aboutsummaryrefslogtreecommitdiff
path: root/lapi.c
diff options
context:
space:
mode:
authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2018-06-15 16:31:22 -0300
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2018-06-15 16:31:22 -0300
commitb95e46621873cfb460e1d11dcd153914d5d69f86 (patch)
treeaeb1db66a8254b5f997bcfd0a8ac606eea2f621c /lapi.c
parentd406d3d05ffe8bc01d6416437963ce092cfc9772 (diff)
downloadlua-b95e46621873cfb460e1d11dcd153914d5d69f86.tar.gz
lua-b95e46621873cfb460e1d11dcd153914d5d69f86.tar.bz2
lua-b95e46621873cfb460e1d11dcd153914d5d69f86.zip
new field 'nilvalue' in struct 'global_State' to avoid the use of
addresses of static variables
Diffstat (limited to 'lapi.c')
-rw-r--r--lapi.c23
1 files changed, 10 insertions, 13 deletions
diff --git a/lapi.c b/lapi.c
index 157c22b2..5d106076 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lapi.c,v 2.292 2018/06/01 17:40:38 roberto Exp roberto $ 2** $Id: lapi.c,v 2.293 2018/06/15 17:30:52 roberto Exp roberto $
3** Lua API 3** Lua API
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -37,13 +37,10 @@ const char lua_ident[] =
37 "$LuaAuthors: " LUA_AUTHORS " $"; 37 "$LuaAuthors: " LUA_AUTHORS " $";
38 38
39 39
40/* value at a non-valid index */
41 40
42static const TValue nonvalidvaluep = {NILCONSTANT}; 41/* test for a valid index */
43#define NONVALIDVALUE cast(TValue *, &nonvalidvaluep) 42#define isvalid(L, o) (!ttisnil(o) || o != &G(L)->nilvalue)
44 43
45/* corresponding test */
46#define isvalid(o) ((o) != &nonvalidvaluep)
47 44
48/* test for pseudo index */ 45/* test for pseudo index */
49#define ispseudo(i) ((i) <= LUA_REGISTRYINDEX) 46#define ispseudo(i) ((i) <= LUA_REGISTRYINDEX)
@@ -57,7 +54,7 @@ static TValue *index2value (lua_State *L, int idx) {
57 if (idx > 0) { 54 if (idx > 0) {
58 StkId o = ci->func + idx; 55 StkId o = ci->func + idx;
59 api_check(L, idx <= L->ci->top - (ci->func + 1), "unacceptable index"); 56 api_check(L, idx <= L->ci->top - (ci->func + 1), "unacceptable index");
60 if (o >= L->top) return NONVALIDVALUE; 57 if (o >= L->top) return &G(L)->nilvalue;
61 else return s2v(o); 58 else return s2v(o);
62 } 59 }
63 else if (!ispseudo(idx)) { /* negative index */ 60 else if (!ispseudo(idx)) { /* negative index */
@@ -70,10 +67,10 @@ static TValue *index2value (lua_State *L, int idx) {
70 idx = LUA_REGISTRYINDEX - idx; 67 idx = LUA_REGISTRYINDEX - idx;
71 api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large"); 68 api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
72 if (ttislcf(s2v(ci->func))) /* light C function? */ 69 if (ttislcf(s2v(ci->func))) /* light C function? */
73 return NONVALIDVALUE; /* it has no upvalues */ 70 return &G(L)->nilvalue; /* it has no upvalues */
74 else { 71 else {
75 CClosure *func = clCvalue(s2v(ci->func)); 72 CClosure *func = clCvalue(s2v(ci->func));
76 return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE; 73 return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : &G(L)->nilvalue;
77 } 74 }
78 } 75 }
79} 76}
@@ -225,7 +222,7 @@ LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
225 lua_lock(L); 222 lua_lock(L);
226 fr = index2value(L, fromidx); 223 fr = index2value(L, fromidx);
227 to = index2value(L, toidx); 224 to = index2value(L, toidx);
228 api_check(l, isvalid(to), "invalid index"); 225 api_check(l, isvalid(L, to), "invalid index");
229 setobj(L, to, fr); 226 setobj(L, to, fr);
230 if (isupvalue(toidx)) /* function upvalue? */ 227 if (isupvalue(toidx)) /* function upvalue? */
231 luaC_barrier(L, clCvalue(s2v(L->ci->func)), fr); 228 luaC_barrier(L, clCvalue(s2v(L->ci->func)), fr);
@@ -251,7 +248,7 @@ LUA_API void lua_pushvalue (lua_State *L, int idx) {
251 248
252LUA_API int lua_type (lua_State *L, int idx) { 249LUA_API int lua_type (lua_State *L, int idx) {
253 const TValue *o = index2value(L, idx); 250 const TValue *o = index2value(L, idx);
254 return (isvalid(o) ? ttype(o) : LUA_TNONE); 251 return (isvalid(L, o) ? ttype(o) : LUA_TNONE);
255} 252}
256 253
257 254
@@ -296,7 +293,7 @@ LUA_API int lua_isuserdata (lua_State *L, int idx) {
296LUA_API int lua_rawequal (lua_State *L, int index1, int index2) { 293LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
297 const TValue *o1 = index2value(L, index1); 294 const TValue *o1 = index2value(L, index1);
298 const TValue *o2 = index2value(L, index2); 295 const TValue *o2 = index2value(L, index2);
299 return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0; 296 return (isvalid(L, o1) && isvalid(L, o2)) ? luaV_rawequalobj(o1, o2) : 0;
300} 297}
301 298
302 299
@@ -323,7 +320,7 @@ LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
323 lua_lock(L); /* may call tag method */ 320 lua_lock(L); /* may call tag method */
324 o1 = index2value(L, index1); 321 o1 = index2value(L, index1);
325 o2 = index2value(L, index2); 322 o2 = index2value(L, index2);
326 if (isvalid(o1) && isvalid(o2)) { 323 if (isvalid(L, o1) && isvalid(L, o2)) {
327 switch (op) { 324 switch (op) {
328 case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break; 325 case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break;
329 case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break; 326 case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-16 12:45:34 +0000