R2024b CodeGen crashes when compiling to C/C++, but .mex no errors. R2018a compiles with no problems.

I recently upgraded to R2024b. This code compiles to .mex or C/C++ without issues using R2018a on a 32gB machine.

However, with R2024b, compiling to C/C++ runs out of memory on a 65gB machine then crashes.

I use the Matlab Coder App to compile to C++, and this code compiles to .mex successfullly using R2024b, but crashes on compile to C/C++

Here's the Test Bench:

%% Test Bench for OFDMRxR1.m
%
load OFDMRxSave                   % Loads v1, v2, v3, & P1 (structure)
Packet = OFDMRxR1(v1,v2,v3,P1);

BitRate = 1153.00
Packet = □□□□Kabcdefghijklmnopqrstuvwxyz01234567899876543210zyxwvutsrqponmlkjihgfedcbabAB□□□
Program Termination:  Successful

CODEGEN requires a MATLAB Coder license.

Code generation failed: To view the report, open('codegen/mex/OFDMRxR1/html/report.mldatx')

Error using codegen

[Dr W Kurt]

I am unable to upload the 'project' file, .prj because this web app doesn't accept that file format. However, here are a few images of the setup, it's simple; autodefine inputs, compile to .mex successfully, then compile to C/C++ and it will run out of memory and then crash.

Answer 1

[Subhajyoti]

Hi @Dr W Kurt,

It is my understanding that you are able to generate the MEX files for your code. But when you are trying to generate C/C++ files, it is throwing out of memory error.

This error is due to implicit expansion operation occurring during run-time.

Refer to following MathWorks Documentation link to know more about ‘Optimize Implicit Expansion in Generated Code’ in MATLAB:

https://www.mathworks.com/help/releases/R2024b/coder/ug/optimizie-implicit-expansion-in-generated-code.html

While generating MEX file, the MATLAB Coder generates C or C++ files (as mentioned in code-generation parameter) and the MEX file acts like an API between MATLAB and the C/C++ file. You can also use these C/C++ files directly as a workaround for code-generation error. The C/C++ build files are generated in the following path:

./codegen/mex/OFDMRxR1/

Additionally, you can refer to the following resources to know more about Analysis and Generation of C/C++ Code from MATLAB Code Using "MATLAB Coder":

• https://www.mathworks.com/help/releases/R2024b/coder/ug/code-generation-workflow.html
• https://www.mathworks.com/help/releases/R2024b/coder/ug/preparing-matlab-code-for-c-c-code-generation-workflow.html