PATCH: cpp include directory search order warning

["John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>]

Here is a fix for the problems noted in this thread:

<http://gcc.gnu.org/ml/gcc/2002-07/msg01463.html>.

The warning from remove_dup_dirs is changed to an information message
generated only when the "-v" option is used.  This allows various
autoconf macros to reorder the search patch for includes and change
system directories to non-system directories without any warnings from
the preprocessor.  This will fix the problems caused by the warning.
However, don't complain to me about an incorrectly ordered include
search :-)

Without the fix, it is not possible to install libintl, libiconv,
etc in either the GCC prefix or local_prefix directories without
there being cpp warnings building packages which use these libraries.
In some cases, these warnings break configure scripts.

I changed the message itself because it's about the change of a
system directory to a non-system directory, and not about reordering.

The change to configure.in just fixes a minor problem of duplicated
directories when local_prefix and prefix have the same value.

I have attempted to summarize the site configuration issues regarding
include searching and library searching in a paragraph added to
install.texi.

Tested with no regressions on hppa2.0-hp-hpux11.00.

OK for main?

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)

2002-08-07  John David Anglin  <dave@hiauly1.hia.nrc.ca>

	* configure.in (PREFIX_INCLUDE_DIR): Don't define if prefix and
	local_prefix are the same.
	* cppinit.c (remove_dup_dirs): Change warnings to verbose information
	messages.  Revise message text.
	* doc/install.texi (--with-local-prefix): Further document usage of
	this option.
	* configure: Rebuilt.

Index: configure.in
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/configure.in,v
retrieving revision 1.613
diff -u -3 -p -r1.613 configure.in
--- configure.in	2 Aug 2002 15:57:09 -0000	1.613
+++ configure.in	7 Aug 2002 15:37:21 -0000
@@ -2202,7 +2202,7 @@ case "$target" in
     ;;
 esac
 
-if test "$prefix" != "/usr" && test "$prefix" != "/usr/local" ; then
+if test "$prefix" != "/usr" && test "x$prefix" != "x$local_prefix" ; then
   AC_DEFINE_UNQUOTED(PREFIX_INCLUDE_DIR, "$prefix/include")
 fi
 
Index: cppinit.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/cppinit.c,v
retrieving revision 1.249
diff -u -3 -p -r1.249 cppinit.c
--- cppinit.c	6 Aug 2002 20:35:41 -0000	1.249
+++ cppinit.c	7 Aug 2002 15:37:22 -0000
@@ -296,18 +296,16 @@ remove_dup_dirs (pfile, head)
       for (other = head; other != cur; other = other->next)
 	if (INO_T_EQ (cur->ino, other->ino) && cur->dev == other->dev)
 	  {
-	    if (cur->sysp && !other->sysp)
+	    if (cur->sysp && !other->sysp && CPP_OPTION (pfile, verbose))
 	      {
-		cpp_error (pfile, DL_WARNING,
-			   "changing search order for system directory \"%s\"",
-			   cur->name);
+		fprintf (stderr, _("system directory \"%s\"\n"), cur->name);
 		if (strcmp (cur->name, other->name))
-		  cpp_error (pfile, DL_WARNING,
-			     "  as it is the same as non-system directory \"%s\"",
-			     other->name);
+		  fprintf (stderr,
+			   _("  is the same as non-system directory \"%s\"\n"),
+			   other->name);
 		else
-		  cpp_error (pfile, DL_WARNING,
-			     "  as it has already been specified as a non-system directory");
+		  fprintf (stderr,
+			   _("  was previously specified as a non-system directory\n"));
 	      }
 	    cur = remove_dup_dir (pfile, prev);
 	    break;
Index: doc/install.texi
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/doc/install.texi,v
retrieving revision 1.130
diff -u -3 -p -r1.130 install.texi
--- doc/install.texi	6 Aug 2002 15:08:07 -0000	1.130
+++ doc/install.texi	7 Aug 2002 15:37:23 -0000
@@ -467,6 +467,21 @@ any in that directory---are not part of 
 programs---perhaps many others.  (GCC installs its own header files in
 another directory which is based on the @option{--prefix} value.)
 
+The local-prefix include directory is searched before the GCC-prefix
+include directory.  Some autoconf macros use @option{-I} to change the
+search order for directories containing installed packages.  This can
+result in a GCC system directory being changed to a non-system directory.
+It may be advisable to not use either of these two prefixes for package
+installation if this is a concern.  On the otherhand, GCC autmatically
+searches for ordinary libraries using @env{GCC_EXEC_PREFIX} without
+the user having to specify a linker search path.  Therefore, using
+the GCC-prefix directory for packages may provide a site configuration
+that is easier use.  It is possible to use the same value for both
+@option{--with-local-prefix} and @option{--prefix} provided the value
+is not @file{/usr}.  This can be used to avoid the default search of
+@file{/usr/local/include} when GCC is installed in a non-standard
+location.
+
 @strong{Do not} specify @file{/usr} as the @option{--with-local-prefix}!
 The directory you use for @option{--with-local-prefix} @strong{must not}
 contain any of the system's standard header files.  If it did contain