c++ - 如何解决 libmysqlclient_r.so 符号引用链接错误？

Question

以下是 make 链接输出。它显示符号引用错误，即使我已经提供了 libmysqlclient_r.so 的路径

如果我将它链接到 libmysqlclient.so 那么它工作正常。但由于我的程序使用多线程，我想链接libmysqlclient_r.so

g++ -L/usr/local/lib -L/lib/64 -L/opt/mysql/mysql/lib -L../../dependencies/glog/lib -L../../dependencies/libevent/lib -L../../dependencies/json/jsoncpp/lib -ljson-gcc-3.4.3_libmt -levent -lglog -lz -lmysqlclient_r -lpthread -lnsl -lumem -lmysys -lmystrings -o ../../dbprocess/bin/dbprocess dbprocess.o sessionlookupcsidrequest.o sessionlookupipv4request.o ../dbframework/connectionpool.o ../dbframework/connectionproxy.o ../dbframework/dbconnection.o  ../framework/rpcmethod.o ../framework/rpcmethoddispatcher.o ../framework/rpcmethodfactory.o ../framework/jsonmethod.o ../framework/libeventmethoddispatcher.o ../framework/tobject.o ../framework/acceptor.o ../framework/configuefile.o ../framework/connmethoddata.o

Undefined                       first referenced
symbol                             in file
mysql_error                         ../dbframework/dbconnection.o
mysql_close                         ../dbframework/dbconnection.o
mysql_stmt_store_result             sessionlookupcsidrequest.o
mysql_stmt_close                    ../dbframework/dbconnection.o
mysql_stmt_fetch                    sessionlookupcsidrequest.o
mysql_stmt_error                    sessionlookupcsidrequest.o
mysql_options                       ../dbframework/dbconnection.o
mysql_stmt_free_result              sessionlookupcsidrequest.o
mysql_stmt_bind_result              sessionlookupcsidrequest.o
mysql_stmt_num_rows                 sessionlookupcsidrequest.o
mysql_stmt_prepare                  ../dbframework/dbconnection.o
mysql_ping                          ../dbframework/dbconnection.o
mysql_init                          ../dbframework/dbconnection.o
mysql_stmt_bind_param               sessionlookupcsidrequest.o
mysql_real_connect                  ../dbframework/dbconnection.o
mysql_stmt_execute                  sessionlookupcsidrequest.o
mysql_stmt_init                     ../dbframework/dbconnection.o
ld: fatal: Symbol referencing errors. No output written to ../../dbprocess/bin/dbprocess
collect2: ld returned 1 exit status
make: *** [../../dbprocess/bin/dbprocess] Error 1

下面是make文件

CPP = g++
LD = $(CPP)
OBJS = dbprocess.o sessionlookupcsidrequest.o sessionlookupipv4request.o ../dbframework/connectionpool.o ../dbframework/connectionproxy.o ../dbframework/dbconnection.o  ../framework/rpcmethod.o ../framework/rpcmethoddispatcher.o ../framework/rpcmethodfactory.o ../framework/jsonmethod.o ../framework/libeventmethoddispatcher.o ../framework/tobject.o ../framework/acceptor.o ../framework/configuefile.o ../framework/connmethoddata.o
CPPFLAGS = -g $(INCFLAGS) -c -Wall -pthreads
LDFLAGS = -L/usr/local/lib -L/lib/64 -L/opt/mysql/mysql/lib/ -L../../dependencies/mysql/lib/solaris -L../../dependencies/glog/lib -L../../dependencies/libevent/lib -L../../dependencies/json/jsoncpp/lib -ljson-gcc-3.4.3_libmt -levent -lglog -lz -lmysqlclient_r -lpthread -lnsl -lumem -lmysys -lmystrings
LIB = ../../dbprocess/bin/dbprocess
INCFLAGS = -I../includes -I/opt/mysql/mysql/include -I../../dependencies/glog/include -I../../dependencies/json/jsoncpp/include -I../../dependencies/libevent/include

all : $(LIB)

$(LIB) : $(OBJS)
$(LD) $(LDFLAGS) -o $(LIB) $(OBJS)

%.o: ../%.cpp
$(CPP) $(CPPFLAGS) $<

clean : 
rm -r -f $(LIB) $(OBJS)

尝试使用不同的标志，但仍然没有变化。请推荐

Answer 1

您的问题可能是您将对象和库传递给 ld (或通过 g++ 的 ld)的顺序很重要，并且您在依赖它的对象文件之前指定-lmysqlclient_r。您应该尝试将所有 -l 参数移至 *.o 之后的行尾，即将 makefile 步骤更改为

(取两点 - 实际上是 Mat 的评论观点:您已将库链接放入 LDFLAGS 变量中)

$(LIB) : $(OBJS)
$(LD) -o $(OBJS) $(LIB) $(LDFLAGS)