@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @node Header Dirs @chapter Standard Header File Directories @code{GCC_INCLUDE_DIR} means the same thing for native and cross. It is where GNU CC stores its private include files, and also where GNU CC stores the fixed include files. A cross compiled GNU CC runs @code{fixincludes} on the header files in @file{$(tooldir)/include}. (If the cross compilation header files need to be fixed, they must be installed before GNU CC is built. If the cross compilation header files are already suitable for ISO C and GNU CC, nothing special need be done). @code{GPLUSPLUS_INCLUDE_DIR} means the same thing for native and cross. It is where @code{g++} looks first for header files. The C++ library installs only target independent header files in that directory. @code{LOCAL_INCLUDE_DIR} is used only by native compilers. GNU CC doesn't install anything there. It is normally @file{/usr/local/include}. This is where local additions to a packaged system should place header files. @code{CROSS_INCLUDE_DIR} is used only by cross compilers. GNU CC doesn't install anything there. @code{TOOL_INCLUDE_DIR} is used for both native and cross compilers. It is the place for other packages to install header files that GNU CC will use. For a cross-compiler, this is the equivalent of @file{/usr/include}. When you build a cross-compiler, @code{fixincludes} processes any header files in this directory.