Squashed 'vendor/compat53/' changes from daebe77..7b783fb

7b783fb Fix repository name in rockspec
7e2b0b5 Add bit32 library
931652a Make it usable on Lua 5.4
a1735f6 Update backports to Lua 5.3.5 versions
01a43c0 Fix feature detection for strerror_r
71293f7 Fix structure initialization in compat53 lua_load
73fb49f Make test C module compile as C++ again.
d7f9021 Link to `lua_getextraspace` quirks in README.md.
45ae6fe Improve `lua_getextraspace` tests.
c325be4 Add an implementation of `lua_getextraspace()`.
3c76f8f Add rockspec for v0.7 release.

git-subtree-dir: vendor/compat53
git-subtree-split: 7b783fb8efac60de8be91522d5731a9716e83d56

1 files changed, 233 insertions, 0 deletions

diff --git a/lbitlib.c b/lbitlib.c
new file mode 100644
index 0000000..4786c0d
--- /dev/null
+++ b/lbitlib.c
@@ -0,0 +1,233 @@
+/*
+** $Id: lbitlib.c,v 1.30.1.1 2017/04/19 17:20:42 roberto Exp $
+** Standard library for bitwise operations
+** See Copyright Notice in lua.h
+*/
+
+#define lbitlib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+#if defined(LUA_COMPAT_BITLIB)		/* { */
+
+
+#define pushunsigned(L,n)	lua_pushinteger(L, (lua_Integer)(n))
+#define checkunsigned(L,i)	((lua_Unsigned)luaL_checkinteger(L,i))
+
+
+/* number of bits to consider in a number */
+#if !defined(LUA_NBITS)
+#define LUA_NBITS	32
+#endif
+
+
+/*
+** a lua_Unsigned with its first LUA_NBITS bits equal to 1. (Shift must
+** be made in two parts to avoid problems when LUA_NBITS is equal to the
+** number of bits in a lua_Unsigned.)
+*/
+#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)))
+
+
+
+static lua_Unsigned andaux (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = ~(lua_Unsigned)0;
+  for (i = 1; i <= n; i++)
+    r &= checkunsigned(L, i);
+  return trim(r);
+}
+
+
+static int b_and (lua_State *L) {
+  lua_Unsigned r = andaux(L);
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_test (lua_State *L) {
+  lua_Unsigned r = andaux(L);
+  lua_pushboolean(L, r != 0);
+  return 1;
+}
+
+
+static int b_or (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = 0;
+  for (i = 1; i <= n; i++)
+    r |= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_xor (lua_State *L) {
+  int i, n = lua_gettop(L);
+  lua_Unsigned r = 0;
+  for (i = 1; i <= n; i++)
+    r ^= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_not (lua_State *L) {
+  lua_Unsigned r = ~checkunsigned(L, 1);
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_shift (lua_State *L, lua_Unsigned r, lua_Integer 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);
+  }
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_lshift (lua_State *L) {
+  return b_shift(L, checkunsigned(L, 1), luaL_checkinteger(L, 2));
+}
+
+
+static int b_rshift (lua_State *L) {
+  return b_shift(L, checkunsigned(L, 1), -luaL_checkinteger(L, 2));
+}
+
+
+static int b_arshift (lua_State *L) {
+  lua_Unsigned r = checkunsigned(L, 1);
+  lua_Integer i = luaL_checkinteger(L, 2);
+  if (i < 0 || !(r & ((lua_Unsigned)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) | ~(trim(~(lua_Unsigned)0) >> i));  /* add signal bit */
+    pushunsigned(L, r);
+    return 1;
+  }
+}
+
+
+static int b_rot (lua_State *L, lua_Integer d) {
+  lua_Unsigned r = checkunsigned(L, 1);
+  int i = d & (LUA_NBITS - 1);  /* i = d % NBITS */
+  r = trim(r);
+  if (i != 0)  /* avoid undefined shift of LUA_NBITS when i == 0 */
+    r = (r << i) | (r >> (LUA_NBITS - i));
+  pushunsigned(L, trim(r));
+  return 1;
+}
+
+
+static int b_lrot (lua_State *L) {
+  return b_rot(L, luaL_checkinteger(L, 2));
+}
+
+
+static int b_rrot (lua_State *L) {
+  return b_rot(L, -luaL_checkinteger(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) {
+  lua_Integer f = luaL_checkinteger(L, farg);
+  lua_Integer w = luaL_optinteger(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 = (int)w;
+  return (int)f;
+}
+
+
+static int b_extract (lua_State *L) {
+  int w;
+  lua_Unsigned r = trim(checkunsigned(L, 1));
+  int f = fieldargs(L, 2, &w);
+  r = (r >> f) & mask(w);
+  pushunsigned(L, r);
+  return 1;
+}
+
+
+static int b_replace (lua_State *L) {
+  int w;
+  lua_Unsigned r = trim(checkunsigned(L, 1));
+  lua_Unsigned v = trim(checkunsigned(L, 2));
+  int f = fieldargs(L, 3, &w);
+  lua_Unsigned m = mask(w);
+  r = (r & ~(m << f)) | ((v & m) << f);
+  pushunsigned(L, r);
+  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},
+  {NULL, NULL}
+};
+
+
+
+LUAMOD_API int luaopen_bit32 (lua_State *L) {
+  luaL_newlib(L, bitlib);
+  return 1;
+}
+
+
+#else					/* }{ */
+
+
+LUAMOD_API int luaopen_bit32 (lua_State *L) {
+  return luaL_error(L, "library 'bit32' has been deprecated");
+}
+
+#endif					/* } */