I would like to bring Simon's patch for the
--with-native-system-header-dir configure option from the
google/integration branch into gcc mainline.  This patch permits
changing the system header directory from /usr/include to something
else.  It's mainly useful in conjunction with sysroot, so that the
header files don't have to live in usr/include under the sysroot.

Simon's original patch:

Bootstrapped and tested on x86_64-unknown-linux-gnu.  OK for mainline?


2011-10-07  Simon Baldwin  <sim...@google.com>

        * configure.ac: Add --with-native-system-header-dir option.
        * configure: Rebuild from configure.ac.
        * Makefile.in: Support --with-native-system-header-dir.
        * doc/install.texi: Document --with-native-system-header-dir.

Index: configure.ac
--- configure.ac	(revision 179665)
+++ configure.ac	(working copy)
@@ -725,6 +725,23 @@ AC_ARG_ENABLE(shared,
 ], [enable_shared=yes])
+# The use of native_system_header_dir here is for the value (optionally)
+# configured here.  Uses of NATIVE_SYSTEM_HEADER_DIR in this file refer
+# to the make variable defined in Makefile or in target make fragments.
+  [  --with-native-system-header-dir=dir
+                          use dir as the directory to look for standard
+                          system header files in.  Defaults to /usr/include.],
+ case ${with_native_system_header_dir} in
+ yes|no) AC_MSG_ERROR([bad value ${withval} given for native system include directory]) ;;
+ /*) ;;
+ *) AC_MSG_ERROR([${withval} should be an absolute directory]) ;;
+ esac
+ native_system_header_dir="${withval}"
+], [native_system_header_dir=/usr/include])
+AC_SUBST(NATIVE_SYSTEM_HEADER_DIR, $native_system_header_dir)
                   [use sysroot as the system root during the build])],
@@ -4515,14 +4532,14 @@ if test x$host != x$target || test "x$TA
   elif test "x$with_sysroot" = x; then
   elif test "x$with_build_sysroot" != "x"; then
-    target_header_dir="${with_build_sysroot}/usr/include"
+    target_header_dir="${with_build_sysroot}${native_system_header_dir}"
   elif test "x$with_sysroot" = xyes; then
-    target_header_dir="${exec_prefix}/${target_noncanonical}/sys-root/usr/include"
+    target_header_dir="${exec_prefix}/${target_noncanonical}/sys-root${native_system_header_dir}"
-    target_header_dir="${with_sysroot}/usr/include"
+    target_header_dir="${with_sysroot}${native_system_header_dir}"
-  target_header_dir=/usr/include
+  target_header_dir=${native_system_header_dir}
 # Test for stack protector support in target C library.
Index: Makefile.in
--- Makefile.in	(revision 179665)
+++ Makefile.in	(working copy)
@@ -455,7 +455,7 @@ LINKER_PLUGIN_API_H = $(srcdir)/../inclu
 LTO_SYMTAB_H = $(srcdir)/../include/lto-symtab.h
 # Default native SYSTEM_HEADER_DIR, to be overridden by targets.
 # Default cross SYSTEM_HEADER_DIR, to be overridden by targets.
Index: doc/install.texi
--- doc/install.texi	(revision 179665)
+++ doc/install.texi	(working copy)
@@ -903,6 +903,18 @@ ideas of what it is for.  People use it 
 install part of GCC@.  Perhaps they make this assumption because
 installing GCC creates the directory.
+@item --with-native-system-header-dir=@var{dirname}
+Specifies that @var{dirname} is the directory that contains native system
+header files, rather than @file{/usr/include}. This option is most useful
+if you are creating a compiler that should be isolated from the system
+as much as possible.  It is most commonly used with the
+@option{--with-sysroot} option and will cause GCC to search
+@var{dirname} inside the system root specified by that option.
+Please note that for certain targets, such as DJGPP, this value is
+ignored. If the target specifies a default value for native system
+header files then this option is ignored.
 @item --enable-shared[=@var{package}[,@dots{}]]
 Build shared versions of libraries, if shared libraries are supported on
 the target platform.  Unlike GCC 2.95.x and earlier, shared libraries
@@ -1736,6 +1748,10 @@ target libraries (which runs on the buil
 installed with @code{make install}; it does not affect the compiler which is
 used to build GCC itself.
+If you specify the @option{--with-native-system-header-dir=@var{dirname}}
+option then the compiler will search that directory within @var{dirname} for
+native system headers rather than the default @file{/usr/include}.
 @item --with-build-sysroot
 @itemx --with-build-sysroot=@var{dir}
 Tells GCC to consider @var{dir} as the system root (see
@@ -1750,6 +1766,10 @@ This option affects the system root for 
 target libraries (which runs on the build system); it does not affect
 the compiler which is used to build GCC itself.
+If you specify the @option{--with-native-system-header-dir=@var{dirname}}
+option then the compiler will search that directory within @var{dirname} for
+native system headers rather than the default @file{/usr/include}.
 @item --with-headers
 @itemx --with-headers=@var{dir}
 Deprecated in favor of @option{--with-sysroot}.

Reply via email to