On MacOSX machine I see such message in messages.log if some #include is added:
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('
line 473:41: expecting RPAREN, found '('

g++ -E main.cpp > test.cpp creates file with 2 unresolved identifiers

# 89 "/usr/include/mach/i386/_structs.h" 3 4
struct __darwin_fp_control
{
    unsigned short __invalid :1,
        __denorm :1,
    __zdiv :1,
    __ovrfl :1,
    __undfl :1,
    __precis :1,
      :2,
    __pc :2,
    __rc :2,
             :1,
      :3;
};
typedef struct __darwin_fp_control __darwin_fp_control_t;
# 147 "/usr/include/mach/i386/_structs.h" 3 4

int main(int argc, char** argv) {

    return 0;
}