Undefined symbols for architecture x86_64 “_min”

Question

I'm having a problem using min() and max() function in my C project. I've imported math.h, but when I compile the file I keep getting the following error (a similar error is displayed even using gcc instead of llvm):

    Undefined symbols for architecture x86_64:
  "_min", referenced from:
      _main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I think the problem is that there isn't a 64 bit library of math.h... or the compiler can't find it. I'm using Mac OS X 10.7. How may I fix this problem?

Answer 1

Even though I can see "min" defined in libSystem.dylib, I don't think there's an exported header for that. And I can't figure out where "_min" is coming in from, in terms of the include files.

Normally "min" is referred to with a macro or with your own function. Check out this very related question somebody else asked a while back.

If you look in math.h, there are some "min" type functions in there but they are for floats and doubles. If you are just working with integers or custom types, roll your own function.