xref: /illumos-gate/usr/src/uts/common/fs/zfs/lua/lfunc.c (revision dfc115332c94a2f62058ac7f2bce7631fbd20b3d)
1  /*
2  ** $Id: lfunc.c,v 2.30.1.1 2013/04/12 18:48:47 roberto Exp $
3  ** Auxiliary functions to manipulate prototypes and closures
4  ** See Copyright Notice in lua.h
5  */
6  
7  
8  #include <sys/zfs_context.h>
9  
10  #define lfunc_c
11  #define LUA_CORE
12  
13  #include "lua.h"
14  
15  #include "lfunc.h"
16  #include "lgc.h"
17  #include "lmem.h"
18  #include "lobject.h"
19  #include "lstate.h"
20  
21  
22  
luaF_newCclosure(lua_State * L,int n)23  Closure *luaF_newCclosure (lua_State *L, int n) {
24    Closure *c = &luaC_newobj(L, LUA_TCCL, sizeCclosure(n), NULL, 0)->cl;
25    c->c.nupvalues = cast_byte(n);
26    return c;
27  }
28  
29  
luaF_newLclosure(lua_State * L,int n)30  Closure *luaF_newLclosure (lua_State *L, int n) {
31    Closure *c = &luaC_newobj(L, LUA_TLCL, sizeLclosure(n), NULL, 0)->cl;
32    c->l.p = NULL;
33    c->l.nupvalues = cast_byte(n);
34    while (n--) c->l.upvals[n] = NULL;
35    return c;
36  }
37  
38  
luaF_newupval(lua_State * L)39  UpVal *luaF_newupval (lua_State *L) {
40    UpVal *uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), NULL, 0)->uv;
41    uv->v = &uv->u.value;
42    setnilvalue(uv->v);
43    return uv;
44  }
45  
46  
luaF_findupval(lua_State * L,StkId level)47  UpVal *luaF_findupval (lua_State *L, StkId level) {
48    global_State *g = G(L);
49    GCObject **pp = &L->openupval;
50    UpVal *p;
51    UpVal *uv;
52    while (*pp != NULL && (p = gco2uv(*pp))->v >= level) {
53      GCObject *o = obj2gco(p);
54      lua_assert(p->v != &p->u.value);
55      lua_assert(!isold(o) || isold(obj2gco(L)));
56      if (p->v == level) {  /* found a corresponding upvalue? */
57        if (isdead(g, o))  /* is it dead? */
58          changewhite(o);  /* resurrect it */
59        return p;
60      }
61      pp = &p->next;
62    }
63    /* not found: create a new one */
64    uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv;
65    uv->v = level;  /* current value lives in the stack */
66    uv->u.l.prev = &g->uvhead;  /* double link it in `uvhead' list */
67    uv->u.l.next = g->uvhead.u.l.next;
68    uv->u.l.next->u.l.prev = uv;
69    g->uvhead.u.l.next = uv;
70    lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
71    return uv;
72  }
73  
74  
unlinkupval(UpVal * uv)75  static void unlinkupval (UpVal *uv) {
76    lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
77    uv->u.l.next->u.l.prev = uv->u.l.prev;  /* remove from `uvhead' list */
78    uv->u.l.prev->u.l.next = uv->u.l.next;
79  }
80  
81  
luaF_freeupval(lua_State * L,UpVal * uv)82  void luaF_freeupval (lua_State *L, UpVal *uv) {
83    if (uv->v != &uv->u.value)  /* is it open? */
84      unlinkupval(uv);  /* remove from open list */
85    luaM_free(L, uv);  /* free upvalue */
86  }
87  
88  
luaF_close(lua_State * L,StkId level)89  void luaF_close (lua_State *L, StkId level) {
90    UpVal *uv;
91    global_State *g = G(L);
92    while (L->openupval != NULL && (uv = gco2uv(L->openupval))->v >= level) {
93      GCObject *o = obj2gco(uv);
94      lua_assert(!isblack(o) && uv->v != &uv->u.value);
95      L->openupval = uv->next;  /* remove from `open' list */
96      if (isdead(g, o))
97        luaF_freeupval(L, uv);  /* free upvalue */
98      else {
99        unlinkupval(uv);  /* remove upvalue from 'uvhead' list */
100        setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
101        uv->v = &uv->u.value;  /* now current value lives here */
102        gch(o)->next = g->allgc;  /* link upvalue into 'allgc' list */
103        g->allgc = o;
104        luaC_checkupvalcolor(g, uv);
105      }
106    }
107  }
108  
109  
luaF_newproto(lua_State * L)110  Proto *luaF_newproto (lua_State *L) {
111    Proto *f = &luaC_newobj(L, LUA_TPROTO, sizeof(Proto), NULL, 0)->p;
112    f->k = NULL;
113    f->sizek = 0;
114    f->p = NULL;
115    f->sizep = 0;
116    f->code = NULL;
117    f->cache = NULL;
118    f->sizecode = 0;
119    f->lineinfo = NULL;
120    f->sizelineinfo = 0;
121    f->upvalues = NULL;
122    f->sizeupvalues = 0;
123    f->numparams = 0;
124    f->is_vararg = 0;
125    f->maxstacksize = 0;
126    f->locvars = NULL;
127    f->sizelocvars = 0;
128    f->linedefined = 0;
129    f->lastlinedefined = 0;
130    f->source = NULL;
131    return f;
132  }
133  
134  
luaF_freeproto(lua_State * L,Proto * f)135  void luaF_freeproto (lua_State *L, Proto *f) {
136    luaM_freearray(L, f->code, f->sizecode);
137    luaM_freearray(L, f->p, f->sizep);
138    luaM_freearray(L, f->k, f->sizek);
139    luaM_freearray(L, f->lineinfo, f->sizelineinfo);
140    luaM_freearray(L, f->locvars, f->sizelocvars);
141    luaM_freearray(L, f->upvalues, f->sizeupvalues);
142    luaM_free(L, f);
143  }
144  
145  
146  /*
147  ** Look for n-th local variable at line `line' in function `func'.
148  ** Returns NULL if not found.
149  */
luaF_getlocalname(const Proto * f,int local_number,int pc)150  const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
151    int i;
152    for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
153      if (pc < f->locvars[i].endpc) {  /* is variable active? */
154        local_number--;
155        if (local_number == 0)
156          return getstr(f->locvars[i].varname);
157      }
158    }
159    return NULL;  /* not found */
160  }
161  
162