Cmake, finding a header file in /usr/local/include and library in /usr/local/lib

Question

I want CMake to find the header for add_executable and find the .so file for target_link_libraries.

The header file I want to find is lcm-cpp.hpp (on ubunthu)

ls /usr/local/include/lcm/
eventlog.h  lcm_coretypes.h  lcm-cpp.hpp  lcm-cpp-impl.hpp  lcm.h

The CMakeLists.txt file in the root of my project

 cmake_minimum_required (VERSION 2.6)
 project (libFoo)
 include_directories(include /usr/local/include/lcm/)

 set(PROJECT_SRC
     src/Foo.cpp )

 set(PROJECT_H
     include/Foo.hpp )

 find_library(LCM_LIBRARY
     NAMES liblcm.so
     PATHS
     /usr/local/lib/
 )

add_library(liblcm STATIC IMPORTED)

add_library(foo_lib ${PROJECT_SRC} ${PROJECT_H})

add_executable(foo_lcm src/lcm_foo.cpp ${PROJECT_H} lcm-cpp.hpp)

The error I get:

  Cannot find source file:

  lcm-cpp.hpp

 Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm .hpp
 .hxx .in .txx

Answer 1

The CMake command include_directories() is used for specifying additional directories where the compiler should search for #included files. It does not affect CMake's search for source files at all.

If the file /usr/local/include/lcm/lcm-cpp.hpp is really a part of your executable (you'd want it listed in the project in Visual Studio, for example), you'll have to specify it with the full path:

add_executable(foo_lcm src/lcm_foo.cpp ${PROJECT_H} /usr/local/include/lcm/lcm-cpp.hpp)

However, based on its location, it looks more like a library external to your executable. If that's the case, it should not be listed in add_executable() at all.