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assignment expression may be multiple
This commit is contained in:
Roberto Ierusalimschy
parent
fb1cf6ab2d
commit
8b2d97d187
@ -1,5 +1,5 @@
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/*
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** $Id: lopcodes.h,v 1.21 1999/02/04 16:36:16 roberto Exp roberto $
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** $Id: lopcodes.h,v 1.22 1999/02/08 17:07:59 roberto Exp roberto $
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** Opcodes for Lua virtual machine
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** See Copyright Notice in lua.h
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*/
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@ -22,6 +22,7 @@ RETCODE,/* b - - */
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PUSHNIL,/* b - nil_0...nil_b */
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POP,/* b - - TOP-=(b+1) */
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POPDUP,/* b v v TOP-=(b+1) */
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PUSHNUMBERW,/* w - (float)(w-NUMOFFSET) */
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PUSHNUMBER,/* b - (float)(b-NUMOFFSET) */
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@ -59,6 +60,7 @@ SETTABLEPOP,/* - v i t - t[i]=v */
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SETTABPPDUP,/* - v i t v t[i]=v */
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SETTABLE,/* b v a_b...a_1 i t a_b...a_1 i t t[i]=v */
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SETTABLEDUP,/* b v a_b...a_1 i t v a_b...a_1 i t t[i]=v */
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SETLISTW,/* w c v_c...v_1 t - t[i+w*FPF]=v_i */
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SETLIST,/* b c v_c...v_1 t - t[i+b*FPF]=v_i */
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45
lparser.c
45
lparser.c
@ -1,5 +1,5 @@
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/*
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** $Id: lparser.c,v 1.16 1999/02/04 17:47:59 roberto Exp roberto $
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** $Id: lparser.c,v 1.17 1999/02/08 17:07:59 roberto Exp roberto $
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** LL(1) Parser and code generator for Lua
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** See Copyright Notice in lua.h
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*/
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@ -102,7 +102,7 @@ typedef struct FuncState {
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/*
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** prototypes for non-terminal functions
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*/
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static int assignment (LexState *ls, vardesc *v, int nvars);
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static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes);
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static int cond (LexState *ls);
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static int funcname (LexState *ls, vardesc *v);
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static int funcparams (LexState *ls, int slf);
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@ -387,7 +387,7 @@ static void check_debugline (LexState *ls) {
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static void adjuststack (LexState *ls, int n) {
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if (n > 0)
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code_oparg(ls, POP, n-1, -n);
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code_oparg(ls, POP, n, -n);
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else if (n < 0)
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code_oparg(ls, PUSHNIL, (-n)-1, -n);
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}
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@ -472,7 +472,13 @@ static void lua_pushvar (LexState *ls, vardesc *var) {
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}
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static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
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/* to be used by "storevar" and assignment */
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static OpCode set_pop[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP, SETTABLE};
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static OpCode set_dup[] = {SETLOCALDUP, SETGLOBALDUP, SETTABPPDUP,
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SETTABLEDUP};
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static void storevar (LexState *ls, vardesc *var, OpCode *codes) {
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switch (var->k) {
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case VLOCAL:
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code_oparg(ls, codes[0], var->info, -1);
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@ -489,12 +495,6 @@ static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
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}
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static void storevar (LexState *ls, vardesc *var) {
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static OpCode codes[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP};
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genstorevar(ls, var, codes);
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}
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static int fix_jump (LexState *ls, int pc, OpCode op, int n) {
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/* jump is relative to position following jump instruction */
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return fix_opcode(ls, pc, op, n-(pc+JMPSIZE));
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@ -748,7 +748,7 @@ static int stat (LexState *ls) {
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next(ls);
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needself = funcname(ls, &v);
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body(ls, needself, line);
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storevar(ls, &v);
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storevar(ls, &v, set_pop);
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return 1;
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}
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@ -773,8 +773,8 @@ static int stat (LexState *ls) {
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luaX_error(ls, "syntax error");
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close_exp(ls, v.info, 0);
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}
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else {
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int left = assignment(ls, &v, 1); /* stat -> ['%'] NAME assignment */
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else { /* stat -> ['%'] NAME assignment */
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int left = assignment(ls, &v, 1, set_pop);
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adjuststack(ls, left); /* remove eventual 'garbage' left on stack */
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}
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return 1;
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@ -953,14 +953,13 @@ static void exp0 (LexState *ls, vardesc *v) {
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static void Gexp (LexState *ls, vardesc *v) {
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/* Gexp -> exp0 | var '=' exp1 */
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static OpCode codes[] = {SETLOCALDUP, SETGLOBALDUP, SETTABPPDUP};
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/* Gexp -> exp0 | assignment */
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exp0(ls, v);
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if (v->k != VEXP && optional(ls, '=')) { /* assignment expression? */
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unloaddot(ls, v);
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exp1(ls);
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genstorevar(ls, v, codes);
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if (v->k != VEXP && (ls->token == '=' || ls->token == ',')) {
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int left = assignment(ls, v, 1, set_dup);
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deltastack(ls, 1); /* DUP operations push an extra value */
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if (left > 0)
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code_oparg(ls, POPDUP, left, -left);
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v->k = VEXP; v->info = 0; /* this expression is closed now */
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}
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}
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@ -1244,7 +1243,7 @@ static void decinit (LexState *ls, listdesc *d) {
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}
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static int assignment (LexState *ls, vardesc *v, int nvars) {
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static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
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int left = 0;
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unloaddot(ls, v);
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if (ls->token == ',') { /* assignment -> ',' NAME assignment */
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@ -1253,7 +1252,7 @@ static int assignment (LexState *ls, vardesc *v, int nvars) {
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var_or_func(ls, &nv);
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if (nv.k == VEXP)
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luaX_error(ls, "syntax error");
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left = assignment(ls, &nv, nvars+1);
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left = assignment(ls, &nv, nvars+1, set_pop);
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}
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else { /* assignment -> '=' explist1 */
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listdesc d;
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@ -1263,10 +1262,10 @@ static int assignment (LexState *ls, vardesc *v, int nvars) {
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}
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if (v->k != VINDEXED || left+(nvars-1) == 0) {
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/* global/local var or indexed var without values in between */
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storevar(ls, v);
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storevar(ls, v, codes);
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}
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else { /* indexed var with values in between*/
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code_oparg(ls, SETTABLE, left+(nvars-1), -1);
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code_oparg(ls, codes[3], left+(nvars-1), -1);
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left += 2; /* table/index are not popped, because they aren't on top */
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}
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return left;
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33
lvm.c
33
lvm.c
@ -1,5 +1,5 @@
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/*
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** $Id: lvm.c,v 1.45 1999/02/04 17:47:59 roberto Exp roberto $
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** $Id: lvm.c,v 1.46 1999/02/08 17:07:59 roberto Exp roberto $
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** Lua virtual machine
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** See Copyright Notice in lua.h
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*/
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@ -344,7 +344,12 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
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break;
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case POP: aux = *pc++;
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S->top -= (aux+1);
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S->top -= aux;
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break;
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case POPDUP: aux = *pc++;
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*(S->top-aux-1) = *(S->top-1);
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S->top -= aux;
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break;
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case PUSHNUMBERW: aux += highbyte(*pc++);
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@ -420,22 +425,28 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
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break;
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case SETTABLEPOP:
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luaV_settable(S->top-3);
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S->top -= 2; /* pop table and index */
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break;
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luaV_settable(S->top-3);
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S->top -= 2; /* pop table and index */
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break;
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case SETTABPPDUP: {
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TObject temp = *(S->top-1);
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luaV_settable(S->top-3);
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S->top--; /* pop index (temp goes into "table" position) */
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*(S->top-1) = temp;
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break;
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}
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TObject temp = *(S->top-1);
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luaV_settable(S->top-3);
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S->top--; /* pop index (temp goes into "table" position) */
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*(S->top-1) = temp;
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break;
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}
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case SETTABLE:
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luaV_settable(S->top-3-(*pc++));
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break;
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case SETTABLEDUP:
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*S->top = *(S->top-1);
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S->top++;
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luaV_settable(S->top-(3+1)-(*pc++));
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break;
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case SETLISTW: aux += highbyte(*pc++);
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case SETLIST: aux += *pc++; {
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int n = *(pc++);
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