使用c++,未定义引用std:: Makefile
Using G++, Undefined Reference std:: Makefile
我一直致力于让一个简单的单线程信使服务的服务器/客户端运行。它能够在Visual Studio上编译,但当我试图通过makefile在Linux上编译它时,使用命令:make client
,我得到了一个非常大的错误列表。我将提供开头部分,然后是错误列表:
这里它说它至少在尝试使用g++:
g++ -g -c -o client。阿端。Cc抄送客户端。0 - 0客户端客户端。函数
编辑:我注意到这里有些不寻常。当我再次调用main': /home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:10: undefined reference to
std::allocator::allocator()'make client
而不调用make clean
时,我得到以下结果:peter@peter-VirtualBox:~/Desktop/CS360/Messaging_Service/messenger$ make clientcc客户机。0 - 0客户端客户端。0:在函数
main': /home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:10: undefined reference to
中std::allocator::allocator()'不确定这是否重要,但它没有再次提到g++。
上述错误的代码片段:
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:7: undefined reference to `std::allocator<char>::allocator()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:7: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:7: undefined reference to `std::allocator<char>::~allocator()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:15: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator=(char const*)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:18: undefined reference to `std::cout'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:18: undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:18: undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:18: undefined reference to `std::ostream::operator<<(std::ostream& (*)(std::ostream&))'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:23: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:23: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:7: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:25: undefined reference to `std::allocator<char>::~allocator()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:25: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:7: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
client.o: In function `Client::Client(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, int)':
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:27: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:27: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string()'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:29: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator=(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:32: undefined reference to `operator new[](unsigned long)'
这让我相信我的makefile有一个错误。我使用g++,我相信它也被设置为编译很好,所以我不太确定从这里去哪里。我的Makefile是:
CXX= g++ $(CCFLAGS)
MSG-SERVER= server.o
MSG-CLIENT= client.o
OBJS = $(MSG-SERVER) $(MSG-CLIENT)
LIBS =
CCFLAGS = -g
all: msg-server msg-client
msg-server:$(MSG-SERVER)
$(CXX) -o server $(MSG-SERVER) $(LIBS)
msg-client:$(MSG-CLIENT)
$(CXX) -o client $(MSG-CLIENT) $(LIBS)
clean:
rm -f $(OBJS) $(OBJS:.o=.d)
realclean:
rm -f $(OBJS) $(OBJS:.o=.d) server client
# These lines ensure that dependencies are handled automatically.
%.d: %.cc
$(SHELL) -ec '$(CC) -M $(CPPFLAGS) $<
| sed '''s/($*).o[ :]*/1.o $@ : /g''' > $@;
[ -s $@ ] || rm -f $@'
include $(OBJS:.o=.d)
如果需要,我将链接我的代码以及:https://bitbucket.org/picklepetters/messenger/src/44e4fa12541948215f874b56e4ba0dedea1766f5/client.cc?at=master&fileviewer=file-view-default
当我用make -d
跟踪make时,它给了我大量的数据。我将发布一些给出的片段,因为我真的不知道我在看什么:
Trying implicit prerequisite '/usr/include/c++/5/SCCS/s.stdexcept.F'.
Trying pattern rule with stem 'stdexcept'.
Trying implicit prerequisite '/usr/include/c++/5/stdexcept.r'.
Looking for a rule with intermediate file '/usr/include/c++/5/stdexcept.r'.
Avoiding implicit rule recursion.
Avoiding implicit rule recursion.
Avoiding implicit rule recursion.
Trying pattern rule with stem 'stdexcept'.
Rejecting impossible implicit prerequisite '/usr/include/c++/5/stdexcept.l'.
Trying pattern rule with stem 'stdexcept.r'.
Trying implicit prerequisite '/usr/include/c++/5/stdexcept.r,v'.
Trying pattern rule with stem 'stdexcept.r'.
Trying implicit prerequisite '/usr/include/c++/5/RCS/stdexcept.r,v'.
Trying pattern rule with stem 'stdexcept.r'.
Trying implicit prerequisite '/usr/include/c++/5/RCS/stdexcept.r'.
Trying pattern rule with stem 'stdexcept.r'.
Trying implicit prerequisite '/usr/include/c++/5/s.stdexcept.r'.
Trying pattern rule with stem 'stdexcept.r'.
Trying implicit prerequisite '/usr/include/c++/5/SCCS/s.stdexcept.r'.
Trying pattern rule with stem 'stdexcept'.
Rejecting impossible implicit prerequisite '/usr/include/c++/5/stdexcept.F'.
Trying pattern rule with stem 'stdexcept'.
Trying implicit prerequisite '/usr/include/c++/5/stdexcept.m'.
Looking for a rule with intermediate file '/usr/include/c++/5/stdexcept.m'.
Avoiding implicit rule recursion.
Avoiding implicit rule recursion.
Trying pattern rule with stem 'stdexcept'.
Trying implicit prerequisite '/usr/include/c++/5/stdexcept.ym'.
Trying pattern rule with stem 'stdexcept.m'.
Trying implicit prerequisite '/usr/include/c++/5/stdexcept.m,v'.
Trying pattern rule with stem 'stdexcept.m'.
Trying implicit prerequisite '/usr/include/c++/5/RCS/stdexcept.m,v'.
Trying pattern rule with stem 'stdexcept.m'.
Trying implicit prerequisite '/usr/include/c++/5/RCS/stdexcept.m'.
Trying pattern rule with stem 'stdexcept.m'.
就像这样,直到大约150~行结束时,它说它已经完成了目标文件的先决条件:
Finished prerequisites of target file 'server.d'.
Prerequisite 'server.cc' is older than target 'server.d'.
Prerequisite 'server.cc' is older than target 'server.d'.
Prerequisite '/usr/include/stdc-predef.h' is older than target 'server.d'.
Prerequisite 'server.h' is older than target 'server.d'.
Prerequisite '/usr/include/errno.h' is older than target 'server.d'.
Prerequisite '/usr/include/features.h' is older than target 'server.d'.
Prerequisite '/usr/include/x86_64-linux-gnu/sys/cdefs.h' is older than target 'server.d'.
Prerequisite '/usr/include/x86_64-linux-gnu/bits/wordsize.h' is older than target 'server.d'.
Prerequisite '/usr/include/x86_64-linux-gnu/gnu/stubs.h' is older than target 'server.d'.
Prerequisite '/usr/include/x86_64-linux-gnu/gnu/stubs-64.h' is older than target 'server.d'.
Prerequisite '/usr/include/x86_64-linux-gnu/bits/errno.h' is older than target 'server.d'.
对于最后100行,它声明:
Must remake target 'server.o'.
g++ -g -c -o server.o server.cc
Putting child 0x13601a0 (server.o) PID 7768 on the chain.
Live child 0x13601a0 (server.o) PID 7768
server.cc: In function ‘int main(int, char**)’:
server.cc:19:17: error: ‘cout’ was not declared in this scope
cout << "server [-p port]" << endl;
^
server.cc:19:47: error: ‘endl’ was not declared in this scope
cout << "server [-p port]" << endl;
^
server.cc: In constructor ‘Server::Server(int)’:
server.cc:34:30: error: ‘>>’ should be ‘> >’ within a nested template argument list
map<string, vector<string>> mappedMessages;
^
server.cc: At global scope:
server.cc:121:36: error: ‘String’ has not been declared
Server::handle_message(int client, String message) {
^
server.cc:121:1: error: prototype for ‘void Server::handle_message(int, int)’ does not match any in class ‘Server’
Server::handle_message(int client, String message) {
^
In file included from server.cc:1:0:
server.h:33:12: error: candidate is: std::__cxx11::string Server::handle_message(int, std::__cxx11::string)
string handle_message(int, string);
^
server.cc:127:35: error: ‘String’ has not been declared
Server::parse_message(int client, String message) {
^
server.cc:127:1: error: prototype for ‘std::__cxx11::string Server::parse_message(int, int)’ does not match any in class ‘Server’
Server::parse_message(int client, String message) {
^
In file included from server.cc:1:0:
server.h:34:12: error: candidate is: std::__cxx11::string Server::parse_message(int, std::__cxx11::string)
string parse_message(int, string);
^
server.cc:190:63: error: ISO C++ forbids declaration of ‘store_message’ with no type [-fpermissive]
Server::store_message(string name, string subject, string data) {
^
server.cc:190:1: error: prototype for ‘int Server::store_message(std::__cxx11::string, std::__cxx11::string, std::__cxx11::string)’ does not match any in class ‘Server’
Server::store_message(string name, string subject, string data) {
^
In file included from server.cc:1:0:
server.h:36:10: error: candidate is: void Server::store_message(std::__cxx11::string, std::__cxx11::string, std::__cxx11::string)
void store_message(string, string, string);
^
server.cc: In member function ‘std::__cxx11::string Server::get_subjects(std::__cxx11::string)’:
server.cc:210:5: error: ‘mappedMessages’ was not declared in this scope
if(mappedMessages.find(name) != mappedMessages.empty()) {
^
server.cc:214:15: error: missing template arguments before ‘it’
for(iterator it = mappedMessages.at(name).begin(); it != mappedMessages.at(name).end(); ++it) {
^
server.cc:214:53: error: ‘it’ was not declared in this scope
for(iterator it = mappedMessages.at(name).begin(); it != mappedMessages.at(name).end(); ++it) {
^
server.cc:214:59: error: ‘mappedMessages’ was not declared in this scope
for(iterator it = mappedMessages.at(name).begin(); it != mappedMessages.at(name).end(); ++it) {
^
server.cc:219:29: error: no match for ‘operator+’ (operand types are ‘std::__cxx11::basic_string<char>’ and ‘int’)
response = response + " " + counter + " " + mappedMessages.at(name).it.front() + "n";
问题在于使用
make client
不是make msg-client
由于客户端没有目标,所以默认使用cc,如原问题中第一个黄色框所示
这些undefined reference to 'std::allocator<char>::allocator()'
错误通常意味着没有链接到libstdc++
,最常见的原因是人们链接到gcc
而不是g++
。
依赖生成规则使用$(CC)
而不是$(CXX)
,这就是导致编译器错误的原因。事实上,这条规则在过去的十年里已经没有必要了。你应该做的是:
- 完全删除
%.d
规则和配方。 -
指示编译器在编译
.cc
到.o
时生成依赖项(-MD -MP
)(您的makefile使用内置规则%.o
:%.cc
):%.o : %.cc $(CXX) -c -o $@ -MD -MP ${CPPFLAGS} ${CXXFLAGS} $<
- 将
include $(OBJS:.o=.d)
改为-include $(OBJS:.o=.d)
。
不需要其他任何东西来生成和使用依赖项。详见https://stackoverflow.com/a/32379965/412080
在命令行中添加g++选项[-std=c++11]
- 使用std::multimap迭代器创建std::list
- C++中std::resize(n)和std::shrink_to_fit之间的区别
- 来自 std::list 的迭代器 .end() 按预期返回"0xcdcdcdcdcdcdcdcd"但 .begin()
- C++17复制构造函数,在std::unordereded_map上进行深度复制
- 如何导出包含具有"std::unique_ptr"值的"std::map"属性的
- 从持续时间构造std::chrono::system_clock::time_point
- std::具有相同基类的类的变体
- std::向量与传递值的动态数组
- 使用std::vector的OpenCL矩阵乘法
- std::map<struct,struct>::find 找不到匹配项,但是如果我循环通过 begin() 到 end(),我在那里看到匹配项
- std::condition_variable::wait()如何评估给定的谓词
- 如何获取std::result_of函数的返回类型
- std::原子加载和存储都需要吗
- 将对象移动到std::shared_ptr
- Makefile with -std=c++11
- C++ Makefile g++和"std="标志似乎不起作用
- 如何在 eclipse makefile 项目中的编译器选项中设置 -std=c++0x
- CFLAGS=-std=c++11 -O3 -wall -pedantic在makefile中无法识别
- makefile 不适用于 -std=c++11 选项
- 使用c++,未定义引用std:: Makefile