I am trying to use pointer references to variable size data with "coder.wref" and then generate DLL.
My current workflow can be illustrated as (please refer to the skeleton function below).
(1) functionB --> (MATLAB Coder) --> functionB.dll
(2) functionA --> (MATLAB Coder) --> functionA.dll
(3) Use functionA.dll from a client program (integrate using Visual C/C++)
<Code Listing>
%---- functionB.m ---------------------------------
function [ result ] = functionB( flg, result )
%#codegen
% Create dll using MATLAB Coder
% Input/output specification: result [:inf×3]
result = [result; rand(1,3)];
end %-functionB-%
%---- functionA.m ---------------------------------
function functionA( flg, result )
%#codegen
coder.ceval('functionB_initialize');
coder.ceval('functionB', flg, coder.wref(result) );
coder.ceval('functionB_terminate');
end %-functionA-%
As you may expect, using variable size data is used for "result" is realized as an emxArray type
and the following code is generated for functionB:
// functionB.h
extern void functionB(double flg, emxArray_real_T *result);
However, the arguments for calling the function (B) from functionA in the generated code
uses the pointer to the data field of the emxArray structure:
// functionA.c
void functionA(double flg, emxArray_real_T *result)
{
functionB_initialize();
functionB(flg, &result->data[0]);
functionB_terminate();
}
//functionB(flg, result);
To my understanding, this would simply give a "incompatible types" warning during the compilation.
If build can be successfull at all (ignoring the warning),
it is highly likely that the address of "result->data[0]" will differ from the intended address of "result"
and will produce something unexpected.
What can I do?
As an workaround I could think of manually changing the function call to
functionB(flg, result);
