Solutions: Undefined reference errors occurr when linking in Insure++ symbols

	Insure++
Product Version	7.4.3
Product Platforms	Linux 32; Linux 64
Solution Symptoms	When linking instrumenting code with Insure++ on Ubuntu v12.04, we get the following messages or a similar message: .../Insure++/lib/libinsure.so: undefined reference to `Insure::Thread::startFunction()' .../Insure++/lib/libinsure.so: undefined reference to `Insure::NativeThread::newThread(Insure::Lock&)' .../Insure++/lib/libinsure.so: undefined reference to `Insure::Mutex::newMutex(Insure::ThisThread*, Insure::LibraryCall&)' .../Insure++/lib/libinsure.so: undefined reference to `Insure::Thread::thisThread()' .../Insure++/lib/libinsure.so:: undefined reference to `Insure::Thread::fiberStartFunction()' collect2: ld returned 1 exit status
Solution Details	Explanation + Solution This behavior occurs because Ubuntu 12.04's linker, by default, attempts to optimize the symbols linked in.  This means the linker will throw away symbols it deems unnecessary, such as the Insure++ libraries.  However, these Insure++ libraries *are* required, as is proved by the linking error.  The solution is to add the linker option "-Wl,--no-as-needed" to prevent the linker from automatically optimizing the link line. Example In this example, let's assume the following. OS : Ubuntu v12.04 Compiler : GCC v4.6.3 Insure++ v7.4.3 We would like to Instrument the following .c file with Insure++. message_rec.c To compile the file with Insure++, perform the following command: $ insure gcc -g message_rec.c Once the compilation is completed, perform the following link command with Insure++: $ insure gcc -g -o message_rec message_rec.o IF a similar output results from the above link command: .../Insure++/lib/libinsure.so: undefined reference to `Insure::Thread::startFunction()' .../Insure++/lib/libinsure.so: undefined reference to `Insure::NativeThread::newThread(Insure::Lock&)' .../Insure++/lib/libinsure.so: undefined reference to `Insure::Mutex::newMutex(Insure::ThisThread*, Insure::LibraryCall&)' .../Insure++/lib/libinsure.so: undefined reference to `Insure::Thread::thisThread()' .../Insure++/lib/libinsure.so: undefined reference to `Insure::Thread::fiberStartFunction()' collect2: ld returned 1 exit status THEN the option "-Wl,--no-as-needed" needs to be added to the link command: $ insure gcc -g -o message_rec message_rec.o -Wl,--no-as-needed This will tell the linker to use all the symbols and do not throw any of the symbols away.  The link should no longer produce the same error.