glibc/Makefile
Joseph Myers 487890009e Support __STDC_WANT_LIB_EXT2__ feature test macro.
This patch implements support for the __STDC_WANT_LIB_EXT2__ feature
test macro from ISO/IEC TR 24731-2:2010, thereby implementing one
possible approach for supporting ISO C feature test macros.

Recall that, as described in
<https://sourceware.org/ml/libc-alpha/2016-05/msg00486.html>, these
macros work based on the definition when affected headers are
included, so cannot be handled once when the first system header is
included because that might not be one of the headers the particular
macro in question affects.
<https://sourceware.org/ml/libc-alpha/2016-05/msg00680.html> expresses
views on possible approaches for implementation and
<https://sourceware.org/ml/libc-alpha/2016-06/msg00039.html> follows
up on that.

This patch arranges things so that the relevant condition is
__GLIBC_USE (LIB_EXT2), following one of the suggestions given.
Headers using these macros include <bits/libc-header-start.h>, which
in turn includes <features.h>.  Headers must define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION before including
<bits/libc-header-start.h>, to discourage inclusion outside glibc as
requested.  __USE_GNU conditions on affected functions are changed to
__GLIBC_USE (LIB_EXT2), while it's added as an additional alternative
on the conditions for functions already enabled for some POSIX
versions.

It would be possible to convert existing __USE_* conditionals to
__GLIBC_USE (with the relevant __GLIBC_USE_* being defined in
<features.h> where __USE_* are presently defined), and so make them
typo-proof (given -Wundef -Werror in glibc builds) because __GLIBC_USE
is used with #if not #ifdef / #if defined.

No attempt is made to enforce the rule about diagnosing different
definitions of __STDC_WANT_LIB_EXT2__ when affected headers are
included; such a diagnostic is incompatible with multiple-include
guards on the affected headers, unless compiler extensions are added
to support it.

As previously noted, glibc does not implement all features from TR
24731-2:2010: the functions aswprintf vaswprintf getwdelim getwline
are not in glibc, although they would be appropriate to add if someone
wished to do so.  But I think it makes sense to support the feature
test macro if *any* of the controlled features are present in glibc.

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	* bits/libc-header-start.h: New file.
	* Makefile (headers): Add bits/libc-header-start.h.
	* include/features.h (__STDC_WANT_LIB_EXT2__): Document.
	(__GLIBC_USE): New macro.
	* libio/stdio.h: Define
	__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
	<bits/libc-header-start.h> instead of including <features.h>.
	(fmemopen): Declare also if [__GLIBC_USE (LIB_EXT2)].
	(open_memstream): Likewise.
	(vasprintf): Declare if [__GLIBC_USE (LIB_EXT2)], not [__USE_GNU].
	(__asprintf): Likewise.
	(asprintf): Likewise.
	(__getdelim): Declare also if [__GLIBC_USE (LIB_EXT2)].
	(getdelim): Likewise.
	(getline): Likewise.
	* string/string.h: Define
	__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
	<bits/libc-header-start.h> instead of including <features.h>.
	(strdup): Declare also if [__GLIBC_USE (LIB_EXT2)]
	(strndup): Likewise.
	* wcsmbs/wchar.h: Define
	__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
	<bits/libc-header-start.h> instead of including <features.h>.
	(open_wmemstream): Declare also if [__GLIBC_USE (LIB_EXT2)].
	* manual/creature.texi (__STDC_WANT_LIB_EXT2__): Document macro.
2016-08-02 17:40:35 +00:00

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# Copyright (C) 1991-2016 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
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# modify it under the terms of the GNU Lesser General Public
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# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.
#
# Master Makefile for the GNU C library
#
ifneq (,)
This makefile requires GNU Make.
endif
include Makeconfig
# This is the default target; it makes everything except the tests.
.PHONY: all
all: lib others
ifneq ($(AUTOCONF),no)
define autoconf-it
@-rm -f $@.new
$(AUTOCONF) $(ACFLAGS) $< > $@.new
chmod a-w$(patsubst %,$(comma)a+x,$(filter .,$(@D))) $@.new
mv -f $@.new $@
endef
configure: configure.ac aclocal.m4; $(autoconf-it)
%/configure: %/configure.ac aclocal.m4; $(autoconf-it)
%/preconfigure: %/preconfigure.ac aclocal.m4; $(autoconf-it)
endif # $(AUTOCONF) = no
# We don't want to run anything here in parallel.
.NOTPARALLEL:
# These are the targets that are made by making them in each subdirectory.
+subdir_targets := subdir_lib objects objs others subdir_mostlyclean \
subdir_clean subdir_distclean subdir_realclean \
tests xtests \
subdir_update-abi subdir_check-abi \
subdir_update-all-abi \
subdir_echo-headers \
subdir_install \
subdir_objs subdir_stubs subdir_testclean \
$(addprefix install-, no-libc.a bin lib data headers others)
headers := limits.h values.h features.h gnu-versions.h \
bits/xopen_lim.h gnu/libc-version.h stdc-predef.h \
bits/libc-header-start.h
echo-headers: subdir_echo-headers
# The headers are in the include directory.
subdir-dirs = include
vpath %.h $(subdir-dirs)
# What to install.
install-others = $(inst_includedir)/gnu/stubs.h
install-bin-script =
ifeq (yes,$(build-shared))
headers += gnu/lib-names.h
endif
include Makerules
ifeq ($(build-programs),yes)
others: $(addprefix $(objpfx),$(install-bin-script))
endif
# Install from subdirectories too.
install: subdir_install
# Explicit dependency so that `make install-headers' works
install-headers: install-headers-nosubdir
# Make sure that the dynamic linker is installed before libc.
$(inst_slibdir)/libc-$(version).so: elf/ldso_install
.PHONY: elf/ldso_install
elf/ldso_install:
$(MAKE) -C $(@D) $(@F)
# Create links for shared libraries using the `ldconfig' program if possible.
# Ignore the error if we cannot update /etc/ld.so.cache.
ifeq (no,$(cross-compiling))
ifeq (yes,$(build-shared))
install: install-symbolic-link
.PHONY: install-symbolic-link
install-symbolic-link: subdir_install
$(symbolic-link-prog) $(symbolic-link-list)
rm -f $(symbolic-link-list)
install:
-test ! -x $(elf-objpfx)ldconfig || LC_ALL=C \
$(elf-objpfx)ldconfig $(addprefix -r ,$(install_root)) \
$(slibdir) $(libdir)
ifneq (no,$(PERL))
ifeq (/usr,$(prefix))
ifeq (,$(install_root))
LD_SO=$(ld.so-version) CC="$(CC)" $(PERL) scripts/test-installation.pl $(common-objpfx)
endif
endif
endif
endif
endif
# Build subdirectory lib objects.
lib-noranlib: subdir_lib
ifeq (yes,$(build-shared))
# Build the shared object from the PIC object library.
lib: $(common-objpfx)libc.so $(common-objpfx)linkobj/libc.so
endif # $(build-shared)
# This is a handy script for running any dynamically linked program against
# the current libc build for testing.
$(common-objpfx)testrun.sh: $(common-objpfx)config.make \
$(..)Makeconfig $(..)Makefile
(echo '#!/bin/sh'; \
echo 'builddir=`dirname "$$0"`'; \
echo 'GCONV_PATH="$${builddir}/iconvdata" \'; \
echo 'exec $(subst $(common-objdir),"$${builddir}",\
$(test-program-prefix)) $${1+"$$@"}'; \
) > $@T
chmod a+x $@T
mv -f $@T $@
postclean-generated += testrun.sh
others: $(common-objpfx)testrun.sh
# Makerules creates a file `stubs' in each subdirectory, which
# contains `#define __stub_FUNCTION' for each function defined in that
# directory which is a stub.
# Here we paste all of these together into <gnu/stubs.h>.
subdir-stubs := $(foreach dir,$(subdirs),$(common-objpfx)$(dir)/stubs)
ifndef abi-variants
installed-stubs = $(inst_includedir)/gnu/stubs.h
else
installed-stubs = $(inst_includedir)/gnu/stubs-$(default-abi).h
$(inst_includedir)/gnu/stubs.h: $(+force)
$(make-target-directory)
{ \
echo '/* This file is automatically generated.';\
echo " This file selects the right generated file of \`__stub_FUNCTION' macros";\
echo ' based on the architecture being compiled for. */'; \
echo ''; \
$(foreach h,$(abi-includes), echo '#include <$(h)>';) \
echo ''; \
$(foreach v,$(abi-variants),\
$(if $(abi-$(v)-condition),\
echo '#if $(abi-$(v)-condition)'; \
echo '# include <gnu/stubs-$(v).h>'); \
$(if $(abi-$(v)-condition),echo '#endif';) \
rm -f $(@:.d=.h).new$(v); \
) \
} > $(@:.d=.h).new
mv -f $(@:.d=.h).new $(@:.d=.h)
install-others-nosubdir: $(installed-stubs)
endif
# Since stubs.h is never needed when building the library, we simplify the
# hairy installation process by producing it in place only as the last part
# of the top-level `make install'. It depends on subdir_install, which
# iterates over all the subdirs; subdir_install in each subdir depends on
# the subdir's stubs file. Having more direct dependencies would result in
# extra iterations over the list for subdirs and many recursive makes.
$(installed-stubs): include/stubs-prologue.h subdir_install
$(make-target-directory)
@rm -f $(objpfx)stubs.h
(sed '/^@/d' $<; LC_ALL=C sort $(subdir-stubs)) > $(objpfx)stubs.h
if test -r $@ && cmp -s $(objpfx)stubs.h $@; \
then echo 'stubs.h unchanged'; \
else $(INSTALL_DATA) $(objpfx)stubs.h $@; fi
rm -f $(objpfx)stubs.h
# This makes the Info or DVI file of the documentation from the Texinfo source.
.PHONY: info dvi pdf html
info dvi pdf html:
$(MAKE) $(PARALLELMFLAGS) -C manual $@
# This makes all the subdirectory targets.
# For each target, make it depend on DIR/target for each subdirectory DIR.
$(+subdir_targets): %: $(addsuffix /%,$(subdirs))
# Compute a list of all those targets.
all-subdirs-targets := $(foreach dir,$(subdirs),\
$(addprefix $(dir)/,$(+subdir_targets)))
# The action for each of those is to cd into the directory and make the
# target there.
$(all-subdirs-targets):
$(MAKE) $(PARALLELMFLAGS) $(subdir-target-args) $(@F)
define subdir-target-args
subdir=$(@D)$(if $($(@D)-srcdir),\
-C $($(@D)-srcdir) ..=`pwd`/,\
-C $(@D) ..=../)
endef
.PHONY: $(+subdir_targets) $(all-subdirs-targets)
# Targets to clean things up to various degrees.
.PHONY: clean realclean distclean distclean-1 parent-clean parent-mostlyclean \
tests-clean
# Subroutines of all cleaning targets.
parent-mostlyclean: common-mostlyclean # common-mostlyclean is in Makerules.
-rm -f $(foreach o,$(object-suffixes-for-libc),\
$(common-objpfx)$(patsubst %,$(libtype$o),c)) \
$(addprefix $(objpfx),$(install-lib))
parent-clean: parent-mostlyclean common-clean
postclean = $(addprefix $(common-objpfx),$(postclean-generated)) \
$(addprefix $(objpfx),sysd-dirs sysd-rules) \
$(addprefix $(objpfx),sysd-sorted soversions.mk soversions.i)
clean: parent-clean
# This is done this way rather than having `subdir_clean' be a
# dependency of this target so that libc.a will be removed before the
# subdirectories are dealt with and so they won't try to remove object
# files from it when it's going to be removed anyway.
@$(MAKE) subdir_clean no_deps=t
-rm -f $(postclean)
mostlyclean: parent-mostlyclean
@$(MAKE) subdir_mostlyclean no_deps=t
-rm -f $(postclean)
tests-clean:
@$(MAKE) subdir_testclean no_deps=t
ifneq (,$(CXX))
vpath c++-types.data $(+sysdep_dirs)
tests-special += $(objpfx)c++-types-check.out
$(objpfx)c++-types-check.out: c++-types.data scripts/check-c++-types.sh
scripts/check-c++-types.sh $< $(CXX) $(filter-out -std=gnu11 $(+gccwarn-c),$(CFLAGS)) $(CPPFLAGS) > $@; \
$(evaluate-test)
endif
tests-special += $(objpfx)check-local-headers.out
$(objpfx)check-local-headers.out: scripts/check-local-headers.sh
AWK='$(AWK)' scripts/check-local-headers.sh \
"$(includedir)" "$(objpfx)" < /dev/null > $@; \
$(evaluate-test)
ifneq ($(PERL),no)
installed-headers = argp/argp.h assert/assert.h catgets/nl_types.h \
crypt/crypt.h ctype/ctype.h debug/execinfo.h \
dirent/dirent.h dlfcn/dlfcn.h elf/elf.h elf/link.h \
gmon/sys/gmon.h gmon/sys/gmon_out.h gmon/sys/profil.h \
grp/grp.h gshadow/gshadow.h iconv/iconv.h iconv/gconv.h \
$(wildcard inet/netinet/*.h) \
$(wildcard inet/arpa/*.h inet/protocols/*.h) \
inet/aliases.h inet/ifaddrs.h inet/netinet/ip6.h \
inet/netinet/icmp6.h intl/libintl.h io/sys/stat.h \
io/sys/statfs.h io/sys/vfs.h io/sys/statvfs.h \
io/fcntl.h io/sys/fcntl.h io/poll.h io/sys/poll.h \
io/utime.h io/ftw.h io/fts.h io/sys/sendfile.h \
libio/stdio.h libio/libio.h locale/locale.h \
locale/langinfo.h locale/xlocale.h login/utmp.h \
login/lastlog.h login/pty.h malloc/malloc.h \
malloc/obstack.h malloc/mcheck.h math/math.h \
math/complex.h math/fenv.h math/tgmath.h misc/sys/uio.h \
$(wildcard nis/rpcsvc/*.h) nptl_db/thread_db.h \
sysdeps/nptl/pthread.h sysdeps/pthread/semaphore.h \
nss/nss.h posix/sys/utsname.h posix/sys/times.h \
posix/sys/wait.h posix/sys/types.h posix/unistd.h \
posix/glob.h posix/regex.h posix/wordexp.h posix/fnmatch.h\
posix/getopt.h posix/tar.h posix/sys/unistd.h \
posix/sched.h posix/re_comp.h posix/wait.h \
posix/cpio.h posix/spawn.h pwd/pwd.h resolv/resolv.h \
resolv/netdb.h $(wildcard resolv/arpa/*.h) \
resource/sys/resource.h resource/sys/vlimit.h \
resource/sys/vtimes.h resource/ulimit.h rt/aio.h \
rt/mqueue.h setjmp/setjmp.h shadow/shadow.h \
signal/signal.h signal/sys/signal.h socket/sys/socket.h \
socket/sys/un.h stdio-common/printf.h \
stdio-common/stdio_ext.h stdlib/stdlib.h stdlib/alloca.h \
stdlib/monetary.h stdlib/fmtmsg.h stdlib/ucontext.h \
sysdeps/generic/inttypes.h sysdeps/generic/stdint.h \
stdlib/errno.h stdlib/sys/errno.h string/string.h \
string/strings.h string/memory.h string/endian.h \
string/argz.h string/envz.h string/byteswap.h \
$(wildcard sunrpc/rpc/*.h sunrpc/rpcsvc/*.h) \
sysvipc/sys/ipc.h sysvipc/sys/msg.h sysvipc/sys/sem.h \
sysvipc/sys/shm.h termios/termios.h \
termios/sys/termios.h termios/sys/ttychars.h time/time.h \
time/sys/time.h time/sys/timeb.h wcsmbs/wchar.h \
wctype/wctype.h
tests-special += $(objpfx)begin-end-check.out
$(objpfx)begin-end-check.out: scripts/begin-end-check.pl
$(PERL) scripts/begin-end-check.pl $(installed-headers) > $@; \
$(evaluate-test)
endif
define summarize-tests
@egrep -v '^(PASS|XFAIL):' $(objpfx)$1 || true
@echo "Summary of test results$2:"
@sed 's/:.*//' < $(objpfx)$1 | sort | uniq -c
@! egrep -q -v '^(X?PASS|XFAIL|UNSUPPORTED):' $(objpfx)$1
endef
tests-special-notdir = $(patsubst $(objpfx)%, %, $(tests-special))
tests: $(tests-special)
$(..)scripts/merge-test-results.sh -s $(objpfx) "" \
$(sort $(tests-special-notdir:.out=)) \
> $(objpfx)subdir-tests.sum
$(..)scripts/merge-test-results.sh -t $(objpfx) subdir-tests.sum \
$(sort $(subdirs) .) \
> $(objpfx)tests.sum
$(call summarize-tests,tests.sum)
xtests:
$(..)scripts/merge-test-results.sh -t $(objpfx) subdir-xtests.sum \
$(sort $(subdirs)) \
> $(objpfx)xtests.sum
$(call summarize-tests,xtests.sum, for extra tests)
# The realclean target is just like distclean for the parent, but we want
# the subdirs to know the difference in case they care.
realclean distclean: parent-clean
# This is done this way rather than having `subdir_distclean' be a
# dependency of this target so that libc.a will be removed before the
# subdirectories are dealt with and so they won't try to remove object
# files from it when it's going to be removed anyway.
@$(MAKE) distclean-1 no_deps=t distclean-1=$@ avoid-generated=yes \
sysdep-subdirs="$(sysdep-subdirs)"
-rm -f $(postclean)
# Subroutine of distclean and realclean.
distclean-1: subdir_$(distclean-1)
-rm -f $(config-generated)
-rm -f $(addprefix $(objpfx),config.status config.cache config.log)
-rm -f $(addprefix $(objpfx),config.make config-name.h config.h)
ifdef objdir
-rm -f $(objpfx)Makefile
endif
-rm -f $(sysdep-$(distclean-1))
# Make the TAGS file for Emacs users.
.PHONY: TAGS
TAGS:
scripts/list-sources.sh | sed -n -e '/Makefile/p' \
$(foreach S,[chsSyl] cxx sh bash pl,\
$(subst .,\.,-e '/.$S\(.in\)*$$/p')) \
| $(ETAGS) -o $@ -
# Make the distribution tarfile.
.PHONY: dist dist-prepare
generated := $(generated) stubs.h
files-for-dist := README INSTALL configure ChangeLog NEWS
# Regenerate stuff, then error if these things are not committed yet.
dist-prepare: $(files-for-dist)
conf=`find sysdeps $(addsuffix /sysdeps,$(sysdeps-add-ons)) \
-name configure`; \
$(MAKE) $$conf && \
git diff --stat HEAD -- $^ $$conf \
| $(AWK) '{ print; rc=1 } END { exit rc }'
%.tar: FORCE
git archive --prefix=$*/ $* > $@.new
mv -f $@.new $@
# Do `make dist dist-version=X.Y.Z' to make tar files of an older version.
ifneq (,$(strip $(dist-version)))
dist: $(foreach Z,.bz2 .gz .xz,$(dist-version).tar$Z)
md5sum $^
else
dist: dist-prepare
@if v=`git describe`; then \
echo Distribution version $$v; \
$(MAKE) dist dist-version=$$v; \
else \
false; \
fi
endif
INSTALL: manual/install-plain.texi manual/macros.texi \
$(common-objpfx)manual/pkgvers.texi manual/install.texi
makeinfo --no-validate --plaintext --no-number-sections \
-I$(common-objpfx)manual $< -o $@-tmp
$(AWK) 'NF == 0 { ++n; next } \
NF != 0 { while (n-- > 0) print ""; n = 0; print }' \
< $@-tmp > $@-tmp2
rm -f $@-tmp
-chmod a-w $@-tmp2
mv -f $@-tmp2 $@
$(common-objpfx)manual/%: FORCE
$(MAKE) $(PARALLELMFLAGS) -C manual $@
FORCE:
iconvdata/% localedata/% po/%: FORCE
$(MAKE) $(PARALLELMFLAGS) -C $(@D) $(@F)