Hello,
As I can remember, in ansi C, global variables must be initialized by constants.
So we can write :
# define MYVAR 5
int a = MYVAR;
because the preprocessor replace MYVAR by 5 before compiling the sources.
But if we write
const int a = 1;
const int b = a;
We want initialise b with the value of a, which is a global variable and the compiler must detect an error (declare a constant variable will generate a compilation error if the variable is reassigned into the program, but it's still a variable, and not a constant).
The same compilation error should appear if we write in the global section
int a = 1;
int b = a;
int c = myFunction ();
However in local sections, initializer does not need to be constant, so we can write
void myfunction (void) {
const a = 1;
const b = a;
const c = myfunction2 ();
...
}
In summary, the keyword "const" is not the reason of this error, you can add or remove this keyword, the error will alway be the same.
It is just impossible to initialize a globale variable with another variable because globale variables are initialized before the execution of any instruction.
Regards
Étienne
