mudgangster

Tiny, scriptable MUD client
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lfunc.cc (3695B)

      1 /*
      2 ** $Id: lfunc.c,v 2.45.1.1 2017/04/19 17:39:34 roberto Exp $
      3 ** Auxiliary functions to manipulate prototypes and closures
      4 ** See Copyright Notice in lua.h
      5 */
      6 
      7 #define lfunc_c
      8 #define LUA_CORE
      9 
     10 #include "lprefix.h"
     11 
     12 
     13 #include <stddef.h>
     14 
     15 #include "lua.h"
     16 
     17 #include "lfunc.h"
     18 #include "lgc.h"
     19 #include "lmem.h"
     20 #include "lobject.h"
     21 #include "lstate.h"
     22 
     23 
     24 
     25 CClosure *luaF_newCclosure (lua_State *L, int n) {
     26   GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
     27   CClosure *c = gco2ccl(o);
     28   c->nupvalues = cast_byte(n);
     29   return c;
     30 }
     31 
     32 
     33 LClosure *luaF_newLclosure (lua_State *L, int n) {
     34   GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
     35   LClosure *c = gco2lcl(o);
     36   c->p = NULL;
     37   c->nupvalues = cast_byte(n);
     38   while (n--) c->upvals[n] = NULL;
     39   return c;
     40 }
     41 
     42 /*
     43 ** fill a closure with new closed upvalues
     44 */
     45 void luaF_initupvals (lua_State *L, LClosure *cl) {
     46   int i;
     47   for (i = 0; i < cl->nupvalues; i++) {
     48     UpVal *uv = luaM_new(L, UpVal);
     49     uv->refcount = 1;
     50     uv->v = &uv->u.value;  /* make it closed */
     51     setnilvalue(uv->v);
     52     cl->upvals[i] = uv;
     53   }
     54 }
     55 
     56 
     57 UpVal *luaF_findupval (lua_State *L, StkId level) {
     58   UpVal **pp = &L->openupval;
     59   UpVal *p;
     60   UpVal *uv;
     61   lua_assert(isintwups(L) || L->openupval == NULL);
     62   while (*pp != NULL && (p = *pp)->v >= level) {
     63     lua_assert(upisopen(p));
     64     if (p->v == level)  /* found a corresponding upvalue? */
     65       return p;  /* return it */
     66     pp = &p->u.open.next;
     67   }
     68   /* not found: create a new upvalue */
     69   uv = luaM_new(L, UpVal);
     70   uv->refcount = 0;
     71   uv->u.open.next = *pp;  /* link it to list of open upvalues */
     72   uv->u.open.touched = 1;
     73   *pp = uv;
     74   uv->v = level;  /* current value lives in the stack */
     75   if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
     76     L->twups = G(L)->twups;  /* link it to the list */
     77     G(L)->twups = L;
     78   }
     79   return uv;
     80 }
     81 
     82 
     83 void luaF_close (lua_State *L, StkId level) {
     84   UpVal *uv;
     85   while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
     86     lua_assert(upisopen(uv));
     87     L->openupval = uv->u.open.next;  /* remove from 'open' list */
     88     if (uv->refcount == 0)  /* no references? */
     89       luaM_free(L, uv);  /* free upvalue */
     90     else {
     91       setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
     92       uv->v = &uv->u.value;  /* now current value lives here */
     93       luaC_upvalbarrier(L, uv);
     94     }
     95   }
     96 }
     97 
     98 
     99 Proto *luaF_newproto (lua_State *L) {
    100   GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
    101   Proto *f = gco2p(o);
    102   f->k = NULL;
    103   f->sizek = 0;
    104   f->p = NULL;
    105   f->sizep = 0;
    106   f->code = NULL;
    107   f->cache = NULL;
    108   f->sizecode = 0;
    109   f->lineinfo = NULL;
    110   f->sizelineinfo = 0;
    111   f->upvalues = NULL;
    112   f->sizeupvalues = 0;
    113   f->numparams = 0;
    114   f->is_vararg = 0;
    115   f->maxstacksize = 0;
    116   f->locvars = NULL;
    117   f->sizelocvars = 0;
    118   f->linedefined = 0;
    119   f->lastlinedefined = 0;
    120   f->source = NULL;
    121   return f;
    122 }
    123 
    124 
    125 void luaF_freeproto (lua_State *L, Proto *f) {
    126   luaM_freearray(L, f->code, f->sizecode);
    127   luaM_freearray(L, f->p, f->sizep);
    128   luaM_freearray(L, f->k, f->sizek);
    129   luaM_freearray(L, f->lineinfo, f->sizelineinfo);
    130   luaM_freearray(L, f->locvars, f->sizelocvars);
    131   luaM_freearray(L, f->upvalues, f->sizeupvalues);
    132   luaM_free(L, f);
    133 }
    134 
    135 
    136 /*
    137 ** Look for n-th local variable at line 'line' in function 'func'.
    138 ** Returns NULL if not found.
    139 */
    140 const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
    141   int i;
    142   for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
    143     if (pc < f->locvars[i].endpc) {  /* is variable active? */
    144       local_number--;
    145       if (local_number == 0)
    146         return getstr(f->locvars[i].varname);
    147     }
    148   }
    149   return NULL;  /* not found */
    150 }
    151