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-rw-r--r--apps/plugins/lua/lbitlib.c268
1 files changed, 91 insertions, 177 deletions
diff --git a/apps/plugins/lua/lbitlib.c b/apps/plugins/lua/lbitlib.c
index 31c7b66..76c8d1d 100644
--- a/apps/plugins/lua/lbitlib.c
+++ b/apps/plugins/lua/lbitlib.c
@@ -1,212 +1,126 @@
-/*
-** $Id: lbitlib.c,v 1.18.1.2 2013/07/09 18:01:41 roberto Exp $
-** Standard library for bitwise operations
-** See Copyright Notice in lua.h
-*/
+/* Bitwise operations library */
+/* (c) Reuben Thomas 2000-2008 */
+/* bitlib is copyright Reuben Thomas 2000-2008, and is released under the MIT
+ license, like Lua (see http://www.lua.org/copyright.html; it's
+ basically the same as the BSD license). There is no warranty. */
-#define lbitlib_c
-#define LUA_LIB
+#include "config.h"
#include "lua.h"
-
#include "lauxlib.h"
#include "lualib.h"
+#include <limits.h>
-/* number of bits to consider in a number */
-#if !defined(LUA_NBITS)
-#define LUA_NBITS 32
-#endif
-
-
-#define ALLONES (~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1))
-
-/* macro to trim extra bits */
-#define trim(x) ((x) & ALLONES)
-
-
-/* builds a number with 'n' ones (1 <= n <= LUA_NBITS) */
-#define mask(n) (~((ALLONES << 1) << ((n) - 1)))
+/* FIXME: Assume lua_Integer is ptrdiff_t */
+#define LUA_INTEGER_MAX INTPTR_MAX
+#define LUA_INTEGER_MIN INTPTR_MIN
+/* FIXME: Assume size_t is an unsigned lua_Integer */
+typedef size_t lua_UInteger;
+#define LUA_UINTEGER_MAX UINT_MAX
-typedef lua_Unsigned b_uint;
+/* Bit type size and limits */
+#define BIT_BITS (CHAR_BIT * sizeof(lua_Integer))
-static b_uint andaux (lua_State *L) {
- int i, n = lua_gettop(L);
- b_uint r = ~(b_uint)0;
- for (i = 1; i <= n; i++)
- r &= luaL_checkunsigned(L, i);
- return trim(r);
-}
+/* This code may give warnings if BITLIB_FLOAT_* are too big to fit in
+ long, but that doesn't matter since in that case they won't be
+ used. */
+#define BIT_MAX (LUA_INTEGER_MAX)
+#define BIT_MIN (LUA_INTEGER_MIN)
-static int b_and (lua_State *L) {
- b_uint r = andaux(L);
- lua_pushunsigned(L, r);
- return 1;
-}
+#define BIT_UMAX (LUA_UINTEGER_MAX)
-static int b_test (lua_State *L) {
- b_uint r = andaux(L);
- lua_pushboolean(L, r != 0);
- return 1;
-}
+/* Define TOBIT to get a bit value */
+#ifdef BUILTIN_CAST
+#define
+#define TOBIT(L, n, res) \
+ ((void)(res), luaL_checkinteger((L), (n)))
+#else
+#define TOBIT(L, n, res) \
+ ((lua_Integer)(((res) = luaL_checknumber(L, (n)) % BIT_UMAX), \
+ (res) > BIT_MAX ? ((res) -= BIT_UMAX, (res) -= 1) : \
+ ((res) < BIT_MIN ? ((res) += BIT_UMAX, (res) += 1) : (res))))
+#endif
-static int b_or (lua_State *L) {
- int i, n = lua_gettop(L);
- b_uint r = 0;
- for (i = 1; i <= n; i++)
- r |= luaL_checkunsigned(L, i);
- lua_pushunsigned(L, trim(r));
- return 1;
-}
+#define BIT_TRUNCATE(i) \
+ ((i) & BIT_UMAX)
-static int b_xor (lua_State *L) {
- int i, n = lua_gettop(L);
- b_uint r = 0;
- for (i = 1; i <= n; i++)
- r ^= luaL_checkunsigned(L, i);
- lua_pushunsigned(L, trim(r));
- return 1;
-}
+/* Operations
-static int b_not (lua_State *L) {
- b_uint r = ~luaL_checkunsigned(L, 1);
- lua_pushunsigned(L, trim(r));
- return 1;
-}
+ The macros MONADIC and VARIADIC only deal with bitwise operations.
+ LOGICAL_SHIFT truncates its left-hand operand before shifting so
+ that any extra bits at the most-significant end are not shifted
+ into the result.
-static int b_shift (lua_State *L, b_uint r, int i) {
- if (i < 0) { /* shift right? */
- i = -i;
- r = trim(r);
- if (i >= LUA_NBITS) r = 0;
- else r >>= i;
- }
- else { /* shift left */
- if (i >= LUA_NBITS) r = 0;
- else r <<= i;
- r = trim(r);
+ ARITHMETIC_SHIFT does not truncate its left-hand operand, so that
+ the sign bits are not removed and right shift work properly.
+ */
+
+#define MONADIC(name, op) \
+ static int bit_ ## name(lua_State *L) { \
+ lua_Number f; \
+ lua_pushinteger(L, BIT_TRUNCATE(op TOBIT(L, 1, f))); \
+ return 1; \
}
- lua_pushunsigned(L, r);
- return 1;
-}
-
-
-static int b_lshift (lua_State *L) {
- return b_shift(L, luaL_checkunsigned(L, 1), luaL_checkint(L, 2));
-}
-
-
-static int b_rshift (lua_State *L) {
- return b_shift(L, luaL_checkunsigned(L, 1), -luaL_checkint(L, 2));
-}
-
-static int b_arshift (lua_State *L) {
- b_uint r = luaL_checkunsigned(L, 1);
- int i = luaL_checkint(L, 2);
- if (i < 0 || !(r & ((b_uint)1 << (LUA_NBITS - 1))))
- return b_shift(L, r, -i);
- else { /* arithmetic shift for 'negative' number */
- if (i >= LUA_NBITS) r = ALLONES;
- else
- r = trim((r >> i) | ~(~(b_uint)0 >> i)); /* add signal bit */
- lua_pushunsigned(L, r);
- return 1;
+#define VARIADIC(name, op) \
+ static int bit_ ## name(lua_State *L) { \
+ lua_Number f; \
+ int n = lua_gettop(L), i; \
+ lua_Integer w = TOBIT(L, 1, f); \
+ for (i = 2; i <= n; i++) \
+ w op TOBIT(L, i, f); \
+ lua_pushinteger(L, BIT_TRUNCATE(w)); \
+ return 1; \
}
-}
-
-
-static int b_rot (lua_State *L, int i) {
- b_uint r = luaL_checkunsigned(L, 1);
- i &= (LUA_NBITS - 1); /* i = i % NBITS */
- r = trim(r);
- if (i != 0) /* avoid undefined shift of LUA_NBITS when i == 0 */
- r = (r << i) | (r >> (LUA_NBITS - i));
- lua_pushunsigned(L, trim(r));
- return 1;
-}
-
-static int b_lrot (lua_State *L) {
- return b_rot(L, luaL_checkint(L, 2));
-}
-
-
-static int b_rrot (lua_State *L) {
- return b_rot(L, -luaL_checkint(L, 2));
-}
-
-
-/*
-** get field and width arguments for field-manipulation functions,
-** checking whether they are valid.
-** ('luaL_error' called without 'return' to avoid later warnings about
-** 'width' being used uninitialized.)
-*/
-static int fieldargs (lua_State *L, int farg, int *width) {
- int f = luaL_checkint(L, farg);
- int w = luaL_optint(L, farg + 1, 1);
- luaL_argcheck(L, 0 <= f, farg, "field cannot be negative");
- luaL_argcheck(L, 0 < w, farg + 1, "width must be positive");
- if (f + w > LUA_NBITS)
- luaL_error(L, "trying to access non-existent bits");
- *width = w;
- return f;
-}
-
-
-static int b_extract (lua_State *L) {
- int w;
- b_uint r = luaL_checkunsigned(L, 1);
- int f = fieldargs(L, 2, &w);
- r = (r >> f) & mask(w);
- lua_pushunsigned(L, r);
- return 1;
-}
-
-
-static int b_replace (lua_State *L) {
- int w;
- b_uint r = luaL_checkunsigned(L, 1);
- b_uint v = luaL_checkunsigned(L, 2);
- int f = fieldargs(L, 3, &w);
- int m = mask(w);
- v &= m; /* erase bits outside given width */
- r = (r & ~(m << f)) | (v << f);
- lua_pushunsigned(L, r);
- return 1;
-}
+#define LOGICAL_SHIFT(name, op) \
+ static int bit_ ## name(lua_State *L) { \
+ lua_Number f; \
+ lua_pushinteger(L, BIT_TRUNCATE(BIT_TRUNCATE((lua_UInteger)TOBIT(L, 1, f)) op \
+ (unsigned)luaL_checknumber(L, 2))); \
+ return 1; \
+ }
+#define ARITHMETIC_SHIFT(name, op) \
+ static int bit_ ## name(lua_State *L) { \
+ lua_Number f; \
+ lua_pushinteger(L, BIT_TRUNCATE((lua_Integer)TOBIT(L, 1, f) op \
+ (unsigned)luaL_checknumber(L, 2))); \
+ return 1; \
+ }
-static const luaL_Reg bitlib[] = {
- {"arshift", b_arshift},
- {"band", b_and},
- {"bnot", b_not},
- {"bor", b_or},
- {"bxor", b_xor},
- {"btest", b_test},
- {"extract", b_extract},
- {"lrotate", b_lrot},
- {"lshift", b_lshift},
- {"replace", b_replace},
- {"rrotate", b_rrot},
- {"rshift", b_rshift},
+MONADIC(bnot, ~)
+VARIADIC(band, &=)
+VARIADIC(bor, |=)
+VARIADIC(bxor, ^=)
+ARITHMETIC_SHIFT(lshift, <<)
+LOGICAL_SHIFT(rshift, >>)
+ARITHMETIC_SHIFT(arshift, >>)
+
+static const struct luaL_reg bitlib[] = {
+ {"bnot", bit_bnot},
+ {"band", bit_band},
+ {"bor", bit_bor},
+ {"bxor", bit_bxor},
+ {"lshift", bit_lshift},
+ {"rshift", bit_rshift},
+ {"arshift", bit_arshift},
{NULL, NULL}
};
-
-
-LUAMOD_API int luaopen_bit32 (lua_State *L) {
- luaL_newlib(L, bitlib);
+LUALIB_API int luaopen_bit (lua_State *L) {
+ luaL_register(L, "bit", bitlib);
+ lua_pushnumber(L, BIT_BITS);
+ lua_setfield(L, -2, "bits");
return 1;
}
-
generated by cgit v1.1 at 2026-04-25 15:39:08 +0000