使用AWS C ++ SDK的基本程序无法编译

Question

I'm having some troubles using AWS C++ SDK, due to a serious lack of documentation. However I managed to compile and install it on my computer.

I'm now trying hard to have a program working and resolved quite a lot of problems, but a (hopefully) last one remains that I cannot defeat alone...

Here is the code :

#include <aws/s3/model/GetObjectRequest.h>

int main()
{
     Aws::S3::Model::GetObjectRequest getObjectRequest;
}

I tried to have the simplest code for my example. That code doesn't compile, I've got the following error :

CMakeFiles/example.dir/example.cpp.o:(.rodata._ZTIN3Aws2S39S3RequestE[_ZTIN3Aws2S39S3RequestE]+0x10): undefined reference to `typeinfo for Aws::AmazonSerializableWebServiceRequest'

I don't get what the problem is. I tried checking in the source code of the library, and no pure virtual function remains in the GetObjectRequest class. I think I linked correctly the libraries. Here is my CMakeLists.txt :

project( TEST_AWS )
cmake_minimum_required(VERSION 3.1.0 FATAL_ERROR)
add_definitions ( -Wall -Wextra )

set(LIBAWSSDK_INCLUDE_DIR /usr/local/include/ CACHE STRING "aws SDK include directories")
set(LIBAWSSDK_CORE_LIB "-l:/usr/local/lib/libaws-cpp-sdk-core.so" CACHE STRING "aws SDK core link lib")
set(LIBAWSSDK_S3_LIB "-l:/usr/local/lib/libaws-cpp-sdk-s3.so" CACHE STRING "aws SDK S3 link lib")

set(target_external_libraries
    ${LIBAWSSDK_CORE_LIB}
    ${LIBAWSSDK_S3_LIB}
)

include_directories(
    ${LIBAWSSDK_INCLUDE_DIR}
)

add_executable( example example.cpp )
target_link_libraries( example ${target_external_libraries} )
target_compile_features(example PRIVATE cxx_lambdas)

I know the way I linked the library with cmake is a little bit dirty, but for the moment I just want the code to compile...

Answer 1

If you are using CMake, I recommend using the cmake export file from the SDK to avoid having to figure out what we are using. https://aws.amazon.com/blogs/developer/using-cmake-exports-with-the-aws-sdk-for-c/

The -fno-rtti flag will be removed and changed to an optional CMake flag.

If you use the CMake exports, it will properly generate your visual studio solution.

Update:

This has been fixed with the latest revision

Answer 2

• Very important: If you're compiling with RTTI (-frtti), make sure your dependent libraries are also compiled with it, and not -fno-rtti. Otherwise you will get the typeinfo error when you subclass a class compiled with -fno-rtti or use dynamic_cast. ( C++: what are the causes of " undefined reference to 'typeinfo for [class name]' "other than virtual functions )

• So, the -fno-rtti works only if you are compiling just the aws-sdk

• Now, for most cases, there'll be many many other libraries that you will be compiling the aws-sdk with. Most libraries, opencv, etc are compiled with -frtti. If aws-sdk is compiled with -fno-rtti, then you will get the above typeinfo madness error

• Solution: checkout the latest aws-sdk-cpp (as of June 1st). It uses the -frtti option..and then link against it, and Life is good