c++ - 库在静态和动态链接中的顺序

Question

我正在尝试构建一些使用 boost 库的示例 C++ 代码。我用 this作为静态链接的引用示例。

当我使用动态库构建时，一切都很好。

g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/main.o src/main.cpp
g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/ThreadExample.o src/ThreadExample.cpp
g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/Utils.o src/Utils.cpp
g++ src/main.o src/ThreadExample.o src/Utils.o -lboost_thread -lboost_filesystem -lboost_system -lboost_timer -o ThreadExampleBinary

但是当我使用静态库时，我得到很多undefined reference错误:

g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/main.o src/main.cpp
g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/ThreadExample.o src/ThreadExample.cpp
g++  -Wall -std=c++0x -O3 -Wfatal-errors -I/usr/include/boost/include  -c -o src/Utils.o src/Utils.cpp
g++ -static src/main.o src/ThreadExample.o src/Utils.o -lboost_thread -lboost_filesystem -lboost_system -lboost_timer -o ThreadExampleBinary

/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o): In function `boost::timer::cpu_timer::start()':
(.text+0x7fd): undefined reference to `boost::chrono::steady_clock::now()'
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o): In function `boost::timer::cpu_timer::stop()':
(.text+0x94c): undefined reference to `boost::chrono::steady_clock::now()'
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o): In function `boost::timer::cpu_timer::elapsed() const':
(.text+0xa59): undefined reference to `boost::chrono::steady_clock::now()'
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o): In function `boost::timer::cpu_timer::resume()':
(.text+0xb60): undefined reference to `boost::chrono::steady_clock::now()'
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o): In function `boost::timer::auto_cpu_timer::auto_cpu_timer(std::ostream&, short)':
(.text+0xca5): undefined reference to `boost::chrono::steady_clock::now()'
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libboost_timer.a(cpu_timer.o):(.text+0xd4e): more undefined references to `boost::chrono::steady_clock::now()' follow
collect2: error: ld returned 1 exit status
make: *** [ThreadExampleBinary] Error 1

似乎这可以通过添加额外的 -lboost_chrono 库来解决。但为什么它在动态环境中有效？

Answer 1

对于静态链接，您还必须静态链接到您要链接到的库所依赖的任何库。