C++ Support in Embedded Studio
Contents
Embedded Studio supports application development in C and C++. Its C runtime library, based on emRun, provides all fundamentals, tweaked for fastest speed or smallest size. In addition, the C++ library provides all required features for efficient C++ applications.
The C++ library adds:
- C++ header files to wrap up their C equivalents. e.g. cmath to math.h.
- C++-specific names and functions and mangled names for math.h. e.g. classification (isinf) and comparison (isless) functions, and cosf to cos(float) / cos to cos(double).
- C++ header files for exception, new, typeinfo.
- C++ unwinding library. Functions used for target unwinding, such as to implement exceptions.
- The C++ ABI library. Low-level support for standard C++ libraries.
- The C++ standard library.
This article describes how to enable the C++ libraries in Embedded Studio to use C++ library functions in target applications.
How to use the C++ Library
Note: For libcxx, Embedded Studio V5.60 or later is required.
Library installation steps (only necessary until ES V7.20)
The C++ standard library is based on the embedded C++ subset of the "libc++" C++ Standard Library.
To limit download and installation size of Embedded Studio, the library is supplied as additional packages for the supported target architectures. To enable the library in a project, only the common package needs to be installed. Embedded Studio takes care of downloading the specific packages if required.
- Open the package manager under Tools -> Package Manager...
- Make sure that you have the latest package list loaded to avoid download errors. To refresh the list manually you will find a refresh button in the top right corner of the package manager. The mouse over tool tip shows "Refresh Package List".
- Select the "ARM libcxx Library Package [Common]" or "RISCV libcxx Library Package [Common]" for installation.
- Optional: Select the specific libcxx Library Packages for your target architecture(s) for installation.
- 'If not done, Embedded Studio will download the specific package for your project. See next steps.'
- Press Next to continue the download and installation.
The library is now ready to use and can be enabled in new and existing projects.
Generic project setup steps
- Open or create a project.
- Option the project options and go to Code -> Libraries.
- In "libcxx Library" select "Yes" or "Yes (No Exceptions)".
- Optional, if you select Yes and you are using std functions that could throw exceptions make sure that project option "Code > Code Generation > Enable Exception Support" is set to Yes
- Press OK to save the project options.
- If the specific package for your project has not been installed, yet, Embedded Studio prompts to download and install the package now.
- Press Yes.
- Press Next to continue the download and installation.
The project is now configured to use the C++ standard library. Include the necessary headers and start using the library functions.
Enabling Exception Support
To enable exception support in your C++ project the following must be considered:
- Make sure your library is installed as explained above. (Project option libcxx Library = Yes)
- Set project option "Code > Code Generation > Enable Exception Support" to Yes.
- Make sure that sections readonly and readexec are placed in your linker script.
Changing the C++ standard
Per default C++ support is set to gnu++98. If you are using more modern features of C++ make sure to change the standard to the respective version in project options under Code->Compiler->C++ Language Standard