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assignment expression may be multiple

v5-2
Roberto Ierusalimschy 26 years ago
parent
fb1cf6ab2d
commit
8b2d97d187
3 changed files with 47 additions and 35 deletions
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  1. 4
      lopcodes.h
  2. 45
      lparser.c
  3. 33
      lvm.c

4
lopcodes.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lopcodes.h,v 1.21 1999/02/04 16:36:16 roberto Exp roberto $
** $Id: lopcodes.h,v 1.22 1999/02/08 17:07:59 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -22,6 +22,7 @@ RETCODE,/* b - - */
PUSHNIL,/* b - nil_0...nil_b */
POP,/* b - - TOP-=(b+1) */
POPDUP,/* b v v TOP-=(b+1) */
PUSHNUMBERW,/* w - (float)(w-NUMOFFSET) */
PUSHNUMBER,/* b - (float)(b-NUMOFFSET) */
@ -59,6 +60,7 @@ SETTABLEPOP,/* - v i t - t[i]=v */
SETTABPPDUP,/* - v i t v t[i]=v */
SETTABLE,/* b v a_b...a_1 i t a_b...a_1 i t t[i]=v */
SETTABLEDUP,/* b v a_b...a_1 i t v a_b...a_1 i t t[i]=v */
SETLISTW,/* w c v_c...v_1 t - t[i+w*FPF]=v_i */
SETLIST,/* b c v_c...v_1 t - t[i+b*FPF]=v_i */

45
lparser.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 1.16 1999/02/04 17:47:59 roberto Exp roberto $
** $Id: lparser.c,v 1.17 1999/02/08 17:07:59 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/
@ -102,7 +102,7 @@ typedef struct FuncState {
/*
** prototypes for non-terminal functions
*/
static int assignment (LexState *ls, vardesc *v, int nvars);
static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes);
static int cond (LexState *ls);
static int funcname (LexState *ls, vardesc *v);
static int funcparams (LexState *ls, int slf);
@ -387,7 +387,7 @@ static void check_debugline (LexState *ls) {
static void adjuststack (LexState *ls, int n) {
if (n > 0)
code_oparg(ls, POP, n-1, -n);
code_oparg(ls, POP, n, -n);
else if (n < 0)
code_oparg(ls, PUSHNIL, (-n)-1, -n);
}
@ -472,7 +472,13 @@ static void lua_pushvar (LexState *ls, vardesc *var) {
}
static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
/* to be used by "storevar" and assignment */
static OpCode set_pop[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP, SETTABLE};
static OpCode set_dup[] = {SETLOCALDUP, SETGLOBALDUP, SETTABPPDUP,
SETTABLEDUP};
static void storevar (LexState *ls, vardesc *var, OpCode *codes) {
switch (var->k) {
case VLOCAL:
code_oparg(ls, codes[0], var->info, -1);
@ -489,12 +495,6 @@ static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
}
static void storevar (LexState *ls, vardesc *var) {
static OpCode codes[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP};
genstorevar(ls, var, codes);
}
static int fix_jump (LexState *ls, int pc, OpCode op, int n) {
/* jump is relative to position following jump instruction */
return fix_opcode(ls, pc, op, n-(pc+JMPSIZE));
@ -748,7 +748,7 @@ static int stat (LexState *ls) {
next(ls);
needself = funcname(ls, &v);
body(ls, needself, line);
storevar(ls, &v);
storevar(ls, &v, set_pop);
return 1;
}
@ -773,8 +773,8 @@ static int stat (LexState *ls) {
luaX_error(ls, "syntax error");
close_exp(ls, v.info, 0);
}
else {
int left = assignment(ls, &v, 1); /* stat -> ['%'] NAME assignment */
else { /* stat -> ['%'] NAME assignment */
int left = assignment(ls, &v, 1, set_pop);
adjuststack(ls, left); /* remove eventual 'garbage' left on stack */
}
return 1;
@ -953,14 +953,13 @@ static void exp0 (LexState *ls, vardesc *v) {
static void Gexp (LexState *ls, vardesc *v) {
/* Gexp -> exp0 | var '=' exp1 */
static OpCode codes[] = {SETLOCALDUP, SETGLOBALDUP, SETTABPPDUP};
/* Gexp -> exp0 | assignment */
exp0(ls, v);
if (v->k != VEXP && optional(ls, '=')) { /* assignment expression? */
unloaddot(ls, v);
exp1(ls);
genstorevar(ls, v, codes);
if (v->k != VEXP && (ls->token == '=' || ls->token == ',')) {
int left = assignment(ls, v, 1, set_dup);
deltastack(ls, 1); /* DUP operations push an extra value */
if (left > 0)
code_oparg(ls, POPDUP, left, -left);
v->k = VEXP; v->info = 0; /* this expression is closed now */
}
}
@ -1244,7 +1243,7 @@ static void decinit (LexState *ls, listdesc *d) {
}
static int assignment (LexState *ls, vardesc *v, int nvars) {
static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
int left = 0;
unloaddot(ls, v);
if (ls->token == ',') { /* assignment -> ',' NAME assignment */
@ -1253,7 +1252,7 @@ static int assignment (LexState *ls, vardesc *v, int nvars) {
var_or_func(ls, &nv);
if (nv.k == VEXP)
luaX_error(ls, "syntax error");
left = assignment(ls, &nv, nvars+1);
left = assignment(ls, &nv, nvars+1, set_pop);
}
else { /* assignment -> '=' explist1 */
listdesc d;
@ -1263,10 +1262,10 @@ static int assignment (LexState *ls, vardesc *v, int nvars) {
}
if (v->k != VINDEXED || left+(nvars-1) == 0) {
/* global/local var or indexed var without values in between */
storevar(ls, v);
storevar(ls, v, codes);
}
else { /* indexed var with values in between*/
code_oparg(ls, SETTABLE, left+(nvars-1), -1);
code_oparg(ls, codes[3], left+(nvars-1), -1);
left += 2; /* table/index are not popped, because they aren't on top */
}
return left;

33
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.45 1999/02/04 17:47:59 roberto Exp roberto $
** $Id: lvm.c,v 1.46 1999/02/08 17:07:59 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -344,7 +344,12 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
break;
case POP: aux = *pc++;
S->top -= (aux+1);
S->top -= aux;
break;
case POPDUP: aux = *pc++;
*(S->top-aux-1) = *(S->top-1);
S->top -= aux;
break;
case PUSHNUMBERW: aux += highbyte(*pc++);
@ -420,22 +425,28 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
break;
case SETTABLEPOP:
luaV_settable(S->top-3);
S->top -= 2; /* pop table and index */
break;
luaV_settable(S->top-3);
S->top -= 2; /* pop table and index */
break;
case SETTABPPDUP: {
TObject temp = *(S->top-1);
luaV_settable(S->top-3);
S->top--; /* pop index (temp goes into "table" position) */
*(S->top-1) = temp;
break;
}
TObject temp = *(S->top-1);
luaV_settable(S->top-3);
S->top--; /* pop index (temp goes into "table" position) */
*(S->top-1) = temp;
break;
}
case SETTABLE:
luaV_settable(S->top-3-(*pc++));
break;
case SETTABLEDUP:
*S->top = *(S->top-1);
S->top++;
luaV_settable(S->top-(3+1)-(*pc++));
break;
case SETLISTW: aux += highbyte(*pc++);
case SETLIST: aux += *pc++; {
int n = *(pc++);

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