How can I set a breakpoint to a function in Xcode4?

H开发者_高级运维ow can I set a breakpoint to a function such as CGErrorBreakpoint in Xcode4?

You need to add a symbolic break point for it. To do that, switch to the Breakpoint Navigator (2nd one from the right in the navigator tabbar). Then press the + button at the bottom of the window. It'll allow you to add the symbolic breakpoint.