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 } 151 152