Cmake add_library with boost source files introduces references to non-existant files

Question

Hello all, we're building a cross-platform utility which must have a small footprint. We've been pulling header files from boost as and when we need them but now we must link against some boost C++ thread code. The easiest immediate solution was to create our own custom library using CMake's "add_library" command to create a static library composed of some boost thread source files. These compile without any problems.

The difficulty arises when I try to link to this library from an executable. Visual Studio 2008 returns an error saying that it cannot link to "libboost_thread-vc90-mt-sgd-1_40.lib". What really puzzles me is that I've grepped through all the source code and CMake config files and I can't find any reference to this libboost library, leading me to think that this has been autogenerated in some way.

This works OK in Linux, can anyone point out why I'm experiencing these issues in Windows?

Answer 1

Ok, well, it turns out that Boost uses this auto-link feature for Visual Studio which embeds references to a mangled (ie, platform-compiler-mult-threaded, etc) boost library name.

The header file which controls this is called "auto_link.hpp" which lives in the config directory of the boost include tree. There's a special preprocessor definition called "BOOST_AUTO_LINK_NOMANGLE" which toggles this behaviour.

Another triumph of mediocrity for Microsoft.

Answer 2

@Gearoid

You found the correct reason for your problem, but not the correct solution. The BOOST_AUTO_LINK_NOMANGLE is an internal, i.e. for library authors, definition to control the auto-linking. The user level definition is BOOST_ALL_NO_LIB which when defined disables the auto-linking feature for all Boost Libraries code you use. This is described in the user.hpp configuration header (see user.hpp near the bottom and the Boost Config documentation). You can also control this on a per library level as describe in that header.