Multiple files and "undefined reference"

[ramboza]

Hi !

Nice plugin, thanks!!!

I have some problem to compile more than one source (ino) file.

example:
CLion 2018.3, plugin v1.4.0

I have simple project with one additional cpp file..

demo.ino

#include <Arduino.h>
#include "User_Setup.h"
#include "xxx.h"

void setup() {
	XXX xx;
	xx.Test();
}

void loop() {}

xxx.cpp

#include "xxx.h"
void XXX::Test() {}

xxx.h

#ifndef DEMO_XXX_H
#define DEMO_XXX_H

class XXX {
public:
	void Test();
};
#endif //DEMO_XXX_H

and result is

[ 92%] Linking CXX executable demo.elf
CMakeFiles/untitledz.dir/demo_demo.ino.cpp.obj: In function `setup':
/Users/jenya/Projects/Temp/demo/demo.ino:9: undefined reference to `XXX::Test()'
collect2: error: ld returned 1 exit status
make[3]: *** [demo.elf] Error 1
make[2]: *** [CMakeFiles/demo.dir/all] Error 2
make[1]: *** [CMakeFiles/demo.dir/rule] Error 2
make: *** [untitledz] Error 2

I tried to use different ways from CMakeLists.txt, result the same ..

#Define additional source and header files or default arduino sketch files
set(${PROJECT_NAME}_SRCS xxx.cpp)
set(${PROJECT_NAME}_HDRS User_Setup.h xxx.h)

so, this is some problem of compiling xxx.cpp and linking together with demo.ino

any ideas how to solve it ?

Thanks a lot!
Jev.

[vsch]

@ramboza, this is one weirdness of the Arduino CMake but you need to add linked directories which hold additional "library" files locally that will be scanned to find included .h/.cpp combinations where the names match. In your case the files are in the root of your project so add this line and it should fix it:

# Extra library directories
link_directories(${CMAKE_CURRENT_SOURCE_DIR})

BTW, I missed a few bugs in the last release which are now fixed. Until now I did not know if anyone was using the plugin. Thank you for being the first one.

[ramboza]

Result the same :(
if you want - you can try to open my empty project (just 1 file added to the project) (attached)

demo.zip

[vsch]

@ramboza, I'll try it now.

[ramboza]

My setup - macOS Mojave, Arduino IDE 1.8.7, tried CMake version 3.13.1 and 3.12.3 (bundled with CLion)

Thanks !!!

[vsch]

@ramboza, forgot that the included lib files should be in a sub-directory with the same name as the files. In your case create xxx sub-directory and move the xxx.h and xxx.cpp to it.

You can include the xxx.h as "xxx.h" or <xxx.h> or <xxx/xxx.h> or "xxx/xxx.h" in your main sketch.

⚠️ One caveat is if you add a new #include to your source you will need to "Reload
CMake project" so the new "library" will be detected and added to the build.

[ramboza]

👍 awesome!! It works now!!

Thank you Vladimir!

[MicheleSaltori]

Exists a more elegant solution for compile multiple cpp sources?

[mweber-ovt]

I just installed Clion 2019.2 and no matter what I try, I am not able to get this simple example to work.

The outcome is always (the name of my .ino file is CLion_Demo):
CMakeFiles/CLion_Demo.dir/CLion_Demo_clion_demo.ino.cpp.obj: In function setup': /Users/michael/Dropbox/onVector/Projects/BG-Counter/Firmware Development/CLion_Demo/clion_demo.ino:7: undefined reference to XXX::Test()'
collect2: error: ld returned 1 exit status
make[3]: *** [CLion_Demo.elf] Error 1
make[2]: *** [CMakeFiles/CLion_Demo.dir/all] Error 2
make[1]: *** [CMakeFiles/CLion_Demo.dir/rule] Error 2
make: *** [CLion_Demo] Error 2

Please help!

[vsch]

@ramboza, the easiest way to make multi-file projects work is to rename the .ino to .cpp and add all your .cpp files to project sources in CMakeLists.txt and .h files to project headers. See: #17

Otherwise, you need to add your xxx files to a subdirectory named xxx located in your source directory if you use to add current source to linked directories with CMakeLists.txt config:

# Extra library directories
link_directories(${CMAKE_CURRENT_SOURCE_DIR})

This is the weirdness of Arduino CMake and this plugin uses that project to make it work in CLion.

[mweber-ovt]

@vsch , unfortunately, this doesn't work. While everything compiles properly, there is the linker error: undefined reference. I am sure there is something really simple that I am overlooking. Could you possibly try this out and let me know what's wrong?
CLion 2019.2
Arduino Support 1.4.4

clion_demo.cpp
#include <Arduino.h>
#include "User_Setup.h"
#include <xxx.h>

void setup() {
XXX xx;
xx.Test();
}

void loop() {}

xxx.h:
#ifndef CLION_DEMO_XXX_H
#define CLION_DEMO_XXX_H

class XXX {
public:
void Test();
};

#endif //CLION_DEMO_XXX_H

My CMakeLists.txt:
cmake_minimum_required(VERSION 2.8.4)
set(CMAKE_TOOLCHAIN_FILE ${CMAKE_SOURCE_DIR}/cmake/ArduinoToolchain.cmake)
set(CMAKE_CXX_STANDARD 98)
set(PROJECT_NAME CLion_Demo)

set(${PROJECT_NAME}_BOARD mega)
set(ARDUINO_CPU atmega2560)
project(${PROJECT_NAME})

Define additional source and header files or default arduino sketch files

set(${PROJECT_NAME}_SRCS clion_demo.cpp xxx.cpp)
set(${PROJECT_NAME}_HDRS User_Setup.h xxx.h)

Additional static libraries to include in the target.

set(${PROJECT_NAME}_LIBS)

Main sketch file

set(${PROJECT_NAME}_SKETCH clion_demo.cpp)

Add project directories into the build

#add_subdirectory()

Additional settings to add non-standard or your own Arduino libraries.

For this example (libs will contain additional arduino libraries)

An Arduino library my_lib will contain files in libs/my_lib/: my_lib.h, my_lib.cpp + any other cpp files

link_directories(${CMAKE_CURRENT_SOURCE_DIR}/libraries)

For nested library sources replace ${LIB_NAME} with library name for each library

set(_RECURSE true)

Additional settings for programmer. From programmers.txt

set(${PROJECT_NAME}_PROGRAMMER avrispmkii)
set(${PROJECT_NAME}_PORT /dev/cu.usbmodem141101)

set(mega.upload.speed 9600)

Verbose build process

set(${PROJECT_NAME}_AFLAGS -v)

generate_arduino_firmware(${CMAKE_PROJECT_NAME})

[vsch]

@mweber-ovt, try commenting out the SKETCH defining line in CMakeLists.txt. If it is defined it will still try to process the project as a sketch and ignore the extra cop files. I’m guessing but the sketch line definitely has to be commented out for multi file project to work.

[jord1e]

For future reference (edit these two lines in your own project): francoiscampbell/arduino-cmake#10

After this de _SKETCH, _SRCS and _HDRS all work.