - body=strdata(gcval(tv['gcr'])), > - address=strx64(gcval(tv['gcr'])) > - ) > - > - > -def dump_lj_tupval(tv): > - return 'upvalue @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tthread(tv): > - return 'thread @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tproto(tv): > - return 'proto @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tfunc(tv): > - func = cast('struct GCfuncC *', gcval(tv['gcr'])) > - ffid = func['ffid'] > - > - if ffid == 0: > - pt = funcproto(func) > - return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format( > - addr=strx64(func), > - nups=int(func['nupvalues']), > - chunk=strdata(cast('GCstr *', gcval(pt['chunkname']))), > - line=pt['firstline'] > - ) > - elif ffid == 1: > - return 'C function @ {}'.format(strx64(func['f'])) > - else: > - return 'fast function #{}'.format(int(ffid)) > - > - > -def dump_lj_ttrace(tv): > - trace = cast('struct GCtrace *', gcval(tv['gcr'])) > - return 'trace {traceno} @ {addr}'.format( > - traceno=strx64(trace['traceno']), > - addr=strx64(trace) > - ) > - > - > -def dump_lj_tcdata(tv): > - return 'cdata @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_ttab(tv): > - table = cast('GCtab *', gcval(tv['gcr'])) > - return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format( > - gcr=strx64(table), > - asize=table['asize'], > - hmask=strx64(table['hmask']), > - ) > - > - > -def dump_lj_tudata(tv): > - return 'userdata @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tnumx(tv): > - if tvisint(tv): > - return 'integer {}'.format(cast('int32_t', tv['i'])) > - else: > - return 'number {}'.format(cast('double', tv['n'])) > - > - > -def dump_lj_invalid(tv): > - return 'not valid type @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -# }}} > - > - > -dumpers = { > - 'LJ_TNIL': dump_lj_tnil, > - 'LJ_TFALSE': dump_lj_tfalse, > - 'LJ_TTRUE': dump_lj_ttrue, > - 'LJ_TLIGHTUD': dump_lj_tlightud, > - 'LJ_TSTR': dump_lj_tstr, > - 'LJ_TUPVAL': dump_lj_tupval, > - 'LJ_TTHREAD': dump_lj_tthread, > - 'LJ_TPROTO': dump_lj_tproto, > - 'LJ_TFUNC': dump_lj_tfunc, > - 'LJ_TTRACE': dump_lj_ttrace, > - 'LJ_TCDATA': dump_lj_tcdata, > - 'LJ_TTAB': dump_lj_ttab, > - 'LJ_TUDATA': dump_lj_tudata, > - 'LJ_TNUMX': dump_lj_tnumx, > -} > - > - > -def dump_tvalue(tvalue): > - return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue) > - > - > -def dump_framelink_slot_address(fr): > - return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \ > - else '{}'.format(fr) + PADDING > - > - > -def dump_framelink(L, fr): > - if fr == frame_sentinel(L): > - return '{addr} [S ] FRAME: dummy L'.format( > - addr=dump_framelink_slot_address(fr), > - ) > - return '{addr} [ ] FRAME: [{pp}] delta={d}, {f}'.format( > - addr=dump_framelink_slot_address(fr), > - pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format( > - frname=frametypes(int(frame_type(fr))), > - p='P' if frame_typep(fr) & FRAME_P else '' > - ), > - d=cast('TValue *', fr) - cast('TValue *', frame_prev(fr)), > - f=dump_lj_tfunc(fr - LJ_FR2), > - ) > - > - > -def dump_stack_slot(L, slot, base=None, top=None): > - base = base or L['base'] > - top = top or L['top'] > - > - return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format( > - addr=strx64(slot), > - padding=PADDING, > - B='B' if slot == base else ' ', > - T='T' if slot == top else ' ', > - M='M' if slot == mref('TValue *', L['maxstack']) else ' ', > - value=dump_tvalue(slot), > - ) > - > - > -def dump_stack(L, base=None, top=None): > - base = base or L['base'] > - top = top or L['top'] > - stack = mref('TValue *', L['stack']) > - maxstack = mref('TValue *', L['maxstack']) > - red = 5 + 3 * LJ_FR2 > - > - dump = [ > - '{padding} Red zone: {nredslots: >2} slots {padding}'.format( > - padding='-' * len(PADDING), > - nredslots=red, > - ), > - ] > - dump.extend([ > - dump_stack_slot(L, maxstack + offset, base, top) > - for offset in range(red, 0, -1) # noqa: E131 > - ]) > - dump.extend([ > - '{padding} Stack: {nstackslots: >5} slots {padding}'.format( > - padding='-' * len(PADDING), > - nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3), > - ), > - dump_stack_slot(L, maxstack, base, top), > - '{start}:{end} [ ] {nfreeslots} slots: Free stack slots'.format( > - start=strx64(top + 1), > - end=strx64(maxstack - 1), > - nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3), > - ), > - ]) > - > - for framelink, frametop in frames(L): > - # Dump all data slots in the (framelink, top) interval. > - dump.extend([ > - dump_stack_slot(L, framelink + offset, base, top) > - for offset in range(frametop - framelink, 0, -1) # noqa: E131 > - ]) > - # Dump frame slot (2 slots in case of GC64). > - dump.append(dump_framelink(L, framelink)) > - > - return '\n'.join(dump) > - > - > -def dump_gc(g): > - gc = g['gc'] > - stats = ['{key}: {value}'.format(key=f, value=gc[f]) for f in ( > - 'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause' > - )] > - > - stats += ['sweepstr: {sweepstr}/{strmask}'.format( > - sweepstr=gc['sweepstr'], > - # String hash mask (size of hash table - 1). > - strmask=g['strmask'] + 1, > - )] > - > - stats += ['{key}: {number} objects'.format( > - key=stat, > - number=handler(gc[stat]) > - ) for stat, handler in gclen.items()] > - > - return '\n'.join(map(lambda s: '\t' + s, stats)) > - > - > -class LJBase(gdb.Command): > - > - def __init__(self, name): > - # XXX Fragile: though the command initialization looks like a crap but > - # it respects both Python 2 and Python 3. > - gdb.Command.__init__(self, name, gdb.COMMAND_DATA) > - gdb.write('{} command initialized\n'.format(name)) > - > - > -class LJDumpArch(LJBase): > - ''' > -lj-arch > - > -The command requires no args and dumps values of LJ_64 and LJ_GC64 > -compile-time flags. These values define the sizes of host and GC > -pointers respectively. > - ''' > - > - def invoke(self, arg, from_tty): > - gdb.write( > - 'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}\n' > - .format( > - LJ_64=LJ_64, > - LJ_GC64=LJ_GC64, > - LJ_DUALNUM=LJ_DUALNUM > - ) > - ) > - > - > -class LJDumpTValue(LJBase): > - ''' > -lj-tv > - > -The command receives a pointer to (TValue address) and dumps > -the type and some info related to it. > - > -* LJ_TNIL: nil > -* LJ_TFALSE: false > -* LJ_TTRUE: true > -* LJ_TLIGHTUD: light userdata @ > -* LJ_TSTR: string @ > -* LJ_TUPVAL: upvalue @ > -* LJ_TTHREAD: thread @ > -* LJ_TPROTO: proto @ > -* LJ_TFUNC: > - : Lua function @ , upvalues, > - : C function > - : fast function # > -* LJ_TTRACE: trace @ > -* LJ_TCDATA: cdata @ > -* LJ_TTAB: table @ (asize: , hmask: ) > -* LJ_TUDATA: userdata @ > -* LJ_TNUMX: number > - > -Whether the type of the given address differs from the listed above, then > -error message occurs. > - ''' > - > - def invoke(self, arg, from_tty): > - tv = cast('TValue *', parse_arg(arg)) > - gdb.write('{}\n'.format(dump_tvalue(tv))) > - > - > -class LJDumpString(LJBase): > - ''' > -lj-str > - > -The command receives a of the corresponding GCstr object and dumps > -the payload, size in bytes and hash. > - > -*Caveat*: Since Python 2 provides no native Unicode support, the payload > -is replaced with the corresponding error when decoding fails. > - ''' > - > - def invoke(self, arg, from_tty): > - string = cast('GCstr *', parse_arg(arg)) > - gdb.write("String: {body} [{len} bytes] with hash {hash}\n".format( > - body=strdata(string), > - hash=strx64(string['hash']), > - len=string['len'], > - )) > - > - > -class LJDumpTable(LJBase): > - ''' > -lj-tab > - > -The command receives a GCtab address and dumps the table contents: > -* Metatable address whether the one is set > -* Array part slots: > - : []: > -* Hash part nodes: > - : { } => { }; next = > - ''' > - > - def invoke(self, arg, from_tty): > - t = cast('GCtab *', parse_arg(arg)) > - array = mref('TValue *', t['array']) > - nodes = mref('struct Node *', t['node']) > - mt = gcval(t['metatable']) > - capacity = { > - 'apart': int(t['asize']), > - 'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0 > - } > - > - if mt != 0: > - gdb.write('Metatable detected: {}\n'.format(strx64(mt))) > - > - gdb.write('Array part: {} slots\n'.format(capacity['apart'])) > - for i in range(capacity['apart']): > - slot = array + i > - gdb.write('{ptr}: [{index}]: {value}\n'.format( > - ptr=slot, > - index=i, > - value=dump_tvalue(slot) > - )) > - > - gdb.write('Hash part: {} nodes\n'.format(capacity['hpart'])) > - # See hmask comment in lj_obj.h > - for i in range(capacity['hpart']): > - node = nodes + i > - gdb.write('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}\n'.format( > - ptr=node, > - key=dump_tvalue(node['key']), > - val=dump_tvalue(node['val']), > - n=mref('struct Node *', node['next']) > - )) > - > - > -class LJDumpStack(LJBase): > - ''' > -lj-stack [] > - > -The command receives a lua_State address and dumps the given Lua > -coroutine guest stack: > - > - [] > - > -* : guest stack slot address > -* : > - - S: Bottom of the stack (the slot L->stack points to) > - - B: Base of the current guest frame (the slot L->base points to) > - - T: Top of the current guest frame (the slot L->top points to) > - - M: Last slot of the stack (the slot L->maxstack points to) > -* : see help lj-tv for more info > -* : framelink slot differs from the value slot: it contains info > - related to the function being executed within this guest frame, its > - type and link to the parent guest frame > - [] delta=, > - - : > - + L: VM performs a call as a result of bytecode execution > - + C: VM performs a call as a result of lj_vm_call > - + M: VM performs a call to a metamethod as a result of bytecode > - execution > - + V: Variable-length frame for storing arguments of a variadic > - function > - + CP: Protected C frame > - + PP: VM performs a call as a result of executinig pcall or xpcall > - > -If L is omitted the main coroutine is used. > - ''' > - > - def invoke(self, arg, from_tty): > - gdb.write('{}\n'.format(dump_stack(L(parse_arg(arg))))) > - > - > -class LJState(LJBase): > - ''' > -lj-state > -The command requires no args and dumps current VM and GC states > -* VM state: > -* GC state: > -* JIT state: > - ''' > - > - def invoke(self, arg, from_tty): > - g = G(L(None)) > - gdb.write('{}\n'.format('\n'.join( > - map(lambda t: '{} state: {}'.format(*t), { > - 'VM': vm_state(g), > - 'GC': gc_state(g), > - 'JIT': jit_state(g), > - }.items()) > - ))) > - > - > -class LJGC(LJBase): > - ''' > -lj-gc > - > -The command requires no args and dumps current GC stats: > -* total: > -* threshold: > -* debt: > -* estimate: > -* stepmul: > -* pause: > -* sweepstr: > -* root: > -* gray: > -* grayagain: > -* weak: > -* mmudata: > - ''' > - > - def invoke(self, arg, from_tty): > - g = G(L(None)) > - gdb.write('GC stats: {state}\n{stats}\n'.format( > - state=gc_state(g), > - stats=dump_gc(g) > - )) > - > - > -def init(commands): > - global LJ_64, LJ_GC64, LJ_FR2, LJ_DUALNUM, LJ_TISNUM, PADDING > - > - # XXX Fragile: though connecting the callback looks like a crap but it > - # respects both Python 2 and Python 3 (see #4828). > - def connect(callback): > - if LEGACY: > - global CONNECTED > - CONNECTED = True > - gdb.events.new_objfile.connect(callback) > - > - # XXX Fragile: though disconnecting the callback looks like a crap but it > - # respects both Python 2 and Python 3 (see #4828). > - def disconnect(callback): > - if LEGACY: > - global CONNECTED > - if not CONNECTED: > - return > - CONNECTED = False > - gdb.events.new_objfile.disconnect(callback) > - > - try: > - # Try to remove the callback at first to not append duplicates to > - # gdb.events.new_objfile internal list. > - disconnect(load) > - except Exception: > - # Callback is not connected. > - pass > - > - try: > - # Detect whether libluajit objfile is loaded. > - gdb.parse_and_eval('luaJIT_setmode') > - except Exception: > - gdb.write('luajit-gdb.py initialization is postponed ' > - 'until libluajit objfile is loaded\n') > - # Add a callback to be executed when the next objfile is loaded. > - connect(load) > - return > - > - try: > - LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64' > - LJ_FR2 = LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64' > - LJ_DUALNUM = gdb.lookup_global_symbol('lj_lib_checknumber') is not None > - except Exception: > - gdb.write('luajit-gdb.py failed to load: ' > - 'no debugging symbols found for libluajit\n') > - return > - > - for name, command in commands.items(): > - command(name) > - > - PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1)) > - LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX'] > - > - gdb.write('luajit-gdb.py is successfully loaded\n') > - > - > -def load(event=None): > - init({ > - 'lj-arch': LJDumpArch, > - 'lj-gc': LJGC, > - 'lj-stack': LJDumpStack, > - 'lj-state': LJState, > - 'lj-str': LJDumpString, > - 'lj-tab': LJDumpTable, > - 'lj-tv': LJDumpTValue, > - }) > - > - > -load(None) > diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py > new file mode 100644 > index 00000000..164f0955 > --- /dev/null > +++ b/src/luajit_dbg.py > @@ -0,0 +1,1281 @@ > +# Debug extension for LuaJIT post-mortem analysis. > +# To use in GDB: > +# `source /src/luajit_dbg.py' > +# To use in LLDB: > +# `command script import /src/luajit_dbg.py' > + > +import abc > +import re > +import struct > +import sys > + > +from importlib import import_module > + > +# Make the script compatible with ancient Python. > +LEGACY = re.match(r'^2\.', sys.version) > + > +if LEGACY: > + int = long # noqa: F821 > + range = xrange # noqa: F821 > + > + > +# Debugger. ###################################################### > + > + > +lldb = None > +gdb = None > + > +# XXX: While the `gdb` library is only available inside a debug > +# session, the `lldb` library can be loaded in any Python script. > +# To address that, we need to perform an additional check to > +# ensure a debug session is actually running. > +debuggers = { > + 'gdb': lambda lib: True, > + 'lldb': lambda lib: lib.debugger is not None, > +} > +for name, healthcheck in debuggers.items(): > + lib = None > + try: > + lib = import_module(name) > + if healthcheck(lib): > + globals()[name] = lib > + break > + except Exception: > + continue > + > +assert (not not lldb) != (not not gdb), 'Debugger must be either LLDB or GDB.' > + > + > +class Debugger(object): > + def __init__(self): > + self.dbgtype_cache = {} > + > + def __new__(self): > + if gdb: > + self.GDB = True > + return super(Debugger, self).__new__(_GDBDebugger) > + elif lldb: > + self.LLDB = True > + return super(Debugger, self).__new__(_LLDBDebugger) > + > + def configure(self): > + global PADDING, LJ_TISNUM > + if not self.check_libluajit(): > + return False > + try: > + self.init_luajit_arch() > + PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1)) > + LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX'] > + except Exception: > + self.write('luajit_dbg.py failed to load: ' > + 'no debugging symbols found for libluajit\n') > + return False > + return True > + > + def initialize_extension(self, commands): > + if self.configure(): > + for name, command in commands.items(): > + self.register_command(command, name) > + self.write('{} command initialized\n'.format(name)) > + self.write('LuaJIT debug extension is successfully loaded\n') > + > + @abc.abstractmethod > + def cast(self, typestr, val): > + '''Cast the value to the required C type.''' > + pass > + > + @abc.abstractmethod > + def sizeof(self, typestr): > + '''Return the size of the given type in bytes.''' > + pass > + > + @abc.abstractmethod > + def offsetof(self, typestr, fieldstr): > + '''Return the offset of the given field in the type in bytes.''' > + pass > + > + @abc.abstractmethod > + def cstr(self, strptr): > + '''Return the content of the string by the given pointer.''' > + pass > + > + @abc.abstractmethod > + def lookup_global(self, symbol): > + '''Look up the global C symbol by the given name.''' > + pass > + > + @abc.abstractmethod > + def eval(self, command): > + '''Parse and evaluate the given debugger command.''' > + pass > + > + @abc.abstractmethod > + def write(self, msg): > + '''Print the message.''' > + pass > + > + @abc.abstractmethod > + def check_libluajit(self): > + '''Check that libluajit is loaded. > + Check that the object file with libluajit symbols is loaded. > + Postpone loading of the extension if needed. > + ''' > + pass > + > + @abc.abstractmethod > + def init_luajit_arch(self): > + '''Initialize LuaJIT architecture-specific globals. > + Initialize build-dependent global constants. > + If no debugging symbols are found raise an error. > + ''' > + pass > + > + @abc.abstractmethod > + def register_command(self, command, name): > + '''Register the command with the corresponding name.''' > + pass > + > + @abc.abstractproperty > + def LJBase(self): > + '''Base command class. > + Provides the base class for the extension commands. > + ''' > + > + > +class _GDBDebugger(Debugger): > + def _dbgtype(self, typestr): > + if typestr in self.dbgtype_cache: > + return self.dbgtype_cache[typestr] > + > + m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr) > + > + dbgtype = gdb.lookup_type(typestr) if m is None \ > + else gdb.lookup_type(m.group(1)).pointer() > + > + self.dbgtype_cache[typestr] = dbgtype > + return dbgtype > + > + def __init__(self): > + super(_GDBDebugger, self).__init__() > + self.CONNECTED = False > + > + def cast(self, typestr, val): > + return gdb.Value(val).cast(self._dbgtype(typestr)) > + > + def sizeof(self, typestr): > + return self._dbgtype(typestr).sizeof > + > + def offsetof(self, typestr, fieldstr): > + return int(self._dbgtype(typestr)[fieldstr].bitpos / 8) > + > + def cstr(self, strptr): > + # A string is printed with a pointer to it. Just strip it. > + return re.sub(r'^0x[a-f0-9]+\s+(?=")', '', str(strptr)) > + > + def lookup_global(self, symbol): > + variable, _ = gdb.lookup_symbol(symbol) > + return variable.value() if variable else None > + > + def eval(self, command): > + if not command: > + return None > + > + ret = gdb.parse_and_eval(command) > + if not ret: > + raise gdb.GdbError('table argument empty') > + return ret > + > + def write(self, msg): > + gdb.write(msg) > + > + def check_libluajit(self): > + # XXX Fragile: Though connecting the callback looks bad, > + # it respects both Python 2 and Python 3 (see #4828). > + def connect(callback): > + if LEGACY: > + self.CONNECTED = True > + gdb.events.new_objfile.connect(callback) > + > + # XXX Fragile: Though disconnecting the callback looks > + # bad, it respects both Python 2 and Python 3 (see #4828). > + def disconnect(callback): > + if LEGACY: > + if not self.CONNECTED: > + return > + self.CONNECTED = False > + gdb.events.new_objfile.disconnect(callback) > + > + try: > + # Try to remove the callback at first to not append > + # duplicates to gdb.events.new_objfile internal list. > + disconnect(load) > + except Exception: > + # Callback is not connected. > + pass > + > + try: > + # Detect whether libluajit objfile is loaded. > + gdb.parse_and_eval('luaJIT_setmode') > + except Exception: > + gdb.write('luajit_dbg.py initialization is postponed ' > + 'until libluajit objfile is loaded\n') > + # Add a callback to be executed when the next objfile > + # is loaded. > + connect(load) > + return False > + return True > + > + def init_luajit_arch(self): > + global LJ_64, LJ_DUALNUM, LJ_FR2, LJ_GC64 > + LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64' > + LJ_DUALNUM = gdb.lookup_global_symbol('lj_lib_checknumber') is not None > + LJ_FR2 = LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64' > + > + def register_command(self, command, name): > + command(name) > + > + class LJBase(gdb and gdb.Command or object): > + def __init__(ljbase, name): > + # XXX Fragile: Though the command initialization looks > + # bad, it respects both Python 2 and Python 3. > + gdb.Command.__init__(ljbase, name, gdb.COMMAND_DATA) > + > + def invoke(ljbase, args, from_tty): > + return ljbase.execute(args) > + > + @abc.abstractmethod > + def execute(ljbase, args): > + '''Implementation of the command. > + Subclasses override this method to implement the logic of a given > + command, e.g. printing a stack. > + ''' > + > + LJBase = LJBase > + > + > +class _LLDBDebugger(Debugger): > + def _lldb_tp_isfp(self, tp): > + return tp.GetBasicType() in [ > + lldb.eBasicTypeFloat, > + lldb.eBasicTypeDouble, > + lldb.eBasicTypeLongDouble > + ] > + > + def _lldb_value_from_raw(self, raw_value, size, tp): > + isfp = self._lldb_tp_isfp(tp) > + pack_flag = ' + raw_data = struct.pack(pack_flag, raw_value) > + sbdata = lldb.SBData() > + sbdata.SetData( > + lldb.SBError(), > + raw_data, > + lldb.eByteOrderLittle, > + size > + ) > + sbval_res = self.target.CreateValueFromData( > + # XXX: Name is required, let's make it meaningful. > + '({tp}){val}'.format( > + tp=tp.name, > + val=raw_value if isfp else hex(raw_value) > + ), > + sbdata, > + tp > + ) > + return lldb.value(sbval_res) > + > + def __init__(self): > + def lldb__add__(lldbval, other): > + other = int(other) > + sbvalue = lldbval.sbvalue > + if sbvalue.TypeIsPointerType(): > + tp = sbvalue.GetType() > + sz = sbvalue.deref.size > + addr = sbvalue.GetValueAsUnsigned() + other * sz > + return self._lldb_value_from_raw( > + addr, sbvalue.GetByteSize(), tp > + ) > + else: > + return int(lldbval) + other > + > + def lldb__bool__(lldbval): > + return int(lldbval) != 0 > + > + def lldb__ge__(lldbval, other): > + return int(lldbval) >= int(other) > + > + def lldb__getitem__(lldbval, key): > + if type(key) is lldb.value: > + key = int(key) > + if type(key) is int: > + # Allow array access. > + return lldb.value( > + lldbval.sbvalue.GetValueForExpressionPath('[%i]' % key) > + ) > + elif type(key) is str: > + return lldb.value(lldbval.sbvalue.GetChildMemberWithName(key)) > + raise Exception(TypeError('No item of type %s' % str(type(key)))) > + > + def lldb__gt__(lldbval, other): > + return int(lldbval) > int(other) > + > + def lldb__le__(lldbval, other): > + return int(lldbval) <= int(other) > + > + def lldb__lt__(lldbval, other): > + return int(lldbval) < int(other) > + > + def lldb__str__(lldbval): > + # Instead of default GetSummary. > + if not lldbval.sbvalue.TypeIsPointerType(): > + tp = lldbval.sbvalue.GetType() > + is_float = self._lldb_tp_isfp(tp) > + if is_float: > + return lldbval.sbvalue.GetValue() > + else: > + return str(int(lldbval)) > + > + s = lldbval.sbvalue.GetValue() > + if s[:2] == '0x': > + # Strip useless leading zeros. > + res = s[2:].lstrip('0') > + return '0x' + (res if res else '0') > + return s > + > + def lldb__sub__(lldbval, other): > + if type(other) is not lldb.value or \ > + type(other) is lldb.value and \ > + not other.sbvalue.TypeIsPointerType(): > + other = int(other) > + if type(other) is int: > + return lldb__add__(lldbval, -other) > + elif lldbval.sbvalue.TypeIsPointerType(): > + sbval = lldbval.sbvalue > + osbval = other.sbvalue > + lldbval_tp = sbval.GetType() > + other_tp = osbval.GetType() > + # Subtract pointers of the same size only. > + elsz = lldbval_tp.GetDereferencedType().size > + if other_tp.GetDereferencedType().size != elsz: > + raise Exception( > + 'Attempt to substruct {otp} from {stp}'.format( > + stp=lldbval_tp.name, > + otp=other_tp.name > + ) > + ) > + diff = sbval.GetValueAsUnsigned() - osbval.GetValueAsUnsigned() > + return int(diff / elsz) > + else: > + return int(lldbval) - int(other) > + > + super(_LLDBDebugger, self).__init__() > + self.target = lldb.debugger.GetSelectedTarget() > + # Monkey-patch the lldb.value class. > + lldb.value.__add__ = lldb__add__ > + lldb.value.__bool__ = lldb__bool__ > + lldb.value.__ge__ = lldb__ge__ > + lldb.value.__getitem__ = lldb__getitem__ > + lldb.value.__gt__ = lldb__gt__ > + lldb.value.__le__ = lldb__le__ > + lldb.value.__lt__ = lldb__lt__ > + lldb.value.__str__ = lldb__str__ > + lldb.value.__sub__ = lldb__sub__ > + > + def lldb_major_version(): > + version_string = lldb.SBDebugger.GetVersionString() > + match = re.search(r'(\d+)', version_string) > + if match: > + return int(match.group(1)) > + return None > + > + # Needed for features detection. > + self.version = lldb_major_version() > + > + def _dbgtype(self, typestr): > + if typestr in self.dbgtype_cache: > + return self.dbgtype_cache[typestr] > + > + m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr) > + > + dbgtype = self.target.FindFirstType(typestr) if m is None \ > + else self.target.FindFirstType(m.group(1)).GetPointerType() > + > + self.dbgtype_cache[typestr] = dbgtype > + return dbgtype > + > + def cast(self, typestr, val): > + if isinstance(val, lldb.value): > + val = val.sbvalue > + elif type(val) is int: > + tp = self._dbgtype(typestr) > + return self._lldb_value_from_raw(val, tp.GetByteSize(), tp) > + elif not isinstance(val, lldb.SBValue): > + raise Exception( > + 'Unexpected cast from type: {t}.'.format(t=type(val)) > + ) > + > + # XXX: Simply SBValue.Cast() works incorrectly since it > + # may take the 8 bytes of memory instead of 4, before the > + # cast. Construct the value on the fly. > + tp = self._dbgtype(typestr) > + is_fp = self._lldb_tp_isfp(tp) > + rawval = float(val.GetValue()) if is_fp else val.GetValueAsUnsigned() > + return self._lldb_value_from_raw(rawval, val.GetByteSize(), tp) > + > + def sizeof(self, typestr): > + return self._dbgtype(typestr).GetByteSize() > + > + def offsetof(self, typestr, fieldstr): > + def _type_member(type_obj, name): > + return next((x for x in type_obj.members if x.name == name), None) > + > + type_obj = self._dbgtype(typestr) > + member = _type_member(type_obj, fieldstr) > + assert member is not None, 'There is no field {f} in {t}'.format( > + f=fieldstr, > + t=typestr, > + ) > + return member.GetOffsetInBytes() > + > + def cstr(self, strptr): > + return strptr.sbvalue.summary > + > + def lookup_global(self, symbol): > + return self.target.FindFirstGlobalVariable(symbol) > + > + def eval(self, command): > + if not command: > + return None > + > + process = self.target.GetProcess() > + thread = process.GetSelectedThread() > + frame = thread.GetSelectedFrame() > + ret = frame.EvaluateExpression(command) > + return ret > + > + def write(self, msg): > + sys.stdout.write(msg) > + > + def check_libluajit(self): > + # TODO: Implement postpone loading for LLDB too. > + return True > + > + def init_luajit_arch(self): > + global LJ_64, LJ_DUALNUM, LJ_FR2, LJ_GC64 > + IRT_P64 = 9 > + module = self.target.modules[0] > + LJ_DUALNUM = module.FindSymbol('lj_lib_checknumber') is not None > + irtype_enum = self.target.FindFirstType('IRType').enum_members > + for member in irtype_enum: > + if member.name == 'IRT_PTR': > + LJ_64 = member.unsigned & 0x1f == IRT_P64 > + if member.name == 'IRT_PGC': > + LJ_FR2 = LJ_GC64 = member.unsigned & 0x1f == IRT_P64 > + > + def register_command(self, command, name): > + command.name = name > + lldb.debugger.HandleCommand( > + 'command script add {o} --class luajit_dbg.{cls} {cmd}'.format( > + o='--overwrite' if self.version >= 14 else '', > + cls=command.__name__, > + cmd=name, > + ) > + ) > + > + class LJBase(object): > + # Ignore given parameters by LLDB. > + def __init__(ljbase, debugger, unused): > + pass > + > + def get_short_help(ljbase): > + return ljbase.__doc__.splitlines()[1] > + > + def get_long_help(ljbase): > + return ljbase.__doc__ > + > + def __call__(ljbase, debugger, args, exe_ctx, result): > + try: > + ljbase.execute(args) > + except Exception as e: > + msg = 'Failed to execute command `{}`: {}'.format( > + ljbase.name, > + e > + ) > + result.SetError(msg) > + > + @abc.abstractmethod > + def execute(ljbase, args): > + '''Implementation of the command. > + Subclasses override this method to implement the logic of a given > + command, e.g. printing a stack. Any unhandled exception will be > + automatically transformed into proper errors. > + ''' > + > + LJBase = LJBase > + > + > +dbg = Debugger() > + > + > +# LuaJIT. ######################################################## > + > + > +# Constants. > + > + > +LJ_64 = None > +LJ_DUALNUM = None > +LJ_FR2 = None > +LJ_GC64 = None > + > +LJ_GCVMASK = ((1 << 47) - 1) > +LJ_TISNUM = None > +PADDING = None > + > +# These constants are meaningful only for 'LJ_64' mode. > +LJ_LIGHTUD_BITS_SEG = 8 > +LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG > +LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1 > +LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1 > + > + > +# Simple converters. > + > + > +def tou64(val): > + return dbg.cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF > + > + > +def tou32(val): > + return int(val) & 0xFFFFFFFF > + > + > +def i2notu32(val): > + return ~int(val) & 0xFFFFFFFF > + > + > +def strx64(val): > + return re.sub('L?$', '', hex(int(tou64(val)))) > + > + > +# Types and TValues. > + > + > +LJ_T = { > + 'NIL': i2notu32(0), > + 'FALSE': i2notu32(1), > + 'TRUE': i2notu32(2), > + 'LIGHTUD': i2notu32(3), > + 'STR': i2notu32(4), > + 'UPVAL': i2notu32(5), > + 'THREAD': i2notu32(6), > + 'PROTO': i2notu32(7), > + 'FUNC': i2notu32(8), > + 'TRACE': i2notu32(9), > + 'CDATA': i2notu32(10), > + 'TAB': i2notu32(11), > + 'UDATA': i2notu32(12), > + 'NUMX': i2notu32(13), > +} > + > + > +def typenames(value): > + return { > + LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys() > + }.get(int(value), 'LJ_TINVALID') > + > + > +def itype(o): > + return tou32(o['it64'] >> 47) if LJ_GC64 else o['it'] > + > + > +def tvisint(o): > + return LJ_DUALNUM and itype(o) == LJ_TISNUM > + > + > +def tvisnumber(o): > + return itype(o) <= LJ_TISNUM > + > + > +def tvislightud(o): > + if LJ_64 and not LJ_GC64: > + return (dbg.cast('int32_t', itype(o)) >> 15) == -2 > + else: > + return itype(o) == LJ_T['LIGHTUD'] > + > + > +def itypemap(o): > + if LJ_64 and not LJ_GC64: > + return LJ_T['NUMX'] if tvisnumber(o) \ > + else LJ_T['LIGHTUD'] if tvislightud(o) \ > + else itype(o) > + else: > + return LJ_T['NUMX'] if tvisnumber(o) else itype(o) > + > + > +# Frames. > + > + > +FRAME_TYPE = 0x3 > +FRAME_P = 0x4 > +FRAME_TYPEP = FRAME_TYPE | FRAME_P > + > +FRAME = { > + 'LUA': 0x0, > + 'C': 0x1, > + 'CONT': 0x2, > + 'VARG': 0x3, > + 'LUAP': 0x4, > + 'CP': 0x5, > + 'PCALL': 0x6, > + 'PCALLH': 0x7, > +} > + > + > +def frametypes(ft): > + return { > + FRAME['LUA']: 'L', > + FRAME['C']: 'C', > + FRAME['CONT']: 'M', > + FRAME['VARG']: 'V', > + }.get(ft, '?') > + > + > +def bc_a(ins): > + return (ins >> 8) & 0xff > + > + > +def frame_ftsz(framelink): > + return dbg.cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2 > + else framelink['fr']['tp']['ftsz']) > + > + > +def frame_pc(framelink): > + return dbg.cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \ > + else mref('BCIns *', framelink['fr']['tp']['pcr']) > + > + > +def frame_prevl(framelink): > + return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1])) > + > + > +def frame_ispcall(framelink): > + return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL'] > + > + > +def frame_sized(framelink): > + return (frame_ftsz(framelink) & ~FRAME_TYPEP) > + > + > +def frame_prevd(framelink): > + return dbg.cast('TValue *', > + dbg.cast('char *', framelink) - frame_sized(framelink)) > + > + > +def frame_type(framelink): > + return frame_ftsz(framelink) & FRAME_TYPE > + > + > +def frame_typep(framelink): > + return frame_ftsz(framelink) & FRAME_TYPEP > + > + > +def frame_islua(framelink): > + return frametypes(int(frame_type(framelink))) == 'L' \ > + and int(frame_ftsz(framelink)) > 0 > + > + > +def frame_prev(framelink): > + return frame_prevl(framelink) if frame_islua(framelink) \ > + else frame_prevd(framelink) > + > + > +def frame_sentinel(L): > + return mref('TValue *', L['stack']) + LJ_FR2 > + > + > +# The generator that implements frame iterator. > +# Every frame is represented as a tuple of framelink and frametop. > +def frames(L): > + frametop = L['top'] > + framelink = L['base'] - 1 > + framelink_sentinel = frame_sentinel(L) > + while True: > + yield framelink, frametop > + frametop = framelink - (1 + LJ_FR2) > + if framelink <= framelink_sentinel: > + break > + framelink = frame_prev(framelink) > + > + > +# LuaJIT macro implementations and structure access. > + > + > +def mref(typename, obj): > + return dbg.cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32']) > + > + > +def gcref(obj): > + return dbg.cast('GCobj *', obj['gcptr64'] if LJ_GC64 > + else dbg.cast('uintptr_t', obj['gcptr32'])) > + > + > +def gcval(obj): > + return dbg.cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64 > + else dbg.cast('uintptr_t', obj['gcptr32'])) > + > + > +def gcnext(obj): > + return gcref(obj)['gch']['nextgc'] > + > + > +def L(L=None): > + # Look up a symbol for the main coroutine considering the host > + # application. > + # XXX Fragile: Though the loop initialization looks bad, it > + # respects both Python 2 and Python 3. > + for lstate in [L] + list(map(lambda main: dbg.lookup_global(main), ( > + # LuaJIT main coro (see luajit/src/luajit.c). > + 'globalL', > + # Tarantool main coro (see tarantool/src/lua/init.h). > + 'tarantool_L', > + # TODO: Add more. > + ))): > + if lstate: > + return dbg.cast('lua_State *', lstate) > + > + > +def G(L): > + return mref('global_State *', L['glref']) > + > + > +def J(g): > + g_offset = dbg.offsetof('GG_State', 'g') > + J_offset = dbg.offsetof('GG_State', 'J') > + return dbg.cast('jit_State *', dbg.cast('char *', g) - g_offset + J_offset) > + > + > +def vm_state(g): > + return { > + i2notu32(0): 'INTERP', > + i2notu32(1): 'LFUNC', > + i2notu32(2): 'FFUNC', > + i2notu32(3): 'CFUNC', > + i2notu32(4): 'GC', > + i2notu32(5): 'EXIT', > + i2notu32(6): 'RECORD', > + i2notu32(7): 'OPT', > + i2notu32(8): 'ASM', > + }.get(int(tou32(g['vmstate'])), 'TRACE') > + > + > +def gc_state(g): > + return { > + 0: 'PAUSE', > + 1: 'PROPAGATE', > + 2: 'ATOMIC', > + 3: 'SWEEPSTRING', > + 4: 'SWEEP', > + 5: 'FINALIZE', > + 6: 'LAST', > + }.get(int(g['gc']['state']), 'INVALID') > + > + > +def jit_state(g): > + return { > + 0: 'IDLE', > + 0x10: 'ACTIVE', > + 0x11: 'RECORD', > + 0x12: 'START', > + 0x13: 'END', > + 0x14: 'ASM', > + 0x15: 'ERR', > + }.get(int(J(g)['state']), 'INVALID') > + > + > +def strdata(obj): > + try: > + return dbg.cstr(dbg.cast('char *', dbg.cast('GCstr *', obj) + 1)) > + except UnicodeEncodeError: > + return "" > + > + > +def funcproto(func): > + assert func['ffid'] == 0, 'Attempt to take a prototype of non-Lua function' > + return dbg.cast('GCproto *', > + mref('char *', func['pc']) - dbg.sizeof('GCproto')) > + > + > +def gclistlen(root, end=0x0): > + count = 0 > + while (gcref(root) != end): > + count += 1 > + root = gcnext(root) > + return count > + > + > +def gcringlen(root): > + if not gcref(root): > + return 0 > + elif gcref(root) == gcref(gcnext(root)): > + return 1 > + else: > + return 1 + gclistlen(gcnext(root), gcref(root)) > + > + > +gclen = { > + 'root': gclistlen, > + 'gray': gclistlen, > + 'grayagain': gclistlen, > + 'weak': gclistlen, > + # XXX: gc.mmudata is a ring-list. > + 'mmudata': gcringlen, > +} > + > + > +def lightudV(tv): > + if LJ_64: > + u = int(tv['u64']) > + # `lightudseg()' macro expanded. > + seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK > + segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg']) > + # `lightudlo()' macro expanded. > + return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK) > + else: > + return gcval(tv['gcr']) > + > + > +# Dumpers. > + > + > +def dump_lj_tnil(tv): > + return 'nil' > + > + > +def dump_lj_tfalse(tv): > + return 'false' > + > + > +def dump_lj_ttrue(tv): > + return 'true' > + > + > +def dump_lj_tlightud(tv): > + return 'light userdata @ {}'.format(strx64(lightudV(tv))) > + > + > +def dump_lj_tstr(tv): > + return 'string {body} @ {address}'.format( > + body=strdata(gcval(tv['gcr'])), > + address=strx64(gcval(tv['gcr'])) > + ) > + > + > +def dump_lj_tupval(tv): > + return 'upvalue @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +def dump_lj_tthread(tv): > + return 'thread @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +def dump_lj_tproto(tv): > + return 'proto @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +def dump_lj_tfunc(tv): > + func = dbg.cast('struct GCfuncC *', gcval(tv['gcr'])) > + ffid = func['ffid'] > + > + if ffid == 0: > + pt = funcproto(func) > + return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format( > + addr=strx64(func), > + nups=int(func['nupvalues']), > + chunk=strdata(dbg.cast('GCstr *', gcval(pt['chunkname']))), > + line=pt['firstline'] > + ) > + elif ffid == 1: > + return 'C function @ {}'.format(strx64(func['f'])) > + else: > + return 'fast function #{}'.format(int(ffid)) > + > + > +def dump_lj_ttrace(tv): > + trace = dbg.cast('struct GCtrace *', gcval(tv['gcr'])) > + return 'trace {traceno} @ {addr}'.format( > + traceno=strx64(trace['traceno']), > + addr=strx64(trace) > + ) > + > + > +def dump_lj_tcdata(tv): > + return 'cdata @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +def dump_lj_ttab(tv): > + table = dbg.cast('GCtab *', gcval(tv['gcr'])) > + return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format( > + gcr=strx64(table), > + asize=table['asize'], > + hmask=strx64(table['hmask']), > + ) > + > + > +def dump_lj_tudata(tv): > + return 'userdata @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +def dump_lj_tnumx(tv): > + if tvisint(tv): > + return 'integer {}'.format(dbg.cast('int32_t', tv['i'])) > + else: > + return 'number {}'.format(dbg.cast('double', tv['n'])) > + > + > +def dump_lj_invalid(tv): > + return 'not valid type @ {}'.format(strx64(gcval(tv['gcr']))) > + > + > +dumpers = { > + 'LJ_TNIL': dump_lj_tnil, > + 'LJ_TFALSE': dump_lj_tfalse, > + 'LJ_TTRUE': dump_lj_ttrue, > + 'LJ_TLIGHTUD': dump_lj_tlightud, > + 'LJ_TSTR': dump_lj_tstr, > + 'LJ_TUPVAL': dump_lj_tupval, > + 'LJ_TTHREAD': dump_lj_tthread, > + 'LJ_TPROTO': dump_lj_tproto, > + 'LJ_TFUNC': dump_lj_tfunc, > + 'LJ_TTRACE': dump_lj_ttrace, > + 'LJ_TCDATA': dump_lj_tcdata, > + 'LJ_TTAB': dump_lj_ttab, > + 'LJ_TUDATA': dump_lj_tudata, > + 'LJ_TNUMX': dump_lj_tnumx, > +} > + > + > +def dump_tvalue(tvalue): > + return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue) > + > + > +def dump_framelink_slot_address(fr): > + return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \ > + else '{}'.format(fr) + PADDING > + > + > +def dump_framelink(L, fr): > + if fr == frame_sentinel(L): > + return '{addr} [S ] FRAME: dummy L'.format( > + addr=dump_framelink_slot_address(fr), > + ) > + return '{addr} [ ] FRAME: [{pp}] delta={d}, {f}'.format( > + addr=dump_framelink_slot_address(fr), > + pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format( > + frname=frametypes(int(frame_type(fr))), > + p='P' if frame_typep(fr) & FRAME_P else '' > + ), > + d=dbg.cast('TValue *', fr) - dbg.cast('TValue *', frame_prev(fr)), > + f=dump_lj_tfunc(fr - LJ_FR2), > + ) > + > + > +def dump_stack_slot(L, slot, base=None, top=None): > + base = base or L['base'] > + top = top or L['top'] > + > + return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format( > + addr=strx64(slot), > + padding=PADDING, > + B='B' if slot == base else ' ', > + T='T' if slot == top else ' ', > + M='M' if slot == mref('TValue *', L['maxstack']) else ' ', > + value=dump_tvalue(slot), > + ) > + > + > +def dump_stack(L, base=None, top=None): > + base = base or L['base'] > + top = top or L['top'] > + stack = mref('TValue *', L['stack']) > + maxstack = mref('TValue *', L['maxstack']) > + red = 5 + 3 * LJ_FR2 > + > + dump = [ > + '{padding} Red zone: {nredslots: >2} slots {padding}'.format( > + padding='-' * len(PADDING), > + nredslots=red, > + ), > + ] > + dump.extend([ > + dump_stack_slot(L, maxstack + offset, base, top) > + for offset in range(red, 0, -1) # noqa: E131 > + ]) > + dump.extend([ > + '{padding} Stack: {nstackslots: >5} slots {padding}'.format( > + padding='-' * len(PADDING), > + nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3), > + ), > + dump_stack_slot(L, maxstack, base, top), > + '{start}:{end} [ ] {nfreeslots} slots: Free stack slots'.format( > + start=strx64(top + 1), > + end=strx64(maxstack - 1), > + nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3), > + ), > + ]) > + > + for framelink, frametop in frames(L): > + # Dump all data slots in the (framelink, top) interval. > + dump.extend([ > + dump_stack_slot(L, framelink + offset, base, top) > + for offset in range(frametop - framelink, 0, -1) # noqa: E131 > + ]) > + # Dump frame slot (2 slots in case of GC64). > + dump.append(dump_framelink(L, framelink)) > + > + return '\n'.join(dump) > + > + > +def dump_gc(g): > + gc = g['gc'] > + stats = ['{key}: {value}'.format(key=f, value=gc[f]) for f in ( > + 'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause' > + )] > + > + stats += ['sweepstr: {sweepstr}/{strmask}'.format( > + sweepstr=gc['sweepstr'], > + # String hash mask (size of hash table - 1). > + strmask=g['strmask'] + 1, > + )] > + > + stats += ['{key}: {number} objects'.format( > + key=stat, > + number=handler(gc[stat]) > + ) for stat, handler in gclen.items()] > + > + return '\n'.join(map(lambda s: '\t' + s, stats)) > + > + > +# Extension commands. ############################################ > + > + > +class LJDumpArch(dbg.LJBase): > + ''' > +lj-arch > + > +The command requires no args and dumps values of LJ_64 and LJ_GC64 > +compile-time flags. These values define the sizes of host and GC > +pointers, respectively. > + ''' > + > + def execute(self, arg): > + dbg.write( > + 'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}\n' > + .format( > + LJ_64=LJ_64, > + LJ_GC64=LJ_GC64, > + LJ_DUALNUM=LJ_DUALNUM > + ) > + ) > + > + > +class LJGC(dbg.LJBase): > + ''' > +lj-gc > + > +The command requires no args and dumps current GC stats: > +* total: > +* threshold: > +* debt: > +* estimate: > +* stepmul: > +* pause: > +* sweepstr: > +* root: > +* gray: > +* grayagain: > +* weak: > +* mmudata: > + ''' > + > + def execute(self, arg): > + g = G(L(None)) > + dbg.write('GC stats: {state}\n{stats}\n'.format( > + state=gc_state(g), > + stats=dump_gc(g) > + )) > + > + > +class LJDumpStack(dbg.LJBase): > + ''' > +lj-stack [] > + > +The command receives a lua_State address and dumps the given Lua > +coroutine guest stack: > + > + [] > + > +* : guest stack slot address > +* : > + - S: Bottom of the stack (the slot L->stack points to) > + - B: Base of the current guest frame (the slot L->base points to) > + - T: Top of the current guest frame (the slot L->top points to) > + - M: Last slot of the stack (the slot L->maxstack points to) > +* : See help lj-tv for more info > +* : Framelink slot differs from the value slot: it contains info > + related to the function being executed within this guest frame, its > + type, and a link to the parent guest frame > + [] delta=, > + - : > + + L: VM performs a call as a result of bytecode execution > + + C: VM performs a call as a result of lj_vm_call > + + M: VM performs a call to a metamethod as a result of bytecode > + execution > + + V: Variable-length frame for storing arguments of a variadic > + function > + + CP: Protected C frame > + + PP: VM performs a call as a result of executing pcall or xpcall > + > +If L is omitted, the main coroutine is used. > + ''' > + > + def execute(self, arg): > + dbg.write('{}\n'.format(dump_stack(L(dbg.eval(arg))))) > + > + > +class LJState(dbg.LJBase): > + ''' > +lj-state > +The command requires no args and dumps current VM and GC states: > +* VM state: > +* GC state: > +* JIT state: > + ''' > + > + def execute(self, arg): > + g = G(L(None)) > + dbg.write('{}\n'.format('\n'.join( > + map(lambda t: '{} state: {}'.format(*t), { > + 'VM': vm_state(g), > + 'GC': gc_state(g), > + 'JIT': jit_state(g), > + }.items()) > + ))) > + > + > +class LJDumpString(dbg.LJBase): > + ''' > +lj-str > + > +The command receives a of the corresponding GCstr object and dumps > +the payload, size in bytes and hash. > + > +*Caveat*: Since Python 2 provides no native Unicode support, the payload > +is replaced with the corresponding error when decoding fails. > + ''' > + > + def execute(self, arg): > + string = dbg.cast('GCstr *', dbg.eval(arg)) > + dbg.write("String: {body} [{len} bytes] with hash {hash}\n".format( > + body=strdata(string), > + hash=strx64(string['hash']), > + len=string['len'], > + )) > + > + > +class LJDumpTable(dbg.LJBase): > + ''' > +lj-tab > + > +The command receives a GCtab address and dumps the table contents: > +* Metatable address whether the one is set > +* Array part slots: > + : []: > +* Hash part nodes: > + : { } => { }; next = > + ''' > + > + def execute(self, arg): > + t = dbg.cast('GCtab *', dbg.eval(arg)) > + array = mref('TValue *', t['array']) > + nodes = mref('struct Node *', t['node']) > + mt = gcval(t['metatable']) > + capacity = { > + 'apart': int(t['asize']), > + 'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0 > + } > + > + if mt != 0: > + dbg.write('Metatable detected: {}\n'.format(strx64(mt))) > + > + dbg.write('Array part: {} slots\n'.format(capacity['apart'])) > + for i in range(capacity['apart']): > + slot = array + i > + dbg.write('{ptr}: [{index}]: {value}\n'.format( > + ptr=slot, > + index=i, > + value=dump_tvalue(slot) > + )) > + > + dbg.write('Hash part: {} nodes\n'.format(capacity['hpart'])) > + # See hmask comment in lj_obj.h > + for i in range(capacity['hpart']): > + node = nodes + i > + dbg.write('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}\n'.format( > + ptr=node, > + key=dump_tvalue(node['key']), > + val=dump_tvalue(node['val']), > + n=mref('struct Node *', node['next']) > + )) > + > + > +class LJDumpTValue(dbg.LJBase): > + ''' > +lj-tv > + > +The command receives a pointer to (TValue address) and dumps > +the type and some info related to it. > + > +* LJ_TNIL: nil > +* LJ_TFALSE: false > +* LJ_TTRUE: true > +* LJ_TLIGHTUD: light userdata @ > +* LJ_TSTR: string @ > +* LJ_TUPVAL: upvalue @ > +* LJ_TTHREAD: thread @ > +* LJ_TPROTO: proto @ > +* LJ_TFUNC: > + : Lua function @ , upvalues, > + : C function > + : fast function # > +* LJ_TTRACE: trace @ > +* LJ_TCDATA: cdata @ > +* LJ_TTAB: table @ (asize: , hmask: ) > +* LJ_TUDATA: userdata @ > +* LJ_TNUMX: > + > +Whether the type of the given address differs from the listed above, then > +error message occurs. > + ''' > + > + def execute(self, arg): > + tv = dbg.cast('TValue *', dbg.eval(arg)) > + dbg.write('{}\n'.format(dump_tvalue(tv))) > + > + > +def load(event=None): > + dbg.initialize_extension({ > + 'lj-arch': LJDumpArch, > + 'lj-gc': LJGC, > + 'lj-stack': LJDumpStack, > + 'lj-state': LJState, > + 'lj-str': LJDumpString, > + 'lj-tab': LJDumpTable, > + 'lj-tv': LJDumpTValue, > + }) > + > + > +if gdb: > + load() > +elif lldb: > + def __lldb_init_module(debugger, internal_dictionary): > + load() > diff --git a/src/luajit_lldb.py b/src/luajit_lldb.py > deleted file mode 100644 > index e3fe82fc..00000000 > --- a/src/luajit_lldb.py > +++ /dev/null > @@ -1,1015 +0,0 @@ > -# LLDB extension for LuaJIT post-mortem analysis. > -# To use, just put 'command script import /src/luajit_lldb.py' > -# in lldb. > - > -import abc > -import re > -import lldb > -import struct > - > -LJ_64 = None > -LJ_GC64 = None > -LJ_FR2 = None > -LJ_DUALNUM = None > -PADDING = None > - > -# Constants > -IRT_P64 = 9 > -LJ_GCVMASK = ((1 << 47) - 1) > -LJ_TISNUM = None > - > -# These constants are meaningful only for 'LJ_64' mode. > -LJ_LIGHTUD_BITS_SEG = 8 > -LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG > -LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1 > -LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1 > - > -# Debugger specific {{{ > - > - > -# Global > -target = None > - > - > -def lldb_tp_isfp(tp): > - return tp.GetBasicType() in [ > - lldb.eBasicTypeFloat, > - lldb.eBasicTypeDouble, > - lldb.eBasicTypeLongDouble > - ] > - > - > -def lldb_value_from_raw(raw_value, size, tp): > - isfp = lldb_tp_isfp(tp) > - pack_flag = ' - raw_data = struct.pack(pack_flag, raw_value) > - sbdata = lldb.SBData() > - sbdata.SetData( > - lldb.SBError(), > - raw_data, > - lldb.eByteOrderLittle, > - size > - ) > - sbval_res = target.CreateValueFromData( > - # XXX: The name is required. Let's make it meaningful. > - '({tp}){val}'.format( > - tp=tp.name, > - val=raw_value if isfp else hex(raw_value) > - ), > - sbdata, > - tp > - ) > - return lldb.value(sbval_res) > - > - > -def lldb__add__(self, other): > - other = int(other) > - sbvalue = self.sbvalue > - if sbvalue.TypeIsPointerType(): > - tp = sbvalue.GetType() > - sz = sbvalue.deref.size > - addr = sbvalue.GetValueAsUnsigned() + other * sz > - return lldb_value_from_raw(addr, sbvalue.GetByteSize(), tp) > - else: > - return int(self) + other > - > - > -def lldb__bool__(self): > - return int(self) != 0 > - > - > -def lldb__ge__(self, other): > - return int(self) >= int(other) > - > - > -def lldb__getitem__(self, key): > - if type(key) is lldb.value: > - key = int(key) > - if type(key) is int: > - # Allow array access. > - return lldb.value(self.sbvalue.GetValueForExpressionPath('[%i]' % key)) > - elif type(key) is str: > - return lldb.value(self.sbvalue.GetChildMemberWithName(key)) > - raise Exception(TypeError('No item of type %s' % str(type(key)))) > - > - > -def lldb__gt__(self, other): > - return int(self) > int(other) > - > - > -def lldb__le__(self, other): > - return int(self) <= int(other) > - > - > -def lldb__lt__(self, other): > - return int(self) < int(other) > - > - > -def lldb__str__(self): > - # Instead of default GetSummary. > - if not self.sbvalue.TypeIsPointerType(): > - tp = self.sbvalue.GetType() > - is_float = lldb_tp_isfp(tp) > - if is_float: > - return self.sbvalue.GetValue() > - else: > - return str(int(self)) > - > - s = self.sbvalue.GetValue() > - if s[:2] == '0x': > - # Strip useless leading zeros. > - res = s[2:].lstrip('0') > - return '0x' + (res if res else '0') > - return s > - > - > -def lldb__sub__(self, other): > - if type(other) is not lldb.value or \ > - type(other) is lldb.value and not other.sbvalue.TypeIsPointerType(): > - other = int(other) > - if type(other) is int: > - return lldb__add__(self, -other) > - elif self.sbvalue.TypeIsPointerType(): > - ssbval = self.sbvalue > - osbval = other.sbvalue > - self_tp = ssbval.GetType() > - other_tp = osbval.GetType() > - # Subtract pointers of the same size only. > - elsz = self_tp.GetDereferencedType().size > - if other_tp.GetDereferencedType().size != elsz: > - raise Exception('Attempt to substruct {otp} from {stp}'.format( > - stp=self_tp.name, > - otp=other_tp.name > - )) > - diff = ssbval.GetValueAsUnsigned() - osbval.GetValueAsUnsigned() > - return int(diff / elsz) > - else: > - return int(self) - int(other) > - > - > -# Monkey-patch the lldb.value class. > -lldb.value.__add__ = lldb__add__ > -lldb.value.__bool__ = lldb__bool__ > -lldb.value.__ge__ = lldb__ge__ > -lldb.value.__getitem__ = lldb__getitem__ > -lldb.value.__gt__ = lldb__gt__ > -lldb.value.__le__ = lldb__le__ > -lldb.value.__lt__ = lldb__lt__ > -lldb.value.__str__ = lldb__str__ > -lldb.value.__sub__ = lldb__sub__ > - > - > -class Command(object): > - def __init__(self, debugger, unused): > - pass > - > - def get_short_help(self): > - return self.__doc__.splitlines()[0] > - > - def get_long_help(self): > - return self.__doc__ > - > - def __call__(self, debugger, command, exe_ctx, result): > - try: > - self.execute(debugger, command, result) > - except Exception as e: > - msg = 'Failed to execute command `{}`: {}'.format(self.command, e) > - result.SetError(msg) > - > - def parse(self, command): > - process = target.GetProcess() > - thread = process.GetSelectedThread() > - frame = thread.GetSelectedFrame() > - > - if not command: > - return None > - > - ret = frame.EvaluateExpression(command) > - return ret > - > - @abc.abstractproperty > - def command(self): > - """Command name. > - This name will be used by LLDB in order to unique/ly identify an > - implementation that should be executed when a command is run > - in the REPL. > - """ > - > - @abc.abstractmethod > - def execute(self, debugger, args, result): > - """Implementation of the command. > - Subclasses override this method to implement the logic of a given > - command, e.g. printing a stacktrace. The command output should be > - communicated back via the provided result object, so that it's > - properly routed to LLDB frontend. Any unhandled exception will be > - automatically transformed into proper errors. > - """ > - > - > -gtype_cache = {} > - > - > -def gtype(typestr): > - if typestr in gtype_cache: > - return gtype_cache[typestr] > - > - m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr) > - > - gtype = target.FindFirstType(typestr) if m is None \ > - else target.FindFirstType(m.group(1)).GetPointerType() > - > - gtype_cache[typestr] = gtype > - return gtype > - > - > -def cast(typestr, val): > - if isinstance(val, lldb.value): > - val = val.sbvalue > - elif type(val) is int: > - tp = gtype(typestr) > - return lldb_value_from_raw(val, tp.GetByteSize(), tp) > - elif not isinstance(val, lldb.SBValue): > - raise Exception('unexpected cast from type: {t}'.format(t=type(val))) > - > - # XXX: Simply SBValue.Cast() works incorrectly since it may > - # take the 8 bytes of memory instead of 4, before the cast. > - # Construct the value on the fly. > - tp = gtype(typestr) > - is_fp = lldb_tp_isfp(tp) > - rawval = float(val.GetValue()) if is_fp else val.GetValueAsUnsigned() > - return lldb_value_from_raw(rawval, val.GetByteSize(), tp) > - > - > -def lookup_global(name): > - return target.FindFirstGlobalVariable(name) > - > - > -def type_member(type_obj, name): > - return next((x for x in type_obj.members if x.name == name), None) > - > - > -def offsetof(typename, membername): > - type_obj = gtype(typename) > - member = type_member(type_obj, membername) > - assert member is not None > - return member.GetOffsetInBytes() > - > - > -def sizeof(typename): > - type_obj = gtype(typename) > - return type_obj.GetByteSize() > - > - > -def tou64(val): > - return cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF > - > - > -def dbg_eval(expr): > - process = target.GetProcess() > - thread = process.GetSelectedThread() > - frame = thread.GetSelectedFrame() > - return frame.EvaluateExpression(expr) > - > - > -# }}} Debugger specific > - > - > -def gcval(obj): > - return cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64 > - else cast('uintptr_t', obj['gcptr32'])) > - > - > -def gcref(obj): > - return cast('GCobj *', obj['gcptr64'] if LJ_GC64 > - else cast('uintptr_t', obj['gcptr32'])) > - > - > -def gcnext(obj): > - return gcref(obj)['gch']['nextgc'] > - > - > -def gclistlen(root, end=0x0): > - count = 0 > - while (gcref(root) != end): > - count += 1 > - root = gcnext(root) > - return count > - > - > -def gcringlen(root): > - if not gcref(root): > - return 0 > - elif gcref(root) == gcref(gcnext(root)): > - return 1 > - else: > - return 1 + gclistlen(gcnext(root), gcref(root)) > - > - > -gclen = { > - 'root': gclistlen, > - 'gray': gclistlen, > - 'grayagain': gclistlen, > - 'weak': gclistlen, > - # XXX: gc.mmudata is a ring-list. > - 'mmudata': gcringlen, > -} > - > - > -def dump_gc(g): > - gc = g['gc'] > - stats = ['{key}: {value}'.format(key=f, value=getattr(gc, f)) for f in ( > - 'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause' > - )] > - > - stats += ['sweepstr: {sweepstr}/{strmask}'.format( > - sweepstr=gc['sweepstr'], > - # String hash mask (size of hash table - 1). > - strmask=g['strmask'] + 1, > - )] > - > - stats += ['{key}: {number} objects'.format( > - key=stat, > - number=handler(getattr(gc, stat)) > - ) for stat, handler in gclen.items()] > - return '\n'.join(map(lambda s: '\t' + s, stats)) > - > - > -def mref(typename, obj): > - return cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32']) > - > - > -def J(g): > - g_offset = offsetof('GG_State', 'g') > - J_offset = offsetof('GG_State', 'J') > - return cast('jit_State *', (cast('char *', g) - g_offset + J_offset)) > - > - > -def G(L): > - return mref('global_State *', L['glref']) > - > - > -def L(L=None): > - # lookup a symbol for the main coroutine considering the host app > - # XXX Fragile: though the loop initialization looks like a crap but it > - # respects both Python 2 and Python 3. > - for lstate in [L] + list(map(lambda main: lookup_global(main), ( > - # LuaJIT main coro (see luajit/src/luajit.c) > - 'globalL', > - # Tarantool main coro (see tarantool/src/lua/init.h) > - 'tarantool_L', > - # TODO: Add more > - ))): > - if lstate: > - return cast('lua_State *', lstate) > - > - > -def tou32(val): > - return val & 0xFFFFFFFF > - > - > -def i2notu32(val): > - return ~int(val) & 0xFFFFFFFF > - > - > -def vm_state(g): > - return { > - i2notu32(0): 'INTERP', > - i2notu32(1): 'LFUNC', > - i2notu32(2): 'FFUNC', > - i2notu32(3): 'CFUNC', > - i2notu32(4): 'GC', > - i2notu32(5): 'EXIT', > - i2notu32(6): 'RECORD', > - i2notu32(7): 'OPT', > - i2notu32(8): 'ASM', > - }.get(int(tou32(g['vmstate'])), 'TRACE') > - > - > -def gc_state(g): > - return { > - 0: 'PAUSE', > - 1: 'PROPAGATE', > - 2: 'ATOMIC', > - 3: 'SWEEPSTRING', > - 4: 'SWEEP', > - 5: 'FINALIZE', > - 6: 'LAST', > - }.get(int(g['gc']['state']), 'INVALID') > - > - > -def jit_state(g): > - return { > - 0: 'IDLE', > - 0x10: 'ACTIVE', > - 0x11: 'RECORD', > - 0x12: 'START', > - 0x13: 'END', > - 0x14: 'ASM', > - 0x15: 'ERR', > - }.get(int(J(g).state), 'INVALID') > - > - > -def strx64(val): > - return re.sub('L?$', '', > - hex(int(cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF))) > - > - > -def funcproto(func): > - assert func.ffid == 0 > - return cast('GCproto *', mref('char *', func.pc) - sizeof('GCproto')) > - > - > -def strdata(obj): > - try: > - ptr = cast('char *', cast('GCstr *', obj) + 1) > - return ptr.sbvalue.summary > - except UnicodeEncodeError: > - return "" > - > - > -def itype(o): > - return tou32(o['it64'] >> 47) if LJ_GC64 else o['it'] > - > - > -def tvisint(o): > - return LJ_DUALNUM and itype(o) == LJ_TISNUM > - > - > -def tvislightud(o): > - if LJ_64 and not LJ_GC64: > - return (int(cast('int32_t', itype(o))) >> 15) == -2 > - else: > - return itype(o) == LJ_T['LIGHTUD'] > - > - > -def tvisnumber(o): > - return itype(o) <= LJ_TISNUM > - > - > -def lightudV(tv): > - if LJ_64: > - u = int(tv['u64']) > - # lightudseg macro expanded. > - seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK > - segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg']) > - # lightudlo macro expanded. > - return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK) > - else: > - return gcval(tv['gcr']) > - > - > -def dump_lj_tnil(tv): > - return 'nil' > - > - > -def dump_lj_tfalse(tv): > - return 'false' > - > - > -def dump_lj_ttrue(tv): > - return 'true' > - > - > -def dump_lj_tlightud(tv): > - return 'light userdata @ {}'.format(strx64(lightudV(tv))) > - > - > -def dump_lj_tstr(tv): > - return 'string {body} @ {address}'.format( > - body=strdata(cast('GCstr *', gcval(tv['gcr']))), > - address=strx64(gcval(tv['gcr'])) > - ) > - > - > -def dump_lj_tupval(tv): > - return 'upvalue @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tthread(tv): > - return 'thread @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tproto(tv): > - return 'proto @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tfunc(tv): > - func = cast('GCfuncC *', gcval(tv['gcr'])) > - ffid = func['ffid'] > - > - if ffid == 0: > - pt = funcproto(func) > - return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format( > - addr=strx64(func), > - nups=func['nupvalues'], > - chunk=strdata(cast('GCstr *', gcval(pt['chunkname']))), > - line=pt['firstline'] > - ) > - elif ffid == 1: > - return 'C function @ {}'.format(strx64(func['f'])) > - else: > - return 'fast function #{}'.format(ffid) > - > - > -def dump_lj_ttrace(tv): > - trace = cast('GCtrace *', gcval(tv['gcr'])) > - return 'trace {traceno} @ {addr}'.format( > - traceno=strx64(trace['traceno']), > - addr=strx64(trace) > - ) > - > - > -def dump_lj_tcdata(tv): > - return 'cdata @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_ttab(tv): > - table = cast('GCtab *', gcval(tv['gcr'])) > - return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format( > - gcr=strx64(table), > - asize=table['asize'], > - hmask=strx64(table['hmask']), > - ) > - > - > -def dump_lj_tudata(tv): > - return 'userdata @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -def dump_lj_tnumx(tv): > - if tvisint(tv): > - return 'integer {}'.format(cast('int32_t', tv['i'])) > - else: > - return 'number {}'.format(cast('double', tv['n'])) > - > - > -def dump_lj_invalid(tv): > - return 'not valid type @ {}'.format(strx64(gcval(tv['gcr']))) > - > - > -dumpers = { > - 'LJ_TNIL': dump_lj_tnil, > - 'LJ_TFALSE': dump_lj_tfalse, > - 'LJ_TTRUE': dump_lj_ttrue, > - 'LJ_TLIGHTUD': dump_lj_tlightud, > - 'LJ_TSTR': dump_lj_tstr, > - 'LJ_TUPVAL': dump_lj_tupval, > - 'LJ_TTHREAD': dump_lj_tthread, > - 'LJ_TPROTO': dump_lj_tproto, > - 'LJ_TFUNC': dump_lj_tfunc, > - 'LJ_TTRACE': dump_lj_ttrace, > - 'LJ_TCDATA': dump_lj_tcdata, > - 'LJ_TTAB': dump_lj_ttab, > - 'LJ_TUDATA': dump_lj_tudata, > - 'LJ_TNUMX': dump_lj_tnumx, > -} > - > - > -LJ_T = { > - 'NIL': i2notu32(0), > - 'FALSE': i2notu32(1), > - 'TRUE': i2notu32(2), > - 'LIGHTUD': i2notu32(3), > - 'STR': i2notu32(4), > - 'UPVAL': i2notu32(5), > - 'THREAD': i2notu32(6), > - 'PROTO': i2notu32(7), > - 'FUNC': i2notu32(8), > - 'TRACE': i2notu32(9), > - 'CDATA': i2notu32(10), > - 'TAB': i2notu32(11), > - 'UDATA': i2notu32(12), > - 'NUMX': i2notu32(13), > -} > - > - > -def itypemap(o): > - if LJ_64 and not LJ_GC64: > - return LJ_T['NUMX'] if tvisnumber(o) \ > - else LJ_T['LIGHTUD'] if tvislightud(o) else itype(o) > - else: > - return LJ_T['NUMX'] if tvisnumber(o) else itype(o) > - > - > -def typenames(value): > - return { > - LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys() > - }.get(int(value), 'LJ_TINVALID') > - > - > -def dump_tvalue(tvalue): > - return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue) > - > - > -FRAME_TYPE = 0x3 > -FRAME_P = 0x4 > -FRAME_TYPEP = FRAME_TYPE | FRAME_P > - > -FRAME = { > - 'LUA': 0x0, > - 'C': 0x1, > - 'CONT': 0x2, > - 'VARG': 0x3, > - 'LUAP': 0x4, > - 'CP': 0x5, > - 'PCALL': 0x6, > - 'PCALLH': 0x7, > -} > - > - > -def frametypes(ft): > - return { > - FRAME['LUA']: 'L', > - FRAME['C']: 'C', > - FRAME['CONT']: 'M', > - FRAME['VARG']: 'V', > - }.get(ft, '?') > - > - > -def bc_a(ins): > - return (ins >> 8) & 0xff > - > - > -def frame_ftsz(framelink): > - return cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2 > - else framelink['fr']['tp']['ftsz']) > - > - > -def frame_pc(framelink): > - return cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \ > - else mref('BCIns *', framelink['fr']['tp']['pcr']) > - > - > -def frame_prevl(framelink): > - return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1])) > - > - > -def frame_ispcall(framelink): > - return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL'] > - > - > -def frame_sized(framelink): > - return (frame_ftsz(framelink) & ~FRAME_TYPEP) > - > - > -def frame_prevd(framelink): > - return framelink - int(frame_sized(framelink) / sizeof('TValue')) > - > - > -def frame_type(framelink): > - return frame_ftsz(framelink) & FRAME_TYPE > - > - > -def frame_typep(framelink): > - return frame_ftsz(framelink) & FRAME_TYPEP > - > - > -def frame_islua(framelink): > - return frametypes(frame_type(framelink)) == 'L' \ > - and frame_ftsz(framelink) > 0 > - > - > -def frame_prev(framelink): > - return frame_prevl(framelink) if frame_islua(framelink) \ > - else frame_prevd(framelink) > - > - > -def frame_sentinel(L): > - return mref('TValue *', L['stack']) + LJ_FR2 > - > - > -# The generator that implements frame iterator. > -# Every frame is represented as a tuple of framelink and frametop. > -def frames(L): > - frametop = L['top'] > - framelink = L['base'] - 1 > - framelink_sentinel = frame_sentinel(L) > - while True: > - yield framelink, frametop > - frametop = framelink - (1 + LJ_FR2) > - if framelink <= framelink_sentinel: > - break > - framelink = frame_prev(framelink) > - > - > -def dump_framelink_slot_address(fr): > - return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \ > - else '{}'.format(fr) + PADDING > - > - > -def dump_framelink(L, fr): > - if fr == frame_sentinel(L): > - return '{addr} [S ] FRAME: dummy L'.format( > - addr=dump_framelink_slot_address(fr), > - ) > - return '{addr} [ ] FRAME: [{pp}] delta={d}, {f}'.format( > - addr=dump_framelink_slot_address(fr), > - pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format( > - frname=frametypes(int(frame_type(fr))), > - p='P' if frame_typep(fr) & FRAME_P else '' > - ), > - d=cast('TValue *', fr) - cast('TValue *', frame_prev(fr)), > - f=dump_lj_tfunc(fr - LJ_FR2), > - ) > - > - > -def dump_stack_slot(L, slot, base=None, top=None): > - base = base or L['base'] > - top = top or L['top'] > - > - return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format( > - addr=strx64(slot), > - padding=PADDING, > - B='B' if slot == base else ' ', > - T='T' if slot == top else ' ', > - M='M' if slot == mref('TValue *', L['maxstack']) else ' ', > - value=dump_tvalue(slot), > - ) > - > - > -def dump_stack(L, base=None, top=None): > - base = base or L['base'] > - top = top or L['top'] > - stack = mref('TValue *', L['stack']) > - maxstack = mref('TValue *', L['maxstack']) > - red = 5 + 3 * LJ_FR2 > - > - dump = [ > - '{padding} Red zone: {nredslots: >2} slots {padding}'.format( > - padding='-' * len(PADDING), > - nredslots=red, > - ), > - ] > - dump.extend([ > - dump_stack_slot(L, maxstack + offset, base, top) > - for offset in range(red, 0, -1) # noqa: E131 > - ]) > - dump.extend([ > - '{padding} Stack: {nstackslots: >5} slots {padding}'.format( > - padding='-' * len(PADDING), > - nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3), > - ), > - dump_stack_slot(L, maxstack, base, top), > - '{start}:{end} [ ] {nfreeslots} slots: Free stack slots'.format( > - start=strx64(top + 1), > - end=strx64(maxstack - 1), > - nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3), > - ), > - ]) > - > - for framelink, frametop in frames(L): > - # Dump all data slots in the (framelink, top) interval. > - dump.extend([ > - dump_stack_slot(L, framelink + offset, base, top) > - for offset in range(frametop - framelink, 0, -1) # noqa: E131 > - ]) > - # Dump frame slot (2 slots in case of GC64). > - dump.append(dump_framelink(L, framelink)) > - > - return '\n'.join(dump) > - > - > -class LJDumpTValue(Command): > - ''' > -lj-tv > - > -The command receives a pointer to (TValue address) and dumps > -the type and some info related to it. > - > -* LJ_TNIL: nil > -* LJ_TFALSE: false > -* LJ_TTRUE: true > -* LJ_TLIGHTUD: light userdata @ > -* LJ_TSTR: string @ > -* LJ_TUPVAL: upvalue @ > -* LJ_TTHREAD: thread @ > -* LJ_TPROTO: proto @ > -* LJ_TFUNC: > - : Lua function @ , upvalues, > - : C function > - : fast function # > -* LJ_TTRACE: trace @ > -* LJ_TCDATA: cdata @ > -* LJ_TTAB: table @ (asize: , hmask: ) > -* LJ_TUDATA: userdata @ > -* LJ_TNUMX: number > - > -Whether the type of the given address differs from the listed above, then > -error message occurs. > - ''' > - def execute(self, debugger, args, result): > - tvptr = cast('TValue *', self.parse(args)) > - print('{}'.format(dump_tvalue(tvptr))) > - > - > -class LJState(Command): > - ''' > -lj-state > -The command requires no args and dumps current VM and GC states > -* VM state: > -* GC state: > -* JIT state: > - ''' > - def execute(self, debugger, args, result): > - g = G(L(None)) > - print('{}'.format('\n'.join( > - map(lambda t: '{} state: {}'.format(*t), { > - 'VM': vm_state(g), > - 'GC': gc_state(g), > - 'JIT': jit_state(g), > - }.items()) > - ))) > - > - > -class LJDumpArch(Command): > - ''' > -lj-arch > - > -The command requires no args and dumps values of LJ_64 and LJ_GC64 > -compile-time flags. These values define the sizes of host and GC > -pointers respectively. > - ''' > - def execute(self, debugger, args, result): > - print( > - 'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}' > - .format( > - LJ_64=LJ_64, > - LJ_GC64=LJ_GC64, > - LJ_DUALNUM=LJ_DUALNUM > - ) > - ) > - > - > -class LJGC(Command): > - ''' > -lj-gc > - > -The command requires no args and dumps current GC stats: > -* total: > -* threshold: > -* debt: > -* estimate: > -* stepmul: > -* pause: > -* sweepstr: > -* root: > -* gray: > -* grayagain: > -* weak: > -* mmudata: > - ''' > - def execute(self, debugger, args, result): > - g = G(L(None)) > - print('GC stats: {state}\n{stats}'.format( > - state=gc_state(g), > - stats=dump_gc(g) > - )) > - > - > -class LJDumpString(Command): > - ''' > -lj-str > - > -The command receives a of the corresponding GCstr object and dumps > -the payload, size in bytes and hash. > - > -*Caveat*: Since Python 2 provides no native Unicode support, the payload > -is replaced with the corresponding error when decoding fails. > - ''' > - def execute(self, debugger, args, result): > - string = cast('GCstr *', self.parse(args)) > - print("String: {body} [{len} bytes] with hash {hash}".format( > - body=strdata(string), > - hash=strx64(string['hash']), > - len=string['len'], > - )) > - > - > -class LJDumpTable(Command): > - ''' > -lj-tab > - > -The command receives a GCtab address and dumps the table contents: > -* Metatable address whether the one is set > -* Array part slots: > - : []: > -* Hash part nodes: > - : { } => { }; next = > - ''' > - def execute(self, debugger, args, result): > - t = cast('GCtab *', self.parse(args)) > - array = mref('TValue *', t['array']) > - nodes = mref('Node *', t['node']) > - mt = gcval(t['metatable']) > - capacity = { > - 'apart': int(t['asize']), > - 'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0 > - } > - > - if mt: > - print('Metatable detected: {}'.format(strx64(mt))) > - > - print('Array part: {} slots'.format(capacity['apart'])) > - for i in range(capacity['apart']): > - slot = array + i > - print('{ptr}: [{index}]: {value}'.format( > - ptr=strx64(slot), > - index=i, > - value=dump_tvalue(slot) > - )) > - > - print('Hash part: {} nodes'.format(capacity['hpart'])) > - # See hmask comment in lj_obj.h > - for i in range(capacity['hpart']): > - node = nodes + i > - print('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}'.format( > - ptr=strx64(node), > - key=dump_tvalue(node['key']), > - val=dump_tvalue(node['val']), > - n=strx64(mref('Node *', node['next'])) > - )) > - > - > -class LJDumpStack(Command): > - ''' > -lj-stack [] > - > -The command receives a lua_State address and dumps the given Lua > -coroutine guest stack: > - > - [] > - > -* : guest stack slot address > -* : > - - S: Bottom of the stack (the slot L->stack points to) > - - B: Base of the current guest frame (the slot L->base points to) > - - T: Top of the current guest frame (the slot L->top points to) > - - M: Last slot of the stack (the slot L->maxstack points to) > -* : see help lj-tv for more info > -* : framelink slot differs from the value slot: it contains info > - related to the function being executed within this guest frame, its > - type and link to the parent guest frame > - [] delta=, > - - : > - + L: VM performs a call as a result of bytecode execution > - + C: VM performs a call as a result of lj_vm_call > - + M: VM performs a call to a metamethod as a result of bytecode > - execution > - + V: Variable-length frame for storing arguments of a variadic > - function > - + CP: Protected C frame > - + PP: VM performs a call as a result of executinig pcall or xpcall > - > -If L is omitted the main coroutine is used. > - ''' > - def execute(self, debugger, args, result): > - print('{}'.format(dump_stack(L(self.parse(args))))) > - > - > -def register_commands(debugger, commands): > - for command, cls in commands.items(): > - cls.command = command > - debugger.HandleCommand( > - 'command script add --overwrite --class luajit_lldb.{cls} {cmd}' > - .format( > - cls=cls.__name__, > - cmd=cls.command, > - ) > - ) > - print('{cmd} command initialized'.format(cmd=cls.command)) > - > - > -def configure(debugger): > - global LJ_64, LJ_GC64, LJ_FR2, LJ_DUALNUM, PADDING, LJ_TISNUM, target > - target = debugger.GetSelectedTarget() > - module = target.modules[0] > - LJ_DUALNUM = module.FindSymbol('lj_lib_checknumber') is not None > - > - try: > - irtype_enum = target.FindFirstType('IRType').enum_members > - for member in irtype_enum: > - if member.name == 'IRT_PTR': > - LJ_64 = member.unsigned & 0x1f == IRT_P64 > - if member.name == 'IRT_PGC': > - LJ_FR2 = LJ_GC64 = member.unsigned & 0x1f == IRT_P64 > - except Exception: > - print('luajit_lldb.py failed to load: ' > - 'no debugging symbols found for libluajit') > - return > - > - PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1)) > - LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX'] > - > - > -def __lldb_init_module(debugger, internal_dict): > - configure(debugger) > - register_commands(debugger, { > - 'lj-arch': LJDumpArch, > - 'lj-gc': LJGC, > - 'lj-stack': LJDumpStack, > - 'lj-state': LJState, > - 'lj-str': LJDumpString, > - 'lj-tab': LJDumpTable, > - 'lj-tv': LJDumpTValue, > - }) > - print('luajit_lldb.py is successfully loaded') > diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py > index 2b67e151..30a2c478 100644 > --- a/test/tarantool-debugger-tests/debug-extension-tests.py > +++ b/test/tarantool-debugger-tests/debug-extension-tests.py > @@ -16,7 +16,7 @@ LUAJIT_BINARY = os.environ['LUAJIT_TEST_BINARY'] > EXTENSION_PATH = os.environ['DEBUGGER_EXTENSION_PATH'] > DEBUGGER = os.environ['DEBUGGER_COMMAND'] > LLDB = 'lldb' in DEBUGGER > -EXTENSION = EXTENSION_PATH + ('/luajit_lldb.py' if LLDB else '/luajit-gdb.py') > +EXTENSION = EXTENSION_PATH + '/luajit_dbg.py' > TIMEOUT = 10 > > # Don't run any initialization scripts. > @@ -137,7 +137,7 @@ class TestLoad(TestCaseBase): > r'lj-str command initialized\n' > r'lj-tab command initialized\n' > r'lj-tv command initialized\n' > - r'.*is successfully loaded' > + r'LuaJIT debug extension is successfully loaded' > ) > > --------------rttd6sOXBrWyY67CsL0Fw8fj Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit

Hi, Sergey,

thanks for the patch! LGTM with a minor comment.

Sergey

On 5/19/26 15:39, Sergey Kaplun wrote:
This patch joins the LLDB and GDB LuaJIT debugging extensions
into one, so now the extension logic can be debugger-agnostic.

To do that, an adapter class is introduced, and all of the
debugger-specific behavior is encapsulated there and in its child
debugger classes with the specific implementations of required methods.
The extension auto-detects the debugger it was loaded into and selects
the correct low-level logic implementation.

The F821 ignore is removed from <.flake8rc> since there is no more need
for it.
---
 .flake8rc                                     |    5 -
 src/luajit-gdb.py                             |  884 ------------
 src/luajit_dbg.py                             | 1281 +++++++++++++++++
 src/luajit_lldb.py                            | 1015 -------------
 .../debug-extension-tests.py                  |    4 +-
 5 files changed, 1283 insertions(+), 1906 deletions(-)
 delete mode 100644 src/luajit-gdb.py
 create mode 100644 src/luajit_dbg.py

"autopep8 -i" generates the following patch:

--- a/src/luajit_dbg.py
+++ b/src/luajit_dbg.py
@@ -651,7 +651,7 @@ def frame_ftsz(framelink):
 
 def frame_pc(framelink):
     return dbg.cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \
-                    else mref('BCIns *', framelink['fr']['tp']['pcr'])
+        else mref('BCIns *', framelink['fr']['tp']['pcr'])
 
 
 def frame_prevl(framelink):

Feel free to ignore, but I propose following PEP8 style from the beginning.


 delete mode 100644 src/luajit_lldb.py

diff --git a/.flake8rc b/.flake8rc
index 13e6178f..e69de29b 100644
--- a/.flake8rc
+++ b/.flake8rc
@@ -1,5 +0,0 @@
-[flake8]
-extend-ignore =
-  # XXX: Suppress F821, since we have autogenerated names for
-  # 'ptr' type complements in luajit_lldb.py.
-  F821
diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py
deleted file mode 100644
index be67bf18..00000000
--- a/src/luajit-gdb.py
+++ /dev/null
@@ -1,884 +0,0 @@
-# GDB extension for LuaJIT post-mortem analysis.
-# To use, just put 'source <path-to-repo>/src/luajit-gdb.py' in gdb.
-
-import re
-import gdb
-import sys
-
-# make script compatible with the ancient Python {{{
-
-
-LEGACY = re.match(r'^2\.', sys.version)
-
-if LEGACY:
-    CONNECTED = False
-    int = long
-    range = xrange
-
-
-# }}}
-
-
-gtype_cache = {}
-
-
-def gtype(typestr):
-    if typestr in gtype_cache:
-        return gtype_cache[typestr]
-
-    m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr)
-
-    gtype = gdb.lookup_type(typestr) if m is None \
-        else gdb.lookup_type(m.group(1)).pointer()
-
-    gtype_cache[typestr] = gtype
-    return gtype
-
-
-def cast(typestr, val):
-    return gdb.Value(val).cast(gtype(typestr))
-
-
-def lookup(symbol):
-    variable, _ = gdb.lookup_symbol(symbol)
-    return variable.value() if variable else None
-
-
-def parse_arg(arg):
-    if not arg:
-        return None
-
-    ret = gdb.parse_and_eval(arg)
-
-    if not ret:
-        raise gdb.GdbError('table argument empty')
-
-    return ret
-
-
-def tou64(val):
-    return cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF
-
-
-def tou32(val):
-    return cast('uint32_t', val) & 0xFFFFFFFF
-
-
-def i2notu32(val):
-    return ~int(val) & 0xFFFFFFFF
-
-
-def strx64(val):
-    return re.sub('L?$', '',
-                  hex(int(cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF)))
-
-
-# Types {{{
-
-
-LJ_T = {
-    'NIL':     i2notu32(0),
-    'FALSE':   i2notu32(1),
-    'TRUE':    i2notu32(2),
-    'LIGHTUD': i2notu32(3),
-    'STR':     i2notu32(4),
-    'UPVAL':   i2notu32(5),
-    'THREAD':  i2notu32(6),
-    'PROTO':   i2notu32(7),
-    'FUNC':    i2notu32(8),
-    'TRACE':   i2notu32(9),
-    'CDATA':   i2notu32(10),
-    'TAB':     i2notu32(11),
-    'UDATA':   i2notu32(12),
-    'NUMX':    i2notu32(13),
-}
-
-
-def typenames(value):
-    return {
-        LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys()
-    }.get(int(value), 'LJ_TINVALID')
-
-
-# }}}
-
-# Frames {{{
-
-
-FRAME_TYPE = 0x3
-FRAME_P = 0x4
-FRAME_TYPEP = FRAME_TYPE | FRAME_P
-
-FRAME = {
-    'LUA':    0x0,
-    'C':      0x1,
-    'CONT':   0x2,
-    'VARG':   0x3,
-    'LUAP':   0x4,
-    'CP':     0x5,
-    'PCALL':  0x6,
-    'PCALLH': 0x7,
-}
-
-
-def frametypes(ft):
-    return {
-        FRAME['LUA']:  'L',
-        FRAME['C']:    'C',
-        FRAME['CONT']: 'M',
-        FRAME['VARG']: 'V',
-    }.get(ft, '?')
-
-
-def bc_a(ins):
-    return (ins >> 8) & 0xff
-
-
-def frame_ftsz(framelink):
-    return cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2
-                else framelink['fr']['tp']['ftsz'])
-
-
-def frame_pc(framelink):
-    return cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \
-        else mref('BCIns *', framelink['fr']['tp']['pcr'])
-
-
-def frame_prevl(framelink):
-    return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1]))
-
-
-def frame_ispcall(framelink):
-    return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL']
-
-
-def frame_sized(framelink):
-    return (frame_ftsz(framelink) & ~FRAME_TYPEP)
-
-
-def frame_prevd(framelink):
-    return cast('TValue *', cast('char *', framelink) - frame_sized(framelink))
-
-
-def frame_type(framelink):
-    return frame_ftsz(framelink) & FRAME_TYPE
-
-
-def frame_typep(framelink):
-    return frame_ftsz(framelink) & FRAME_TYPEP
-
-
-def frame_islua(framelink):
-    return frametypes(int(frame_type(framelink))) == 'L' \
-        and int(frame_ftsz(framelink)) > 0
-
-
-def frame_prev(framelink):
-    return frame_prevl(framelink) if frame_islua(framelink) \
-        else frame_prevd(framelink)
-
-
-def frame_sentinel(L):
-    return mref('TValue *', L['stack']) + LJ_FR2
-
-
-# }}}
-
-# Const {{{
-
-
-LJ_64 = None
-LJ_GC64 = None
-LJ_FR2 = None
-LJ_DUALNUM = None
-
-LJ_GCVMASK = ((1 << 47) - 1)
-LJ_TISNUM = None
-PADDING = None
-
-# These constants are meaningful only for 'LJ_64' mode.
-LJ_LIGHTUD_BITS_SEG = 8
-LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG
-LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1
-LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1
-
-
-# }}}
-
-
-def itype(o):
-    return cast('uint32_t', o['it64'] >> 47) if LJ_GC64 else o['it']
-
-
-def mref(typename, obj):
-    return cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32'])
-
-
-def gcref(obj):
-    return cast('GCobj *', obj['gcptr64'] if LJ_GC64
-                else cast('uintptr_t', obj['gcptr32']))
-
-
-def gcval(obj):
-    return cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64
-                else cast('uintptr_t', obj['gcptr32']))
-
-
-def gcnext(obj):
-    return gcref(obj)['gch']['nextgc']
-
-
-def L(L=None):
-    # lookup a symbol for the main coroutine considering the host app
-    # XXX Fragile: though the loop initialization looks like a crap but it
-    # respects both Python 2 and Python 3.
-    for lstate in [L] + list(map(lambda main: lookup(main), (
-        # LuaJIT main coro (see luajit/src/luajit.c)
-        'globalL',
-        # Tarantool main coro (see tarantool/src/lua/init.h)
-        'tarantool_L',
-        # TODO: Add more
-    ))):
-        if lstate:
-            return cast('lua_State *', lstate)
-
-
-def G(L):
-    return mref('global_State *', L['glref'])
-
-
-def J(g):
-    typeGG = gtype('GG_State')
-
-    return cast('jit_State *', int(cast('char *', g))
-                - int(typeGG['g'].bitpos / 8)
-                + int(typeGG['J'].bitpos / 8))
-
-
-def vm_state(g):
-    return {
-        i2notu32(0): 'INTERP',
-        i2notu32(1): 'LFUNC',
-        i2notu32(2): 'FFUNC',
-        i2notu32(3): 'CFUNC',
-        i2notu32(4): 'GC',
-        i2notu32(5): 'EXIT',
-        i2notu32(6): 'RECORD',
-        i2notu32(7): 'OPT',
-        i2notu32(8): 'ASM',
-    }.get(int(tou32(g['vmstate'])), 'TRACE')
-
-
-def gc_state(g):
-    return {
-        0: 'PAUSE',
-        1: 'PROPAGATE',
-        2: 'ATOMIC',
-        3: 'SWEEPSTRING',
-        4: 'SWEEP',
-        5: 'FINALIZE',
-        6: 'LAST',
-    }.get(int(g['gc']['state']), 'INVALID')
-
-
-def jit_state(g):
-    return {
-        0:    'IDLE',
-        0x10: 'ACTIVE',
-        0x11: 'RECORD',
-        0x12: 'START',
-        0x13: 'END',
-        0x14: 'ASM',
-        0x15: 'ERR',
-    }.get(int(J(g)['state']), 'INVALID')
-
-
-def tvisint(o):
-    return LJ_DUALNUM and itype(o) == LJ_TISNUM
-
-
-def tvisnumber(o):
-    return itype(o) <= LJ_TISNUM
-
-
-def tvislightud(o):
-    if LJ_64 and not LJ_GC64:
-        return (cast('int32_t', itype(o)) >> 15) == -2
-    else:
-        return itype(o) == LJ_T['LIGHTUD']
-
-
-def strdata(obj):
-    # String is printed with pointer to it, thanks to gdb. Just strip it.
-    try:
-        return str(cast('char *', cast('GCstr *', obj) + 1))[len(PADDING):]
-    except UnicodeEncodeError:
-        return "<luajit-gdb: error occurred while rendering non-ascii slot>"
-
-
-def itypemap(o):
-    if LJ_64 and not LJ_GC64:
-        return LJ_T['NUMX'] if tvisnumber(o)       \
-            else LJ_T['LIGHTUD'] if tvislightud(o) \
-            else itype(o)
-    else:
-        return LJ_T['NUMX'] if tvisnumber(o) else itype(o)
-
-
-def funcproto(func):
-    assert func['ffid'] == 0
-
-    return cast('GCproto *',
-                mref('char *', func['pc']) - gdb.lookup_type('GCproto').sizeof)
-
-
-def gclistlen(root, end=0x0):
-    count = 0
-    while (gcref(root) != end):
-        count += 1
-        root = gcnext(root)
-    return count
-
-
-def gcringlen(root):
-    if not gcref(root):
-        return 0
-    elif gcref(root) == gcref(gcnext(root)):
-        return 1
-    else:
-        return 1 + gclistlen(gcnext(root), gcref(root))
-
-
-gclen = {
-    'root':      gclistlen,
-    'gray':      gclistlen,
-    'grayagain': gclistlen,
-    'weak':      gclistlen,
-    # XXX: gc.mmudata is a ring-list.
-    'mmudata':   gcringlen,
-}
-
-
-# The generator that implements frame iterator.
-# Every frame is represented as a tuple of framelink and frametop.
-def frames(L):
-    frametop = L['top']
-    framelink = L['base'] - 1
-    framelink_sentinel = frame_sentinel(L)
-    while True:
-        yield framelink, frametop
-        frametop = framelink - (1 + LJ_FR2)
-        if framelink <= framelink_sentinel:
-            break
-        framelink = frame_prev(framelink)
-
-
-def lightudV(tv):
-    if LJ_64:
-        u = int(tv['u64'])
-        # lightudseg macro expanded.
-        seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK
-        segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg'])
-        # lightudlo macro expanded.
-        return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK)
-    else:
-        return gcval(tv['gcr'])
-
-
-# Dumpers {{{
-
-
-def dump_lj_tnil(tv):
-    return 'nil'
-
-
-def dump_lj_tfalse(tv):
-    return 'false'
-
-
-def dump_lj_ttrue(tv):
-    return 'true'
-
-
-def dump_lj_tlightud(tv):
-    return 'light userdata @ {}'.format(strx64(lightudV(tv)))
-
-
-def dump_lj_tstr(tv):
-    return 'string {body} @ {address}'.format(
-        body=strdata(gcval(tv['gcr'])),
-        address=strx64(gcval(tv['gcr']))
-    )
-
-
-def dump_lj_tupval(tv):
-    return 'upvalue @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tthread(tv):
-    return 'thread @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tproto(tv):
-    return 'proto @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tfunc(tv):
-    func = cast('struct GCfuncC *', gcval(tv['gcr']))
-    ffid = func['ffid']
-
-    if ffid == 0:
-        pt = funcproto(func)
-        return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format(
-            addr=strx64(func),
-            nups=int(func['nupvalues']),
-            chunk=strdata(cast('GCstr *', gcval(pt['chunkname']))),
-            line=pt['firstline']
-        )
-    elif ffid == 1:
-        return 'C function @ {}'.format(strx64(func['f']))
-    else:
-        return 'fast function #{}'.format(int(ffid))
-
-
-def dump_lj_ttrace(tv):
-    trace = cast('struct GCtrace *', gcval(tv['gcr']))
-    return 'trace {traceno} @ {addr}'.format(
-        traceno=strx64(trace['traceno']),
-        addr=strx64(trace)
-    )
-
-
-def dump_lj_tcdata(tv):
-    return 'cdata @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_ttab(tv):
-    table = cast('GCtab *', gcval(tv['gcr']))
-    return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format(
-        gcr=strx64(table),
-        asize=table['asize'],
-        hmask=strx64(table['hmask']),
-    )
-
-
-def dump_lj_tudata(tv):
-    return 'userdata @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tnumx(tv):
-    if tvisint(tv):
-        return 'integer {}'.format(cast('int32_t', tv['i']))
-    else:
-        return 'number {}'.format(cast('double', tv['n']))
-
-
-def dump_lj_invalid(tv):
-    return 'not valid type @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-# }}}
-
-
-dumpers = {
-    'LJ_TNIL':     dump_lj_tnil,
-    'LJ_TFALSE':   dump_lj_tfalse,
-    'LJ_TTRUE':    dump_lj_ttrue,
-    'LJ_TLIGHTUD': dump_lj_tlightud,
-    'LJ_TSTR':     dump_lj_tstr,
-    'LJ_TUPVAL':   dump_lj_tupval,
-    'LJ_TTHREAD':  dump_lj_tthread,
-    'LJ_TPROTO':   dump_lj_tproto,
-    'LJ_TFUNC':    dump_lj_tfunc,
-    'LJ_TTRACE':   dump_lj_ttrace,
-    'LJ_TCDATA':   dump_lj_tcdata,
-    'LJ_TTAB':     dump_lj_ttab,
-    'LJ_TUDATA':   dump_lj_tudata,
-    'LJ_TNUMX':    dump_lj_tnumx,
-}
-
-
-def dump_tvalue(tvalue):
-    return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue)
-
-
-def dump_framelink_slot_address(fr):
-    return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \
-        else '{}'.format(fr) + PADDING
-
-
-def dump_framelink(L, fr):
-    if fr == frame_sentinel(L):
-        return '{addr} [S   ] FRAME: dummy L'.format(
-            addr=dump_framelink_slot_address(fr),
-        )
-    return '{addr} [    ] FRAME: [{pp}] delta={d}, {f}'.format(
-        addr=dump_framelink_slot_address(fr),
-        pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format(
-            frname=frametypes(int(frame_type(fr))),
-            p='P' if frame_typep(fr) & FRAME_P else ''
-        ),
-        d=cast('TValue *', fr) - cast('TValue *', frame_prev(fr)),
-        f=dump_lj_tfunc(fr - LJ_FR2),
-    )
-
-
-def dump_stack_slot(L, slot, base=None, top=None):
-    base = base or L['base']
-    top = top or L['top']
-
-    return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format(
-        addr=strx64(slot),
-        padding=PADDING,
-        B='B' if slot == base else ' ',
-        T='T' if slot == top else ' ',
-        M='M' if slot == mref('TValue *', L['maxstack']) else ' ',
-        value=dump_tvalue(slot),
-    )
-
-
-def dump_stack(L, base=None, top=None):
-    base = base or L['base']
-    top = top or L['top']
-    stack = mref('TValue *', L['stack'])
-    maxstack = mref('TValue *', L['maxstack'])
-    red = 5 + 3 * LJ_FR2
-
-    dump = [
-        '{padding} Red zone: {nredslots: >2} slots {padding}'.format(
-            padding='-' * len(PADDING),
-            nredslots=red,
-        ),
-    ]
-    dump.extend([
-        dump_stack_slot(L, maxstack + offset, base, top)
-            for offset in range(red, 0, -1)  # noqa: E131
-    ])
-    dump.extend([
-        '{padding} Stack: {nstackslots: >5} slots {padding}'.format(
-            padding='-' * len(PADDING),
-            nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3),
-        ),
-        dump_stack_slot(L, maxstack, base, top),
-        '{start}:{end} [    ] {nfreeslots} slots: Free stack slots'.format(
-            start=strx64(top + 1),
-            end=strx64(maxstack - 1),
-            nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3),
-        ),
-    ])
-
-    for framelink, frametop in frames(L):
-        # Dump all data slots in the (framelink, top) interval.
-        dump.extend([
-            dump_stack_slot(L, framelink + offset, base, top)
-                for offset in range(frametop - framelink, 0, -1)  # noqa: E131
-        ])
-        # Dump frame slot (2 slots in case of GC64).
-        dump.append(dump_framelink(L, framelink))
-
-    return '\n'.join(dump)
-
-
-def dump_gc(g):
-    gc = g['gc']
-    stats = ['{key}: {value}'.format(key=f, value=gc[f]) for f in (
-        'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause'
-    )]
-
-    stats += ['sweepstr: {sweepstr}/{strmask}'.format(
-        sweepstr=gc['sweepstr'],
-        # String hash mask (size of hash table - 1).
-        strmask=g['strmask'] + 1,
-    )]
-
-    stats += ['{key}: {number} objects'.format(
-        key=stat,
-        number=handler(gc[stat])
-    ) for stat, handler in gclen.items()]
-
-    return '\n'.join(map(lambda s: '\t' + s, stats))
-
-
-class LJBase(gdb.Command):
-
-    def __init__(self, name):
-        # XXX Fragile: though the command initialization looks like a crap but
-        # it respects both Python 2 and Python 3.
-        gdb.Command.__init__(self, name, gdb.COMMAND_DATA)
-        gdb.write('{} command initialized\n'.format(name))
-
-
-class LJDumpArch(LJBase):
-    '''
-lj-arch
-
-The command requires no args and dumps values of LJ_64 and LJ_GC64
-compile-time flags. These values define the sizes of host and GC
-pointers respectively.
-    '''
-
-    def invoke(self, arg, from_tty):
-        gdb.write(
-            'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}\n'
-            .format(
-                LJ_64=LJ_64,
-                LJ_GC64=LJ_GC64,
-                LJ_DUALNUM=LJ_DUALNUM
-            )
-        )
-
-
-class LJDumpTValue(LJBase):
-    '''
-lj-tv <TValue *>
-
-The command receives a pointer to <tv> (TValue address) and dumps
-the type and some info related to it.
-
-* LJ_TNIL: nil
-* LJ_TFALSE: false
-* LJ_TTRUE: true
-* LJ_TLIGHTUD: light userdata @ <gcr>
-* LJ_TSTR: string <string payload> @ <gcr>
-* LJ_TUPVAL: upvalue @ <gcr>
-* LJ_TTHREAD: thread @ <gcr>
-* LJ_TPROTO: proto @ <gcr>
-* LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
-  <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
-  <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
-* LJ_TTRACE: trace <traceno> @ <gcr>
-* LJ_TCDATA: cdata @ <gcr>
-* LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
-* LJ_TUDATA: userdata @ <gcr>
-* LJ_TNUMX: number <numeric payload>
-
-Whether the type of the given address differs from the listed above, then
-error message occurs.
-    '''
-
-    def invoke(self, arg, from_tty):
-        tv = cast('TValue *', parse_arg(arg))
-        gdb.write('{}\n'.format(dump_tvalue(tv)))
-
-
-class LJDumpString(LJBase):
-    '''
-lj-str <GCstr *>
-
-The command receives a <gcr> of the corresponding GCstr object and dumps
-the payload, size in bytes and hash.
-
-*Caveat*: Since Python 2 provides no native Unicode support, the payload
-is replaced with the corresponding error when decoding fails.
-    '''
-
-    def invoke(self, arg, from_tty):
-        string = cast('GCstr *', parse_arg(arg))
-        gdb.write("String: {body} [{len} bytes] with hash {hash}\n".format(
-            body=strdata(string),
-            hash=strx64(string['hash']),
-            len=string['len'],
-        ))
-
-
-class LJDumpTable(LJBase):
-    '''
-lj-tab <GCtab *>
-
-The command receives a GCtab address and dumps the table contents:
-* Metatable address whether the one is set
-* Array part <asize> slots:
-  <aslot ptr>: [<index>]: <tv>
-* Hash part <hsize> nodes:
-  <hnode ptr>: { <tv> } => { <tv> }; next = <next hnode ptr>
-    '''
-
-    def invoke(self, arg, from_tty):
-        t = cast('GCtab *', parse_arg(arg))
-        array = mref('TValue *', t['array'])
-        nodes = mref('struct Node *', t['node'])
-        mt = gcval(t['metatable'])
-        capacity = {
-            'apart': int(t['asize']),
-            'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0
-        }
-
-        if mt != 0:
-            gdb.write('Metatable detected: {}\n'.format(strx64(mt)))
-
-        gdb.write('Array part: {} slots\n'.format(capacity['apart']))
-        for i in range(capacity['apart']):
-            slot = array + i
-            gdb.write('{ptr}: [{index}]: {value}\n'.format(
-                ptr=slot,
-                index=i,
-                value=dump_tvalue(slot)
-            ))
-
-        gdb.write('Hash part: {} nodes\n'.format(capacity['hpart']))
-        # See hmask comment in lj_obj.h
-        for i in range(capacity['hpart']):
-            node = nodes + i
-            gdb.write('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}\n'.format(
-                ptr=node,
-                key=dump_tvalue(node['key']),
-                val=dump_tvalue(node['val']),
-                n=mref('struct Node *', node['next'])
-            ))
-
-
-class LJDumpStack(LJBase):
-    '''
-lj-stack [<lua_State *>]
-
-The command receives a lua_State address and dumps the given Lua
-coroutine guest stack:
-
-<slot ptr> [<slot attributes>] <VALUE|FRAME>
-
-* <slot ptr>: guest stack slot address
-* <slot attributes>:
-  - S: Bottom of the stack (the slot L->stack points to)
-  - B: Base of the current guest frame (the slot L->base points to)
-  - T: Top of the current guest frame (the slot L->top points to)
-  - M: Last slot of the stack (the slot L->maxstack points to)
-* <VALUE>: see help lj-tv for more info
-* <FRAME>: framelink slot differs from the value slot: it contains info
-  related to the function being executed within this guest frame, its
-  type and link to the parent guest frame
-  [<frame type>] delta=<slots in frame>, <lj-tv for LJ_TFUNC slot>
-  - <frame type>:
-    + L:  VM performs a call as a result of bytecode execution
-    + C:  VM performs a call as a result of lj_vm_call
-    + M:  VM performs a call to a metamethod as a result of bytecode
-          execution
-    + V:  Variable-length frame for storing arguments of a variadic
-          function
-    + CP: Protected C frame
-    + PP: VM performs a call as a result of executinig pcall or xpcall
-
-If L is omitted the main coroutine is used.
-    '''
-
-    def invoke(self, arg, from_tty):
-        gdb.write('{}\n'.format(dump_stack(L(parse_arg(arg)))))
-
-
-class LJState(LJBase):
-    '''
-lj-state
-The command requires no args and dumps current VM and GC states
-* VM state: <INTERP|C|GC|EXIT|RECORD|OPT|ASM|TRACE>
-* GC state: <PAUSE|PROPAGATE|ATOMIC|SWEEPSTRING|SWEEP|FINALIZE|LAST>
-* JIT state: <IDLE|ACTIVE|RECORD|START|END|ASM|ERR>
-    '''
-
-    def invoke(self, arg, from_tty):
-        g = G(L(None))
-        gdb.write('{}\n'.format('\n'.join(
-            map(lambda t: '{} state: {}'.format(*t), {
-                'VM':  vm_state(g),
-                'GC':  gc_state(g),
-                'JIT': jit_state(g),
-            }.items())
-        )))
-
-
-class LJGC(LJBase):
-    '''
-lj-gc
-
-The command requires no args and dumps current GC stats:
-* total: <total number of allocated bytes in GC area>
-* threshold: <limit when gc step is triggered>
-* debt: <how much GC is behind schedule>
-* estimate: <estimate of memory actually in use>
-* stepmul: <incremental GC step granularity>
-* pause: <pause between successive GC cycles>
-* sweepstr: <sweep position in string table>
-* root: <number of all collectable objects>
-* gray: <number of gray objects>
-* grayagain: <number of objects for atomic traversal>
-* weak: <number of weak tables (to be cleared)>
-* mmudata: <number of udata|cdata to be finalized>
-    '''
-
-    def invoke(self, arg, from_tty):
-        g = G(L(None))
-        gdb.write('GC stats: {state}\n{stats}\n'.format(
-            state=gc_state(g),
-            stats=dump_gc(g)
-        ))
-
-
-def init(commands):
-    global LJ_64, LJ_GC64, LJ_FR2, LJ_DUALNUM, LJ_TISNUM, PADDING
-
-    # XXX Fragile: though connecting the callback looks like a crap but it
-    # respects both Python 2 and Python 3 (see #4828).
-    def connect(callback):
-        if LEGACY:
-            global CONNECTED
-            CONNECTED = True
-        gdb.events.new_objfile.connect(callback)
-
-    # XXX Fragile: though disconnecting the callback looks like a crap but it
-    # respects both Python 2 and Python 3 (see #4828).
-    def disconnect(callback):
-        if LEGACY:
-            global CONNECTED
-            if not CONNECTED:
-                return
-            CONNECTED = False
-        gdb.events.new_objfile.disconnect(callback)
-
-    try:
-        # Try to remove the callback at first to not append duplicates to
-        # gdb.events.new_objfile internal list.
-        disconnect(load)
-    except Exception:
-        # Callback is not connected.
-        pass
-
-    try:
-        # Detect whether libluajit objfile is loaded.
-        gdb.parse_and_eval('luaJIT_setmode')
-    except Exception:
-        gdb.write('luajit-gdb.py initialization is postponed '
-                  'until libluajit objfile is loaded\n')
-        # Add a callback to be executed when the next objfile is loaded.
-        connect(load)
-        return
-
-    try:
-        LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64'
-        LJ_FR2 = LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64'
-        LJ_DUALNUM = gdb.lookup_global_symbol('lj_lib_checknumber') is not None
-    except Exception:
-        gdb.write('luajit-gdb.py failed to load: '
-                  'no debugging symbols found for libluajit\n')
-        return
-
-    for name, command in commands.items():
-        command(name)
-
-    PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1))
-    LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX']
-
-    gdb.write('luajit-gdb.py is successfully loaded\n')
-
-
-def load(event=None):
-    init({
-        'lj-arch':  LJDumpArch,
-        'lj-gc':    LJGC,
-        'lj-stack': LJDumpStack,
-        'lj-state': LJState,
-        'lj-str':   LJDumpString,
-        'lj-tab':   LJDumpTable,
-        'lj-tv':    LJDumpTValue,
-    })
-
-
-load(None)
diff --git a/src/luajit_dbg.py b/src/luajit_dbg.py
new file mode 100644
index 00000000..164f0955
--- /dev/null
+++ b/src/luajit_dbg.py
@@ -0,0 +1,1281 @@
+# Debug extension for LuaJIT post-mortem analysis.
+# To use in GDB:
+# `source <path-to-repo>/src/luajit_dbg.py'
+# To use in LLDB:
+# `command script import <path-to-repo>/src/luajit_dbg.py'
+
+import abc
+import re
+import struct
+import sys
+
+from importlib import import_module
+
+# Make the script compatible with ancient Python.
+LEGACY = re.match(r'^2\.', sys.version)
+
+if LEGACY:
+    int = long  # noqa: F821
+    range = xrange  # noqa: F821
+
+
+# Debugger. ######################################################
+
+
+lldb = None
+gdb = None
+
+# XXX: While the `gdb` library is only available inside a debug
+# session, the `lldb` library can be loaded in any Python script.
+# To address that, we need to perform an additional check to
+# ensure a debug session is actually running.
+debuggers = {
+    'gdb': lambda lib: True,
+    'lldb': lambda lib: lib.debugger is not None,
+}
+for name, healthcheck in debuggers.items():
+    lib = None
+    try:
+        lib = import_module(name)
+        if healthcheck(lib):
+            globals()[name] = lib
+            break
+    except Exception:
+        continue
+
+assert (not not lldb) != (not not gdb), 'Debugger must be either LLDB or GDB.'
+
+
+class Debugger(object):
+    def __init__(self):
+        self.dbgtype_cache = {}
+
+    def __new__(self):
+        if gdb:
+            self.GDB = True
+            return super(Debugger, self).__new__(_GDBDebugger)
+        elif lldb:
+            self.LLDB = True
+            return super(Debugger, self).__new__(_LLDBDebugger)
+
+    def configure(self):
+        global PADDING, LJ_TISNUM
+        if not self.check_libluajit():
+            return False
+        try:
+            self.init_luajit_arch()
+            PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1))
+            LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX']
+        except Exception:
+            self.write('luajit_dbg.py failed to load: '
+                       'no debugging symbols found for libluajit\n')
+            return False
+        return True
+
+    def initialize_extension(self, commands):
+        if self.configure():
+            for name, command in commands.items():
+                self.register_command(command, name)
+                self.write('{} command initialized\n'.format(name))
+            self.write('LuaJIT debug extension is successfully loaded\n')
+
+    @abc.abstractmethod
+    def cast(self, typestr, val):
+        '''Cast the value to the required C type.'''
+        pass
+
+    @abc.abstractmethod
+    def sizeof(self, typestr):
+        '''Return the size of the given type in bytes.'''
+        pass
+
+    @abc.abstractmethod
+    def offsetof(self, typestr, fieldstr):
+        '''Return the offset of the given field in the type in bytes.'''
+        pass
+
+    @abc.abstractmethod
+    def cstr(self, strptr):
+        '''Return the content of the string by the given pointer.'''
+        pass
+
+    @abc.abstractmethod
+    def lookup_global(self, symbol):
+        '''Look up the global C symbol by the given name.'''
+        pass
+
+    @abc.abstractmethod
+    def eval(self, command):
+        '''Parse and evaluate the given debugger command.'''
+        pass
+
+    @abc.abstractmethod
+    def write(self, msg):
+        '''Print the message.'''
+        pass
+
+    @abc.abstractmethod
+    def check_libluajit(self):
+        '''Check that libluajit is loaded.
+        Check that the object file with libluajit symbols is loaded.
+        Postpone loading of the extension if needed.
+        '''
+        pass
+
+    @abc.abstractmethod
+    def init_luajit_arch(self):
+        '''Initialize LuaJIT architecture-specific globals.
+        Initialize build-dependent global constants.
+        If no debugging symbols are found raise an error.
+        '''
+        pass
+
+    @abc.abstractmethod
+    def register_command(self, command, name):
+        '''Register the command with the corresponding name.'''
+        pass
+
+    @abc.abstractproperty
+    def LJBase(self):
+        '''Base command class.
+        Provides the base class for the extension commands.
+        '''
+
+
+class _GDBDebugger(Debugger):
+    def _dbgtype(self, typestr):
+        if typestr in self.dbgtype_cache:
+            return self.dbgtype_cache[typestr]
+
+        m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr)
+
+        dbgtype = gdb.lookup_type(typestr) if m is None \
+            else gdb.lookup_type(m.group(1)).pointer()
+
+        self.dbgtype_cache[typestr] = dbgtype
+        return dbgtype
+
+    def __init__(self):
+        super(_GDBDebugger, self).__init__()
+        self.CONNECTED = False
+
+    def cast(self, typestr, val):
+        return gdb.Value(val).cast(self._dbgtype(typestr))
+
+    def sizeof(self, typestr):
+        return self._dbgtype(typestr).sizeof
+
+    def offsetof(self, typestr, fieldstr):
+        return int(self._dbgtype(typestr)[fieldstr].bitpos / 8)
+
+    def cstr(self, strptr):
+        # A string is printed with a pointer to it. Just strip it.
+        return re.sub(r'^0x[a-f0-9]+\s+(?=")', '', str(strptr))
+
+    def lookup_global(self, symbol):
+        variable, _ = gdb.lookup_symbol(symbol)
+        return variable.value() if variable else None
+
+    def eval(self, command):
+        if not command:
+            return None
+
+        ret = gdb.parse_and_eval(command)
+        if not ret:
+            raise gdb.GdbError('table argument empty')
+        return ret
+
+    def write(self, msg):
+        gdb.write(msg)
+
+    def check_libluajit(self):
+        # XXX Fragile: Though connecting the callback looks bad,
+        # it respects both Python 2 and Python 3 (see #4828).
+        def connect(callback):
+            if LEGACY:
+                self.CONNECTED = True
+            gdb.events.new_objfile.connect(callback)
+
+        # XXX Fragile: Though disconnecting the callback looks
+        # bad, it respects both Python 2 and Python 3 (see #4828).
+        def disconnect(callback):
+            if LEGACY:
+                if not self.CONNECTED:
+                    return
+                self.CONNECTED = False
+            gdb.events.new_objfile.disconnect(callback)
+
+        try:
+            # Try to remove the callback at first to not append
+            # duplicates to gdb.events.new_objfile internal list.
+            disconnect(load)
+        except Exception:
+            # Callback is not connected.
+            pass
+
+        try:
+            # Detect whether libluajit objfile is loaded.
+            gdb.parse_and_eval('luaJIT_setmode')
+        except Exception:
+            gdb.write('luajit_dbg.py initialization is postponed '
+                      'until libluajit objfile is loaded\n')
+            # Add a callback to be executed when the next objfile
+            # is loaded.
+            connect(load)
+            return False
+        return True
+
+    def init_luajit_arch(self):
+        global LJ_64, LJ_DUALNUM, LJ_FR2, LJ_GC64
+        LJ_64 = str(gdb.parse_and_eval('IRT_PTR')) == 'IRT_P64'
+        LJ_DUALNUM = gdb.lookup_global_symbol('lj_lib_checknumber') is not None
+        LJ_FR2 = LJ_GC64 = str(gdb.parse_and_eval('IRT_PGC')) == 'IRT_P64'
+
+    def register_command(self, command, name):
+        command(name)
+
+    class LJBase(gdb and gdb.Command or object):
+        def __init__(ljbase, name):
+            # XXX Fragile: Though the command initialization looks
+            # bad, it respects both Python 2 and Python 3.
+            gdb.Command.__init__(ljbase, name, gdb.COMMAND_DATA)
+
+        def invoke(ljbase, args, from_tty):
+            return ljbase.execute(args)
+
+        @abc.abstractmethod
+        def execute(ljbase, args):
+            '''Implementation of the command.
+            Subclasses override this method to implement the logic of a given
+            command, e.g. printing a stack.
+            '''
+
+    LJBase = LJBase
+
+
+class _LLDBDebugger(Debugger):
+    def _lldb_tp_isfp(self, tp):
+        return tp.GetBasicType() in [
+            lldb.eBasicTypeFloat,
+            lldb.eBasicTypeDouble,
+            lldb.eBasicTypeLongDouble
+        ]
+
+    def _lldb_value_from_raw(self, raw_value, size, tp):
+        isfp = self._lldb_tp_isfp(tp)
+        pack_flag = '<d' if isfp else '<Q'
+        raw_data = struct.pack(pack_flag, raw_value)
+        sbdata = lldb.SBData()
+        sbdata.SetData(
+            lldb.SBError(),
+            raw_data,
+            lldb.eByteOrderLittle,
+            size
+        )
+        sbval_res = self.target.CreateValueFromData(
+            # XXX: Name is required, let's make it meaningful.
+            '({tp}){val}'.format(
+                tp=tp.name,
+                val=raw_value if isfp else hex(raw_value)
+            ),
+            sbdata,
+            tp
+        )
+        return lldb.value(sbval_res)
+
+    def __init__(self):
+        def lldb__add__(lldbval, other):
+            other = int(other)
+            sbvalue = lldbval.sbvalue
+            if sbvalue.TypeIsPointerType():
+                tp = sbvalue.GetType()
+                sz = sbvalue.deref.size
+                addr = sbvalue.GetValueAsUnsigned() + other * sz
+                return self._lldb_value_from_raw(
+                    addr, sbvalue.GetByteSize(), tp
+                )
+            else:
+                return int(lldbval) + other
+
+        def lldb__bool__(lldbval):
+            return int(lldbval) != 0
+
+        def lldb__ge__(lldbval, other):
+            return int(lldbval) >= int(other)
+
+        def lldb__getitem__(lldbval, key):
+            if type(key) is lldb.value:
+                key = int(key)
+            if type(key) is int:
+                # Allow array access.
+                return lldb.value(
+                    lldbval.sbvalue.GetValueForExpressionPath('[%i]' % key)
+                )
+            elif type(key) is str:
+                return lldb.value(lldbval.sbvalue.GetChildMemberWithName(key))
+            raise Exception(TypeError('No item of type %s' % str(type(key))))
+
+        def lldb__gt__(lldbval, other):
+            return int(lldbval) > int(other)
+
+        def lldb__le__(lldbval, other):
+            return int(lldbval) <= int(other)
+
+        def lldb__lt__(lldbval, other):
+            return int(lldbval) < int(other)
+
+        def lldb__str__(lldbval):
+            # Instead of default GetSummary.
+            if not lldbval.sbvalue.TypeIsPointerType():
+                tp = lldbval.sbvalue.GetType()
+                is_float = self._lldb_tp_isfp(tp)
+                if is_float:
+                    return lldbval.sbvalue.GetValue()
+                else:
+                    return str(int(lldbval))
+
+            s = lldbval.sbvalue.GetValue()
+            if s[:2] == '0x':
+                # Strip useless leading zeros.
+                res = s[2:].lstrip('0')
+                return '0x' + (res if res else '0')
+            return s
+
+        def lldb__sub__(lldbval, other):
+            if type(other) is not lldb.value or \
+               type(other) is lldb.value and \
+               not other.sbvalue.TypeIsPointerType():
+                other = int(other)
+            if type(other) is int:
+                return lldb__add__(lldbval, -other)
+            elif lldbval.sbvalue.TypeIsPointerType():
+                sbval = lldbval.sbvalue
+                osbval = other.sbvalue
+                lldbval_tp = sbval.GetType()
+                other_tp = osbval.GetType()
+                # Subtract pointers of the same size only.
+                elsz = lldbval_tp.GetDereferencedType().size
+                if other_tp.GetDereferencedType().size != elsz:
+                    raise Exception(
+                        'Attempt to substruct {otp} from {stp}'.format(
+                            stp=lldbval_tp.name,
+                            otp=other_tp.name
+                        )
+                    )
+                diff = sbval.GetValueAsUnsigned() - osbval.GetValueAsUnsigned()
+                return int(diff / elsz)
+            else:
+                return int(lldbval) - int(other)
+
+        super(_LLDBDebugger, self).__init__()
+        self.target = lldb.debugger.GetSelectedTarget()
+        # Monkey-patch the lldb.value class.
+        lldb.value.__add__ = lldb__add__
+        lldb.value.__bool__ = lldb__bool__
+        lldb.value.__ge__ = lldb__ge__
+        lldb.value.__getitem__ = lldb__getitem__
+        lldb.value.__gt__ = lldb__gt__
+        lldb.value.__le__ = lldb__le__
+        lldb.value.__lt__ = lldb__lt__
+        lldb.value.__str__ = lldb__str__
+        lldb.value.__sub__ = lldb__sub__
+
+        def lldb_major_version():
+            version_string = lldb.SBDebugger.GetVersionString()
+            match = re.search(r'(\d+)', version_string)
+            if match:
+                return int(match.group(1))
+            return None
+
+        # Needed for features detection.
+        self.version = lldb_major_version()
+
+    def _dbgtype(self, typestr):
+        if typestr in self.dbgtype_cache:
+            return self.dbgtype_cache[typestr]
+
+        m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr)
+
+        dbgtype = self.target.FindFirstType(typestr) if m is None \
+            else self.target.FindFirstType(m.group(1)).GetPointerType()
+
+        self.dbgtype_cache[typestr] = dbgtype
+        return dbgtype
+
+    def cast(self, typestr, val):
+        if isinstance(val, lldb.value):
+            val = val.sbvalue
+        elif type(val) is int:
+            tp = self._dbgtype(typestr)
+            return self._lldb_value_from_raw(val, tp.GetByteSize(), tp)
+        elif not isinstance(val, lldb.SBValue):
+            raise Exception(
+                'Unexpected cast from type: {t}.'.format(t=type(val))
+            )
+
+        # XXX: Simply SBValue.Cast() works incorrectly since it
+        # may take the 8 bytes of memory instead of 4, before the
+        # cast. Construct the value on the fly.
+        tp = self._dbgtype(typestr)
+        is_fp = self._lldb_tp_isfp(tp)
+        rawval = float(val.GetValue()) if is_fp else val.GetValueAsUnsigned()
+        return self._lldb_value_from_raw(rawval, val.GetByteSize(), tp)
+
+    def sizeof(self, typestr):
+        return self._dbgtype(typestr).GetByteSize()
+
+    def offsetof(self, typestr, fieldstr):
+        def _type_member(type_obj, name):
+            return next((x for x in type_obj.members if x.name == name), None)
+
+        type_obj = self._dbgtype(typestr)
+        member = _type_member(type_obj, fieldstr)
+        assert member is not None, 'There is no field {f} in {t}'.format(
+            f=fieldstr,
+            t=typestr,
+        )
+        return member.GetOffsetInBytes()
+
+    def cstr(self, strptr):
+        return strptr.sbvalue.summary
+
+    def lookup_global(self, symbol):
+        return self.target.FindFirstGlobalVariable(symbol)
+
+    def eval(self, command):
+        if not command:
+            return None
+
+        process = self.target.GetProcess()
+        thread = process.GetSelectedThread()
+        frame = thread.GetSelectedFrame()
+        ret = frame.EvaluateExpression(command)
+        return ret
+
+    def write(self, msg):
+        sys.stdout.write(msg)
+
+    def check_libluajit(self):
+        # TODO: Implement postpone loading for LLDB too.
+        return True
+
+    def init_luajit_arch(self):
+        global LJ_64, LJ_DUALNUM, LJ_FR2, LJ_GC64
+        IRT_P64 = 9
+        module = self.target.modules[0]
+        LJ_DUALNUM = module.FindSymbol('lj_lib_checknumber') is not None
+        irtype_enum = self.target.FindFirstType('IRType').enum_members
+        for member in irtype_enum:
+            if member.name == 'IRT_PTR':
+                LJ_64 = member.unsigned & 0x1f == IRT_P64
+            if member.name == 'IRT_PGC':
+                LJ_FR2 = LJ_GC64 = member.unsigned & 0x1f == IRT_P64
+
+    def register_command(self, command, name):
+        command.name = name
+        lldb.debugger.HandleCommand(
+            'command script add {o} --class luajit_dbg.{cls} {cmd}'.format(
+                o='--overwrite' if self.version >= 14 else '',
+                cls=command.__name__,
+                cmd=name,
+            )
+        )
+
+    class LJBase(object):
+        # Ignore given parameters by LLDB.
+        def __init__(ljbase, debugger, unused):
+            pass
+
+        def get_short_help(ljbase):
+            return ljbase.__doc__.splitlines()[1]
+
+        def get_long_help(ljbase):
+            return ljbase.__doc__
+
+        def __call__(ljbase, debugger, args, exe_ctx, result):
+            try:
+                ljbase.execute(args)
+            except Exception as e:
+                msg = 'Failed to execute command `{}`: {}'.format(
+                    ljbase.name,
+                    e
+                )
+                result.SetError(msg)
+
+        @abc.abstractmethod
+        def execute(ljbase, args):
+            '''Implementation of the command.
+            Subclasses override this method to implement the logic of a given
+            command, e.g. printing a stack. Any unhandled exception will be
+            automatically transformed into proper errors.
+            '''
+
+    LJBase = LJBase
+
+
+dbg = Debugger()
+
+
+# LuaJIT. ########################################################
+
+
+# Constants.
+
+
+LJ_64 = None
+LJ_DUALNUM = None
+LJ_FR2 = None
+LJ_GC64 = None
+
+LJ_GCVMASK = ((1 << 47) - 1)
+LJ_TISNUM = None
+PADDING = None
+
+# These constants are meaningful only for 'LJ_64' mode.
+LJ_LIGHTUD_BITS_SEG = 8
+LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG
+LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1
+LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1
+
+
+# Simple converters.
+
+
+def tou64(val):
+    return dbg.cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF
+
+
+def tou32(val):
+    return int(val) & 0xFFFFFFFF
+
+
+def i2notu32(val):
+    return ~int(val) & 0xFFFFFFFF
+
+
+def strx64(val):
+    return re.sub('L?$', '', hex(int(tou64(val))))
+
+
+# Types and TValues.
+
+
+LJ_T = {
+    'NIL':     i2notu32(0),
+    'FALSE':   i2notu32(1),
+    'TRUE':    i2notu32(2),
+    'LIGHTUD': i2notu32(3),
+    'STR':     i2notu32(4),
+    'UPVAL':   i2notu32(5),
+    'THREAD':  i2notu32(6),
+    'PROTO':   i2notu32(7),
+    'FUNC':    i2notu32(8),
+    'TRACE':   i2notu32(9),
+    'CDATA':   i2notu32(10),
+    'TAB':     i2notu32(11),
+    'UDATA':   i2notu32(12),
+    'NUMX':    i2notu32(13),
+}
+
+
+def typenames(value):
+    return {
+        LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys()
+    }.get(int(value), 'LJ_TINVALID')
+
+
+def itype(o):
+    return tou32(o['it64'] >> 47) if LJ_GC64 else o['it']
+
+
+def tvisint(o):
+    return LJ_DUALNUM and itype(o) == LJ_TISNUM
+
+
+def tvisnumber(o):
+    return itype(o) <= LJ_TISNUM
+
+
+def tvislightud(o):
+    if LJ_64 and not LJ_GC64:
+        return (dbg.cast('int32_t', itype(o)) >> 15) == -2
+    else:
+        return itype(o) == LJ_T['LIGHTUD']
+
+
+def itypemap(o):
+    if LJ_64 and not LJ_GC64:
+        return LJ_T['NUMX'] if tvisnumber(o)       \
+            else LJ_T['LIGHTUD'] if tvislightud(o) \
+            else itype(o)
+    else:
+        return LJ_T['NUMX'] if tvisnumber(o) else itype(o)
+
+
+# Frames.
+
+
+FRAME_TYPE = 0x3
+FRAME_P = 0x4
+FRAME_TYPEP = FRAME_TYPE | FRAME_P
+
+FRAME = {
+    'LUA':    0x0,
+    'C':      0x1,
+    'CONT':   0x2,
+    'VARG':   0x3,
+    'LUAP':   0x4,
+    'CP':     0x5,
+    'PCALL':  0x6,
+    'PCALLH': 0x7,
+}
+
+
+def frametypes(ft):
+    return {
+        FRAME['LUA']:  'L',
+        FRAME['C']:    'C',
+        FRAME['CONT']: 'M',
+        FRAME['VARG']: 'V',
+    }.get(ft, '?')
+
+
+def bc_a(ins):
+    return (ins >> 8) & 0xff
+
+
+def frame_ftsz(framelink):
+    return dbg.cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2
+                    else framelink['fr']['tp']['ftsz'])
+
+
+def frame_pc(framelink):
+    return dbg.cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \
+                    else mref('BCIns *', framelink['fr']['tp']['pcr'])
+
+
+def frame_prevl(framelink):
+    return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1]))
+
+
+def frame_ispcall(framelink):
+    return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL']
+
+
+def frame_sized(framelink):
+    return (frame_ftsz(framelink) & ~FRAME_TYPEP)
+
+
+def frame_prevd(framelink):
+    return dbg.cast('TValue *',
+                    dbg.cast('char *', framelink) - frame_sized(framelink))
+
+
+def frame_type(framelink):
+    return frame_ftsz(framelink) & FRAME_TYPE
+
+
+def frame_typep(framelink):
+    return frame_ftsz(framelink) & FRAME_TYPEP
+
+
+def frame_islua(framelink):
+    return frametypes(int(frame_type(framelink))) == 'L' \
+        and int(frame_ftsz(framelink)) > 0
+
+
+def frame_prev(framelink):
+    return frame_prevl(framelink) if frame_islua(framelink) \
+        else frame_prevd(framelink)
+
+
+def frame_sentinel(L):
+    return mref('TValue *', L['stack']) + LJ_FR2
+
+
+# The generator that implements frame iterator.
+# Every frame is represented as a tuple of framelink and frametop.
+def frames(L):
+    frametop = L['top']
+    framelink = L['base'] - 1
+    framelink_sentinel = frame_sentinel(L)
+    while True:
+        yield framelink, frametop
+        frametop = framelink - (1 + LJ_FR2)
+        if framelink <= framelink_sentinel:
+            break
+        framelink = frame_prev(framelink)
+
+
+# LuaJIT macro implementations and structure access.
+
+
+def mref(typename, obj):
+    return dbg.cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32'])
+
+
+def gcref(obj):
+    return dbg.cast('GCobj *', obj['gcptr64'] if LJ_GC64
+                    else dbg.cast('uintptr_t', obj['gcptr32']))
+
+
+def gcval(obj):
+    return dbg.cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64
+                    else dbg.cast('uintptr_t', obj['gcptr32']))
+
+
+def gcnext(obj):
+    return gcref(obj)['gch']['nextgc']
+
+
+def L(L=None):
+    # Look up a symbol for the main coroutine considering the host
+    # application.
+    # XXX Fragile: Though the loop initialization looks bad, it
+    # respects both Python 2 and Python 3.
+    for lstate in [L] + list(map(lambda main: dbg.lookup_global(main), (
+        # LuaJIT main coro (see luajit/src/luajit.c).
+        'globalL',
+        # Tarantool main coro (see tarantool/src/lua/init.h).
+        'tarantool_L',
+        # TODO: Add more.
+    ))):
+        if lstate:
+            return dbg.cast('lua_State *', lstate)
+
+
+def G(L):
+    return mref('global_State *', L['glref'])
+
+
+def J(g):
+    g_offset = dbg.offsetof('GG_State', 'g')
+    J_offset = dbg.offsetof('GG_State', 'J')
+    return dbg.cast('jit_State *', dbg.cast('char *', g) - g_offset + J_offset)
+
+
+def vm_state(g):
+    return {
+        i2notu32(0): 'INTERP',
+        i2notu32(1): 'LFUNC',
+        i2notu32(2): 'FFUNC',
+        i2notu32(3): 'CFUNC',
+        i2notu32(4): 'GC',
+        i2notu32(5): 'EXIT',
+        i2notu32(6): 'RECORD',
+        i2notu32(7): 'OPT',
+        i2notu32(8): 'ASM',
+    }.get(int(tou32(g['vmstate'])), 'TRACE')
+
+
+def gc_state(g):
+    return {
+        0: 'PAUSE',
+        1: 'PROPAGATE',
+        2: 'ATOMIC',
+        3: 'SWEEPSTRING',
+        4: 'SWEEP',
+        5: 'FINALIZE',
+        6: 'LAST',
+    }.get(int(g['gc']['state']), 'INVALID')
+
+
+def jit_state(g):
+    return {
+        0:    'IDLE',
+        0x10: 'ACTIVE',
+        0x11: 'RECORD',
+        0x12: 'START',
+        0x13: 'END',
+        0x14: 'ASM',
+        0x15: 'ERR',
+    }.get(int(J(g)['state']), 'INVALID')
+
+
+def strdata(obj):
+    try:
+        return dbg.cstr(dbg.cast('char *', dbg.cast('GCstr *', obj) + 1))
+    except UnicodeEncodeError:
+        return "<luajit_dbg: error occurred while rendering non-ascii slot>"
+
+
+def funcproto(func):
+    assert func['ffid'] == 0, 'Attempt to take a prototype of non-Lua function'
+    return dbg.cast('GCproto *',
+                    mref('char *', func['pc']) - dbg.sizeof('GCproto'))
+
+
+def gclistlen(root, end=0x0):
+    count = 0
+    while (gcref(root) != end):
+        count += 1
+        root = gcnext(root)
+    return count
+
+
+def gcringlen(root):
+    if not gcref(root):
+        return 0
+    elif gcref(root) == gcref(gcnext(root)):
+        return 1
+    else:
+        return 1 + gclistlen(gcnext(root), gcref(root))
+
+
+gclen = {
+    'root':      gclistlen,
+    'gray':      gclistlen,
+    'grayagain': gclistlen,
+    'weak':      gclistlen,
+    # XXX: gc.mmudata is a ring-list.
+    'mmudata':   gcringlen,
+}
+
+
+def lightudV(tv):
+    if LJ_64:
+        u = int(tv['u64'])
+        # `lightudseg()' macro expanded.
+        seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK
+        segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg'])
+        # `lightudlo()' macro expanded.
+        return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK)
+    else:
+        return gcval(tv['gcr'])
+
+
+# Dumpers.
+
+
+def dump_lj_tnil(tv):
+    return 'nil'
+
+
+def dump_lj_tfalse(tv):
+    return 'false'
+
+
+def dump_lj_ttrue(tv):
+    return 'true'
+
+
+def dump_lj_tlightud(tv):
+    return 'light userdata @ {}'.format(strx64(lightudV(tv)))
+
+
+def dump_lj_tstr(tv):
+    return 'string {body} @ {address}'.format(
+        body=strdata(gcval(tv['gcr'])),
+        address=strx64(gcval(tv['gcr']))
+    )
+
+
+def dump_lj_tupval(tv):
+    return 'upvalue @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+def dump_lj_tthread(tv):
+    return 'thread @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+def dump_lj_tproto(tv):
+    return 'proto @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+def dump_lj_tfunc(tv):
+    func = dbg.cast('struct GCfuncC *', gcval(tv['gcr']))
+    ffid = func['ffid']
+
+    if ffid == 0:
+        pt = funcproto(func)
+        return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format(
+            addr=strx64(func),
+            nups=int(func['nupvalues']),
+            chunk=strdata(dbg.cast('GCstr *', gcval(pt['chunkname']))),
+            line=pt['firstline']
+        )
+    elif ffid == 1:
+        return 'C function @ {}'.format(strx64(func['f']))
+    else:
+        return 'fast function #{}'.format(int(ffid))
+
+
+def dump_lj_ttrace(tv):
+    trace = dbg.cast('struct GCtrace *', gcval(tv['gcr']))
+    return 'trace {traceno} @ {addr}'.format(
+        traceno=strx64(trace['traceno']),
+        addr=strx64(trace)
+    )
+
+
+def dump_lj_tcdata(tv):
+    return 'cdata @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+def dump_lj_ttab(tv):
+    table = dbg.cast('GCtab *', gcval(tv['gcr']))
+    return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format(
+        gcr=strx64(table),
+        asize=table['asize'],
+        hmask=strx64(table['hmask']),
+    )
+
+
+def dump_lj_tudata(tv):
+    return 'userdata @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+def dump_lj_tnumx(tv):
+    if tvisint(tv):
+        return 'integer {}'.format(dbg.cast('int32_t', tv['i']))
+    else:
+        return 'number {}'.format(dbg.cast('double', tv['n']))
+
+
+def dump_lj_invalid(tv):
+    return 'not valid type @ {}'.format(strx64(gcval(tv['gcr'])))
+
+
+dumpers = {
+    'LJ_TNIL':     dump_lj_tnil,
+    'LJ_TFALSE':   dump_lj_tfalse,
+    'LJ_TTRUE':    dump_lj_ttrue,
+    'LJ_TLIGHTUD': dump_lj_tlightud,
+    'LJ_TSTR':     dump_lj_tstr,
+    'LJ_TUPVAL':   dump_lj_tupval,
+    'LJ_TTHREAD':  dump_lj_tthread,
+    'LJ_TPROTO':   dump_lj_tproto,
+    'LJ_TFUNC':    dump_lj_tfunc,
+    'LJ_TTRACE':   dump_lj_ttrace,
+    'LJ_TCDATA':   dump_lj_tcdata,
+    'LJ_TTAB':     dump_lj_ttab,
+    'LJ_TUDATA':   dump_lj_tudata,
+    'LJ_TNUMX':    dump_lj_tnumx,
+}
+
+
+def dump_tvalue(tvalue):
+    return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue)
+
+
+def dump_framelink_slot_address(fr):
+    return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \
+        else '{}'.format(fr) + PADDING
+
+
+def dump_framelink(L, fr):
+    if fr == frame_sentinel(L):
+        return '{addr} [S   ] FRAME: dummy L'.format(
+            addr=dump_framelink_slot_address(fr),
+        )
+    return '{addr} [    ] FRAME: [{pp}] delta={d}, {f}'.format(
+        addr=dump_framelink_slot_address(fr),
+        pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format(
+            frname=frametypes(int(frame_type(fr))),
+            p='P' if frame_typep(fr) & FRAME_P else ''
+        ),
+        d=dbg.cast('TValue *', fr) - dbg.cast('TValue *', frame_prev(fr)),
+        f=dump_lj_tfunc(fr - LJ_FR2),
+    )
+
+
+def dump_stack_slot(L, slot, base=None, top=None):
+    base = base or L['base']
+    top = top or L['top']
+
+    return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format(
+        addr=strx64(slot),
+        padding=PADDING,
+        B='B' if slot == base else ' ',
+        T='T' if slot == top else ' ',
+        M='M' if slot == mref('TValue *', L['maxstack']) else ' ',
+        value=dump_tvalue(slot),
+    )
+
+
+def dump_stack(L, base=None, top=None):
+    base = base or L['base']
+    top = top or L['top']
+    stack = mref('TValue *', L['stack'])
+    maxstack = mref('TValue *', L['maxstack'])
+    red = 5 + 3 * LJ_FR2
+
+    dump = [
+        '{padding} Red zone: {nredslots: >2} slots {padding}'.format(
+            padding='-' * len(PADDING),
+            nredslots=red,
+        ),
+    ]
+    dump.extend([
+        dump_stack_slot(L, maxstack + offset, base, top)
+            for offset in range(red, 0, -1)  # noqa: E131
+    ])
+    dump.extend([
+        '{padding} Stack: {nstackslots: >5} slots {padding}'.format(
+            padding='-' * len(PADDING),
+            nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3),
+        ),
+        dump_stack_slot(L, maxstack, base, top),
+        '{start}:{end} [    ] {nfreeslots} slots: Free stack slots'.format(
+            start=strx64(top + 1),
+            end=strx64(maxstack - 1),
+            nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3),
+        ),
+    ])
+
+    for framelink, frametop in frames(L):
+        # Dump all data slots in the (framelink, top) interval.
+        dump.extend([
+            dump_stack_slot(L, framelink + offset, base, top)
+                for offset in range(frametop - framelink, 0, -1)  # noqa: E131
+        ])
+        # Dump frame slot (2 slots in case of GC64).
+        dump.append(dump_framelink(L, framelink))
+
+    return '\n'.join(dump)
+
+
+def dump_gc(g):
+    gc = g['gc']
+    stats = ['{key}: {value}'.format(key=f, value=gc[f]) for f in (
+        'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause'
+    )]
+
+    stats += ['sweepstr: {sweepstr}/{strmask}'.format(
+        sweepstr=gc['sweepstr'],
+        # String hash mask (size of hash table - 1).
+        strmask=g['strmask'] + 1,
+    )]
+
+    stats += ['{key}: {number} objects'.format(
+        key=stat,
+        number=handler(gc[stat])
+    ) for stat, handler in gclen.items()]
+
+    return '\n'.join(map(lambda s: '\t' + s, stats))
+
+
+# Extension commands. ############################################
+
+
+class LJDumpArch(dbg.LJBase):
+    '''
+lj-arch
+
+The command requires no args and dumps values of LJ_64 and LJ_GC64
+compile-time flags. These values define the sizes of host and GC
+pointers, respectively.
+    '''
+
+    def execute(self, arg):
+        dbg.write(
+            'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}\n'
+            .format(
+                LJ_64=LJ_64,
+                LJ_GC64=LJ_GC64,
+                LJ_DUALNUM=LJ_DUALNUM
+            )
+        )
+
+
+class LJGC(dbg.LJBase):
+    '''
+lj-gc
+
+The command requires no args and dumps current GC stats:
+* total: <total number of allocated bytes in GC area>
+* threshold: <limit when gc step is triggered>
+* debt: <how much GC is behind schedule>
+* estimate: <estimate of memory actually in use>
+* stepmul: <incremental GC step granularity>
+* pause: <pause between successive GC cycles>
+* sweepstr: <sweep position in string table>
+* root: <number of all collectable objects>
+* gray: <number of gray objects>
+* grayagain: <number of objects for atomic traversal>
+* weak: <number of weak tables (to be cleared)>
+* mmudata: <number of udata|cdata to be finalized>
+    '''
+
+    def execute(self, arg):
+        g = G(L(None))
+        dbg.write('GC stats: {state}\n{stats}\n'.format(
+            state=gc_state(g),
+            stats=dump_gc(g)
+        ))
+
+
+class LJDumpStack(dbg.LJBase):
+    '''
+lj-stack [<lua_State *>]
+
+The command receives a lua_State address and dumps the given Lua
+coroutine guest stack:
+
+<slot ptr> [<slot attributes>] <VALUE|FRAME>
+
+* <slot ptr>: guest stack slot address
+* <slot attributes>:
+  - S: Bottom of the stack (the slot L->stack points to)
+  - B: Base of the current guest frame (the slot L->base points to)
+  - T: Top of the current guest frame (the slot L->top points to)
+  - M: Last slot of the stack (the slot L->maxstack points to)
+* <VALUE>: See help lj-tv for more info
+* <FRAME>: Framelink slot differs from the value slot: it contains info
+  related to the function being executed within this guest frame, its
+  type, and a link to the parent guest frame
+  [<frame type>] delta=<slots in frame>, <lj-tv for LJ_TFUNC slot>
+  - <frame type>:
+    + L:  VM performs a call as a result of bytecode execution
+    + C:  VM performs a call as a result of lj_vm_call
+    + M:  VM performs a call to a metamethod as a result of bytecode
+          execution
+    + V:  Variable-length frame for storing arguments of a variadic
+          function
+    + CP: Protected C frame
+    + PP: VM performs a call as a result of executing pcall or xpcall
+
+If L is omitted, the main coroutine is used.
+    '''
+
+    def execute(self, arg):
+        dbg.write('{}\n'.format(dump_stack(L(dbg.eval(arg)))))
+
+
+class LJState(dbg.LJBase):
+    '''
+lj-state
+The command requires no args and dumps current VM and GC states:
+* VM state: <INTERP|C|GC|EXIT|RECORD|OPT|ASM|TRACE>
+* GC state: <PAUSE|PROPAGATE|ATOMIC|SWEEPSTRING|SWEEP|FINALIZE|LAST>
+* JIT state: <IDLE|ACTIVE|RECORD|START|END|ASM|ERR>
+    '''
+
+    def execute(self, arg):
+        g = G(L(None))
+        dbg.write('{}\n'.format('\n'.join(
+            map(lambda t: '{} state: {}'.format(*t), {
+                'VM':  vm_state(g),
+                'GC':  gc_state(g),
+                'JIT': jit_state(g),
+            }.items())
+        )))
+
+
+class LJDumpString(dbg.LJBase):
+    '''
+lj-str <GCstr *>
+
+The command receives a <gcr> of the corresponding GCstr object and dumps
+the payload, size in bytes and hash.
+
+*Caveat*: Since Python 2 provides no native Unicode support, the payload
+is replaced with the corresponding error when decoding fails.
+    '''
+
+    def execute(self, arg):
+        string = dbg.cast('GCstr *', dbg.eval(arg))
+        dbg.write("String: {body} [{len} bytes] with hash {hash}\n".format(
+            body=strdata(string),
+            hash=strx64(string['hash']),
+            len=string['len'],
+        ))
+
+
+class LJDumpTable(dbg.LJBase):
+    '''
+lj-tab <GCtab *>
+
+The command receives a GCtab address and dumps the table contents:
+* Metatable address whether the one is set
+* Array part <asize> slots:
+  <aslot ptr>: [<index>]: <tv>
+* Hash part <hsize> nodes:
+  <hnode ptr>: { <tv> } => { <tv> }; next = <next hnode ptr>
+    '''
+
+    def execute(self, arg):
+        t = dbg.cast('GCtab *', dbg.eval(arg))
+        array = mref('TValue *', t['array'])
+        nodes = mref('struct Node *', t['node'])
+        mt = gcval(t['metatable'])
+        capacity = {
+            'apart': int(t['asize']),
+            'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0
+        }
+
+        if mt != 0:
+            dbg.write('Metatable detected: {}\n'.format(strx64(mt)))
+
+        dbg.write('Array part: {} slots\n'.format(capacity['apart']))
+        for i in range(capacity['apart']):
+            slot = array + i
+            dbg.write('{ptr}: [{index}]: {value}\n'.format(
+                ptr=slot,
+                index=i,
+                value=dump_tvalue(slot)
+            ))
+
+        dbg.write('Hash part: {} nodes\n'.format(capacity['hpart']))
+        # See hmask comment in lj_obj.h
+        for i in range(capacity['hpart']):
+            node = nodes + i
+            dbg.write('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}\n'.format(
+                ptr=node,
+                key=dump_tvalue(node['key']),
+                val=dump_tvalue(node['val']),
+                n=mref('struct Node *', node['next'])
+            ))
+
+
+class LJDumpTValue(dbg.LJBase):
+    '''
+lj-tv <TValue *>
+
+The command receives a pointer to <tv> (TValue address) and dumps
+the type and some info related to it.
+
+* LJ_TNIL: nil
+* LJ_TFALSE: false
+* LJ_TTRUE: true
+* LJ_TLIGHTUD: light userdata @ <gcr>
+* LJ_TSTR: string <string payload> @ <gcr>
+* LJ_TUPVAL: upvalue @ <gcr>
+* LJ_TTHREAD: thread @ <gcr>
+* LJ_TPROTO: proto @ <gcr>
+* LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
+  <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
+  <CFUNC>: C function <mcode address>
+  <FFUNC>: fast function #<ffid>
+* LJ_TTRACE: trace <traceno> @ <gcr>
+* LJ_TCDATA: cdata @ <gcr>
+* LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
+* LJ_TUDATA: userdata @ <gcr>
+* LJ_TNUMX: <number|integer> <numeric payload>
+
+Whether the type of the given address differs from the listed above, then
+error message occurs.
+    '''
+
+    def execute(self, arg):
+        tv = dbg.cast('TValue *', dbg.eval(arg))
+        dbg.write('{}\n'.format(dump_tvalue(tv)))
+
+
+def load(event=None):
+    dbg.initialize_extension({
+        'lj-arch':  LJDumpArch,
+        'lj-gc':    LJGC,
+        'lj-stack': LJDumpStack,
+        'lj-state': LJState,
+        'lj-str':   LJDumpString,
+        'lj-tab':   LJDumpTable,
+        'lj-tv':    LJDumpTValue,
+    })
+
+
+if gdb:
+    load()
+elif lldb:
+    def __lldb_init_module(debugger, internal_dictionary):
+        load()
diff --git a/src/luajit_lldb.py b/src/luajit_lldb.py
deleted file mode 100644
index e3fe82fc..00000000
--- a/src/luajit_lldb.py
+++ /dev/null
@@ -1,1015 +0,0 @@
-# LLDB extension for LuaJIT post-mortem analysis.
-# To use, just put 'command script import <path-to-repo>/src/luajit_lldb.py'
-# in lldb.
-
-import abc
-import re
-import lldb
-import struct
-
-LJ_64 = None
-LJ_GC64 = None
-LJ_FR2 = None
-LJ_DUALNUM = None
-PADDING = None
-
-# Constants
-IRT_P64 = 9
-LJ_GCVMASK = ((1 << 47) - 1)
-LJ_TISNUM = None
-
-# These constants are meaningful only for 'LJ_64' mode.
-LJ_LIGHTUD_BITS_SEG = 8
-LJ_LIGHTUD_BITS_LO = 47 - LJ_LIGHTUD_BITS_SEG
-LIGHTUD_SEG_MASK = (1 << LJ_LIGHTUD_BITS_SEG) - 1
-LIGHTUD_LO_MASK = (1 << LJ_LIGHTUD_BITS_LO) - 1
-
-# Debugger specific {{{
-
-
-# Global
-target = None
-
-
-def lldb_tp_isfp(tp):
-    return tp.GetBasicType() in [
-        lldb.eBasicTypeFloat,
-        lldb.eBasicTypeDouble,
-        lldb.eBasicTypeLongDouble
-    ]
-
-
-def lldb_value_from_raw(raw_value, size, tp):
-    isfp = lldb_tp_isfp(tp)
-    pack_flag = '<d' if isfp else '<Q'
-    raw_data = struct.pack(pack_flag, raw_value)
-    sbdata = lldb.SBData()
-    sbdata.SetData(
-        lldb.SBError(),
-        raw_data,
-        lldb.eByteOrderLittle,
-        size
-    )
-    sbval_res = target.CreateValueFromData(
-        # XXX: The name is required. Let's make it meaningful.
-        '({tp}){val}'.format(
-            tp=tp.name,
-            val=raw_value if isfp else hex(raw_value)
-        ),
-        sbdata,
-        tp
-    )
-    return lldb.value(sbval_res)
-
-
-def lldb__add__(self, other):
-    other = int(other)
-    sbvalue = self.sbvalue
-    if sbvalue.TypeIsPointerType():
-        tp = sbvalue.GetType()
-        sz = sbvalue.deref.size
-        addr = sbvalue.GetValueAsUnsigned() + other * sz
-        return lldb_value_from_raw(addr, sbvalue.GetByteSize(), tp)
-    else:
-        return int(self) + other
-
-
-def lldb__bool__(self):
-    return int(self) != 0
-
-
-def lldb__ge__(self, other):
-    return int(self) >= int(other)
-
-
-def lldb__getitem__(self, key):
-    if type(key) is lldb.value:
-        key = int(key)
-    if type(key) is int:
-        # Allow array access.
-        return lldb.value(self.sbvalue.GetValueForExpressionPath('[%i]' % key))
-    elif type(key) is str:
-        return lldb.value(self.sbvalue.GetChildMemberWithName(key))
-    raise Exception(TypeError('No item of type %s' % str(type(key))))
-
-
-def lldb__gt__(self, other):
-    return int(self) > int(other)
-
-
-def lldb__le__(self, other):
-    return int(self) <= int(other)
-
-
-def lldb__lt__(self, other):
-    return int(self) < int(other)
-
-
-def lldb__str__(self):
-    # Instead of default GetSummary.
-    if not self.sbvalue.TypeIsPointerType():
-        tp = self.sbvalue.GetType()
-        is_float = lldb_tp_isfp(tp)
-        if is_float:
-            return self.sbvalue.GetValue()
-        else:
-            return str(int(self))
-
-    s = self.sbvalue.GetValue()
-    if s[:2] == '0x':
-        # Strip useless leading zeros.
-        res = s[2:].lstrip('0')
-        return '0x' + (res if res else '0')
-    return s
-
-
-def lldb__sub__(self, other):
-    if type(other) is not lldb.value or \
-       type(other) is lldb.value and not other.sbvalue.TypeIsPointerType():
-        other = int(other)
-    if type(other) is int:
-        return lldb__add__(self, -other)
-    elif self.sbvalue.TypeIsPointerType():
-        ssbval = self.sbvalue
-        osbval = other.sbvalue
-        self_tp = ssbval.GetType()
-        other_tp = osbval.GetType()
-        # Subtract pointers of the same size only.
-        elsz = self_tp.GetDereferencedType().size
-        if other_tp.GetDereferencedType().size != elsz:
-            raise Exception('Attempt to substruct {otp} from {stp}'.format(
-                stp=self_tp.name,
-                otp=other_tp.name
-            ))
-        diff = ssbval.GetValueAsUnsigned() - osbval.GetValueAsUnsigned()
-        return int(diff / elsz)
-    else:
-        return int(self) - int(other)
-
-
-# Monkey-patch the lldb.value class.
-lldb.value.__add__ = lldb__add__
-lldb.value.__bool__ = lldb__bool__
-lldb.value.__ge__ = lldb__ge__
-lldb.value.__getitem__ = lldb__getitem__
-lldb.value.__gt__ = lldb__gt__
-lldb.value.__le__ = lldb__le__
-lldb.value.__lt__ = lldb__lt__
-lldb.value.__str__ = lldb__str__
-lldb.value.__sub__ = lldb__sub__
-
-
-class Command(object):
-    def __init__(self, debugger, unused):
-        pass
-
-    def get_short_help(self):
-        return self.__doc__.splitlines()[0]
-
-    def get_long_help(self):
-        return self.__doc__
-
-    def __call__(self, debugger, command, exe_ctx, result):
-        try:
-            self.execute(debugger, command, result)
-        except Exception as e:
-            msg = 'Failed to execute command `{}`: {}'.format(self.command, e)
-            result.SetError(msg)
-
-    def parse(self, command):
-        process = target.GetProcess()
-        thread = process.GetSelectedThread()
-        frame = thread.GetSelectedFrame()
-
-        if not command:
-            return None
-
-        ret = frame.EvaluateExpression(command)
-        return ret
-
-    @abc.abstractproperty
-    def command(self):
-        """Command name.
-        This name will be used by LLDB in order to unique/ly identify an
-        implementation that should be executed when a command is run
-        in the REPL.
-        """
-
-    @abc.abstractmethod
-    def execute(self, debugger, args, result):
-        """Implementation of the command.
-        Subclasses override this method to implement the logic of a given
-        command, e.g. printing a stacktrace. The command output should be
-        communicated back via the provided result object, so that it's
-        properly routed to LLDB frontend. Any unhandled exception will be
-        automatically transformed into proper errors.
-        """
-
-
-gtype_cache = {}
-
-
-def gtype(typestr):
-    if typestr in gtype_cache:
-        return gtype_cache[typestr]
-
-    m = re.match(r'((?:(?:struct|union) )?\S*)\s*[*]', typestr)
-
-    gtype = target.FindFirstType(typestr) if m is None \
-        else target.FindFirstType(m.group(1)).GetPointerType()
-
-    gtype_cache[typestr] = gtype
-    return gtype
-
-
-def cast(typestr, val):
-    if isinstance(val, lldb.value):
-        val = val.sbvalue
-    elif type(val) is int:
-        tp = gtype(typestr)
-        return lldb_value_from_raw(val, tp.GetByteSize(), tp)
-    elif not isinstance(val, lldb.SBValue):
-        raise Exception('unexpected cast from type: {t}'.format(t=type(val)))
-
-    # XXX: Simply SBValue.Cast() works incorrectly since it may
-    # take the 8 bytes of memory instead of 4, before the cast.
-    # Construct the value on the fly.
-    tp = gtype(typestr)
-    is_fp = lldb_tp_isfp(tp)
-    rawval = float(val.GetValue()) if is_fp else val.GetValueAsUnsigned()
-    return lldb_value_from_raw(rawval, val.GetByteSize(), tp)
-
-
-def lookup_global(name):
-    return target.FindFirstGlobalVariable(name)
-
-
-def type_member(type_obj, name):
-    return next((x for x in type_obj.members if x.name == name), None)
-
-
-def offsetof(typename, membername):
-    type_obj = gtype(typename)
-    member = type_member(type_obj, membername)
-    assert member is not None
-    return member.GetOffsetInBytes()
-
-
-def sizeof(typename):
-    type_obj = gtype(typename)
-    return type_obj.GetByteSize()
-
-
-def tou64(val):
-    return cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF
-
-
-def dbg_eval(expr):
-    process = target.GetProcess()
-    thread = process.GetSelectedThread()
-    frame = thread.GetSelectedFrame()
-    return frame.EvaluateExpression(expr)
-
-
-# }}} Debugger specific
-
-
-def gcval(obj):
-    return cast('GCobj *', obj['gcptr64'] & LJ_GCVMASK if LJ_GC64
-                else cast('uintptr_t', obj['gcptr32']))
-
-
-def gcref(obj):
-    return cast('GCobj *', obj['gcptr64'] if LJ_GC64
-                else cast('uintptr_t', obj['gcptr32']))
-
-
-def gcnext(obj):
-    return gcref(obj)['gch']['nextgc']
-
-
-def gclistlen(root, end=0x0):
-    count = 0
-    while (gcref(root) != end):
-        count += 1
-        root = gcnext(root)
-    return count
-
-
-def gcringlen(root):
-    if not gcref(root):
-        return 0
-    elif gcref(root) == gcref(gcnext(root)):
-        return 1
-    else:
-        return 1 + gclistlen(gcnext(root), gcref(root))
-
-
-gclen = {
-    'root':      gclistlen,
-    'gray':      gclistlen,
-    'grayagain': gclistlen,
-    'weak':      gclistlen,
-    # XXX: gc.mmudata is a ring-list.
-    'mmudata':   gcringlen,
-}
-
-
-def dump_gc(g):
-    gc = g['gc']
-    stats = ['{key}: {value}'.format(key=f, value=getattr(gc, f)) for f in (
-        'total', 'threshold', 'debt', 'estimate', 'stepmul', 'pause'
-    )]
-
-    stats += ['sweepstr: {sweepstr}/{strmask}'.format(
-        sweepstr=gc['sweepstr'],
-        # String hash mask (size of hash table - 1).
-        strmask=g['strmask'] + 1,
-    )]
-
-    stats += ['{key}: {number} objects'.format(
-        key=stat,
-        number=handler(getattr(gc, stat))
-    ) for stat, handler in gclen.items()]
-    return '\n'.join(map(lambda s: '\t' + s, stats))
-
-
-def mref(typename, obj):
-    return cast(typename, obj['ptr64'] if LJ_GC64 else obj['ptr32'])
-
-
-def J(g):
-    g_offset = offsetof('GG_State', 'g')
-    J_offset = offsetof('GG_State', 'J')
-    return cast('jit_State *', (cast('char *', g) - g_offset + J_offset))
-
-
-def G(L):
-    return mref('global_State *', L['glref'])
-
-
-def L(L=None):
-    # lookup a symbol for the main coroutine considering the host app
-    # XXX Fragile: though the loop initialization looks like a crap but it
-    # respects both Python 2 and Python 3.
-    for lstate in [L] + list(map(lambda main: lookup_global(main), (
-        # LuaJIT main coro (see luajit/src/luajit.c)
-        'globalL',
-        # Tarantool main coro (see tarantool/src/lua/init.h)
-        'tarantool_L',
-        # TODO: Add more
-    ))):
-        if lstate:
-            return cast('lua_State *', lstate)
-
-
-def tou32(val):
-    return val & 0xFFFFFFFF
-
-
-def i2notu32(val):
-    return ~int(val) & 0xFFFFFFFF
-
-
-def vm_state(g):
-    return {
-        i2notu32(0): 'INTERP',
-        i2notu32(1): 'LFUNC',
-        i2notu32(2): 'FFUNC',
-        i2notu32(3): 'CFUNC',
-        i2notu32(4): 'GC',
-        i2notu32(5): 'EXIT',
-        i2notu32(6): 'RECORD',
-        i2notu32(7): 'OPT',
-        i2notu32(8): 'ASM',
-    }.get(int(tou32(g['vmstate'])), 'TRACE')
-
-
-def gc_state(g):
-    return {
-        0: 'PAUSE',
-        1: 'PROPAGATE',
-        2: 'ATOMIC',
-        3: 'SWEEPSTRING',
-        4: 'SWEEP',
-        5: 'FINALIZE',
-        6: 'LAST',
-    }.get(int(g['gc']['state']), 'INVALID')
-
-
-def jit_state(g):
-    return {
-        0:    'IDLE',
-        0x10: 'ACTIVE',
-        0x11: 'RECORD',
-        0x12: 'START',
-        0x13: 'END',
-        0x14: 'ASM',
-        0x15: 'ERR',
-    }.get(int(J(g).state), 'INVALID')
-
-
-def strx64(val):
-    return re.sub('L?$', '',
-                  hex(int(cast('uint64_t', val) & 0xFFFFFFFFFFFFFFFF)))
-
-
-def funcproto(func):
-    assert func.ffid == 0
-    return cast('GCproto *', mref('char *', func.pc) - sizeof('GCproto'))
-
-
-def strdata(obj):
-    try:
-        ptr = cast('char *', cast('GCstr *', obj) + 1)
-        return ptr.sbvalue.summary
-    except UnicodeEncodeError:
-        return "<luajit-lldb: error occurred while rendering non-ascii slot>"
-
-
-def itype(o):
-    return tou32(o['it64'] >> 47) if LJ_GC64 else o['it']
-
-
-def tvisint(o):
-    return LJ_DUALNUM and itype(o) == LJ_TISNUM
-
-
-def tvislightud(o):
-    if LJ_64 and not LJ_GC64:
-        return (int(cast('int32_t', itype(o))) >> 15) == -2
-    else:
-        return itype(o) == LJ_T['LIGHTUD']
-
-
-def tvisnumber(o):
-    return itype(o) <= LJ_TISNUM
-
-
-def lightudV(tv):
-    if LJ_64:
-        u = int(tv['u64'])
-        # lightudseg macro expanded.
-        seg = (u >> LJ_LIGHTUD_BITS_LO) & LIGHTUD_SEG_MASK
-        segmap = mref('uint32_t *', G(L(None))['gc']['lightudseg'])
-        # lightudlo macro expanded.
-        return (int(segmap[seg]) << 32) | (u & LIGHTUD_LO_MASK)
-    else:
-        return gcval(tv['gcr'])
-
-
-def dump_lj_tnil(tv):
-    return 'nil'
-
-
-def dump_lj_tfalse(tv):
-    return 'false'
-
-
-def dump_lj_ttrue(tv):
-    return 'true'
-
-
-def dump_lj_tlightud(tv):
-    return 'light userdata @ {}'.format(strx64(lightudV(tv)))
-
-
-def dump_lj_tstr(tv):
-    return 'string {body} @ {address}'.format(
-        body=strdata(cast('GCstr *', gcval(tv['gcr']))),
-        address=strx64(gcval(tv['gcr']))
-    )
-
-
-def dump_lj_tupval(tv):
-    return 'upvalue @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tthread(tv):
-    return 'thread @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tproto(tv):
-    return 'proto @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tfunc(tv):
-    func = cast('GCfuncC *', gcval(tv['gcr']))
-    ffid = func['ffid']
-
-    if ffid == 0:
-        pt = funcproto(func)
-        return 'Lua function @ {addr}, {nups} upvalues, {chunk}:{line}'.format(
-            addr=strx64(func),
-            nups=func['nupvalues'],
-            chunk=strdata(cast('GCstr *', gcval(pt['chunkname']))),
-            line=pt['firstline']
-        )
-    elif ffid == 1:
-        return 'C function @ {}'.format(strx64(func['f']))
-    else:
-        return 'fast function #{}'.format(ffid)
-
-
-def dump_lj_ttrace(tv):
-    trace = cast('GCtrace *', gcval(tv['gcr']))
-    return 'trace {traceno} @ {addr}'.format(
-        traceno=strx64(trace['traceno']),
-        addr=strx64(trace)
-    )
-
-
-def dump_lj_tcdata(tv):
-    return 'cdata @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_ttab(tv):
-    table = cast('GCtab *', gcval(tv['gcr']))
-    return 'table @ {gcr} (asize: {asize}, hmask: {hmask})'.format(
-        gcr=strx64(table),
-        asize=table['asize'],
-        hmask=strx64(table['hmask']),
-    )
-
-
-def dump_lj_tudata(tv):
-    return 'userdata @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-def dump_lj_tnumx(tv):
-    if tvisint(tv):
-        return 'integer {}'.format(cast('int32_t', tv['i']))
-    else:
-        return 'number {}'.format(cast('double', tv['n']))
-
-
-def dump_lj_invalid(tv):
-    return 'not valid type @ {}'.format(strx64(gcval(tv['gcr'])))
-
-
-dumpers = {
-    'LJ_TNIL':     dump_lj_tnil,
-    'LJ_TFALSE':   dump_lj_tfalse,
-    'LJ_TTRUE':    dump_lj_ttrue,
-    'LJ_TLIGHTUD': dump_lj_tlightud,
-    'LJ_TSTR':     dump_lj_tstr,
-    'LJ_TUPVAL':   dump_lj_tupval,
-    'LJ_TTHREAD':  dump_lj_tthread,
-    'LJ_TPROTO':   dump_lj_tproto,
-    'LJ_TFUNC':    dump_lj_tfunc,
-    'LJ_TTRACE':   dump_lj_ttrace,
-    'LJ_TCDATA':   dump_lj_tcdata,
-    'LJ_TTAB':     dump_lj_ttab,
-    'LJ_TUDATA':   dump_lj_tudata,
-    'LJ_TNUMX':    dump_lj_tnumx,
-}
-
-
-LJ_T = {
-    'NIL':     i2notu32(0),
-    'FALSE':   i2notu32(1),
-    'TRUE':    i2notu32(2),
-    'LIGHTUD': i2notu32(3),
-    'STR':     i2notu32(4),
-    'UPVAL':   i2notu32(5),
-    'THREAD':  i2notu32(6),
-    'PROTO':   i2notu32(7),
-    'FUNC':    i2notu32(8),
-    'TRACE':   i2notu32(9),
-    'CDATA':   i2notu32(10),
-    'TAB':     i2notu32(11),
-    'UDATA':   i2notu32(12),
-    'NUMX':    i2notu32(13),
-}
-
-
-def itypemap(o):
-    if LJ_64 and not LJ_GC64:
-        return LJ_T['NUMX'] if tvisnumber(o) \
-            else LJ_T['LIGHTUD'] if tvislightud(o) else itype(o)
-    else:
-        return LJ_T['NUMX'] if tvisnumber(o) else itype(o)
-
-
-def typenames(value):
-    return {
-        LJ_T[k]: 'LJ_T' + k for k in LJ_T.keys()
-    }.get(int(value), 'LJ_TINVALID')
-
-
-def dump_tvalue(tvalue):
-    return dumpers.get(typenames(itypemap(tvalue)), dump_lj_invalid)(tvalue)
-
-
-FRAME_TYPE = 0x3
-FRAME_P = 0x4
-FRAME_TYPEP = FRAME_TYPE | FRAME_P
-
-FRAME = {
-    'LUA':    0x0,
-    'C':      0x1,
-    'CONT':   0x2,
-    'VARG':   0x3,
-    'LUAP':   0x4,
-    'CP':     0x5,
-    'PCALL':  0x6,
-    'PCALLH': 0x7,
-}
-
-
-def frametypes(ft):
-    return {
-        FRAME['LUA']:  'L',
-        FRAME['C']:    'C',
-        FRAME['CONT']: 'M',
-        FRAME['VARG']: 'V',
-    }.get(ft, '?')
-
-
-def bc_a(ins):
-    return (ins >> 8) & 0xff
-
-
-def frame_ftsz(framelink):
-    return cast('ptrdiff_t', framelink['ftsz'] if LJ_FR2
-                else framelink['fr']['tp']['ftsz'])
-
-
-def frame_pc(framelink):
-    return cast('BCIns *', frame_ftsz(framelink)) if LJ_FR2 \
-        else mref('BCIns *', framelink['fr']['tp']['pcr'])
-
-
-def frame_prevl(framelink):
-    return framelink - (1 + LJ_FR2 + bc_a(frame_pc(framelink)[-1]))
-
-
-def frame_ispcall(framelink):
-    return (frame_ftsz(framelink) & FRAME['PCALL']) == FRAME['PCALL']
-
-
-def frame_sized(framelink):
-    return (frame_ftsz(framelink) & ~FRAME_TYPEP)
-
-
-def frame_prevd(framelink):
-    return framelink - int(frame_sized(framelink) / sizeof('TValue'))
-
-
-def frame_type(framelink):
-    return frame_ftsz(framelink) & FRAME_TYPE
-
-
-def frame_typep(framelink):
-    return frame_ftsz(framelink) & FRAME_TYPEP
-
-
-def frame_islua(framelink):
-    return frametypes(frame_type(framelink)) == 'L' \
-        and frame_ftsz(framelink) > 0
-
-
-def frame_prev(framelink):
-    return frame_prevl(framelink) if frame_islua(framelink) \
-        else frame_prevd(framelink)
-
-
-def frame_sentinel(L):
-    return mref('TValue *', L['stack']) + LJ_FR2
-
-
-# The generator that implements frame iterator.
-# Every frame is represented as a tuple of framelink and frametop.
-def frames(L):
-    frametop = L['top']
-    framelink = L['base'] - 1
-    framelink_sentinel = frame_sentinel(L)
-    while True:
-        yield framelink, frametop
-        frametop = framelink - (1 + LJ_FR2)
-        if framelink <= framelink_sentinel:
-            break
-        framelink = frame_prev(framelink)
-
-
-def dump_framelink_slot_address(fr):
-    return '{}:{}'.format(fr - 1, fr) if LJ_FR2 \
-        else '{}'.format(fr) + PADDING
-
-
-def dump_framelink(L, fr):
-    if fr == frame_sentinel(L):
-        return '{addr} [S   ] FRAME: dummy L'.format(
-            addr=dump_framelink_slot_address(fr),
-        )
-    return '{addr} [    ] FRAME: [{pp}] delta={d}, {f}'.format(
-        addr=dump_framelink_slot_address(fr),
-        pp='PP' if frame_ispcall(fr) else '{frname}{p}'.format(
-            frname=frametypes(int(frame_type(fr))),
-            p='P' if frame_typep(fr) & FRAME_P else ''
-        ),
-        d=cast('TValue *', fr) - cast('TValue *', frame_prev(fr)),
-        f=dump_lj_tfunc(fr - LJ_FR2),
-    )
-
-
-def dump_stack_slot(L, slot, base=None, top=None):
-    base = base or L['base']
-    top = top or L['top']
-
-    return '{addr}{padding} [ {B}{T}{M}] VALUE: {value}'.format(
-        addr=strx64(slot),
-        padding=PADDING,
-        B='B' if slot == base else ' ',
-        T='T' if slot == top else ' ',
-        M='M' if slot == mref('TValue *', L['maxstack']) else ' ',
-        value=dump_tvalue(slot),
-    )
-
-
-def dump_stack(L, base=None, top=None):
-    base = base or L['base']
-    top = top or L['top']
-    stack = mref('TValue *', L['stack'])
-    maxstack = mref('TValue *', L['maxstack'])
-    red = 5 + 3 * LJ_FR2
-
-    dump = [
-        '{padding} Red zone: {nredslots: >2} slots {padding}'.format(
-            padding='-' * len(PADDING),
-            nredslots=red,
-        ),
-    ]
-    dump.extend([
-        dump_stack_slot(L, maxstack + offset, base, top)
-            for offset in range(red, 0, -1)  # noqa: E131
-    ])
-    dump.extend([
-        '{padding} Stack: {nstackslots: >5} slots {padding}'.format(
-            padding='-' * len(PADDING),
-            nstackslots=int((tou64(maxstack) - tou64(stack)) >> 3),
-        ),
-        dump_stack_slot(L, maxstack, base, top),
-        '{start}:{end} [    ] {nfreeslots} slots: Free stack slots'.format(
-            start=strx64(top + 1),
-            end=strx64(maxstack - 1),
-            nfreeslots=int((tou64(maxstack) - tou64(top) - 8) >> 3),
-        ),
-    ])
-
-    for framelink, frametop in frames(L):
-        # Dump all data slots in the (framelink, top) interval.
-        dump.extend([
-            dump_stack_slot(L, framelink + offset, base, top)
-                for offset in range(frametop - framelink, 0, -1)  # noqa: E131
-        ])
-        # Dump frame slot (2 slots in case of GC64).
-        dump.append(dump_framelink(L, framelink))
-
-    return '\n'.join(dump)
-
-
-class LJDumpTValue(Command):
-    '''
-lj-tv <TValue *>
-
-The command receives a pointer to <tv> (TValue address) and dumps
-the type and some info related to it.
-
-* LJ_TNIL: nil
-* LJ_TFALSE: false
-* LJ_TTRUE: true
-* LJ_TLIGHTUD: light userdata @ <gcr>
-* LJ_TSTR: string <string payload> @ <gcr>
-* LJ_TUPVAL: upvalue @ <gcr>
-* LJ_TTHREAD: thread @ <gcr>
-* LJ_TPROTO: proto @ <gcr>
-* LJ_TFUNC: <LFUNC|CFUNC|FFUNC>
-  <LFUNC>: Lua function @ <gcr>, <nupvals> upvalues, <chunk:line>
-  <CFUNC>: C function <mcode address>
-  <FFUNC>: fast function #<ffid>
-* LJ_TTRACE: trace <traceno> @ <gcr>
-* LJ_TCDATA: cdata @ <gcr>
-* LJ_TTAB: table @ <gcr> (asize: <asize>, hmask: <hmask>)
-* LJ_TUDATA: userdata @ <gcr>
-* LJ_TNUMX: number <numeric payload>
-
-Whether the type of the given address differs from the listed above, then
-error message occurs.
-    '''
-    def execute(self, debugger, args, result):
-        tvptr = cast('TValue *', self.parse(args))
-        print('{}'.format(dump_tvalue(tvptr)))
-
-
-class LJState(Command):
-    '''
-lj-state
-The command requires no args and dumps current VM and GC states
-* VM state: <INTERP|C|GC|EXIT|RECORD|OPT|ASM|TRACE>
-* GC state: <PAUSE|PROPAGATE|ATOMIC|SWEEPSTRING|SWEEP|FINALIZE|LAST>
-* JIT state: <IDLE|ACTIVE|RECORD|START|END|ASM|ERR>
-    '''
-    def execute(self, debugger, args, result):
-        g = G(L(None))
-        print('{}'.format('\n'.join(
-            map(lambda t: '{} state: {}'.format(*t), {
-                'VM':  vm_state(g),
-                'GC':  gc_state(g),
-                'JIT': jit_state(g),
-            }.items())
-        )))
-
-
-class LJDumpArch(Command):
-    '''
-lj-arch
-
-The command requires no args and dumps values of LJ_64 and LJ_GC64
-compile-time flags. These values define the sizes of host and GC
-pointers respectively.
-    '''
-    def execute(self, debugger, args, result):
-        print(
-            'LJ_64: {LJ_64}, LJ_GC64: {LJ_GC64}, LJ_DUALNUM: {LJ_DUALNUM}'
-            .format(
-                LJ_64=LJ_64,
-                LJ_GC64=LJ_GC64,
-                LJ_DUALNUM=LJ_DUALNUM
-            )
-        )
-
-
-class LJGC(Command):
-    '''
-lj-gc
-
-The command requires no args and dumps current GC stats:
-* total: <total number of allocated bytes in GC area>
-* threshold: <limit when gc step is triggered>
-* debt: <how much GC is behind schedule>
-* estimate: <estimate of memory actually in use>
-* stepmul: <incremental GC step granularity>
-* pause: <pause between successive GC cycles>
-* sweepstr: <sweep position in string table>
-* root: <number of all collectable objects>
-* gray: <number of gray objects>
-* grayagain: <number of objects for atomic traversal>
-* weak: <number of weak tables (to be cleared)>
-* mmudata: <number of udata|cdata to be finalized>
-    '''
-    def execute(self, debugger, args, result):
-        g = G(L(None))
-        print('GC stats: {state}\n{stats}'.format(
-            state=gc_state(g),
-            stats=dump_gc(g)
-        ))
-
-
-class LJDumpString(Command):
-    '''
-lj-str <GCstr *>
-
-The command receives a <gcr> of the corresponding GCstr object and dumps
-the payload, size in bytes and hash.
-
-*Caveat*: Since Python 2 provides no native Unicode support, the payload
-is replaced with the corresponding error when decoding fails.
-    '''
-    def execute(self, debugger, args, result):
-        string = cast('GCstr *', self.parse(args))
-        print("String: {body} [{len} bytes] with hash {hash}".format(
-            body=strdata(string),
-            hash=strx64(string['hash']),
-            len=string['len'],
-        ))
-
-
-class LJDumpTable(Command):
-    '''
-lj-tab <GCtab *>
-
-The command receives a GCtab address and dumps the table contents:
-* Metatable address whether the one is set
-* Array part <asize> slots:
-  <aslot ptr>: [<index>]: <tv>
-* Hash part <hsize> nodes:
-  <hnode ptr>: { <tv> } => { <tv> }; next = <next hnode ptr>
-    '''
-    def execute(self, debugger, args, result):
-        t = cast('GCtab *', self.parse(args))
-        array = mref('TValue *', t['array'])
-        nodes = mref('Node *', t['node'])
-        mt = gcval(t['metatable'])
-        capacity = {
-            'apart': int(t['asize']),
-            'hpart': int(t['hmask'] + 1) if t['hmask'] > 0 else 0
-        }
-
-        if mt:
-            print('Metatable detected: {}'.format(strx64(mt)))
-
-        print('Array part: {} slots'.format(capacity['apart']))
-        for i in range(capacity['apart']):
-            slot = array + i
-            print('{ptr}: [{index}]: {value}'.format(
-                ptr=strx64(slot),
-                index=i,
-                value=dump_tvalue(slot)
-            ))
-
-        print('Hash part: {} nodes'.format(capacity['hpart']))
-        # See hmask comment in lj_obj.h
-        for i in range(capacity['hpart']):
-            node = nodes + i
-            print('{ptr}: {{ {key} }} => {{ {val} }}; next = {n}'.format(
-                ptr=strx64(node),
-                key=dump_tvalue(node['key']),
-                val=dump_tvalue(node['val']),
-                n=strx64(mref('Node *', node['next']))
-            ))
-
-
-class LJDumpStack(Command):
-    '''
-lj-stack [<lua_State *>]
-
-The command receives a lua_State address and dumps the given Lua
-coroutine guest stack:
-
-<slot ptr> [<slot attributes>] <VALUE|FRAME>
-
-* <slot ptr>: guest stack slot address
-* <slot attributes>:
-  - S: Bottom of the stack (the slot L->stack points to)
-  - B: Base of the current guest frame (the slot L->base points to)
-  - T: Top of the current guest frame (the slot L->top points to)
-  - M: Last slot of the stack (the slot L->maxstack points to)
-* <VALUE>: see help lj-tv for more info
-* <FRAME>: framelink slot differs from the value slot: it contains info
-  related to the function being executed within this guest frame, its
-  type and link to the parent guest frame
-  [<frame type>] delta=<slots in frame>, <lj-tv for LJ_TFUNC slot>
-  - <frame type>:
-    + L:  VM performs a call as a result of bytecode execution
-    + C:  VM performs a call as a result of lj_vm_call
-    + M:  VM performs a call to a metamethod as a result of bytecode
-          execution
-    + V:  Variable-length frame for storing arguments of a variadic
-          function
-    + CP: Protected C frame
-    + PP: VM performs a call as a result of executinig pcall or xpcall
-
-If L is omitted the main coroutine is used.
-    '''
-    def execute(self, debugger, args, result):
-        print('{}'.format(dump_stack(L(self.parse(args)))))
-
-
-def register_commands(debugger, commands):
-    for command, cls in commands.items():
-        cls.command = command
-        debugger.HandleCommand(
-            'command script add --overwrite --class luajit_lldb.{cls} {cmd}'
-            .format(
-                cls=cls.__name__,
-                cmd=cls.command,
-            )
-        )
-        print('{cmd} command initialized'.format(cmd=cls.command))
-
-
-def configure(debugger):
-    global LJ_64, LJ_GC64, LJ_FR2, LJ_DUALNUM, PADDING, LJ_TISNUM, target
-    target = debugger.GetSelectedTarget()
-    module = target.modules[0]
-    LJ_DUALNUM = module.FindSymbol('lj_lib_checknumber') is not None
-
-    try:
-        irtype_enum = target.FindFirstType('IRType').enum_members
-        for member in irtype_enum:
-            if member.name == 'IRT_PTR':
-                LJ_64 = member.unsigned & 0x1f == IRT_P64
-            if member.name == 'IRT_PGC':
-                LJ_FR2 = LJ_GC64 = member.unsigned & 0x1f == IRT_P64
-    except Exception:
-        print('luajit_lldb.py failed to load: '
-              'no debugging symbols found for libluajit')
-        return
-
-    PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1))
-    LJ_TISNUM = 0xfffeffff if LJ_64 and not LJ_GC64 else LJ_T['NUMX']
-
-
-def __lldb_init_module(debugger, internal_dict):
-    configure(debugger)
-    register_commands(debugger, {
-        'lj-arch':  LJDumpArch,
-        'lj-gc':    LJGC,
-        'lj-stack': LJDumpStack,
-        'lj-state': LJState,
-        'lj-str':   LJDumpString,
-        'lj-tab':   LJDumpTable,
-        'lj-tv':    LJDumpTValue,
-    })
-    print('luajit_lldb.py is successfully loaded')
diff --git a/test/tarantool-debugger-tests/debug-extension-tests.py b/test/tarantool-debugger-tests/debug-extension-tests.py
index 2b67e151..30a2c478 100644
--- a/test/tarantool-debugger-tests/debug-extension-tests.py
+++ b/test/tarantool-debugger-tests/debug-extension-tests.py
@@ -16,7 +16,7 @@ LUAJIT_BINARY = os.environ['LUAJIT_TEST_BINARY']
 EXTENSION_PATH = os.environ['DEBUGGER_EXTENSION_PATH']
 DEBUGGER = os.environ['DEBUGGER_COMMAND']
 LLDB = 'lldb' in DEBUGGER
-EXTENSION = EXTENSION_PATH + ('/luajit_lldb.py' if LLDB else '/luajit-gdb.py')
+EXTENSION = EXTENSION_PATH + '/luajit_dbg.py'
 TIMEOUT = 10
 
 # Don't run any initialization scripts.
@@ -137,7 +137,7 @@ class TestLoad(TestCaseBase):
         r'lj-str command initialized\n'
         r'lj-tab command initialized\n'
         r'lj-tv command initialized\n'
-        r'.*is successfully loaded'
+        r'LuaJIT debug extension is successfully loaded'
     )
--------------rttd6sOXBrWyY67CsL0Fw8fj--