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Enabling C++

This page was last updated: September 3, 2024

Separating C & C++

  • Reference article: Where to add new h and cpp file in stm32cubeide project
  • Creating a separate Program/ folder with app.hpp and app.cpp that contains a new super loop function to escape from the auto-generated main.c super loop.
  • Right-click Project > Properties > C/C++ Build > Tool Setting (tab) > MCU GCC Compiler or MCU G++ Compiler > Include paths
  • For C++ files, change the Include Paths config for the G++ compiler instead of the GCC compiler

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Then, you may get an "undefined reference" error for the calling code. In this case, cppMain() had an undefined reference, despite the #include "" lines and changing the Include Paths settings of the compiler. - Reference article: Undefined reference to function stm32cubeide - Right-click Project > Properties > C/C++ General > Paths and Symbols > "Source Location" tab > Add Folder

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Finally, you may need to add extern guards. In this case because C++ code was calling for retarget.h, a C file, the following changes was made: 

// All credit to Carmine Noviello for this code
// https://github.com/cnoviello/mastering-stm32/blob/master/nucleo-f030R8/system/include/retarget/retarget.h

#ifndef _RETARGET_H__
#define _RETARGET_H__

#ifdef __cplusplus
extern "C" {
#endif

// The rest of the code
...

#ifdef __cplusplus
}
#endif

#endif //#ifndef _RETARGET_H__

Excluding from Build

Sometimes it may be useful to exclude specific files or sub-directories from being compiled. This can be done by double-clicking the parent-folder of interest in the "Source Location" tab of the "Paths and Symbols" window. Then, add any directories you do not want to be compiled when building the CubeIDE project.

For example, after moving our firmware libraries to a separate repository as a git submodule, we do not want the Tests/ and Docs/ directory to be compiled and flashed to the microcontroller as they are intended to run in different environments. So, for firmware development, exclude them from build as shown below.

Excluding folders from build