arduino compile issue,really not know what's

Projects Programming
1

i have successfully finished a project,the sketch compiled ok,let's call it project A, HEX size is about 34KB.
base on project A,i made another project B, actully i delete most functions compare to A,but compile problems appear,such as:
TestLib\sysdrv.cpp.o: In function __static_initialization_and_destruction_0': D:\arduino\arduino-1.0.6\libraries\TestLib/sysdrv.cpp:51: undefined reference to TinyGPS::TinyGPS()'
D:\arduino\arduino-1.0.6\libraries\TestLib/sysdrv.cpp:52: undefined reference to SoftwareSerial::SoftwareSerial(unsigned char, unsigned char, bool)' D:\arduino\arduino-1.0.6\libraries\TestLib/sysdrv.cpp:53: undefined reference to SoftwareSerial::~SoftwareSerial()'
TestLib\sysdrv.cpp.o: In function sysDrvLib::board_init()': D:\arduino\arduino-1.0.6\libraries\TestLib/sysdrv.cpp:616: undefined reference to SoftwareSerial::begin(long)'
TestLib\sysdrv.cpp.o: In function sysDrvLib::processing_udp_data()': D:\arduino\arduino-1.0.6\libraries\TestLib/sysdrv.cpp:76: undefined reference to encode_cmd(char*)'

what's the problem??

2

Most of the problems appear to be associated with libraries and functions, or the lack of them in the correct location.

Mind you, without actually seeing the code it is hard to say.......