glibc/string/Makefile
Joseph Myers 6a1cefac19 Make endian-conversion macros always return correct types (bug 16458).
Bug 16458 reports that the endian-conversion macros in <endian.h> and
<netinet/in.h>, in the case where no endian conversion is needed, just
return their arguments without converting to the expected return type,
so failing to act as expected for a macro version of a function.  (The
<netinet/in.h> macros, in particular, are described with prototypes in
POSIX so should act like correspondingly prototyped functions.)

Where previously this was a fairly obscure issue, it now results in
glibc build with GCC mainline breaking for big-endian systems:

nss_hesiod/hesiod-service.c: In function '_nss_hesiod_getservbyport_r':
nss_hesiod/hesiod-service.c:142:39: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 6 [-Werror=format-truncation=]
   snprintf (portstr, sizeof portstr, "%d", ntohs (port));
                                       ^~
nss_hesiod/hesiod-service.c:142:38: note: using the range [1, -2147483648] for directive argument
   snprintf (portstr, sizeof portstr, "%d", ntohs (port));
                                      ^~~~
nss_hesiod/hesiod-service.c:142:3: note: format output between 2 and 12 bytes into a destination of size 6
   snprintf (portstr, sizeof portstr, "%d", ntohs (port));
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The port argument is passed as int to this function, so when ntohs
does not convert the compiler cannot tell that the result is within
the range of uint16_t.  (I don't know if in fact it's possible for
out-of-range values to reach this function and so get truncated as
strings without this patch or as integers with it.)

This patch arranges for these macros to use identity functions to
ensure appropriate conversions while having warnings for implicit
conversions of function arguments that might not occur with a cast.

Tested for x86_64 and x86; with build-many-glibcs.py with GCC 6; and
with build-many-glibcs.py with GCC mainline for powerpc to test the
build fix.

	[BZ #16458]
	* bits/uintn-identity.h: New file.
	* inet/netinet/in.h: Include <bits/uintn-identity.h>.
	[__BYTE_ORDER == __BIG_ENDIAN] (ntohl): Use __uint32_identity.
	[__BYTE_ORDER == __BIG_ENDIAN] (ntohs): Use __uint16_identity.
	[__BYTE_ORDER == __BIG_ENDIAN] (htonl): Use __uint32_identity.
	[__BYTE_ORDER == __BIG_ENDIAN] (htohs): Use __uint16_identity.
	* string/endian.h: Include <bits/uintn-identity.h>.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (htole16): Use
	__uint16_identity.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (le16toh): Likewise.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (htole32): Use
	__uint32_identity.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (le32toh): Likewise.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (htole64): Use
	__uint64_identity.
	[__BYTE_ORDER == __LITTLE_ENDIAN] (le64toh): Likewise.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe16): Use
	__uint16_identity.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (be16toh): Likewise.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe32): Use
	__uint32_identity.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (be32toh): Likewise.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe64): Use
	__uint64_identity.
	[__BYTE_ORDER != __LITTLE_ENDIAN] (be64toh): Likewise.
	* string/Makefile (headers): Add bits/uintn-identity.h.
	(tests): Add test-endian-types.
	* string/test-endian-types.c: New file.
	* inet/Makefile (tests): Add test-hnto-types.
	* inet/test-hnto-types.c: New file.
2017-01-11 15:28:08 +00:00

100 lines
3.5 KiB
Makefile

# Copyright (C) 1991-2017 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.
#
# Sub-makefile for string portion of library.
#
subdir := string
include ../Makeconfig
headers := string.h strings.h memory.h endian.h bits/endian.h \
argz.h envz.h byteswap.h bits/byteswap.h bits/byteswap-16.h \
bits/string.h bits/string2.h bits/string3.h \
bits/strings_fortified.h bits/uintn-identity.h
routines := strcat strchr strcmp strcoll strcpy strcspn \
strverscmp strdup strndup \
strerror _strerror strlen strnlen \
strncat strncmp strncpy \
strrchr strpbrk strsignal strspn strstr strtok \
strtok_r strxfrm memchr memcmp memmove memset \
mempcpy bcopy bzero ffs ffsll stpcpy stpncpy \
strcasecmp strncase strcasecmp_l strncase_l \
memccpy memcpy wordcopy strsep strcasestr \
swab strfry memfrob memmem rawmemchr strchrnul \
$(addprefix argz-,append count create ctsep next \
delete extract insert stringify \
addsep replace) \
envz basename \
strcoll_l strxfrm_l string-inlines memrchr \
xpg-strerror strerror_l explicit_bzero
strop-tests := memchr memcmp memcpy memmove mempcpy memset memccpy \
stpcpy stpncpy strcat strchr strcmp strcpy strcspn \
strlen strncmp strncpy strpbrk strrchr strspn memmem \
strstr strcasestr strnlen strcasecmp strncasecmp \
strncat rawmemchr strchrnul bcopy bzero memrchr \
explicit_bzero
tests := tester inl-tester noinl-tester testcopy test-ffs \
tst-strlen stratcliff tst-svc tst-inlcall \
bug-strncat1 bug-strspn1 bug-strpbrk1 tst-bswap \
tst-strtok tst-strxfrm bug-strcoll1 tst-strfry \
bug-strtok1 $(addprefix test-,$(strop-tests)) \
bug-envz1 tst-strxfrm2 tst-endian tst-svc2 \
tst-strtok_r bug-strcoll2 tst-cmp tst-xbzero-opt \
test-endian-types
xtests = tst-strcoll-overflow
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-svc-cmp.out
endif
include ../Rules
CFLAGS-inl-tester.c = -fno-builtin
CFLAGS-noinl-tester.c = -fno-builtin
CFLAGS-tst-strlen.c = -fno-builtin
CFLAGS-stratcliff.c = -fno-builtin
CFLAGS-test-ffs.c = -fno-builtin
CFLAGS-tst-inlcall.c = -fno-builtin
CFLAGS-tst-xbzero-opt.c = -O3
# Called during TLS initialization.
CFLAGS-memcpy.c = $(no-stack-protector)
CFLAGS-wordcopy.c = $(no-stack-protector)
ifeq ($(run-built-tests),yes)
$(objpfx)tst-svc-cmp.out: tst-svc.expect $(objpfx)tst-svc.out
cmp $^ > $@; \
$(evaluate-test)
LOCALES := de_DE.UTF-8 en_US.ISO-8859-1 en_US.UTF-8 \
tr_TR.ISO-8859-9 tr_TR.UTF-8 cs_CZ.UTF-8 \
da_DK.ISO-8859-1
include ../gen-locales.mk
$(objpfx)test-strcasecmp.out: $(gen-locales)
$(objpfx)test-strncasecmp.out: $(gen-locales)
$(objpfx)tst-strxfrm.out: $(gen-locales)
$(objpfx)tst-strxfrm2.out: $(gen-locales)
# bug-strcoll2 needs cs_CZ.UTF-8 and da_DK.ISO-8859-1.
$(objpfx)bug-strcoll2.out: $(gen-locales)
endif