Re: [Boost-users] NEWBIE: Undefined references: How do I find the library that resolves an undefined reference - Expanded with log example and hope for a general solution
Thanks Richard and Andy for the timely response! Andy's answers provides the perfect example of my dilemma. When Andy said to check the MSDN documentation for ms742213, I quickly found that I needed the Ws2_32.lib library, which I was able to solve my issue. However, I also have the following: 1. boost::log::add_log_file(...) with a sinks::file::rotation_at_time_point(...) 2. boost::random::random_device range; I made a guess with the log and added boost_log_setup_mgw48-mt-d-1_61 and boost_log_ mgw48-mt-d-1_61, but these libraries didn't resolve my issue. When I check the boost documentation (I realize that many of the boost additions just require header files, which the examples are careful to specify. I figure this must require a library because I am getting an undefined error.), there were many mentions of a library, but I couldn't find where the name of the library was specified! So I hope there is a general way to determine the name of the boost library so I do not need to keeping asking about particular undefined errors. In the past, I have been able to google the undefined error and find the library reference, but Thanks again for all of your help! -----Original Message----- On 1/24/2017 3:44 PM, Richard Hodges wrote:
That would be the winsock library.
https://msdn.microsoft.com/en-us/library/ms740673.aspx
On 24 January 2017 at 20:33, JENNINGS, LYNN M NH-03 USAF AFMC 517 SMXS/MXDPB <lynn.jennings_at_[hidden]> wrote:
NEWBIE question: Undefined references: How do I find the library that resolves an undefined reference. For example, the output for the gcc linker running in MinGW shows:
C:/boost/boost/asio/detail/impl/winsock_init.ipp:39: Undefined reference to `WSAStartup_at_8'
I have googled the documentation a number of ways, but I cannot find the library that will resolve this error. I am sure that this is a common problem. Please point me to the documentation so I can fix this and the undefined references.
Thanks!
In the future, you can check Microsoft's documentation [1] for info on their functions. I searched for "WSAStartup", and found [2]. At the bottom of that page is a "Requirements" box, which tells you the library it's in. Andy 1. http://msdn.microsoft.com 2. https://msdn.microsoft.com/en-us/library/windows/desktop/ms742213(v=vs.85).a...
On 1/25/2017 12:45 PM, JENNINGS, LYNN M NH-03 USAF AFMC 517 SMXS/MXDPB wrote:
Thanks Richard and Andy for the timely response! Andy's answers provides the perfect example of my dilemma. When Andy said to check the MSDN documentation for ms742213, I quickly found that I needed the Ws2_32.lib library, which I was able to solve my issue. However, I also have the following:
1. boost::log::add_log_file(...) with a sinks::file::rotation_at_time_point(...) 2. boost::random::random_device range;
I made a guess with the log and added boost_log_setup_mgw48-mt-d-1_61 and boost_log_ mgw48-mt-d-1_61, but these libraries didn't resolve my issue. When I check the boost documentation (I realize that many of the boost additions just require header files, which the examples are careful to specify. I figure this must require a library because I am getting an undefined error.), there were many mentions of a library, but I couldn't find where the name of the library was specified!
So I hope there is a general way to determine the name of the boost library so I do not need to keeping asking about particular undefined errors. In the past, I have been able to google the undefined error and find the library reference, but
Thanks again for all of your help!
I see you're using MinGW-built libraries. MinGW comes with some tools that might help you. So this isn't boost-specific advice, but more general. Have you tried some of the relevant MinGW tools? I found some old MinGW-built boost libs lying around, and the following worked to show me exports. From a MinGW shell: $ nm -Cg ./libboost_log-mgw48-mt-1_54.dll that dumped a ton of info to the console. You can filter using 'grep' to search for things: $ nm -Cg ./libboost_log-mgw48-mt-1_54.dll | grep rotation_at_time_point One of the entries I got was: 00000000653d4f00 T boost::log::v2_mt_nt5::sinks::file::rotation_at_time_point::rotation_at_time_point(unsigned char, unsigned char, unsigned char) (it's one of several overloads.) If someone suggests an easier way of matching up boost symbols to DLLs, great, but if you have nothing else, this can help. (There some other similar tools too, but hopefully 'nm' will work.) Additionally, with gcc, order of libraries given on the commandline matters. If you get it wrong, then even if the symbol you need is in the DLL, and the DLL is on your commandline, you'll get the linker error. Dependent libraries should always come before their dependencies. Hope this helps, Andy
participants (2)
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JENNINGS, LYNN M NH-03 USAF AFMC 517 SMXS/MXDPB -
Michael Chisholm