C Syntax error after using #define - c

Question

I am using Microsoft Visual Studio 2010 to write a C code. This is the piece of code that I defined :
#define setImagVal_Matrix(matrix,type,x,y,val) \
(getImagVal_Matrix(matrix,type,x,y) = (val))
Then I am using it inside this function :
for(bands=0; bands < no_of_bands; bands++) {
outputmatrix[bands] = new_Matrix(yrange,xrange,getDataType_Image(inputImage),getDataFormat_Image(inputImage));
for(r=0; r < no_of_rows; r++) {
for(c=0; c < no_of_cols; c++) {
if(c<x1 || c>x2 || r<y1 || r>y2)
{
continue;
}
else
{
setImagVal_Matrix(outputmatrix[bands],getDataType_Matrix(outputmatrix[bands]),c-x1,r-y1,123);
}
}
}
}
However, it shows me this error on setImagVal_Matrix function call:
"Error:expected an expression"
And when I build the solution , here is the output which shows a syntax error on the same line:
1>c:\cviplab-net-2010\cviplab\crop.c(50): error C2059: syntax error : ')'
After spending couple of hours, I still cannot find the cause of the error . Any idea how to fix it?
EDIT:
I analyzed the pre-processed file and found the syntax error but still I don't know how to fix it. Here is the line which makes the error :
((((((outputmatrix[bands])->data_type) **)((outputmatrix[bands])->iptr))[r-y1][c-x1]) = (123));
the error is for the ) after **

Answer 1

Just stop using macros as functions. Try this:
inline void setImagVal_Matrix(int matrix, int type, int x, int y, int val) {
getImagVal_Matrix(matrix, type, x, y) = val;
}
Change the int types as appropriate, and you'll get the compiler helping you with useful error messages instead of cryptic ones. Heck, it'll even help you figure out the argument types.

Answer 2

Within your macro, you do an assignment to something that does not look like an lvalue. Do you mean ==?

Answer 3

I would like to propose at least to use brackets for the macro arguments:
#define setImagVal_Matrix((matrix),(type),(x),(y),(val)) \
(getImagVal_Matrix((matrix),(type),(x),(y)) = (val))
Also, to see if it is really bracket issue, you can try to look at preprocessed file.
But, actually using macro for this purpose is not a good one practice. If you care about function call you can make the function inline:
inline void setImagVal_Matrix(matrix,type,x,y,val) {
getImagVal_Matrix(matrix,type,x,y) = val;
}
In spite of the fact that inline is only recommendation for the compiler, this will allow to avoid a lot of compilation errors and hardly debugging run-time errors.