Question

我找不到谷歌的直接答案，因为我很长一段时间都没有在Linux上做过什么希望在这里找到帮助。在构建共享对象时，我在Ubuntu上遇到链接错误。链接器告诉我应该使用-fPIC重新编译，即使我为所有源文件设置了-fPIC。 make的输出：

mkdir -p ../_Bin/Debug/HttpClientApi
g++ -fPIC -pedantic -Wall -Wextra -std=c++11 -c CentralServerClient.cpp -o ../_Bin/Debug/HttpClientApi/CentralServerClient.o
CentralServerClient.cpp:4:80: warning: unused parameter ‘pEventListener’ [-Wunused-parameter]
 void CCentralServerClient::AddEventListener(ICentralServerClientEventListener* pEventListener)
                                                                            ^
CentralServerClient.cpp:29:83: warning: unused parameter ‘pEventListener’ [-Wunused-parameter]
 void CCentralServerClient::RemoveEventListener(ICentralServerClientEventListener* pEventListener)
                                                                               ^
g++ -fPIC -pedantic -Wall -Wextra -std=c++11 -c HttpRequest.cpp -o ../_Bin/Debug/HttpClientApi/HttpRequest.o
g++ -fPIC -pedantic -Wall -Wextra -std=c++11 -c HttpResponse.cpp -o ../_Bin/Debug/HttpClientApi/HttpResponse.o
g++ -fPIC -pedantic -Wall -Wextra -std=c++11 -c IOService.cpp -o ../_Bin/Debug/HttpClientApi/IOService.o
g++ -Wl,-shared -Wl,-v -Wl,-g -o ../_Bin/Debug/HttpClientApi.so ../_Bin/Debug/HttpClientApi/CentralServerClient.o ../_Bin/Debug/HttpClientApi/HttpRequest.o ../_Bin/Debug/HttpClientApi/HttpResponse.o ../_Bin/Debug/HttpClientApi/IOService.o
collect2 version 4.9.2
/usr/bin/ld -plugin /usr/lib/gcc/x86_64-linux-gnu/4.9/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper -plugin-opt=-fresolution=/tmp/ccZ9RMHe.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro -o ../_Bin/Debug/HttpClientApi.so /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.9/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/4.9 -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.9/../../.. -shared -v -g ../_Bin/Debug/HttpClientApi/CentralServerClient.o ../_Bin/Debug/HttpClientApi/HttpRequest.o ../_Bin/Debug/HttpClientApi/HttpResponse.o ../_Bin/Debug/HttpClientApi/IOService.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/4.9/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crtn.o
GNU ld (GNU Binutils for Ubuntu) 2.25
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crt1.o: relocation R_X86_64_32S against `__libc_csu_fini' can not be used when making a shared object; recompile with -fPIC
/usr/lib/gcc/x86_64-linux-gnu/4.9/../../../x86_64-linux-gnu/crt1.o: error adding symbols: Bad value
collect2: error: ld returned 1 exit status
Makefile:15: recipe for target '../_Bin/Debug/HttpClientApi.so' failed
make: *** [../_Bin/Debug/HttpClientApi.so] Error 1

gcc是gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu13)

感谢任何帮助。

Answer 1

而不是给予g ++ -Wl,-shared，你应该给它-shared。原因是g ++需要知道使用哪个crt1.o - 一个适合共享库（使用-fPIC编译，scrt1.o）或一个不适合的。

当你向g ++提供-shared时，它知道使用scrt1.o。但是当你传递`-Wl，-shared'时，g ++不知道你正在构建共享库 - 它'思考'，你正在构建一个普通的可执行文件（链接器确实知道发生了什么）并要求链接器与crt1链接的.o。链接器拒绝，你有错误。

即使所有源都使用-fPIC

1 个答案: