"undefined reference to" errors while linking

[wlmparker]

hi,
i'm using gcc compilers to migrate a small java app into c++ in cygwin
environment under win32.my classes use the xercesc c++ libraries which
i have built with cygwin on windows.
my c++ source code compiles into .o files but the linker just wont
work.
i am getting lots of "undefined reference to" errors.

williamP@master-77 ~/workspace/splits/asy g++ -L$LIB -lcygxerces-c27 -
lxerces-depdom.dll -osplits.exe Trs_Main.o Trs.o Descriptor.o
Trs.o: In function
`_ZNSt6vectorISsSaISsEE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPSsS1_EERKSs':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
(.text+0x126): undefined reference to `Trs::trs_desc'
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
(.text+0x16d): undefined reference to `Trs::trs_desc'
Trs.o: In function
`_ZN8Trs9splitItemEPN11xercesc_2_711DOMDocumentEPNS0_10DOMElementE':
/cygdrive/c/Documents and Settings/williamP/workspace/splits/asy/Trs.h:
16: undefined reference to `Trs::trs_items'
Trs.o: In function
`_ZN8Trs9splitItemEPN11xercesc_2_711DOMDocumentEPNS0_10DOMElementE':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
255: undefined reference to `Trs::trs_items'
Trs.o: In function `_ZN8TrsC1EPcS0_':
/cygdrive/c/Documents and Settings/williamP/workspace/splits/asy/
Trs.cpp:107: undefined reference to `vtable for Trs'
Trs.o: In function `_ZN8TrsC2EPcS0_':
/cygdrive/c/Documents and Settings/williamP/workspace/splits/asy/
Trs.cpp:107: undefined reference to `vtable for Trs'
Descriptor.o: In function
`_ZN8Descriptor12startElementEPKtRN11xercesc_2_713AttributeListE':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
1459: undefined reference to `Descriptor::mandatoryElements'
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
Descriptor.o: In function `_ZN8Descriptor10endElementEPKt':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
Descriptor.o: In function `_ZN8Descriptor10endElementEPKtS1_S1_':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
Descriptor.o:/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/
basic_string.h:687: more undefined references to
`Descriptor::null_char' follow
Descriptor.o: In function
`_ZN8Descriptor12startElementEPKtS1_S1_RN11xercesc_2_710AttributesE':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
1459: undefined reference to `Descriptor::mandatoryElements'
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
687: undefined reference to `Descriptor::null_char'
Descriptor.o: In function `_ZN8Descriptor10charactersEPKtj':
/bin/../lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/basic_string.h:
1459: undefined reference to `Descriptor::null_char'
Info: resolving xercesc_2_7::XMLUni::fgXercescDefaultLocale       by
linking to __imp___ZN11xercesc_2_76XMLUni22fgXercescDefaultLocaleE
(auto-import)
Info: resolving xercesc_2_7::XMLPlatformUtils::fgMemoryManager
by linking to
__imp___ZN11xercesc_2_716XMLPlatformUtils15fgMemoryManagerE (auto-
import)