?login_element?

Subversion Repositories NedoOS

Rev

Blame | Last modification | View Log | Download

  1. /*
  2. ** $Id: lfunc.c $
  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 "ldebug.h"
  18. #include "ldo.h"
  19. #include "lfunc.h"
  20. #include "lgc.h"
  21. #include "lmem.h"
  22. #include "lobject.h"
  23. #include "lstate.h"
  24.  
  25.  
  26.  
  27. CClosure *luaF_newCclosure (lua_State *L, int nupvals) {
  28.   GCObject *o = luaC_newobj(L, LUA_VCCL, sizeCclosure(nupvals));
  29.   CClosure *c = gco2ccl(o);
  30.   c->nupvalues = cast_byte(nupvals);
  31.   return c;
  32. }
  33.  
  34.  
  35. LClosure *luaF_newLclosure (lua_State *L, int nupvals) {
  36.   GCObject *o = luaC_newobj(L, LUA_VLCL, sizeLclosure(nupvals));
  37.   LClosure *c = gco2lcl(o);
  38.   c->p = NULL;
  39.   c->nupvalues = cast_byte(nupvals);
  40.   while (nupvals--) c->upvals[nupvals] = NULL;
  41.   return c;
  42. }
  43.  
  44.  
  45. /*
  46. ** fill a closure with new closed upvalues
  47. */
  48. void luaF_initupvals (lua_State *L, LClosure *cl) {
  49.   int i;
  50.   for (i = 0; i < cl->nupvalues; i++) {
  51.     GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
  52.     UpVal *uv = gco2upv(o);
  53.     uv->v = &uv->u.value;  /* make it closed */
  54.     setnilvalue(uv->v);
  55.     cl->upvals[i] = uv;
  56.     luaC_objbarrier(L, cl, uv);
  57.   }
  58. }
  59.  
  60.  
  61. /*
  62. ** Create a new upvalue at the given level, and link it to the list of
  63. ** open upvalues of 'L' after entry 'prev'.
  64. **/
  65. static UpVal *newupval (lua_State *L, int tbc, StkId level, UpVal **prev) {
  66.   GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
  67.   UpVal *uv = gco2upv(o);
  68.   UpVal *next = *prev;
  69.   uv->v = s2v(level);  /* current value lives in the stack */
  70.   uv->tbc = tbc;
  71.   uv->u.open.next = next;  /* link it to list of open upvalues */
  72.   uv->u.open.previous = prev;
  73.   if (next)
  74.     next->u.open.previous = &uv->u.open.next;
  75.   *prev = uv;
  76.   if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
  77.     L->twups = G(L)->twups;  /* link it to the list */
  78.     G(L)->twups = L;
  79.   }
  80.   return uv;
  81. }
  82.  
  83.  
  84. /*
  85. ** Find and reuse, or create if it does not exist, an upvalue
  86. ** at the given level.
  87. */
  88. UpVal *luaF_findupval (lua_State *L, StkId level) {
  89.   UpVal **pp = &L->openupval;
  90.   UpVal *p;
  91.   lua_assert(isintwups(L) || L->openupval == NULL);
  92.   while ((p = *pp) != NULL && uplevel(p) >= level) {  /* search for it */
  93.     lua_assert(!isdead(G(L), p));
  94.     if (uplevel(p) == level)  /* corresponding upvalue? */
  95.       return p;  /* return it */
  96.     pp = &p->u.open.next;
  97.   }
  98.   /* not found: create a new upvalue after 'pp' */
  99.   return newupval(L, 0, level, pp);
  100. }
  101.  
  102.  
  103. /*
  104. ** Call closing method for object 'obj' with error message 'err'. The
  105. ** boolean 'yy' controls whether the call is yieldable.
  106. ** (This function assumes EXTRA_STACK.)
  107. */
  108. static void callclosemethod (lua_State *L, TValue *obj, TValue *err, int yy) {
  109.   StkId top = L->top;
  110.   const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
  111.   setobj2s(L, top, tm);  /* will call metamethod... */
  112.   setobj2s(L, top + 1, obj);  /* with 'self' as the 1st argument */
  113.   setobj2s(L, top + 2, err);  /* and error msg. as 2nd argument */
  114.   L->top = top + 3;  /* add function and arguments */
  115.   if (yy)
  116.     luaD_call(L, top, 0);
  117.   else
  118.     luaD_callnoyield(L, top, 0);
  119. }
  120.  
  121.  
  122. /*
  123. ** Check whether object at given level has a close metamethod and raise
  124. ** an error if not.
  125. */
  126. static void checkclosemth (lua_State *L, StkId level) {
  127.   const TValue *tm = luaT_gettmbyobj(L, s2v(level), TM_CLOSE);
  128.   if (ttisnil(tm)) {  /* no metamethod? */
  129.     int idx = cast_int(level - L->ci->func);  /* variable index */
  130.     const char *vname = luaG_findlocal(L, L->ci, idx, NULL);
  131.     if (vname == NULL) vname = "?";
  132.     luaG_runerror(L, "variable '%s' got a non-closable value", vname);
  133.   }
  134. }
  135.  
  136.  
  137. /*
  138. ** Prepare and call a closing method.
  139. ** If status is CLOSEKTOP, the call to the closing method will be pushed
  140. ** at the top of the stack. Otherwise, values can be pushed right after
  141. ** the 'level' of the upvalue being closed, as everything after that
  142. ** won't be used again.
  143. */
  144. static void prepcallclosemth (lua_State *L, StkId level, int status, int yy) {
  145.   TValue *uv = s2v(level);  /* value being closed */
  146.   TValue *errobj;
  147.   if (status == CLOSEKTOP)
  148.     errobj = &G(L)->nilvalue;  /* error object is nil */
  149.   else {  /* 'luaD_seterrorobj' will set top to level + 2 */
  150.     errobj = s2v(level + 1);  /* error object goes after 'uv' */
  151.     luaD_seterrorobj(L, status, level + 1);  /* set error object */
  152.   }
  153.   callclosemethod(L, uv, errobj, yy);
  154. }
  155.  
  156.  
  157. /*
  158. ** Maximum value for deltas in 'tbclist', dependent on the type
  159. ** of delta. (This macro assumes that an 'L' is in scope where it
  160. ** is used.)
  161. */
  162. #define MAXDELTA  \
  163.         ((256ul << ((sizeof(L->stack->tbclist.delta) - 1) * 8)) - 1)
  164.  
  165.  
  166. /*
  167. ** Insert a variable in the list of to-be-closed variables.
  168. */
  169. void luaF_newtbcupval (lua_State *L, StkId level) {
  170.   lua_assert(level > L->tbclist);
  171.   if (l_isfalse(s2v(level)))
  172.     return;  /* false doesn't need to be closed */
  173.   checkclosemth(L, level);  /* value must have a close method */
  174.   while (cast_uint(level - L->tbclist) > MAXDELTA) {
  175.     L->tbclist += MAXDELTA;  /* create a dummy node at maximum delta */
  176.     L->tbclist->tbclist.delta = 0;
  177.   }
  178.   level->tbclist.delta = cast(unsigned short, level - L->tbclist);
  179.   L->tbclist = level;
  180. }
  181.  
  182.  
  183. void luaF_unlinkupval (UpVal *uv) {
  184.   lua_assert(upisopen(uv));
  185.   *uv->u.open.previous = uv->u.open.next;
  186.   if (uv->u.open.next)
  187.     uv->u.open.next->u.open.previous = uv->u.open.previous;
  188. }
  189.  
  190.  
  191. /*
  192. ** Close all upvalues up to the given stack level.
  193. */
  194. void luaF_closeupval (lua_State *L, StkId level) {
  195.   UpVal *uv;
  196.   StkId upl;  /* stack index pointed by 'uv' */
  197.   while ((uv = L->openupval) != NULL && (upl = uplevel(uv)) >= level) {
  198.     TValue *slot = &uv->u.value;  /* new position for value */
  199.     lua_assert(uplevel(uv) < L->top);
  200.     luaF_unlinkupval(uv);  /* remove upvalue from 'openupval' list */
  201.     setobj(L, slot, uv->v);  /* move value to upvalue slot */
  202.     uv->v = slot;  /* now current value lives here */
  203.     if (!iswhite(uv)) {  /* neither white nor dead? */
  204.       nw2black(uv);  /* closed upvalues cannot be gray */
  205.       luaC_barrier(L, uv, slot);
  206.     }
  207.   }
  208. }
  209.  
  210.  
  211. /*
  212. ** Remove firt element from the tbclist plus its dummy nodes.
  213. */
  214. static void poptbclist (lua_State *L) {
  215.   StkId tbc = L->tbclist;
  216.   lua_assert(tbc->tbclist.delta > 0);  /* first element cannot be dummy */
  217.   tbc -= tbc->tbclist.delta;
  218.   while (tbc > L->stack && tbc->tbclist.delta == 0)
  219.     tbc -= MAXDELTA;  /* remove dummy nodes */
  220.   L->tbclist = tbc;
  221. }
  222.  
  223.  
  224. /*
  225. ** Close all upvalues and to-be-closed variables up to the given stack
  226. ** level.
  227. */
  228. void luaF_close (lua_State *L, StkId level, int status, int yy) {
  229.   ptrdiff_t levelrel = savestack(L, level);
  230.   luaF_closeupval(L, level);  /* first, close the upvalues */
  231.   while (L->tbclist >= level) {  /* traverse tbc's down to that level */
  232.     StkId tbc = L->tbclist;  /* get variable index */
  233.     poptbclist(L);  /* remove it from list */
  234.     prepcallclosemth(L, tbc, status, yy);  /* close variable */
  235.     level = restorestack(L, levelrel);
  236.   }
  237. }
  238.  
  239.  
  240. Proto *luaF_newproto (lua_State *L) {
  241.   GCObject *o = luaC_newobj(L, LUA_VPROTO, sizeof(Proto));
  242.   Proto *f = gco2p(o);
  243.   f->k = NULL;
  244.   f->sizek = 0;
  245.   f->p = NULL;
  246.   f->sizep = 0;
  247.   f->code = NULL;
  248.   f->sizecode = 0;
  249.   f->lineinfo = NULL;
  250.   f->sizelineinfo = 0;
  251.   f->abslineinfo = NULL;
  252.   f->sizeabslineinfo = 0;
  253.   f->upvalues = NULL;
  254.   f->sizeupvalues = 0;
  255.   f->numparams = 0;
  256.   f->is_vararg = 0;
  257.   f->maxstacksize = 0;
  258.   f->locvars = NULL;
  259.   f->sizelocvars = 0;
  260.   f->linedefined = 0;
  261.   f->lastlinedefined = 0;
  262.   f->source = NULL;
  263.   return f;
  264. }
  265.  
  266.  
  267. void luaF_freeproto (lua_State *L, Proto *f) {
  268.   luaM_freearray(L, f->code, f->sizecode);
  269.   luaM_freearray(L, f->p, f->sizep);
  270.   luaM_freearray(L, f->k, f->sizek);
  271.   luaM_freearray(L, f->lineinfo, f->sizelineinfo);
  272.   luaM_freearray(L, f->abslineinfo, f->sizeabslineinfo);
  273.   luaM_freearray(L, f->locvars, f->sizelocvars);
  274.   luaM_freearray(L, f->upvalues, f->sizeupvalues);
  275.   luaM_free(L, f);
  276. }
  277.  
  278.  
  279. /*
  280. ** Look for n-th local variable at line 'line' in function 'func'.
  281. ** Returns NULL if not found.
  282. */
  283. const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
  284.   int i;
  285.   for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
  286.     if (pc < f->locvars[i].endpc) {  /* is variable active? */
  287.       local_number--;
  288.       if (local_number == 0)
  289.         return getstr(f->locvars[i].varname);
  290.     }
  291.   }
  292.   return NULL;  /* not found */
  293. }
  294.  
  295.