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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>1999-03-10 11:09:45 -0300
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>1999-03-10 11:09:45 -0300
commit26794616374fee54532d0030ae006abb77dfb7ba (patch)
treeebc4595695eb616e66b4f63779404e8ea6644b48 /lparser.c
parent0870a2d1d8a1434eecae1923886ba219c4e699c7 (diff)
downloadlua-26794616374fee54532d0030ae006abb77dfb7ba.tar.gz
lua-26794616374fee54532d0030ae006abb77dfb7ba.tar.bz2
lua-26794616374fee54532d0030ae006abb77dfb7ba.zip
no more assignment expressions (they don't fit in Lua...)
Diffstat (limited to 'lparser.c')
-rw-r--r--lparser.c51
1 files changed, 16 insertions, 35 deletions
diff --git a/lparser.c b/lparser.c
index eb1e0236..91f585f0 100644
--- a/lparser.c
+++ b/lparser.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lparser.c,v 1.26 1999/03/04 21:17:26 roberto Exp roberto $ 2** $Id: lparser.c,v 1.27 1999/03/05 21:16:07 roberto Exp roberto $
3** LL(1) Parser and code generator for Lua 3** LL(1) Parser and code generator for Lua
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -99,7 +99,7 @@ typedef struct FuncState {
99/* 99/*
100** prototypes for non-terminal functions 100** prototypes for non-terminal functions
101*/ 101*/
102static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes); 102static int assignment (LexState *ls, vardesc *v, int nvars);
103static int cond (LexState *ls); 103static int cond (LexState *ls);
104static int funcname (LexState *ls, vardesc *v); 104static int funcname (LexState *ls, vardesc *v);
105static int funcparams (LexState *ls, int slf); 105static int funcparams (LexState *ls, int slf);
@@ -114,7 +114,6 @@ static void chunk (LexState *ls);
114static void constructor (LexState *ls); 114static void constructor (LexState *ls);
115static void decinit (LexState *ls, listdesc *d); 115static void decinit (LexState *ls, listdesc *d);
116static void exp0 (LexState *ls, vardesc *v); 116static void exp0 (LexState *ls, vardesc *v);
117static void Gexp (LexState *ls, vardesc *v);
118static void exp1 (LexState *ls); 117static void exp1 (LexState *ls);
119static void exp2 (LexState *ls, vardesc *v); 118static void exp2 (LexState *ls, vardesc *v);
120static void explist (LexState *ls, listdesc *e); 119static void explist (LexState *ls, listdesc *e);
@@ -467,22 +466,16 @@ static void lua_pushvar (LexState *ls, vardesc *var) {
467} 466}
468 467
469 468
470/* to be used by "storevar" and assignment */ 469static void storevar (LexState *ls, vardesc *var) {
471static OpCode set_pop[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP, SETTABLE};
472static OpCode set_dup[] = {SETLOCALDUP, SETGLOBALDUP, SETTABLEPOPDUP,
473 SETTABLEDUP};
474
475
476static void storevar (LexState *ls, vardesc *var, OpCode *codes) {
477 switch (var->k) { 470 switch (var->k) {
478 case VLOCAL: 471 case VLOCAL:
479 code_oparg(ls, codes[0], var->info, -1); 472 code_oparg(ls, SETLOCAL, var->info, -1);
480 break; 473 break;
481 case VGLOBAL: 474 case VGLOBAL:
482 code_oparg(ls, codes[1], var->info, -1); 475 code_oparg(ls, SETGLOBAL, var->info, -1);
483 break; 476 break;
484 case VINDEXED: 477 case VINDEXED:
485 code_opcode(ls, codes[2], -3); 478 code_opcode(ls, SETTABLEPOP, -3);
486 break; 479 break;
487 default: 480 default:
488 LUA_INTERNALERROR("invalid var kind to store"); 481 LUA_INTERNALERROR("invalid var kind to store");
@@ -739,7 +732,7 @@ static int stat (LexState *ls) {
739 next(ls); 732 next(ls);
740 needself = funcname(ls, &v); 733 needself = funcname(ls, &v);
741 body(ls, needself, line); 734 body(ls, needself, line);
742 storevar(ls, &v, set_pop); 735 storevar(ls, &v);
743 return 1; 736 return 1;
744 } 737 }
745 738
@@ -765,7 +758,7 @@ static int stat (LexState *ls) {
765 close_exp(ls, v.info, 0); 758 close_exp(ls, v.info, 0);
766 } 759 }
767 else { /* stat -> ['%'] NAME assignment */ 760 else { /* stat -> ['%'] NAME assignment */
768 int left = assignment(ls, &v, 1, set_pop); 761 int left = assignment(ls, &v, 1);
769 adjuststack(ls, left); /* remove eventual 'garbage' left on stack */ 762 adjuststack(ls, left); /* remove eventual 'garbage' left on stack */
770 } 763 }
771 return 1; 764 return 1;
@@ -948,19 +941,6 @@ static void exp0 (LexState *ls, vardesc *v) {
948} 941}
949 942
950 943
951static void Gexp (LexState *ls, vardesc *v) {
952 /* Gexp -> exp0 | assignment */
953 exp0(ls, v);
954 if (v->k != VEXP && (ls->token == '=' || ls->token == ',')) {
955 int left = assignment(ls, v, 1, set_dup);
956 deltastack(ls, 1); /* DUP operations push an extra value */
957 if (left > 0)
958 code_oparg(ls, POPDUP, left, -left);
959 v->k = VEXP; v->info = 0; /* this expression is closed now */
960 }
961}
962
963
964static void push (LexState *ls, stack_op *s, int op) { 944static void push (LexState *ls, stack_op *s, int op) {
965 if (s->top >= MAXOPS) 945 if (s->top >= MAXOPS)
966 luaX_error(ls, "expression too complex"); 946 luaX_error(ls, "expression too complex");
@@ -1015,9 +995,9 @@ static void simpleexp (LexState *ls, vardesc *v, stack_op *s) {
1015 ifpart(ls, 1, ls->linenumber); 995 ifpart(ls, 1, ls->linenumber);
1016 break; 996 break;
1017 997
1018 case '(': /* simpleexp -> '(' Gexp ')' */ 998 case '(': /* simpleexp -> '(' exp0 ')' */
1019 next(ls); 999 next(ls);
1020 Gexp(ls, v); 1000 exp0(ls, v);
1021 check(ls, ')'); 1001 check(ls, ')');
1022 return; 1002 return;
1023 1003
@@ -1239,7 +1219,7 @@ static void decinit (LexState *ls, listdesc *d) {
1239} 1219}
1240 1220
1241 1221
1242static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) { 1222static int assignment (LexState *ls, vardesc *v, int nvars) {
1243 int left = 0; 1223 int left = 0;
1244 unloaddot(ls, v); 1224 unloaddot(ls, v);
1245 if (ls->token == ',') { /* assignment -> ',' NAME assignment */ 1225 if (ls->token == ',') { /* assignment -> ',' NAME assignment */
@@ -1248,7 +1228,7 @@ static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
1248 var_or_func(ls, &nv); 1228 var_or_func(ls, &nv);
1249 if (nv.k == VEXP) 1229 if (nv.k == VEXP)
1250 luaX_error(ls, "syntax error"); 1230 luaX_error(ls, "syntax error");
1251 left = assignment(ls, &nv, nvars+1, set_pop); 1231 left = assignment(ls, &nv, nvars+1);
1252 } 1232 }
1253 else { /* assignment -> '=' explist1 */ 1233 else { /* assignment -> '=' explist1 */
1254 listdesc d; 1234 listdesc d;
@@ -1258,15 +1238,16 @@ static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
1258 } 1238 }
1259 if (v->k != VINDEXED || left+(nvars-1) == 0) { 1239 if (v->k != VINDEXED || left+(nvars-1) == 0) {
1260 /* global/local var or indexed var without values in between */ 1240 /* global/local var or indexed var without values in between */
1261 storevar(ls, v, codes); 1241 storevar(ls, v);
1262 } 1242 }
1263 else { /* indexed var with values in between*/ 1243 else { /* indexed var with values in between*/
1264 code_oparg(ls, codes[3], left+(nvars-1), -1); 1244 code_oparg(ls, SETTABLE, left+(nvars-1), -1);
1265 left += 2; /* table/index are not popped, because they aren't on top */ 1245 left += 2; /* table&index are not popped, because they aren't on top */
1266 } 1246 }
1267 return left; 1247 return left;
1268} 1248}
1269 1249
1250
1270static void constructor (LexState *ls) { 1251static void constructor (LexState *ls) {
1271 /* constructor -> '{' part [';' part] '}' */ 1252 /* constructor -> '{' part [';' part] '}' */
1272 int line = ls->linenumber; 1253 int line = ls->linenumber;