__FUNCTION__ and friends act weird in Xcode

问题

This works

printf("%s body\n",__PRETTY_FUNCTION__);

But this does not (Error Expected ')'):

printf(__PRETTY_FUNCTION__" body\n");

I can't get the IDE to show me what __PRETTY_FUNCTION__ evaluates to to determine why it does not work.

回答1:

__PRETTY_FUNCTION__ is not a macro. It behaves like a static variable created on the fly scoped in that function.

The last paragraph in the link above reads:

These identifiers are not preprocessor macros. In GCC 3.3 and earlier, in C only, __FUNCTION__ and __PRETTY_FUNCTION__ were treated as string literals; they could be used to initialize char arrays, and they could be concatenated with other string literals. GCC 3.4 and later treat them as variables, like __func__. In C++, __FUNCTION__ and __PRETTY_FUNCTION__ have always been variables.

来源：https://stackoverflow.com/questions/11142779/function-and-friends-act-weird-in-xcode