Question

虽然对此有很多疑问，但我找不到解决问题的正确方法。我在项目中使用libboost_system，并在makefile中添加Libs:=libconfig++ libboost_thread libboost_system ，但它仍然无法运作。

我机器的环境：

 - Ubuntu 14.04.5 LTS
 - gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4
 - libboost_1.54

到目前为止，我已尝试过以下

我编写了一个测试文件，看看是否正确安装了boost库，测试文件如下所示： [TEST.CPP] [1] https://i.stack.imgur.com/Tb4I0.png，然后我用这个命令编译：{{1}}，它确实以正确的方式工作。这是否意味着正确安装了boost库？在我看来，我认为它已安装。
我搜索stackoverflow并发现很多答案都提到库的顺序很重要，所以我检查了libs的顺序并将g++ test.cpp -g -o main -lboost_system -lboost_thread放在Lib的末尾。它仍然得到了同样的错误。
然后我发现很少有答案推断libbost_system，我不知道如何添加这个定义，所以我最终无法解决问题。

我项目的部分makefile如下所示：

#define BOOST_ERROR_CODE_HEADER_ONLY

我收到的错误如下：

SOURCE_DIR := src
COMPILER := g++
BINARY_DIR := bin/lrelease
CPPFLAGS := -Wall -g -O3 -std=c++11
LIBS := -lpthread -lboost_thread -lconfig++ -lboost_system
COMPILE.cpp = $(COMPILER) $(CFLAGS) $(CPPFLAGS) -c
LINK.cpp = $(COMPILER) $(LIBS)
%.o: %.cpp
#$(call make-depend,$<,$@,$(subst .o,.d,$@))
$(COMPILE.cpp) $< -o $@

# $(call source-dir-to-binary-dir, directory-list)
source-dir-to-binary-dir = $(addprefix $(BINARY_DIR)/,$1)

# $(call source-to-object, source-file-list)
source-to-object = $(call source-dir-to-binary-dir, $(subst .cpp,.o,$1))

# $(subdirectory)
subdirectory = $(patsubst %/module.mk,%,                \
                 $(word                                 \
                   $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST)))
define make-depend
    g++ -MM    \
         -MF$3         \
         -MP            \
         -MT$2         \
         $(CFLAGS)      \
         $(CPPFLAGS)    \
         $(TARGET_ARCH) \
         $1
endef

# $(call make-library, library-name, source-file-list)
define make-library
  libraries += $(BINARY_DIR)/$1
  sources   += $2

  $(BINARY_DIR)/$1: $(call source-dir-to-binary-dir, $(subst .cpp,.o,$2))
    $(AR) $(ARFLAGS) $$@ $$^
endef

# $(call make-program, program-name, library-list, source-file-list)
define make-program
  programs  += $(BINARY_DIR)/$1
  sources   += $3

  $(BINARY_DIR)/$1: $(call source-dir-to-binary-dir, $(subst .cpp,.o,$3) $2 )
    $(LINK.cpp) -o $$@ $$^ -lpthread
endef

# $(compile-rules)
define compile-rules
  $(foreach f,$(local_src),$(call one-compile-rule,$(call source-to-object,$f),$f))
endef

# $(call one-compile-rule, binary-file, source-file)
define one-compile-rule
  $1: $2
    $(call make-depend,$2,$1,$(subst .o,.d,$1))
    $(COMPILE.cpp) -o $1 $2
endef

# then the output dirs and make clean
#
#

添加或不添加g++ -lpthread -lboost_thread -lconfig++ -lboost_system -o bin/lrelease/ buildmyProjectFromN3 bin/lrelease/BuildmyProjectFromN3/BuildmyProject.o bin/lrelease/libmyProject.a -lpthread bin/lrelease/libmyProject.a(myProjectBuilder.o):(.gcc_except_table+0x48c): undefined reference to `typeinfo for libconfig::FileIOException' bin/lrelease/libmyProject.a(myProjectBuilder.o): In function `boost:: thread_exception::thread_exception(int, char const*)': /usr/include/boost/thread/exceptions.hpp:51: undefined reference to `boost::system::system_category()' bin/lrelease/libmyProject.a(myProjectBuilder.o): In function `boost:: condition_error::condition_error(int, char const*)': /usr/include/boost/thread/exceptions.hpp:84: undefined reference to `boost: : system::system_category()' bin/lrelease/libmyProject.a(myProjectBuilder.o): In function `interruption_checker': /usr/include/boost/thread/pthread/thread_data.hpp:187: undefined reference to `boost::detail::get_current_thread_data()' bin/lrelease/libmyProject.a(myProjectBuilder.o): In function `boost:: condition_variable::wait(boost::unique_lock<boost::mutex>&)': /usr/include/boost/thread/pthread/condition_variable.hpp:84: undefined reference to `boost: : this_thread::interruption_point()' bin/lrelease/libmyProject.a(myProjectBuilder.o): In function `boost:: shared_mutex::lock_shared()': /usr/include/boost/thread/pthread/shared_mutex.hpp:186: undefined reference to `boost::this_thread::disable_interruption::disable_interruption()' /usr/include/boost/thread/pthread/shared_mutex.hpp:193: undefined reference to `boost::this_thread::disable_interruption::~disable_interruption()' /usr/include/boost/thread/pthread/shared_mutex.hpp:193: undefined reference to `boost::this_thread::disable_interruption::~disable_interruption()' ... ... ...：L/usr/lib似乎没有任何区别。两者都无法正常工作。

我可以确定代码是正确的，并且可以在其他服务器上正确运行。所以，我真的不知道问题出在哪里。如果我能获得有关错误的任何有用信息，我将不胜感激，非常感谢：）

Answer 1

错误消息表明您的libmyProject.a库依赖于Boost.Thread和Boost.System。但是在链接器命令行中，它在Boost库之后指定，因此未解析其Boost依赖项。请注意，链接器命令行中的库和目标文件的顺序为significant。在您的情况下，您需要在命令行中的库和目标文件之后移动-lboost_thread和-lboost_system。

未定义的引用`boost :: system :: system_category（）＆＃39;

1 个答案: