From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpng3.m.smailru.net (smtpng3.m.smailru.net [94.100.177.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 07F12440F3C for ; Wed, 20 Nov 2019 15:56:13 +0300 (MSK) Date: Wed, 20 Nov 2019 15:54:07 +0300 From: Igor Munkin Message-ID: <20191120125407.GC18878@tarantool.org> References: <20191120085333.57725-1-arkholga@tarantool.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191120085333.57725-1-arkholga@tarantool.org> Subject: Re: [Tarantool-patches] [PATCH v2] luajit: adde flag of partial comp. with Lua 5.2 List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Olga Arkhangelskaia Cc: tarantool-patches@dev.tarantool.org Olya, Thanks for the patch, the changes you made since v1 are relevant, however please consider several new comments I left below. On 20.11.19, Olga Arkhangelskaia wrote: > Although we do not turn on full compatibility with Lua 5.2 we do need pairs/ipairs > metamethods. Patch introduces LUAJIT_ENABLE_PAIRSMM flag. > If the flag is set - metamethods are available. Please adjust the subject of the commit (there is a typo and its format doesn't respect the contribution guide). > --- > Closes #4560 Strictly saying this commit will never "close" the #4560, due to it's not in the projects queue. I propose to append "Part of"/"Needed by" label to the commit message (move it prior to three dashes). > Branch https://github.com/tarantool/luajit/tree/OKriw/gh-4560-Enable-LUAJIT_ENABLE_LUA52COMPAT-when-bulding-luajit > > Changes in v2: > - flag is renamed > - now flag is used only for pairsmm > - added test case > > > src/Makefile | 3 +++ > src/lib_base.c | 4 ++-- > src/lj_arch.h | 6 ++++++ > src/lj_obj.h | 2 +- > src/vm_x86.dasc | 4 ++-- > test/mmpairs_test.lua | 48 +++++++++++++++++++++++++++++++++++++++++++ > 6 files changed, 62 insertions(+), 5 deletions(-) > create mode 100755 test/mmpairs_test.lua > > diff --git a/src/Makefile b/src/Makefile > index 827d4a4..af84f0c 100644 > --- a/src/Makefile > +++ b/src/Makefile > @@ -101,6 +101,9 @@ XCFLAGS= > # Note: this does not provide full compatibility with Lua 5.2 at this time. > #XCFLAGS+= -DLUAJIT_ENABLE_LUA52COMPAT > # > +#Enable pairs/ipairs methametods from Lua 5.2. > +XCFLAGS+= -DLUAJIT_ENABLE_PAIRSMM IMHO there is no need to enable this flag by default within the root Makefile. > +# > # Disable the JIT compiler, i.e. turn LuaJIT into a pure interpreter. > #XCFLAGS+= -DLUAJIT_DISABLE_JIT > # > diff --git a/src/lib_base.c b/src/lib_base.c > index 3a75787..950a580 100644 > --- a/src/lib_base.c > +++ b/src/lib_base.c > @@ -81,12 +81,12 @@ LJLIB_ASM(next) > return FFH_UNREACHABLE; > } > > -#if LJ_52 || LJ_HASFFI > +#if LJ_PAIRSMM || LJ_HASFFI > static int ffh_pairs(lua_State *L, MMS mm) > { > TValue *o = lj_lib_checkany(L, 1); > cTValue *mo = lj_meta_lookup(L, o, mm); > - if ((LJ_52 || tviscdata(o)) && !tvisnil(mo)) { > + if ((LJ_PAIRSMM || tviscdata(o)) && !tvisnil(mo)) { > L->top = o+1; /* Only keep one argument. */ > copyTV(L, L->base-1-LJ_FR2, mo); /* Replace callable. */ > return FFH_TAILCALL; > diff --git a/src/lj_arch.h b/src/lj_arch.h > index c8d7138..6dfb4fb 100644 > --- a/src/lj_arch.h > +++ b/src/lj_arch.h > @@ -564,4 +564,10 @@ > #define LJ_52 0 > #endif > > +/* Partial compatibility with Lua 5.2 */ Please adjust the comment. > +#if defined(LUAJIT_ENABLE_PAIRSMM) || defined (LUAJIT_ENABLE_LUA52COMPAT) > +#define LJ_PAIRSMM 1 > +#else > +#define LJ_PAIRSMM 0 > +#endif > #endif > diff --git a/src/lj_obj.h b/src/lj_obj.h > index f368578..4d0693f 100644 > --- a/src/lj_obj.h > +++ b/src/lj_obj.h > @@ -530,7 +530,7 @@ enum { > #define MMDEF_FFI(_) > #endif > > -#if LJ_52 || LJ_HASFFI > +#if LJ_HASFFI || LJ_PAIRSMM > #define MMDEF_PAIRS(_) _(pairs) _(ipairs) > #else > #define MMDEF_PAIRS(_) > diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc > index 56bee14..eae07f7 100644 > --- a/src/vm_x86.dasc > +++ b/src/vm_x86.dasc I see no option except either introducing the flag for all others VMs or adjusting its enabling in lj_arch.h only for those supported by Tarantool (x64, arm). Considering the changes to be done, I guess the first approach is the right way to fix the current inconsistency, but feel free to choose the one that seems to be the most convenient to you. > @@ -1724,7 +1724,7 @@ static void build_subroutines(BuildCtx *ctx) > |.ffunc_1 pairs > | mov TAB:RB, [BASE] > | cmp dword [BASE+4], LJ_TTAB; jne ->fff_fallback > -#if LJ_52 > +#if LJ_PAIRSMM > | cmp dword TAB:RB->metatable, 0; jne ->fff_fallback > #endif > | mov CFUNC:RB, [BASE-8] > @@ -1791,7 +1791,7 @@ static void build_subroutines(BuildCtx *ctx) > |.ffunc_1 ipairs > | mov TAB:RB, [BASE] > | cmp dword [BASE+4], LJ_TTAB; jne ->fff_fallback > -#if LJ_52 > +#if LJ_PAIRSMM > | cmp dword TAB:RB->metatable, 0; jne ->fff_fallback > #endif > | mov CFUNC:RB, [BASE-8] > diff --git a/test/mmpairs_test.lua b/test/mmpairs_test.lua > new file mode 100755 > index 0000000..3334c2d > --- /dev/null > +++ b/test/mmpairs_test.lua > @@ -0,0 +1,48 @@ > +#!/usr/bin/env tarantool > + > +tap = require('tap') > + > +test = tap.test("PAIRSMM-is-set") > +test:plan(2) > + > +--- To make sure that we are using only pairs/ipairs mmethods within Lua5.1 > +--- we use os.execute, because its interface has changed significantly in 5.2 I guess the comment can be extended with the following rationale. | Currently there is no Lua way to detect whether LJ_PAIRSMM is enabled | or not. Therefore taking into account the fact it's enabled by default | in tarantool built and considering the existing testing pipeline we | can check the following scenario: while we can overload the | pairs/ipairs behaviour via metamethod as designed in Lua 5.2, | os.execute still preserves the Lua 5.1 interface. > + > +local mt = { > + __pairs = function(self) > + local function stateless_iter(tbl, k) > + local v > + k, v = next(tbl, k) > + while k and v > 0 do k, v = next(tbl, k) end > + if v then return k,v end > + end > + return stateless_iter, self, nil > + end, > + __ipairs = function(self) > + local function stateless_iter(tbl, k) > + local v > + k, v = next(tbl, k) > + while k and v < 0 do k, v = next(tbl, k) end > + if v then return k,v end > + end > + return stateless_iter, self, nil > + end > +} > + > +local t = setmetatable({ }, mt) > +t[1] = 10 > +t[2] = 20 > +t[3] = -10 > +t[4] = -20 > + > +local pairs_res = 0 > +local ipairs_res = 0 > +for k, v in pairs(t) do > + pairs_res = v + pairs_res > +end > +for k, v in ipairs(t) do > + ipairs_res = v + ipairs_res > +end > +test:is(pairs_res + ipairs_res, 0) > +os_exec_res = os.execute() > +test:is(os_exec_res, 1) > -- > 2.20.1 (Apple Git-117) > -- Best regards, IM