How to link my .h and .c files in the same project but different directory using CMake - eclipse

Question

I'm currently working on an embedded C project in Eclipse, cross-compiling to an M4 Cortex target. This project will create 3 separate executable files: apple.hex, orange.hex, and pear.hex. The "apple" source directory compiles, builds, and links without any dependencies on "orange" or "pear". The "orange" source directory also compiles, builds, and links without any dependencies.
However, "pear" needs to access numerous .h and .c assets from "orange". I've had many attempts at getting my CMakeLists.txt to "find" and "link" the code from "orange" to "pear", but to no avail.
Here is my current CMakeLists.txt file:
cmake_minimum_required(VERSION 3.0)
file(GLOB LD_FILE *gcc_nrf52.ld)
set(MY_APP_DIR ${CMAKE_SOURCE_DIR}/apps/orange)
create_application(
NAME
"pear"
PLATFORM
target
INCLUDE_DIRS
./
${MY_APP_DIR}
LINKER_SCRIPT
${LD_FILE}
SOURCES
${MY_APP_DIR}/foo.c
${MY_APP_DIR}/foo_bar.c
main.c
LIBRARIES
SomeLib_1
SomeLib_2
SomeLib_3
)
However, the compiler keeps complaining, saying that it cannot find "foo.h" and "foo_bar.h".
1) Do I need to separately create a static library in orange in order to access it in pear?
2) If I don't need to create a static library to access orange from pear, how do I link orange to pear?
3) I cannot find where CMake places the object files. Where are they?
This project is all under a single makefile.
Any help would be greatly appreciated, thanks!
I was able to fix my directory issues so that all of the include directories in ${MY_APP_DIR} are being linked into "Pear". However, a new issues has arisen. The linker cannot find the map file needed to create the executable image:
/usr/local/Caskroom/gcc-arm-embedded/5_4-2016q3,20160926/gcc-arm-none-eabi-5_4-2016q3/bin/../lib/gcc/arm-none-eabi/5.4.1/../../../../arm-none-eabi/bin/ld: cannot open map file /Users/admin/Github/target/apps/pear/pear.map: No such file or directory.
I'm not sure why a map find isn't being created. Is the linker (ld) still missing files?

Answer 1

I'll try to answer your questions
You are not linking your libraries to your target.
You need something like:
$target_link_libraries(yourtarget yourlibraries)
after your add_executable command.
3) I cannot find where CMake places the object files. Where are they?
CMake puts all of its outputs in the build tree by default, so unless you are liberally using ${CMAKE_SOURCE_DIR} or ${CMAKE_CURRENT_SOURCE_DIR} in your cmake files, you should find the output files in the folder where your CMakeLists.txt file is.