如何在 C++ 编译中正确链接 xercesc 库？

Question

I am completely new to C++ and am working on a piece of code that will be inserted into a larger program. The piece of code will use the xercesc library to read an XML file. I wrote a very basic main function to test things out. But I cannot get it compiled. Help will be much appreciated.

Test1.cpp

#include <xercesc/dom/DOMNode.hpp>
#include <xercesc/dom/DOMElement.hpp>
#include <xercesc/dom/DOMNodeList.hpp>
#include <xercesc/parsers/XercesDOMParser.hpp>
#include <string>
#include <iostream>
#include <map>

using namespace std;
using namespace xercesc;


int main() {

  string scRes = "scRes.xml";

  XercesDOMParser* parser = new XercesDOMParser;
  parser->parse(scRes.c_str());

  DOMNodeList* nodeList = parser->getDocument()->getDocumentElement()->getChildNodes();
  DOMNode* root = nodeList->item(0);

  std::cout << root->getNodeName() << endl;

  for (unsigned int i = 0; i < nodeList->getLength(); i++) {
    DOMNode* curr = root->getChildNodes()->item(i);
    std::cout << curr << endl;
  }
}

My Makefile is like:

CXX             = g++

LIBDIR          = -L/usr/local/lib -L$(XERCES_LIB) -L$(PWD)

ROOT            = $(PROJDIR)
XERCES_INCLUDE  = $(ROOT)/libs/xercesc/include
XERCES_LIB      = $(ROOT)/libs/xercesc/lib
INCLUDE         = -I$(XERCES_INCLUDE) -I${HOME}/include

CXXFLAGS        = $(INCLUDE) -MMD -std=c++14 -Wno-deprecated
LDFLAGS         = $(LIBDIR) -Wl,-rpath,$(XERCES_LIB)
LDLIBS          = -lxerces-c -lm -Wl,-rpath
AR              = ar ru

all: Test1

Test1: Test1.o
        $(CXX) $(CXXFLAGS) $(LDFLAGS) $(LDLIBS) -o $@ $^

Test1.o: Test1.cpp
        $(CXX) -c $(CXXFLAGS) $^

clean:
        rm *.d *.o

If I type make, I receive the following errors.

/bin/ld: warning: libicui18n.so.68, needed by /some/server/dir/libs/xercesc/lib/libxerces-c.so, not found (try using -rpath or -rpath-link)

/bin/ld: warning: libicudata.so.68, needed by /some/server/dir/libs/xercesc/lib/libxerces-c.so, not found (try using -rpath or -rpath-link)

/lib/../lib64/crt1.o: In function `_start':

(.text+0x20): undefined reference to `main'

/some/server/dir/libs/xercesc/lib/libxerces-c.so: undefined reference to `uset_setSerializedToOne_68'/bin/ld: warning: libicuuc.so.68, needed by /some/server/dir/libs/xercesc/lib/libxerces-c.so, not found (try using -rpath or -rpath-link)

Answer 1

As Frank commented, I did not realize it is necessary to include the ICU library in the Makefile. I also made a few other mistakes in the Makefile, so I will post the now-working version here for other people's reference.

CXX             = g++

LIBDIR          = -L/usr/local/lib -L$(XERCES_LIB) -L$(ICU_LIB)

ROOT            = $(PROJDIR)
XERCES_INCLUDE  = $(ROOT)/libs/xercesc/include
XERCES_LIB      = $(ROOT)/libs/xercesc/lib
ICU_INCLUDE     = $(ROOT)/libs/icu/include/unicode
ICU_LIB         = $(ROOT)/libs/icu/lib
INCLUDE         = -I${HOME}/include -I$(XERCES_INCLUDE) -I$(ICU_INCLUDE)

CXXFLAGS        = $(INCLUDE) -MMD -std=c++14 -Wno-deprecated -Wall
LDFLAGS         = $(LIBDIR) -Wl,-rpath,$(ICU_LIB) -Wl,-rpath,$(XERCES_LIB)
LDLIBS          = -lxerces-c -lm
AR              = ar ru

all: Test1

Test1: main.o
        $(CXX) $(CXXFLAGS) $(LDFLAGS) $(LDLIBS) -o $@ $<

main.o: main.cpp
        $(CXX) $(CXXFLAGS) -c $<

clean:
        rm *.d *.o