我正在处理 LLVM Tutorial ，但我在编译时遇到了麻烦。我写了一个重现该问题的最小示例:

#include "llvm/Module.h"
#include "llvm/LLVMContext.h"

int main(int argc, char **argv) {
    llvm::Module *module = new llvm::Module("test", llvm::getGlobalContext());
    return 0;
}

当我尝试编译时，我得到一堆“ undefined reference ”错误:

clang++ `llvm-config --cxxflags`   -c -o test.o test.cpp
clang++  test.o  `llvm-config --ldflags --libs core` -o test
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Signals.o): In function `PrintStackTrace(void*)':
(.text+0x6c): undefined reference to `dladdr'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Signals.o): In function `PrintStackTrace(void*)':
(.text+0x1f6): undefined reference to `dladdr'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::MutexImpl(bool)':
(.text+0x53): undefined reference to `pthread_mutexattr_init'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::MutexImpl(bool)':
(.text+0x64): undefined reference to `pthread_mutexattr_settype'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::MutexImpl(bool)':
(.text+0x74): undefined reference to `pthread_mutexattr_setpshared'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::MutexImpl(bool)':
(.text+0x88): undefined reference to `pthread_mutexattr_destroy'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::tryacquire()':
(.text+0x179): undefined reference to `pthread_mutex_trylock'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::RWMutexImpl()':
(.text+0x3e): undefined reference to `pthread_rwlock_init'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::~RWMutexImpl()':
(.text+0x80): undefined reference to `pthread_rwlock_destroy'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::reader_acquire()':
(.text+0xb9): undefined reference to `pthread_rwlock_rdlock'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::reader_release()':
(.text+0xe9): undefined reference to `pthread_rwlock_unlock'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::writer_acquire()':
(.text+0x119): undefined reference to `pthread_rwlock_wrlock'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(RWMutex.o): In function `llvm::sys::RWMutexImpl::writer_release()':
(.text+0x149): undefined reference to `pthread_rwlock_unlock'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Threading.o): In function `llvm::llvm_execute_on_thread(void (*)(void*), void*, unsigned int)':
(.text+0x1cc): undefined reference to `pthread_create'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Threading.o): In function `llvm::llvm_execute_on_thread(void (*)(void*), void*, unsigned int)':
(.text+0x208): undefined reference to `pthread_attr_setstacksize'
/usr/lib/llvm-2.9/lib/libLLVMSupport.a(Threading.o): In function `llvm::llvm_execute_on_thread(void (*)(void*), void*, unsigned int)':
(.text+0x228): undefined reference to `pthread_join'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [test] Error 1

如果我查看 dladdr 的联机帮助页，它说我需要与 -ldl 链接。但我已经在使用 llvm-config:

$ llvm-config --ldflags --libs core
-L/usr/lib/llvm-2.9/lib  -lpthread -lffi -ldl -lm 
-lLLVMCore -lLLVMSupport -L/usr/lib/llvm-2.9/lib

此外，-ldl 以正确的顺序出现(即，在需要符号的 .o 文件之后)。

我对调试此问题的下一步感到茫然。谁能指出我正确的方向？我在 Ubuntu 12.04 上运行 LVVM 2.9-7。

最佳答案

需要符号的库包含在 -lLLVMSupport 中，因此 -ldl 必须在 -lLLVMSupport 之后。我改变了这个:

`llvm-config --ldflags --libs core`

到这里:

`llvm-config --libs core` `llvm-config --ldflags`

链接器成功了。

关于c++ - 为什么我得到 "undefined reference to ` dladdr'"即使使用 -ldl 这个简单的程序？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12993460/