cmake: target_link_libraries use static library not shared

Question

Is it possible to tell cmake to link against a static library instead of shared?

At the top of my CMakeLists.txt I have the following configured:

set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES}) 

Later, I add a binary, and tell it to link against tcmalloc in release mode:

target_link_libraries(${BIN_NAME} optimized tcmalloc_minimal) 

The resulting makefile links aginst the shared version of tcmalloc:

$ make VERBOSE=1 | grep tcmalloc /usr/bin/c++ ... -Wl,-Bdynamic ltcmalloc_minimal  

Further proof:

$ ldd app      ...     libtcmalloc_minimal.so.4 => /usr/local/lib/libtcmalloc_minimal.so.4 (0x00007eff89733000)     ... 

Both static and shared versions of tcmalloc exist:

$ ls -1 /usr/local/lib/libtcmalloc_minimal* /usr/local/lib/libtcmalloc_minimal.a /usr/local/lib/libtcmalloc_minimal_debug.a /usr/local/lib/libtcmalloc_minimal_debug.la /usr/local/lib/libtcmalloc_minimal_debug.so /usr/local/lib/libtcmalloc_minimal_debug.so.4 /usr/local/lib/libtcmalloc_minimal_debug.so.4.2.6 /usr/local/lib/libtcmalloc_minimal.la /usr/local/lib/libtcmalloc_minimal.so /usr/local/lib/libtcmalloc_minimal.so.4 /usr/local/lib/libtcmalloc_minimal.so.4.2.6 

Question:

How can I configure cmake to link against the static version of tcmalloc?

Answer 1

You can create a helper function which sets CMAKE_FIND_LIBRARY_SUFFIXES at function scope (so therefore doesn't affect the parent scope) which searches for the library in question and sets an output variable with the result

function(find_static_library LIB_NAME OUT)      if (WIN32 OR MSVC)         set(CMAKE_FIND_LIBRARY_SUFFIXES ".lib")     elseif (UNIX)         set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")     endif()            find_library(         FOUND_${LIB_NAME}_STATIC         ${LIB_NAME}         )      if (FOUND_${LIB_NAME}_STATIC)         get_filename_component(ABS_FILE ${FOUND_${LIB_NAME}_STATIC} ABSOLUTE)     else()         message(SEND_ERROR "Unable to find library ${LIB_NAME}")     endif()      set(${OUT} ${ABS_FILE} PARENT_SCOPE)  endfunction() 

You can then call this function from somewhere in your CMakeLists.txt to populate a variable with the location of the library.

Failure to find it results in a hard failure

find_static_library(tcmalloc_minimal TCMALLOC) 

You can then use this variable in your call to target_link_libraries and be sure you're linking against the static version

target_link_libraries(${BIN_NAME} optimized ${TCMALLOC}) 

Here you can see the result:

$ make VERBOSE=1 | grep tcmalloc 

/usr/bin/c++ ... /usr/local/lib/libtcmalloc_minimal.a ...