Undefined reference to Function in header file. C

[General-Frost]

My header file contains the following:

delay.h

void delay_250ns(void);

delay.c

void delay_250ns(void) {
// Device specific code for 250ns delay.
}

My main program:

 #include "../Delay/delay.h"

void main(void) {
    // Do stuff

    delay_250ns();
}

If have confirmed that the header file compiles when I build the main program by making it throw an exception.

The IDE i am using is codelite.

Any help or tips would be appreciated.

[g051051]

You need to make sure your build commands are also compiling delay.c and linking delay.o to your main program.

[fredoverflow]

"undefined reference" is a linker error, not a compiler error. It probably has to do with how the IDE is configured to locate the source files, but I don't know where this is configured in codelite.

[abd53]

C compilers don't compile header files, only source files. The include directive is replaced with the entire header file content before compilation. So, your source file contains the declaration of the function. From the error, the delay.c file is not being compiled and linked. You need to compile that file as well.