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first implementation of lexical environments

pull/9/head
Roberto Ierusalimschy 15 years ago
parent
5938212748
commit
0ac3d07ea6
7 changed files with 68 additions and 22 deletions
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  1. 3
      ldump.c
  2. 4
      lfunc.c
  3. 3
      lobject.h
  4. 62
      lparser.c
  5. 5
      lparser.h
  6. 3
      lundump.c
  7. 10
      lvm.c

3
ldump.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ldump.c,v 2.10 2008/07/03 14:25:05 roberto Exp roberto $
** $Id: ldump.c,v 2.11 2009/09/28 16:32:50 roberto Exp roberto $
** save precompiled Lua chunks
** See Copyright Notice in lua.h
*/
@ -145,6 +145,7 @@ static void DumpFunction(const Proto* f, const TString* p, DumpState* D)
DumpChar(f->numparams,D);
DumpChar(f->is_vararg,D);
DumpChar(f->maxstacksize,D);
DumpChar(f->envreg,D);
DumpCode(f,D);
DumpConstants(f,D);
DumpUpvalues(f,D);

4
lfunc.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lfunc.c,v 2.14 2009/04/17 14:40:13 roberto Exp roberto $
** $Id: lfunc.c,v 2.15 2009/09/28 16:32:50 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
@ -16,6 +16,7 @@
#include "lgc.h"
#include "lmem.h"
#include "lobject.h"
#include "lopcodes.h"
#include "lstate.h"
@ -133,6 +134,7 @@ Proto *luaF_newproto (lua_State *L) {
f->linedefined = 0;
f->lastlinedefined = 0;
f->source = NULL;
f->envreg = NO_REG;
return f;
}

3
lobject.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lobject.h,v 2.28 2009/07/15 18:37:19 roberto Exp roberto $
** $Id: lobject.h,v 2.29 2009/09/28 16:32:50 roberto Exp roberto $
** Type definitions for Lua objects
** See Copyright Notice in lua.h
*/
@ -261,6 +261,7 @@ typedef struct Proto {
lu_byte numparams;
lu_byte is_vararg;
lu_byte maxstacksize;
lu_byte envreg; /* register in outer function with initial environment */
} Proto;

62
lparser.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lparser.c,v 2.66 2009/09/23 20:14:00 roberto Exp roberto $
** $Id: lparser.c,v 2.67 2009/09/28 16:32:50 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@ -227,10 +227,8 @@ static void markupval (FuncState *fs, int level) {
static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
if (fs == NULL) { /* no more levels? */
init_exp(var, VGLOBAL, NO_REG); /* default is global variable */
return VGLOBAL;
}
if (fs == NULL) /* no more levels? */
return VGLOBAL; /* default is global variable */
else {
int v = searchvar(fs, n); /* look up at current level */
if (v >= 0) {
@ -253,8 +251,16 @@ static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
static void singlevar (LexState *ls, expdesc *var) {
TString *varname = str_checkname(ls);
FuncState *fs = ls->fs;
if (singlevaraux(fs, varname, var, 1) == VGLOBAL)
var->u.s.info = luaK_stringK(fs, varname); /* info points to global name */
if (singlevaraux(fs, varname, var, 1) == VGLOBAL) {
if (fs->envreg == NO_REG) /* regular global? */
init_exp(var, VGLOBAL, luaK_stringK(fs, varname));
else { /* "globals" are in current lexical environment */
expdesc key;
init_exp(var, VLOCAL, fs->envreg); /* current environment */
codestring(ls, &key, varname); /* key is variable name */
luaK_indexed(fs, var, &key); /* env[varname] */
}
}
}
@ -313,15 +319,17 @@ static void leaveblock (FuncState *fs) {
}
static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
static void pushclosure (LexState *ls, Proto *clp, expdesc *v) {
FuncState *fs = ls->fs->prev;
Proto *f = fs->f;
Proto *f = fs->f; /* prototype of function creating new closure */
int oldsize = f->sizep;
luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
MAXARG_Bx, "functions");
while (oldsize < f->sizep) f->p[oldsize++] = NULL;
f->p[fs->np++] = func->f;
luaC_objbarrier(ls->L, f, func->f);
f->p[fs->np++] = clp;
/* initial environment for new function is current lexical environment */
clp->envreg = fs->envreg;
luaC_objbarrier(ls->L, f, clp);
init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
}
@ -342,6 +350,7 @@ static void open_func (LexState *ls, FuncState *fs) {
fs->nups = 0;
fs->nlocvars = 0;
fs->nactvar = 0;
fs->envreg = NO_REG;
fs->bl = NULL;
fs->h = luaH_new(L);
/* anchor table of constants (to avoid being collected) */
@ -589,7 +598,7 @@ static void body (LexState *ls, expdesc *e, int needself, int line) {
chunk(ls);
new_fs.f->lastlinedefined = ls->linenumber;
check_match(ls, TK_END, TK_FUNCTION, line);
pushclosure(ls, &new_fs, e);
pushclosure(ls, new_fs.f, e);
close_func(ls);
}
@ -1035,11 +1044,12 @@ static void repeatstat (LexState *ls, int line) {
static int exp1 (LexState *ls) {
expdesc e;
int k;
int reg;
expr(ls, &e);
k = e.k;
luaK_exp2nextreg(ls->fs, &e);
return k;
lua_assert(e.k == VNONRELOC);
reg = e.u.s.info;
return reg;
}
@ -1226,6 +1236,24 @@ static void funcstat (LexState *ls, int line) {
}
static void instat (LexState *ls, int line) {
/* instat -> IN exp DO block END */
FuncState *fs = ls->fs;
int oldenv = fs->envreg; /* save current environment */
BlockCnt bl;
luaX_next(ls); /* skip IN */
enterblock(fs, &bl, 0); /* scope for environment variable */
new_localvarliteral(ls, "(environment)", 0);
fs->envreg = exp1(ls); /* new environment */
adjustlocalvars(ls, 1);
checknext(ls, TK_DO);
block(ls);
leaveblock(fs);
check_match(ls, TK_END, TK_IN, line);
fs->envreg = oldenv; /* restore outer environment */
}
static void exprstat (LexState *ls) {
/* stat -> func | assignment */
FuncState *fs = ls->fs;
@ -1290,6 +1318,10 @@ static int statement (LexState *ls) {
check_match(ls, TK_END, TK_DO, line);
return 0;
}
case TK_IN: {
instat(ls, line);
return 0;
}
case TK_FOR: { /* stat -> forstat */
forstat(ls, line);
return 0;

5
lparser.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lparser.h,v 1.58 2008/05/08 15:44:51 roberto Exp roberto $
** $Id: lparser.h,v 1.59 2009/09/28 16:32:50 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@ -71,7 +71,8 @@ typedef struct FuncState {
short nlocvars; /* number of elements in `locvars' */
lu_byte nactvar; /* number of active local variables */
lu_byte nups; /* number of upvalues */
vardesc actvar[LUAI_MAXVARS]; /* declared-variable stack */
lu_byte envreg; /* register holding current lexical environment */
vardesc actvar[LUAI_MAXVARS]; /* stack of active variables */
} FuncState;

3
lundump.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lundump.c,v 2.10 2009/04/30 17:42:21 roberto Exp roberto $
** $Id: lundump.c,v 2.11 2009/09/28 16:32:50 roberto Exp roberto $
** load precompiled Lua chunks
** See Copyright Notice in lua.h
*/
@ -180,6 +180,7 @@ static Proto* LoadFunction(LoadState* S, TString* p)
f->numparams=LoadByte(S);
f->is_vararg=LoadByte(S);
f->maxstacksize=LoadByte(S);
f->envreg=LoadByte(S);
LoadCode(S,f);
LoadConstants(S,f);
LoadUpvalues(S,f);

10
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 2.97 2009/09/23 20:33:05 roberto Exp roberto $
** $Id: lvm.c,v 2.98 2009/09/28 16:32:50 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -780,6 +780,14 @@ void luaV_execute (lua_State *L) {
int j;
ncl->l.p = p;
setclvalue(L, ra, ncl); /* anchor new closure in stack */
if (p->envreg != NO_REG) { /* lexical environment? */
StkId env = base + p->envreg;
if (!ttistable(env))
luaG_runerror(L, "environment is not a table: "
"cannot create closure");
else
ncl->l.env = hvalue(env);
}
for (j = 0; j < nup; j++) { /* fill in upvalues */
if (uv[j].instack) /* upvalue refers to local variable? */
ncl->l.upvals[j] = luaF_findupval(L, base + uv[j].idx);

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