Linker command failed with exit code 1 In Xcode

问题

I'm writing C program in Xcode, and I got this problem:

ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Any idea to solve it?

Note: I've just update my OS to Mountain Lion yesterday.

回答1:

A common error is to define a symbol in a header when you wanted to declare it:

When you for instance declare a global variable and forget the extern or you define an inline function and forget the inline. In these cases the compiler emits the symbol in each compile unit that includes this header and you end up with multiple definitions of a symbol.

Anyway you should just look for the symbol in question.

来源：https://stackoverflow.com/questions/11704448/linker-command-failed-with-exit-code-1-in-xcode