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.

66 files changed, 470 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index 47ea83666f..fa6d945ed1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,44 @@
 2016-09-23  Zack Weinberg  <zackw@panix.com>
 
+	* 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.
+
+2016-09-23  Zack Weinberg  <zackw@panix.com>
+
 	* sysdeps/generic/sys/ucontext.h
 	* sysdeps/arm/sys/ucontext.h
 	* sysdeps/i386/sys/ucontext.h
diff --git a/Makefile b/Makefile
index 4478c97126..1ae3281184 100644
--- a/Makefile
+++ b/Makefile
@@ -318,6 +318,29 @@ $(objpfx)begin-end-check.out: scripts/begin-end-check.pl
 	$(evaluate-test)
 endif
 
+ifneq "$(headers)" ""
+# Special test of all the installed headers in this directory.
+tests-special += $(objpfx)check-installed-headers-c.out
+libof-check-installed-headers-c := nonlib
+$(objpfx)check-installed-headers-c.out: \
+    scripts/check-installed-headers.sh $(headers)
+	$(SHELL) $(..)scripts/check-installed-headers.sh c \
+	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(headers) > $@; \
+	$(evaluate-test)
+
+ifneq "$(CXX)" ""
+tests-special += $(objpfx)check-installed-headers-cxx.out
+libof-check-installed-headers-cxx := nonlib
+$(objpfx)check-installed-headers-cxx.out: \
+    scripts/check-installed-headers.sh $(headers)
+	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
+	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(headers) > $@; \
+	$(evaluate-test)
+endif
+endif
+
 define summarize-tests
 @egrep -v '^(PASS|XFAIL):' $(objpfx)$1 || true
 @echo "Summary of test results$2:"
diff --git a/Rules b/Rules
index 8306d36a07..342d659408 100644
--- a/Rules
+++ b/Rules
@@ -80,6 +80,29 @@ $(common-objpfx)dummy.c:
 	(echo 'extern void __dummy__ (void);'; \
 	 echo 'void __dummy__ (void) { }') > $@
 common-generated += dummy.o dummy.c
+
+ifneq "$(headers)" ""
+# Special test of all the installed headers in this directory.
+tests-special += $(objpfx)check-installed-headers-c.out
+libof-check-installed-headers-c := nonlib
+$(objpfx)check-installed-headers-c.out: \
+    $(..)scripts/check-installed-headers.sh $(headers)
+	$(SHELL) $(..)scripts/check-installed-headers.sh c \
+	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(headers) > $@; \
+	$(evaluate-test)
+
+ifneq "$(CXX)" ""
+tests-special += $(objpfx)check-installed-headers-cxx.out
+libof-check-installed-headers-cxx := nonlib
+$(objpfx)check-installed-headers-cxx.out: \
+    $(..)scripts/check-installed-headers.sh $(headers)
+	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
+	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
+	  $(headers) > $@; \
+	$(evaluate-test)
+endif
+endif
 
 # This makes all the auxiliary and test programs.
 
diff --git a/include/aliases.h b/include/aliases.h
index f7cfafcd6c..ece69ebe43 100644
--- a/include/aliases.h
+++ b/include/aliases.h
@@ -1,6 +1,8 @@
 #ifndef _ALIASES_H
 #include <inet/aliases.h>
 
+# ifndef _ISOMAC
+
 extern int __getaliasent_r (struct aliasent *__restrict __result_buf,
 			    char *__restrict __buffer, size_t __buflen,
 			    struct aliasent **__restrict __result)
@@ -34,4 +36,5 @@ DECLARE_NSS_PROTOTYPES (nis)
 DECLARE_NSS_PROTOTYPES (nisplus)
 #undef DECLARE_NSS_PROTOTYPES
 
+# endif /* !_ISOMAC */
 #endif
diff --git a/include/alloca.h b/include/alloca.h
index 01500259b8..fd90664f0a 100644
--- a/include/alloca.h
+++ b/include/alloca.h
@@ -1,6 +1,9 @@
 #ifndef _ALLOCA_H
 
 #include <stdlib/alloca.h>
+
+# ifndef _ISOMAC
+
 #include <stackinfo.h>
 
 #undef	__alloca
@@ -73,4 +76,5 @@ libc_hidden_proto (__libc_alloca_cutoff)
      extend_alloca (buf, len, s__); })
 #endif
 
+# endif /* !_ISOMAC */
 #endif
diff --git a/include/argz.h b/include/argz.h
index 4eab0b680b..0388c23277 100644
--- a/include/argz.h
+++ b/include/argz.h
@@ -2,8 +2,11 @@
 
 #include <string/argz.h>
 
+# ifndef _ISOMAC
+
 libc_hidden_proto (argz_delete)
 libc_hidden_proto (__argz_count)
 libc_hidden_proto (__argz_stringify)
 
+# endif /* !_ISOMAC */
 #endif
diff --git a/include/arpa/nameser.h b/include/arpa/nameser.h
inde