我一直致力于让服务器/客户端运行简单的单线程信使服务。它能够在Visual Studio上编译，但是当我尝试使用命令：make client通过makefile在Linux上编译它时，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：
这里说它至少试图使用g ++：
g ++ -g -c -o client.o client.cc cc client.o -o client client.o： 在函数
中 编辑：我发现这里有些异常。当我再次致电main': /home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:10: undefined reference tostd :: allocator :: allocator（）＆＃39;make client而不致电make clean时，我会收到以下信息：peter @ peter-VirtualBox：〜/ Desktop / CS360 / Messaging_Service / messenger $ make client cc client.o -o client client.o：在函数
main': /home/peter/Desktop/CS360/Messaging_Service/messenger/client.cc:10: undefined reference tostd :: allocator :: allocator（）＆＃39; 不确定这是否重要，但它没有再提及g ++。
所述错误的片段：
/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出错了。我使用g ++，我相信它也可以编译得很好，所以我不太清楚从哪里开始。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)
当我使用make -d跟踪制作时，它会为我提供大量数据。我会发布一些所提供内容的片段，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'.
它就像那样，直到它说完它已经完成了目标文件的先决条件的150~行：
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'.
表示最后100行：
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";
答案 0 :(得分：1)
这些undefined reference to 'std::allocator<char>::allocator()'错误通常意味着libstdc++未被关联，最常见的原因是人们与gcc而不是g++相关联。
依赖关系生成规则使用$(CC)而不是$(CXX)，这是导致这些编译器错误的原因。事实上，这条规则已经十年不用了。你应该做的是以下几点：
%.d规则及其配方。在编译-MD -MP到.cc（您的makefile使用the built-in rule %.o : %.cc）时，指示编译器生成依赖项（.o）：
%.o : %.cc
$(CXX) -c -o $@ -MD -MP ${CPPFLAGS} ${CXXFLAGS} $<
include $(OBJS:.o=.d)更改为-include $(OBJS:.o=.d)。生成和使用依赖项不需要任何其他内容。有关详细信息，请参阅https://stackoverflow.com/a/32379965/412080。
答案 1 :(得分：1)
这里的问题是使用
make client
而不是
make msg-client
由于客户端没有目标，因此默认使用cc。这显示在原始问题的第一个黄色框中。
答案 2 :(得分：0)
在你的命令行中为g ++添加选项[-std = c ++ 11]