* lib/fcntl_.h: Prefer #include_next <foo.h> to #include @ABSOLUTE_FOO_H@ if @HAVE_INCLUDE_NEXT@. This works better with GCC 4.2, which otherwise issues a lot of warnings. * lib/inttypes_.h, lib/math_.h, lib/search_.h, lib/signal_.h: * lib/stdint_.h, lib/stdio_.h, lib/stdlib_.h, lib/string_.h: * lib/sys_time_.h, lib/time_.h, lib/wchar_.h, lib/wctype_.h: Likewise. * lib/stdlib_.h: Don't bother with #pragma GCC system_header, as it should no longer be needed. * lib/string_.h: Likewise. * modules/absolute-header (HAVE_INCLUDE_NEXT): New 'make' define. * modules/fcntl (fcntl.h): Substitute @HAVE_INCLUDE_NEXT@. * modules/inttypes (inttypes.h): Likewise. * modules/math (math.h): Likewise. * modules/search (search.h): Likewise. * modules/signal (signal.h): Likewise. * modules/stdint (stdint.h): Likewise. * modules/stdio (stdio.h): Likewise. * modules/stdlib (stdlib.h): Likewise. * modules/string (string.h): Likewise. * modules/sys_time (sys/time.h): Likewise. * modules/time (time.h): Likewise. * modules/wchar (wchar.h): Likewise. * modules/wctype (wtype.h): Likewise.

--- a/modules/absolute-header
+++ b/modules/absolute-header
@@ -9,6 +9,10 @@
 configure.ac:
 
 Makefile.am:
+# Use this preprocessor expression to decide whether #include_next works.
+# Do not rely on a 'configure'-time test for this, since the expression
+# might appear in an installed header, which is used by some other compiler.
+HAVE_INCLUDE_NEXT = (__GNUC__ || 60000000 <= __DECC_VER)
 
 Include: