Installed header hygiene (BZ#20366): Test of installed headers.

This adds a test to ensure that the problems fixed in the last several
patches do not recur.  Each directory checks the headers that it
installs for two properties: first, each header must be compilable in
isolation, as both C and C++, under a representative combination of
language and library conformance levels; second, there is a blacklist
of identifiers that may not appear in any installed header, currently
consisting of the legacy BSD typedefs.  (There is an exemption for the
headers that define those typedefs, and for the RPC headers.  It may be
necessary to make this more sophisticated if we add more stuff to the
blacklist in the future.)

In order for this test to work correctly, every wrapper header
that actually defines something must guard those definitions with
 #ifndef _ISOMAC.  This is the existing mechanism used by the conform/
tests to tell wrapper headers not to define anything that the public
header wouldn't, and not to use anything from libc-symbols.h.  conform/
only cares for headers that we need to check for standards conformance,
whereas this test applies to *every* header.  (Headers in include/ that
are either installed directly, or are internal-use-only and do *not*
correspond to any installed header, are not affected.)

	* scripts/check-installed-headers.sh: New script.
	* Rules: In each directory that defines header files to be installed,
	run check-installed-headers.sh on them as a special test.
	* Makefile: Likewise for the headers installed at top level.

	* include/aliases.h, include/alloca.h, include/argz.h
	* include/arpa/nameser.h, include/arpa/nameser_compat.h
	* include/elf.h, include/envz.h, include/err.h
	* include/execinfo.h, include/fpu_control.h, include/getopt.h
	* include/gshadow.h, include/ifaddrs.h, include/libintl.h
	* include/link.h, include/malloc.h, include/mcheck.h
	* include/mntent.h, include/netinet/ether.h
	* include/nss.h, include/obstack.h, include/printf.h
	* include/pty.h, include/resolv.h, include/rpc/auth.h
	* include/rpc/auth_des.h, include/rpc/auth_unix.h
	* include/rpc/clnt.h, include/rpc/des_crypt.h
	* include/rpc/key_prot.h, include/rpc/netdb.h
	* include/rpc/pmap_clnt.h, include/rpc/pmap_prot.h
	* include/rpc/pmap_rmt.h, include/rpc/rpc.h
	* include/rpc/rpc_msg.h, include/rpc/svc.h
	* include/rpc/svc_auth.h, include/rpc/xdr.h
	* include/rpcsvc/nis_callback.h, include/rpcsvc/nislib.h
	* include/rpcsvc/yp.h, include/rpcsvc/ypclnt.h
	* include/rpcsvc/ypupd.h, include/shadow.h
	* include/stdio_ext.h, include/sys/epoll.h
	* include/sys/file.h, include/sys/gmon.h, include/sys/ioctl.h
	* include/sys/prctl.h, include/sys/profil.h
	* include/sys/statfs.h, include/sys/sysctl.h
	* include/sys/sysinfo.h, include/ttyent.h, include/utmp.h
	* sysdeps/arm/nacl/include/bits/setjmp.h
	* sysdeps/mips/include/sys/asm.h
	* sysdeps/unix/sysv/linux/include/sys/sysinfo.h
	* sysdeps/unix/sysv/linux/include/sys/timex.h
	* sysdeps/x86/fpu/include/bits/fenv.h:
	Add #ifndef _ISOMAC guard around internal declarations.
	Add multiple-inclusion guard if not already present.

2 files changed, 6 insertions, 0 deletions

diff --git a/include/arpa/nameser.h b/include/arpa/nameser.h
index ce6f023..cd7ab6e 100644
--- a/include/arpa/nameser.h
+++ b/include/arpa/nameser.h
@@ -2,6 +2,8 @@
 
 #include <resolv/arpa/nameser.h>
 
+# ifndef _ISOMAC
+
 /* If the machine allows unaligned access we can do better than using
    the NS_GET16, NS_GET32, NS_PUT16, and NS_PUT32 macros from the
    installed header.  */
@@ -74,4 +76,5 @@ libresolv_hidden_proto (ns_samename)
 libresolv_hidden_proto (ns_makecanon)
 libresolv_hidden_proto (ns_format_ttl)
 
+# endif /* !_ISOMAC */
 #endif
diff --git a/include/arpa/nameser_compat.h b/include/arpa/nameser_compat.h
index 2e735ed..6928000 100644
--- a/include/arpa/nameser_compat.h
+++ b/include/arpa/nameser_compat.h
@@ -1,8 +1,11 @@
 #ifndef _ARPA_NAMESER_COMPAT_
 #include <resolv/arpa/nameser_compat.h>
 
+# ifndef _ISOMAC
+
 /* Picksome unused number to represent lookups of IPv4 and IPv6 (i.e.,
    T_A and T_AAAA).  */
 #define T_UNSPEC 62321
 
+# endif /* !_ISOMAC */
 #endif