Bug Summary

File:deps/lua/src/lua_bit.c
Warning:line 117, column 1
The result of the right shift is undefined due to shifting by '32', which is greater or equal to the width of type 'UBits'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name lua_bit.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mthread-model posix -mframe-pointer=none -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D LUA_ANSI -D ENABLE_CJSON_GLOBAL -D REDIS_STATIC= -D LUA_USE_MKSTEMP -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir /home/netto/Desktop/redis-6.2.1/deps/lua/src -ferror-limit 19 -fmessage-length 0 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -o /tmp/scan-build-2021-03-14-133648-8817-1 -x c lua_bit.c
1/*
2** Lua BitOp -- a bit operations library for Lua 5.1/5.2.
3** http://bitop.luajit.org/
4**
5** Copyright (C) 2008-2012 Mike Pall. All rights reserved.
6**
7** Permission is hereby granted, free of charge, to any person obtaining
8** a copy of this software and associated documentation files (the
9** "Software"), to deal in the Software without restriction, including
10** without limitation the rights to use, copy, modify, merge, publish,
11** distribute, sublicense, and/or sell copies of the Software, and to
12** permit persons to whom the Software is furnished to do so, subject to
13** the following conditions:
14**
15** The above copyright notice and this permission notice shall be
16** included in all copies or substantial portions of the Software.
17**
18** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
22** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25**
26** [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
27*/
28
29#define LUA_BITOP_VERSION"1.0.2" "1.0.2"
30
31#define LUA_LIB
32#include "lua.h"
33#include "lauxlib.h"
34
35#ifdef _MSC_VER
36/* MSVC is stuck in the last century and doesn't have C99's stdint.h. */
37typedef __int32 int32_t;
38typedef unsigned __int32 uint32_t;
39typedef unsigned __int64 uint64_t;
40#else
41#include <stdint.h>
42#endif
43
44typedef int32_t SBits;
45typedef uint32_t UBits;
46
47typedef union {
48 lua_Number n;
49#ifdef LUA_NUMBER_DOUBLE
50 uint64_t b;
51#else
52 UBits b;
53#endif
54} BitNum;
55
56/* Convert argument to bit type. */
57static UBits barg(lua_State *L, int idx)
58{
59 BitNum bn;
60 UBits b;
61#if LUA_VERSION_NUM501 < 502
62 bn.n = lua_tonumber(L, idx);
63#else
64 bn.n = luaL_checknumber(L, idx);
65#endif
66#if defined(LUA_NUMBER_DOUBLE)
67 bn.n += 6755399441055744.0; /* 2^52+2^51 */
68#ifdef SWAPPED_DOUBLE
69 b = (UBits)(bn.b >> 32);
70#else
71 b = (UBits)bn.b;
72#endif
73#elif defined(LUA_NUMBER_INT) || defined(LUA_NUMBER_LONG) || \
74 defined(LUA_NUMBER_LONGLONG) || defined(LUA_NUMBER_LONG_LONG) || \
75 defined(LUA_NUMBER_LLONG)
76 if (sizeof(UBits) == sizeof(lua_Number))
77 b = bn.b;
78 else
79 b = (UBits)(SBits)bn.n;
80#elif defined(LUA_NUMBER_FLOAT)
81#error "A 'float' lua_Number type is incompatible with this library"
82#else
83#error "Unknown number type, check LUA_NUMBER_* in luaconf.h"
84#endif
85#if LUA_VERSION_NUM501 < 502
86 if (b == 0 && !lua_isnumber(L, idx)) {
87 luaL_typerror(L, idx, "number");
88 }
89#endif
90 return b;
91}
92
93/* Return bit type. */
94#define BRET(b)lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1; lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1;
95
96static int bit_tobit(lua_State *L) { BRET(barg(L, 1))lua_pushnumber(L, (lua_Number)(SBits)(barg(L, 1))); return 1; }
97static int bit_bnot(lua_State *L) { BRET(~barg(L, 1))lua_pushnumber(L, (lua_Number)(SBits)(~barg(L, 1))); return 1
; }
98
99#define BIT_OP(func, opr)static int func(lua_State *L) { int i; UBits b = barg(L, 1); for
(i = lua_gettop(L); i > 1; i--) b opr barg(L, i); lua_pushnumber
(L, (lua_Number)(SBits)(b)); return 1; } \
100 static int func(lua_State *L) { int i; UBits b = barg(L, 1); \
101 for (i = lua_gettop(L); i > 1; i--) b opr barg(L, i); BRET(b)lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1; }
102BIT_OP(bit_band, &=)static int bit_band(lua_State *L) { int i; UBits b = barg(L, 1
); for (i = lua_gettop(L); i > 1; i--) b &= barg(L, i)
; lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1; }
103BIT_OP(bit_bor, |=)static int bit_bor(lua_State *L) { int i; UBits b = barg(L, 1
); for (i = lua_gettop(L); i > 1; i--) b |= barg(L, i); lua_pushnumber
(L, (lua_Number)(SBits)(b)); return 1; }
104BIT_OP(bit_bxor, ^=)static int bit_bxor(lua_State *L) { int i; UBits b = barg(L, 1
); for (i = lua_gettop(L); i > 1; i--) b ^= barg(L, i); lua_pushnumber
(L, (lua_Number)(SBits)(b)); return 1; }
105
106#define bshl(b, n)(b << n) (b << n)
107#define bshr(b, n)(b >> n) (b >> n)
108#define bsar(b, n)((SBits)b >> n) ((SBits)b >> n)
109#define brol(b, n)((b << n) | (b >> (32-n))) ((b << n) | (b >> (32-n)))
110#define bror(b, n)((b << (32-n)) | (b >> n)) ((b << (32-n)) | (b >> n))
111#define BIT_SH(func, fn)static int func(lua_State *L) { UBits b = barg(L, 1); UBits n
= barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits)
(fn(b, n))); return 1; } \
112 static int func(lua_State *L) { \
113 UBits b = barg(L, 1); UBits n = barg(L, 2) & 31; BRET(fn(b, n))lua_pushnumber(L, (lua_Number)(SBits)(fn(b, n))); return 1; }
114BIT_SH(bit_lshift, bshl)static int bit_lshift(lua_State *L) { UBits b = barg(L, 1); UBits
n = barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits
)((b << n))); return 1; }
115BIT_SH(bit_rshift, bshr)static int bit_rshift(lua_State *L) { UBits b = barg(L, 1); UBits
n = barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits
)((b >> n))); return 1; }
116BIT_SH(bit_arshift, bsar)static int bit_arshift(lua_State *L) { UBits b = barg(L, 1); UBits
n = barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits
)(((SBits)b >> n))); return 1; }
117BIT_SH(bit_rol, brol)static int bit_rol(lua_State *L) { UBits b = barg(L, 1); UBits
n = barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits
)(((b << n) | (b >> (32-n))))); return 1; }
The result of the right shift is undefined due to shifting by '32', which is greater or equal to the width of type 'UBits'
118BIT_SH(bit_ror, bror)static int bit_ror(lua_State *L) { UBits b = barg(L, 1); UBits
n = barg(L, 2) & 31; lua_pushnumber(L, (lua_Number)(SBits
)(((b << (32-n)) | (b >> n)))); return 1; }
119
120static int bit_bswap(lua_State *L)
121{
122 UBits b = barg(L, 1);
123 b = (b >> 24) | ((b >> 8) & 0xff00) | ((b & 0xff00) << 8) | (b << 24);
124 BRET(b)lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1;
125}
126
127static int bit_tohex(lua_State *L)
128{
129 UBits b = barg(L, 1);
130 SBits n = lua_isnone(L, 2)(lua_type(L, (2)) == (-1)) ? 8 : (SBits)barg(L, 2);
131 const char *hexdigits = "0123456789abcdef";
132 char buf[8];
133 int i;
134 if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
135 if (n > 8) n = 8;
136 for (i = (int)n; --i >= 0; ) { buf[i] = hexdigits[b & 15]; b >>= 4; }
137 lua_pushlstring(L, buf, (size_t)n);
138 return 1;
139}
140
141static const struct luaL_Reg bit_funcs[] = {
142 { "tobit", bit_tobit },
143 { "bnot", bit_bnot },
144 { "band", bit_band },
145 { "bor", bit_bor },
146 { "bxor", bit_bxor },
147 { "lshift", bit_lshift },
148 { "rshift", bit_rshift },
149 { "arshift", bit_arshift },
150 { "rol", bit_rol },
151 { "ror", bit_ror },
152 { "bswap", bit_bswap },
153 { "tohex", bit_tohex },
154 { NULL((void*)0), NULL((void*)0) }
155};
156
157/* Signed right-shifts are implementation-defined per C89/C99.
158** But the de facto standard are arithmetic right-shifts on two's
159** complement CPUs. This behaviour is required here, so test for it.
160*/
161#define BAD_SAR(((SBits)-8 >> 2) != (SBits)-2) (bsar(-8, 2)((SBits)-8 >> 2) != (SBits)-2)
162
163LUALIB_APIextern int luaopen_bit(lua_State *L)
164{
165 UBits b;
166 lua_pushnumber(L, (lua_Number)1437217655L);
167 b = barg(L, -1);
168 if (b != (UBits)1437217655L || BAD_SAR(((SBits)-8 >> 2) != (SBits)-2)) { /* Perform a simple self-test. */
169 const char *msg = "compiled with incompatible luaconf.h";
170#ifdef LUA_NUMBER_DOUBLE
171#ifdef _WIN32
172 if (b == (UBits)1610612736L)
173 msg = "use D3DCREATE_FPU_PRESERVE with DirectX";
174#endif
175 if (b == (UBits)1127743488L)
176 msg = "not compiled with SWAPPED_DOUBLE";
177#endif
178 if (BAD_SAR(((SBits)-8 >> 2) != (SBits)-2))
179 msg = "arithmetic right-shift broken";
180 luaL_error(L, "bit library self-test failed (%s)", msg);
181 }
182#if LUA_VERSION_NUM501 < 502
183 luaL_register(L, "bit", bit_funcs);
184#else
185 luaL_newlib(L, bit_funcs);
186#endif
187 return 1;
188}
189