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native lua_Number may be neither float nor double (in pack/unpackfloat)

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Roberto Ierusalimschy 2014-03-21 11:26:44 -03:00
parent da4811238a
commit 2d5e2212d4
1 changed files with 22 additions and 17 deletions
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39
lstrlib.c
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@ -1,5 +1,5 @@
/*
** $Id: lstrlib.c,v 1.187 2014/03/12 18:09:06 roberto Exp roberto $
** $Id: lstrlib.c,v 1.188 2014/03/21 13:52:33 roberto Exp roberto $
** Standard library for string operations and pattern-matching
** See Copyright Notice in lua.h
*/
@ -1088,12 +1088,9 @@ static void correctendianess (lua_State *L, char *b, int size, int endianarg) {
}
#define DEFAULTFLOATSIZE \
(sizeof(lua_Number) == sizeof(float) ? "f" : "d")
static int getfloatsize (lua_State *L, int arg) {
const char *size = luaL_optstring(L, arg, "n");
if (*size == 'n') size = DEFAULTFLOATSIZE;
if (*size == 'n') return sizeof(lua_Number);
luaL_argcheck(L, *size == 'd' || *size == 'f', arg,
"size must be 'f'/'d'/'n'");
return (*size == 'd' ? sizeof(double) : sizeof(float));
@ -1105,13 +1102,16 @@ static int packfloat_l (lua_State *L) {
char *pn; /* pointer to number */
lua_Number n = luaL_checknumber(L, 1);
int size = getfloatsize(L, 2);
if (size == sizeof(double)) {
d = (double)n;
pn = (char*)&d;
}
else {
if (size == sizeof(lua_Number))
pn = (char*)&n;
else if (size == sizeof(float)) {
f = (float)n;
pn = (char*)&f;
}
else { /* native lua_Number may be neither float nor double */
lua_assert(size == sizeof(double));
d = (double)n;
pn = (char*)&d;
}
correctendianess(L, pn, size, 3);
lua_pushlstring(L, pn, size);
@ -1127,17 +1127,22 @@ static int unpackfloat_l (lua_State *L) {
int size = getfloatsize(L, 3);
luaL_argcheck(L, 1 <= pos && (size_t)pos + size - 1 <= len, 1,
"string too short");
if (size == sizeof(double)) {
double d;
memcpy(&d, s + pos - 1, size);
correctendianess(L, (char*)&d, size, 4);
res = (lua_Number)d;
}
else {
if (size == sizeof(lua_Number)) {
memcpy(&res, s + pos - 1, size);
correctendianess(L, (char*)&res, size, 4);
}
else if (size == sizeof(float)) {
float f;
memcpy(&f, s + pos - 1, size);
correctendianess(L, (char*)&f, size, 4);
res = (lua_Number)f;
}
else { /* native lua_Number may be neither float nor double */
double d;
lua_assert(size == sizeof(double));
memcpy(&d, s + pos - 1, size);
correctendianess(L, (char*)&d, size, 4);
res = (lua_Number)d;
}
lua_pushnumber(L, res);
return 1;