Why do I get an error while parsing custom code for my Simulink model?

Hi there,

I am trying to run a simulink model in which some C caller blocks are used ( external custom c code). The Model is legacy model but I am trying to run it on Matlab 2021b

The C comoiler is MinGW64 Compiler (C)

I already updated the model advisor befoer I try to RUN the model. I received the follwoing error:

Error while parsing custom code for model 'mymodel'. Fix the errors in your custom code or disable 'Import custom code' if your custom code has incompatibilities.

Caused by:

• In line 539 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\_mingw.h, incomplete type is not allowed: | void __cdecl __debugbreak(void); | ^
• In line 539 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\_mingw.h, expected a ";": | void __cdecl __debugbreak(void); | ^
• In line 540 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\_mingw.h, expected a ")": | __MINGW_INTRIN_INLINE void __cdecl __debugbreak(void) | ^
• In line 540 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\_mingw.h, expected a ";": | __MINGW_INTRIN_INLINE void __cdecl __debugbreak(void) | ^
• In line 18 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\stddef.h, expected a ";": | _CRTIMP extern int *__cdecl _errno(void); | ^
• In line 20 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\stddef.h, expected a ";": | errno_t __cdecl _set_errno(int _Value); | ^
• In line 21 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\stddef.h, expected a ";": | errno_t __cdecl _get_errno(int *_Value); | ^
• In line 24 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\stddef.h, expected a ";": | _CRTIMP extern unsigned long __cdecl __threadid(void); | ^
• In line 26 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\x86_64-w64-mingw32\include\stddef.h, expected a ";": | _CRTIMP extern uintptr_t __cdecl __threadhandle(void); | ^
• In line 428 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\lib\gcc\x86_64-w64-mingw32\6.3.0\include\stddef.h, expected a type specifier: | long long __max_align_ll __attribute__((__aligned__(__alignof__(long long)))); | ^
• In line 428 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\lib\gcc\x86_64-w64-mingw32\6.3.0\include\stddef.h, a function type is not allowed here: | long long __max_align_ll __attribute__((__aligned__(__alignof__(long long)))); | ^
• In line 429 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\lib\gcc\x86_64-w64-mingw32\6.3.0\include\stddef.h, expected a type specifier: | long double __max_align_ld __attribute__((__aligned__(__alignof__(long double)))); | ^
• In line 429 of C:\ProgramData\MATLAB\SupportPackages\R2021b\3P.instrset\mingw_w64.instrset\lib\gcc\x86_64-w64-mingw32\6.3.0\include\stddef.h, a function type is not allowed here: | long double __max_align_ld __attribute__((__aligned__(__alignof__(long double)))); | ^

Component:Simulink | Category:Block diagram error

Advice and input very welcome, thanks!

[Walter Roberson]

It looks to me as if MinGW is not recognizing _cdecl as a keyword. It is not part of C itself, it is a Microsoft extension (that is also implemented by several other companies for Microsoft compatibility.)

It looks to me as if there is a command line option that controls recognition of _cdecl

[David Tong]

Thanks Walter! Do you have any idea what is the command?

[David Balbuena]

Is this error specific to your custom code? You could try an example model to make sure this isn't some compiler configuration issue.

Here is an example: https://www.mathworks.com/help/releases/R2021b/simulink/slref/call-c-functions-using-c-caller-block.html

[David Tong]

Thanks David for your input, Actually I did try the example you listed above and valid it in the Configruration Parameters, The functions ( Custom code ) are imported and built successfully.

I am not sure how the errors be specific to my custom code since all the errors point to MinGW?

[David Balbuena]

It could be an issue with the code parser. Are you able to share your code? I'd recommend contacting technical support, just in case this is a bug: https://www.mathworks.com/support/contact_us.html

[Vincent Massart]

We have a very similar problem with R2018b and C Caller

all work on my colleague machine and not anymore on mine....

In line 12 of c:\xxxxxxxxxx\xxxxxxxxxxxxxxxxxxxx\xxxx_fpga_raw_convert.h, expected a ";": | typedef struct __attribute__ ((packed)) function_name {