1*ec02198aSmrg@c Copyright (C) 1988-2020 Free Software Foundation, Inc. 210d565efSmrg@c This is part of the GCC manual. 310d565efSmrg@c For copying conditions, see the file gcc.texi. 410d565efSmrg 510d565efSmrg@node Header Dirs 610d565efSmrg@chapter Standard Header File Directories 710d565efSmrg 810d565efSmrg@code{GCC_INCLUDE_DIR} means the same thing for native and cross. It is 910d565efSmrgwhere GCC stores its private include files, and also where GCC 1010d565efSmrgstores the fixed include files. A cross compiled GCC runs 1110d565efSmrg@code{fixincludes} on the header files in @file{$(tooldir)/include}. 1210d565efSmrg(If the cross compilation header files need to be fixed, they must be 1310d565efSmrginstalled before GCC is built. If the cross compilation header files 1410d565efSmrgare already suitable for GCC, nothing special need be done). 1510d565efSmrg 1610d565efSmrg@code{GPLUSPLUS_INCLUDE_DIR} means the same thing for native and cross. It 1710d565efSmrgis where @command{g++} looks first for header files. The C++ library 1810d565efSmrginstalls only target independent header files in that directory. 1910d565efSmrg 2010d565efSmrg@code{LOCAL_INCLUDE_DIR} is used only by native compilers. GCC 2110d565efSmrgdoesn't install anything there. It is normally 2210d565efSmrg@file{/usr/local/include}. This is where local additions to a packaged 2310d565efSmrgsystem should place header files. 2410d565efSmrg 2510d565efSmrg@code{CROSS_INCLUDE_DIR} is used only by cross compilers. GCC 2610d565efSmrgdoesn't install anything there. 2710d565efSmrg 2810d565efSmrg@code{TOOL_INCLUDE_DIR} is used for both native and cross compilers. It 2910d565efSmrgis the place for other packages to install header files that GCC will 3010d565efSmrguse. For a cross-compiler, this is the equivalent of 3110d565efSmrg@file{/usr/include}. When you build a cross-compiler, 3210d565efSmrg@code{fixincludes} processes any header files in this directory. 33