lua5.1字节码文件分析
http://www.doc88.com/p-2853755460794.html
其中对lua5.1字节码已做出详细介绍,我这里就不重复了,只讲解一个字节码分析的例子
概要
lua源文件
sample.lua
local a = 0;
local c = 1.1
b = "stringType"
d = false
e = {}
f ={1,2,3}
function HaveParameter(x,y)
end
function NoParameter()
local function NoParameter1()
local m=4
end
function NoParameter2()
local m=5
end
return
end
for i = 1, 10 do
a = a + 2
end
for k,v in pairs(f) do
print(k)
end
编译后的lua文件
luac.out
阅读注意,大小有关的指令从后往前阅读(小端) 比如 01000000代表的是0x00000001
Pos Hex Data Description or Code
----------------------------------------------------------------------
0000 ** source chunk: sample.lua
** global header start **
0000 1B4C7561 header signature: "\27Lua"
0004 51 version (major:minor hex digits)
0005 00 format (0=official)
0006 01 endianness (1=little endian)
0007 04 size of int (bytes)
0008 04 size of size_t (bytes)
0009 04 size of Instruction (bytes)
000A 08 size of number (bytes)
000B 00 integral (1=integral)
* number type: double
* x86 standard (32-bit, little endian, double
** global header end **
000C ** function [0] definition (level 1)
** start of function **
000C 0B000000 string size (11)
0010 73616D706C652E6C+ "sample.l"
0018 756100 "ua\0"
source name: sample.lua
001B 00000000 line defined (0)
001F 00000000 last line defined (0)
0023 00 nups (0)
0024 00 numparams (0)
0025 02 is_vararg (2)
0026 09 maxstacksize (9)
* code:
0027 22000000 sizecode (34)
002B 01000000 [01] loadk 0 0 ; 0
002F 41400000 [02] loadk 1 1 ; 1.1
0033 81C00000 [03] loadk 2 3 ; "stringType"
0037 87800000 [04] setglobal 2 2 ; b
003B 82000000 [05] loadbool 2 0 0 ; false
003F 87000100 [06] setglobal 2 4 ; d
0043 8A000000 [07] newtable 2 0 0 ; array=0, hash=
0047 87400100 [08] setglobal 2 5 ; e
004B 8A008001 [09] newtable 2 3 0 ; array=3, hash=
004F C1C00100 [10] loadk 3 7 ; 1
0053 01010200 [11] loadk 4 8 ; 2
0057 41410200 [12] loadk 5 9 ; 3
005B A2408001 [13] setlist 2 3 1 ; index 1 to 3
005F 87800100 [14] setglobal 2 6 ; f
0063 A4000000 [15] closure 2 0 ; 0 upvalues
0067 87800200 [16] setglobal 2 10 ; HaveParameter
006B A4400000 [17] closure 2 1 ; 0 upvalues
006F 87C00200 [18] setglobal 2 11 ; NoParameter
0073 81C00100 [19] loadk 2 7 ; 1
0077 C1000300 [20] loadk 3 12 ; 10
007B 01C10100 [21] loadk 4 7 ; 1
007F A0000080 [22] forprep 2 1 ; to [24]
0083 0C004200 [23] add 0 0 264 ; 2
0087 9F40FF7F [24] forloop 2 -2 ; to [23] if loo
008B 85400300 [25] getglobal 2 13 ; pairs
008F C5800100 [26] getglobal 3 6 ; f
0093 9C000101 [27] call 2 2 4
0097 16800080 [28] jmp 3 ; to [32]
009B C5810300 [29] getglobal 7 14 ; print
009F 00028002 [30] move 8 5
00A3 DC410001 [31] call 7 2 1
00A7 A1800000 [32] tforloop 2 2 ; to [34] if exi
00AB 1680FE7F [33] jmp -5 ; to [29]
00AF 1E008000 [34] return 0 1
* constants:
00B3 0F000000 sizek (15)
00B7 03 const type 3
00B8 0000000000000000 const [0]: (0)
00C0 03 const type 3
00C1 9A9999999999F13F const [1]: (1.1)
00C9 04 const type 4
00CA 02000000 string size (2)
00CE 6200 "b\0"
const [2]: "b"
00D0 04 const type 4
00D1 0B000000 string size (11)
00D5 737472696E675479+ "stringTy"
00DD 706500 "pe\0"
const [3]: "stringType"
00E0 04 const type 4
00E1 02000000 string size (2)
00E5 6400 "d\0"
const [4]: "d"
00E7 04 const type 4
00E8 02000000 string size (2)
00EC 6500 "e\0"
const [5]: "e"
00EE 04 const type 4
00EF 02000000 string size (2)
00F3 6600 "f\0"
const [6]: "f"
00F5 03 const type 3
00F6 000000000000F03F const [7]: (1)
00FE 03 const type 3
00FF 0000000000000040 const [8]: (2)
0107 03 const type 3
0108 0000000000000840 const [9]: (3)
0110 04 const type 4
0111 0E000000 string size (14)
0115 4861766550617261+ "HavePara"
011D 6D6574657200 "meter\0"
const [10]: "HaveParameter"
0123 04 const type 4
0124 0C000000 string size (12)
0128 4E6F506172616D65+ "NoParame"
0130 74657200 "ter\0"
const [11]: "NoParameter"
0134 03 const type 3
0135 0000000000002440 const [12]: (10)
013D 04 const type 4
013E 06000000 string size (6)
0142 706169727300 "pairs\0"
const [13]: "pairs"
0148 04 const type 4
0149 06000000 string size (6)
014D 7072696E7400 "print\0"
const [14]: "print"
* functions:
0153 02000000 sizep (2)
0157 ** function [0] definition (level 2)
** start of function **
0157 00000000 string size (0)
source name: (none)
015B 08000000 line defined (8)
015F 0A000000 last line defined (10)
0163 00 nups (0)
0164 02 numparams (2)
0165 00 is_vararg (0)
0166 02 maxstacksize (2)
* code:
0167 01000000 sizecode (1)
016B 1E008000 [1] return 0 1
* constants:
016F 00000000 sizek (0)
* functions:
0173 00000000 sizep (0)
* lines:
0177 01000000 sizelineinfo (1)
[pc] (line)
017B 0A000000 [1] (10)
* locals:
017F 02000000 sizelocvars (2)
0183 02000000 string size (2)
0187 7800 "x\0"
local [0]: x
0189 00000000 startpc (0)
018D 00000000 endpc (0)
0191 02000000 string size (2)
0195 7900 "y\0"
local [1]: y
0197 00000000 startpc (0)
019B 00000000 endpc (0)
* upvalues:
019F 00000000 sizeupvalues (0)
** end of function **
01A3 ** function [1] definition (level 2)
** start of function **
01A3 00000000 string size (0)
source name: (none)
01A7 0C000000 line defined (12)
01AB 14000000 last line defined (20)
01AF 00 nups (0)
01B0 00 numparams (0)
01B1 00 is_vararg (0)
01B2 02 maxstacksize (2)
* code:
01B3 05000000 sizecode (5)
01B7 24000000 [1] closure 0 0 ; 0 upvalues
01BB 64400000 [2] closure 1 1 ; 0 upvalues
01BF 47000000 [3] setglobal 1 0 ; NoParameter2
01C3 1E008000 [4] return 0 1
01C7 1E008000 [5] return 0 1
* constants:
01CB 01000000 sizek (1)
01CF 04 const type 4
01D0 0D000000 string size (13)
01D4 4E6F506172616D65+ "NoParame"
01DC 7465723200 "ter2\0"
const [0]: "NoParameter2"
* functions:
01E1 02000000 sizep (2)
01E5 ** function [0] definition (level 3)
** start of function **
01E5 00000000 string size (0)
source name: (none)
01E9 0D000000 line defined (13)
01ED 0F000000 last line defined (15)
01F1 00 nups (0)
01F2 00 numparams (0)
01F3 00 is_vararg (0)
01F4 02 maxstacksize (2)
* code:
01F5 02000000 sizecode (2)
01F9 01000000 [1] loadk 0 0 ; 4
01FD 1E008000 [2] return 0 1
* constants:
0201 01000000 sizek (1)
0205 03 const type 3
0206 0000000000001040 const [0]: (4)
* functions:
020E 00000000 sizep (0)
* lines:
0212 02000000 sizelineinfo (2)
[pc] (line)
0216 0E000000 [1] (14)
021A 0F000000 [2] (15)
* locals:
021E 01000000 sizelocvars (1)
0222 02000000 string size (2)
0226 6D00 "m\0"
local [0]: m
0228 01000000 startpc (1)
022C 01000000 endpc (1)
* upvalues:
0230 00000000 sizeupvalues (0)
** end of function **
0234 ** function [1] definition (level 3)
** start of function **
0234 00000000 string size (0)
source name: (none)
0238 10000000 line defined (16)
023C 12000000 last line defined (18)
0240 00 nups (0)
0241 00 numparams (0)
0242 00 is_vararg (0)
0243 02 maxstacksize (2)
* code:
0244 02000000 sizecode (2)
0248 01000000 [1] loadk 0 0 ; 5
024C 1E008000 [2] return 0 1
* constants:
0250 01000000 sizek (1)
0254 03 const type 3
0255 0000000000001440 const [0]: (5)
* functions:
025D 00000000 sizep (0)
* lines:
0261 02000000 sizelineinfo (2)
[pc] (line)
0265 11000000 [1] (17)
0269 12000000 [2] (18)
* locals:
026D 01000000 sizelocvars (1)
0271 02000000 string size (2)
0275 6D00 "m\0"
local [0]: m
0277 01000000 startpc (1)
027B 01000000 endpc (1)
* upvalues:
027F 00000000 sizeupvalues (0)
** end of function **
* lines:
0283 05000000 sizelineinfo (5)
[pc] (line)
0287 0F000000 [1] (15)
028B 12000000 [2] (18)
028F 10000000 [3] (16)
0293 13000000 [4] (19)
0297 14000000 [5] (20)
* locals:
029B 01000000 sizelocvars (1)
029F 0D000000 string size (13)
02A3 4E6F506172616D65+ "NoParame"
02AB 7465723100 "ter1\0"
local [0]: NoParameter1
02B0 01000000 startpc (1)
02B4 04000000 endpc (4)
* upvalues:
02B8 00000000 sizeupvalues (0)
** end of function **
* lines:
02BC 22000000 sizelineinfo (34)
[pc] (line)
02C0 01000000 [01] (1)
02C4 02000000 [02] (2)
02C8 03000000 [03] (3)
02CC 03000000 [04] (3)
02D0 04000000 [05] (4)
02D4 04000000 [06] (4)
02D8 05000000 [07] (5)
02DC 05000000 [08] (5)
02E0 06000000 [09] (6)
02E4 06000000 [10] (6)
02E8 06000000 [11] (6)
02EC 06000000 [12] (6)
02F0 06000000 [13] (6)
02F4 06000000 [14] (6)
02F8 0A000000 [15] (10)
02FC 08000000 [16] (8)
0300 14000000 [17] (20)
0304 0C000000 [18] (12)
0308 16000000 [19] (22)
030C 16000000 [20] (22)
0310 16000000 [21] (22)
0314 16000000 [22] (22)
0318 17000000 [23] (23)
031C 16000000 [24] (22)
0320 1A000000 [25] (26)
0324 1A000000 [26] (26)
0328 1A000000 [27] (26)
032C 1A000000 [28] (26)
0330 1B000000 [29] (27)
0334 1B000000 [30] (27)
0338 1B000000 [31] (27)
033C 1A000000 [32] (26)
0340 1B000000 [33] (27)
0344 1C000000 [34] (28)
* locals:
0348 0B000000 sizelocvars (11)
034C 02000000 string size (2)
0350 6100 "a\0"
local [0]: a
0352 01000000 startpc (1)
0356 21000000 endpc (33)
035A 02000000 string size (2)
035E 6300 "c\0"
local [1]: c
0360 02000000 startpc (2)
0364 21000000 endpc (33)
0368 0C000000 string size (12)
036C 28666F7220696E64+ "(for ind"
0374 65782900 "ex)\0"
local [2]: (for index)
0378 15000000 startpc (21)
037C 18000000 endpc (24)
0380 0C000000 string size (12)
0384 28666F72206C696D+ "(for lim"
038C 69742900 "it)\0"
local [3]: (for limit)
0390 15000000 startpc (21)
0394 18000000 endpc (24)
0398 0B000000 string size (11)
039C 28666F7220737465+ "(for ste"
03A4 702900 "p)\0"
local [4]: (for step)
03A7 15000000 startpc (21)
03AB 18000000 endpc (24)
03AF 02000000 string size (2)
03B3 6900 "i\0"
local [5]: i
03B5 16000000 startpc (22)
03B9 17000000 endpc (23)
03BD 10000000 string size (16)
03C1 28666F722067656E+ "(for gen"
03C9 657261746F722900 "erator)\0"
local [6]: (for generator)
03D1 1B000000 startpc (27)
03D5 21000000 endpc (33)
03D9 0C000000 string size (12)
03DD 28666F7220737461+ "(for sta"
03E5 74652900 "te)\0"
local [7]: (for state)
03E9 1B000000 startpc (27)
03ED 21000000 endpc (33)
03F1 0E000000 string size (14)
03F5 28666F7220636F6E+ "(for con"
03FD 74726F6C2900 "trol)\0"
local [8]: (for control)
0403 1B000000 startpc (27)
0407 21000000 endpc (33)
040B 02000000 string size (2)
040F 6B00 "k\0"
local [9]: k
0411 1C000000 startpc (28)
0415 1F000000 endpc (31)
0419 02000000 string size (2)
041D 7600 "v\0"
local [10]: v
041F 1C000000 startpc (28)
0423 1F000000 endpc (31)
* upvalues:
0427 00000000 sizeupvalues (0)
** end of function **
042B ** end of chunk **提供一个把32位指令转换为字节码函数
extern "C"
{
#include "lauxlib.h"
#include "lualib.h"
#include "lua.h"
#include "lopcodes.h"
}
#include "stdlib.h"
static void PrintInstruction(Instruction i)
{
OpCode o = GET_OPCODE(i);
int a = GETARG_A(i);
int b = GETARG_B(i);
int c = GETARG_C(i);
int bx = GETARG_Bx(i);
int sbx = GETARG_sBx(i);
//输出操作码对应的名字
printf("%-9s\t", luaP_opnames[o]);
switch (getOpMode(o))
{
//操作码对应的基本指令有3种,enum OpMode {iABC, iABx, iAsBx};
//操作属性 操作寄存器还是常量还是无 enum OpArgMask {OpArgN, OpArgU, OpArgR, OpArgK };
case iABC:
//3个操作数
printf("%d", a);
//常量的话去掉最高位取负减1,用负数来区分寄存器和常量
if (getBMode(o) != OpArgN) printf(" %d", ISK(b) ? (-1 - INDEXK(b)) : b);
if (getCMode(o) != OpArgN) printf(" %d", ISK(c) ? (-1 - INDEXK(c)) : c);
break;
case iABx:
//2个操作数
//常量就直接取负减1,用负数来区分寄存器和常量
if (getBMode(o) == OpArgK) printf("%d %d", a, -1 - bx); else printf("%d %d", a, bx);
break;
case iAsBx:
//带符号的2个操作数,或者只有一个,还有一个操作数可能不用的
if (o == OP_JMP) printf("%d", sbx); else printf("%d %d", a, sbx);
break;
default:
break;
}
printf("\n");
}
//#define BITRK (1 << (8))
/* test whether value is a constant */
/* this bit 1 means constant (0 means register) */
#define ISK(x) ((x) & BITRK)
int main(int argc, char* argv[])
{
//比如LOADK 0 -1,这里生成的和前面LOADK 0 0 不一样是因为表达方式不一样,负数来区分常量表还是注册表,易于阅读
//保持和luac -l -l sample.lua 生成的指令格式一致
Instruction i = 0x00000001;
PrintInstruction(i);
return 0;
}其它阅读笔记,主要参考lopcodes.h ,lopcodes.c,print.c
#define BITRK (1 << (8))
/* test whether value is a constant */
/* this bit 1 means constant (0 means register) */
#define ISK(x) ((x) & BITRK)
1代表常量,最高位为1,常量的话去掉这位,实际8位,寄存器最大255
#define INDEXK(r) ((int)(r) & ~BITRK)1代表常量,最高位为1,常量的话去掉这位,实际8位,寄存器最大255
#define INDEXK(r) ((int)(r) & ~BITRK)
总结:
lua中的常量是直接保存在文件中的,比如字符,数字(整数和浮点数),数字是采用浮点数编码
指令长度为32位,包含操作码和操作数
每个结尾指令后面都会默认添加return 0 1
lua5.2的字节码文件有变化,由于参考资料较少,先用lua5.1做个基础
执行过程主要可参考lcode.c,生成字节码lparser.c解析字节码,lvm.c执行字节码
附录
浮点数计算方式:http://blog.csdn.net/chenyujing1234/article/details/7683635