2012-07-03 128 views
0

我试图在Linux中创建一个共享库我在尝试编译这个当出现以下错误时是什么-fPIC平均:编译共享库

relocation R_X86_64_32S against `.rodata' can not be used when making a shared object; recompile with -fPIC 

如果我删除的内容GetCrc16有用。我究竟做错了什么 ?

/* 
* main.c 
* 
* Created on: Jul 3, 2012 
*  Author: opc0de 
*/ 


#include <sys/types.h> 
#include <sys/stat.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <fcntl.h> 
#include <netinet/in.h> 
#include <resolv.h> 
#include <sys/socket.h> 
#include <arpa/inet.h> 
#include <pthread.h> 
#include <errno.h> 
#include <unistd.h> 
#include <syslog.h> 
#include <string.h> 
#include <mysql/mysql.h> 
#include <arpa/inet.h> 
#include <curl/curl.h> 

typedef struct param 
{ 
    int * csock; 
    char * IMEI; 
}param; 

#define DAEMON_NAME "MEGA_TRACKER" 


static const unsigned short crctab16[] = 
{ 
0X0000, 0X1189, 0X2312, 0X329B, 0X4624, 0X57AD, 0X6536, 0X74BF, 
0X8C48, 0X9DC1, 0XAF5A, 0XBED3, 0XCA6C, 0XDBE5, 0XE97E, 0XF8F7, 
0X1081, 0X0108, 0X3393, 0X221A, 0X56A5, 0X472C, 0X75B7, 0X643E, 
0X9CC9, 0X8D40, 0XBFDB, 0XAE52, 0XDAED, 0XCB64, 0XF9FF, 0XE876, 
0X2102, 0X308B, 0X0210, 0X1399, 0X6726, 0X76AF, 0X4434, 0X55BD, 
0XAD4A, 0XBCC3, 0X8E58, 0X9FD1, 0XEB6E, 0XFAE7, 0XC87C, 0XD9F5, 
0X3183, 0X200A, 0X1291, 0X0318, 0X77A7, 0X662E, 0X54B5, 0X453C, 
0XBDCB, 0XAC42, 0X9ED9, 0X8F50, 0XFBEF, 0XEA66, 0XD8FD, 0XC974, 
0X4204, 0X538D, 0X6116, 0X709F, 0X0420, 0X15A9, 0X2732, 0X36BB, 
0XCE4C, 0XDFC5, 0XED5E, 0XFCD7, 0X8868, 0X99E1, 0XAB7A, 0XBAF3, 
0X5285, 0X430C, 0X7197, 0X601E, 0X14A1, 0X0528, 0X37B3, 0X263A, 
0XDECD, 0XCF44, 0XFDDF, 0XEC56, 0X98E9, 0X8960, 0XBBFB, 0XAA72, 
0X6306, 0X728F, 0X4014, 0X519D, 0X2522, 0X34AB, 0X0630, 0X17B9, 
0XEF4E, 0XFEC7, 0XCC5C, 0XDDD5, 0XA96A, 0XB8E3, 0X8A78, 0X9BF1, 
0X7387, 0X620E, 0X5095, 0X411C, 0X35A3, 0X242A, 0X16B1, 0X0738, 
0XFFCF, 0XEE46, 0XDCDD, 0XCD54, 0XB9EB, 0XA862, 0X9AF9, 0X8B70, 
0X8408, 0X9581, 0XA71A, 0XB693, 0XC22C, 0XD3A5, 0XE13E, 0XF0B7, 
0X0840, 0X19C9, 0X2B52, 0X3ADB, 0X4E64, 0X5FED, 0X6D76, 0X7CFF, 
0X9489, 0X8500, 0XB79B, 0XA612, 0XD2AD, 0XC324, 0XF1BF, 0XE036, 
0X18C1, 0X0948, 0X3BD3, 0X2A5A, 0X5EE5, 0X4F6C, 0X7DF7, 0X6C7E, 
0XA50A, 0XB483, 0X8618, 0X9791, 0XE32E, 0XF2A7, 0XC03C, 0XD1B5, 
0X2942, 0X38CB, 0X0A50, 0X1BD9, 0X6F66, 0X7EEF, 0X4C74, 0X5DFD, 
0XB58B, 0XA402, 0X9699, 0X8710, 0XF3AF, 0XE226, 0XD0BD, 0XC134, 
0X39C3, 0X284A, 0X1AD1, 0X0B58, 0X7FE7, 0X6E6E, 0X5CF5, 0X4D7C, 
0XC60C, 0XD785, 0XE51E, 0XF497, 0X8028, 0X91A1, 0XA33A, 0XB2B3, 
0X4A44, 0X5BCD, 0X6956, 0X78DF, 0X0C60, 0X1DE9, 0X2F72, 0X3EFB, 
0XD68D, 0XC704, 0XF59F, 0XE416, 0X90A9, 0X8120, 0XB3BB, 0XA232, 
0X5AC5, 0X4B4C, 0X79D7, 0X685E, 0X1CE1, 0X0D68, 0X3FF3, 0X2E7A, 
0XE70E, 0XF687, 0XC41C, 0XD595, 0XA12A, 0XB0A3, 0X8238, 0X93B1, 
0X6B46, 0X7ACF, 0X4854, 0X59DD, 0X2D62, 0X3CEB, 0X0E70, 0X1FF9, 
0XF78F, 0XE606, 0XD49D, 0XC514, 0XB1AB, 0XA022, 0X92B9, 0X8330, 
0X7BC7, 0X6A4E, 0X58D5, 0X495C, 0X3DE3, 0X2C6A, 0X1EF1, 0X0F78, 
}; 

unsigned char response[] = { 0x78, 0x78, 0x05 , 0x00 ,0x00, 0x00, 0x00, 0x00,0x0D, 0x0A}; 
char Hexars[] = {'0', '1', '2', '3', '4', '5','6', '7', '8', '9', 'a', 'b','c', 'd', 'e', 'f' }; 



unsigned short GetCrc16(const unsigned char* pData, int nLength) 
{ 
unsigned short fcs = 0xffff; // initialize 
while(nLength>0){ 
fcs = (fcs >> 8)^crctab16[(fcs^*pData) & 0xff]; 
nLength--; 
pData++; 
} 
return ~fcs; 
} 
+0

“创建共享目标的时候......能不能使用; **与-fPIC编译**” – Mat

+0

@Mat你能更具体的我是新来的linux.I会尝试用-fPIC重新编译,但为什么? – opc0de

+0

你需要用'-fPIC'标志重新编译你的代码。 – Mat

回答

4

-fPIC指示编译器将您的代码编译为位置独立代码。这是必要的,以便机器代码正确执行而不管绝对地址如何。

这些主要是所需的共享库,因为相同的库代码可以在每个程序的地址空间中的位置,它不会与存储器的其它用途重叠加载等

以下链接可以提供更多的信息。

百科:http://en.wikipedia.org/wiki/Position_independent_code
SO:Why isn't all code compiled position independent?

1

命令行选项-fPIC表示使位置无关的代码。当为64位编译共享对象(.so)时,这是必需的。你可以在32位上不使用它;即使它被推荐。