Xcode和Clang神秘地包含了我没有指定的标题

Question

I have a header with the following code which has mysterious errors stemming from the definition of CROUND in the header file /usr/include/sys/param.h which is not included either in the code itself or via the command line parameters:

#ifndef _PARSERTYPES_H_
#define _PARSERTYPES_H_    

#ifdef CROUND
#warning #undef CROUND applied, defined in /usr/include/sys/param.h  
#undef CROUND
#endif // CROUND
enum TokType
{
  FLOATING, INTEGER, STRING, SYMBOL,
    OCURLY, CCURLY, OROUND, CROUND, OSQUARE, CSQUARE, 
};    

#endif // _PARSERTYPES_H_

Compiled with the simplified clang (c++) or gcc (g++) compiler command:

cd /path/to/build3/modules/device/examples/sweep && /usr/bin/g++   -DQT_OPENGL_LIB -DQT_DESIGNER_LIB -DQT_GUI_LIB -DQT_SQL_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -D__DC1394__ - -DQT_NO_DEBUG -O3 -DNDEBUG -I/path/to/modules//. -I/opt/local/include -I/opt/local/include/opencv -I/usr/local/include -I/opt/local/include/QtOpenGL -I/opt/local/include/QtDesigner -I/opt/local/include/QtGui -I/opt/local/include/QtSql -I/opt/local/include/QtNetwork -I/opt/local/include/QtCore -I/Library/Frameworks/FreeType.framework/Headers -F/Library/Frameworks -I/opt/local/include/glib-2.0 -I/opt/local/lib/glib-2.0/include -I/opt/local/include/gdk-pixbuf-2.0 -I/opt/local/include/gtk-2.0 -I/opt/local/lib/gtk-2.0/include -I/Library/Frameworks/cairo.framework/Headers -I/opt/local/include/pango-1.0 -I/opt/local/include/atk-1.0    -o CMakeFiles/Example.dir/Example.cpp.o -c /path/to/modules/Example.cpp

That produces the following (clang) error:

In file included from /path/to/parser/parser.h:69:
path/to/parser/parserTypes.h:58:26: error: expected '}'
        OCURLY, CCURLY, OROUND, CROUND, OSQUARE, CSQUARE, 
                                ^
/usr/include/sys/param.h:171:16: note: expanded from macro 'CROUND'
#define CROUND  (CBLOCK - 1)    /* Clist rounding. */
                ^
/path/to/parser/parserTypes.h:56:1: note: to match this '{'
{

I was able to work around the problem with #undef CROUND, but obviously this is a very temporary solution.

What could be the source of and proper solution to this problem?

Answer 1

You are probably including SOME system header file, right? These usually include a whole pile of other headers...

EDIT: as for a solution...

a) use other names that's don't conflict

b) on reasonably recent compilers, use enum class (unless you are conflicting with a macro... which appears to be the case here)

EDIT 2: in general, I would NOT recommend trying to "work around" that other header by cheap tricks such as #defining the include guard macro or similar stuff. System headers are best left alone.