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new syntax: assignment expressions + better order for opcodes

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This commit is contained in:
Roberto Ierusalimschy
1999-02-02 17:41:17 -02:00
parent 1a17da2ff9
commit 27407fc1f5
3 changed files with 111 additions and 67 deletions
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54
lparser.c
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@@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 1.12 1999/02/02 13:47:31 roberto Exp roberto $
** $Id: lparser.c,v 1.13 1999/02/02 17:57:49 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -114,6 +114,7 @@ static void chunk (LexState *ls);
static void constructor (LexState *ls);
static void decinit (LexState *ls, listdesc *d);
static void exp0 (LexState *ls, vardesc *v);
static void Gexp (LexState *ls, vardesc *v);
static void exp1 (LexState *ls);
static void exp2 (LexState *ls, vardesc *v);
static void explist (LexState *ls, listdesc *e);
@@ -162,7 +163,7 @@ static int code_oparg_at (LexState *ls, int pc, OpCode op, int arg, int delta) {
return 2; /* code size (opcode + 1 byte) */
}
else if (arg <= MAX_WORD) {
code[pc] = (Byte)(op+1);
code[pc] = (Byte)(op-1);
code[pc+1] = (Byte)(arg>>8);
code[pc+2] = (Byte)(arg&0xFF);
return 3; /* code size (opcode + 1 word) */
@@ -429,6 +430,15 @@ static void code_args (LexState *ls, int nparams, int dots) {
}
static void unloaddot (LexState *ls, vardesc *v) {
/* dotted variables <a.x> must be stored like regular indexed vars <a["x"]> */
if (v->k == VDOT) {
code_constant(ls, v->info);
v->k = VINDEXED;
}
}
static void lua_pushvar (LexState *ls, vardesc *var) {
switch (var->k) {
case VLOCAL:
@@ -452,16 +462,16 @@ static void lua_pushvar (LexState *ls, vardesc *var) {
}
static void storevar (LexState *ls, vardesc *var) {
static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
switch (var->k) {
case VLOCAL:
code_oparg(ls, SETLOCAL, var->info, -1);
code_oparg(ls, codes[0], var->info, -1);
break;
case VGLOBAL:
code_oparg(ls, SETGLOBAL, var->info, -1);
code_oparg(ls, codes[1], var->info, -1);
break;
case VINDEXED:
code_opcode(ls, SETTABLE0, -3);
code_opcode(ls, codes[2], -3);
break;
default:
LUA_INTERNALERROR("invalid var kind to store");
@@ -469,6 +479,12 @@ static void storevar (LexState *ls, vardesc *var) {
}
static void storevar (LexState *ls, vardesc *var) {
static OpCode codes[] = {SETLOCAL, SETGLOBAL, SETTABLE0};
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));
@@ -932,6 +948,21 @@ static void exp0 (LexState *ls, vardesc *v) {
}
static void Gexp (LexState *ls, vardesc *v) {
/* Gexp -> exp0 | var '=' exp1 */
static OpCode codes[] = {SETLOCALDUP, SETGLOBALDUP, SETTABLEDUP};
exp0(ls, v);
if (ls->token == '=' && v->k != VEXP) { /* assignment expression? */
next(ls); /* skip '=' */
unloaddot(ls, v);
exp1(ls);
genstorevar(ls, v, codes);
deltastack(ls, 1); /* DUP operations push an extra value */
v->k = VEXP; v->info = 0;
}
}
static void push (LexState *ls, stack_op *s, int op) {
if (s->top == MAXOPS)
luaX_error(ls, "expression too complex");
@@ -993,9 +1024,9 @@ static void simpleexp (LexState *ls, vardesc *v, stack_op *s) {
ifpart(ls, 1, ls->linenumber);
break;
case '(': /* simpleexp -> '(' exp0 ')' */
case '(': /* simpleexp -> '(' Gexp ')' */
next(ls);
exp0(ls, v);
Gexp(ls, v);
check(ls, ')');
return;
@@ -1206,13 +1237,10 @@ static void decinit (LexState *ls, listdesc *d) {
}
}
static int assignment (LexState *ls, vardesc *v, int nvars) {
int left = 0;
/* dotted variables <a.x> must be stored like regular indexed vars <a["x"]> */
if (v->k == VDOT) {
code_constant(ls, v->info);
v->k = VINDEXED;
}
unloaddot(ls, v);
if (ls->token == ',') { /* assignment -> ',' NAME assignment */
vardesc nv;
next(ls);