undefined reference

This is a discussion on undefined reference within the C Programming forums, part of the General Programming Boards category; Hello, I have a problem. When trying to compile my sourcecode I get following warning: undefined reference to `add' This ...

  1. #1
    Registered User
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    Oct 2010
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    undefined reference

    Hello,

    I have a problem. When trying to compile my sourcecode I get following warning:

    undefined reference to `add'

    This is where I get it:

    Code:
    #include <stdio.h>
    #include <string.h>
    #include "mytype.h"
    
    int main(int argc, char *argv[])
    {
        MyType ps = {0,0};
        add(3, &ps);
        ...
    This is the header:

    Code:
    typedef struct 
    {
        int counter;
        int lastindex;
        unsigned int codes[100];
    } MyType;
    
    void add(unsigned int code, MyType *ps);
    What did I get wrong? Both files are in the same directory.

  2. #2
    a_capitalist_story
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    You need to actually define the add function.

  3. #3
    Registered User Swarvy's Avatar
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    United Kingdom
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    195
    It appears that you have included a function prototype for the function 'add', but no actual function. Hence the error 'undefined reference', since you are calling a function which you haven't included in your source code.

  4. #4
    Registered User
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    Hello, I defined the function in a file called mytype.c which includes mytype.h.
    How do I get it from there?

  5. #5
    a_capitalist_story
    Join Date
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    Depends on what you're using to compile your code. You need to compile it along with your other code.

  6. #6
    Registered User
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    Oct 2010
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    Oh yeah, I have to compile all source files at once, that was my mistake.

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