glibc/sysdeps/x86/configure
Matt Whitlock 0835c0f0ba x86: fix Autoconf caching of instruction support checks [BZ #27991]
The Autoconf documentation for the AC_CACHE_CHECK macro states:

  The commands-to-set-it must have no side effects except for setting
  the variable cache-id, see below.

However, the tests for support of -msahf and -mmovbe were embedded in
the commands-to-set-it for lib_cv_include_x86_isa_level. This had the
consequence that libc_cv_have_x86_lahf_sahf and libc_cv_have_x86_movbe
were not defined whenever lib_cv_include_x86_isa_level was read from
cache. These variables' being undefined meant that their unquoted use
in later test expressions led to the 'test' built-in's misparsing its
arguments and emitting errors like "test: =: unexpected operator" or
"test: =: unary operator expected", depending on the particular shell.

This commit refactors the tests for LAHF/SAHF and MOVBE instruction
support into their own AC_CACHE_CHECK macro invocations to obey the
rule that the commands-to-set-it must have no side effects other than
setting the variable named by cache-id.

Signed-off-by: Matt Whitlock <sourceware@mattwhitlock.name>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-08-19 09:11:35 -03:00

192 lines
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# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
# Local configure fragment for sysdeps/x86.
if test $enable_cet != no; then
# Check if CET can be enabled.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether CET can be enabled" >&5
$as_echo_n "checking whether CET can be enabled... " >&6; }
if ${libc_cv_x86_cet_available+:} false; then :
$as_echo_n "(cached) " >&6
else
cat > conftest.c <<EOF
#if !defined __CET__ || __CET__ != 3
# error CET isn't available.
#endif
EOF
if { ac_try='${CC-cc} -c $CFLAGS -fcf-protection -include cet.h conftest.c 1>&5'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; }; then
libc_cv_x86_cet_available=yes
else
libc_cv_x86_cet_available=no
fi
rm -rf conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_x86_cet_available" >&5
$as_echo "$libc_cv_x86_cet_available" >&6; }
if test $libc_cv_x86_cet_available != yes; then
as_fn_error $? "$CC doesn't support CET" "$LINENO" 5
fi
fi
if test $enable_cet != no; then
# Check if assembler supports CET.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $AS supports CET" >&5
$as_echo_n "checking whether $AS supports CET... " >&6; }
if ${libc_cv_x86_cet_as+:} false; then :
$as_echo_n "(cached) " >&6
else
cat > conftest.s <<EOF
incsspd %ecx
EOF
if { ac_try='${CC-cc} -c $CFLAGS conftest.s -o conftest.o 1>&5'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; }; then
libc_cv_x86_cet_as=yes
else
libc_cv_x86_cet_as=no
fi
rm -rf conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_x86_cet_as" >&5
$as_echo "$libc_cv_x86_cet_as" >&6; }
if test $libc_cv_x86_cet_as = no; then
as_fn_error $? "$AS doesn't support CET" "$LINENO" 5
fi
fi
if test $enable_cet = yes; then
$as_echo "#define DEFAULT_DL_X86_CET_CONTROL cet_elf_property" >>confdefs.h
elif test $enable_cet = permissive; then
$as_echo "#define DEFAULT_DL_X86_CET_CONTROL cet_permissive" >>confdefs.h
fi
config_vars="$config_vars
enable-cet = $enable_cet"
# Check if linker supports x86 ISA level.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker x86 ISA level support" >&5
$as_echo_n "checking for linker x86 ISA level support... " >&6; }
if ${libc_cv_include_x86_isa_level+:} false; then :
$as_echo_n "(cached) " >&6
else
cat > conftest1.S <<EOF
#ifdef __LP64__
# define P2ALIGN 3
#else
# define P2ALIGN 2
#endif
.section ".note.gnu.property", "a"
.p2align P2ALIGN
.long 1f - 0f /* name length. */
.long 4f - 1f /* data length. */
/* NT_GNU_PROPERTY_TYPE_0 */
.long 5 /* note type. */
0:
.asciz "GNU" /* vendor name. */
1:
.p2align P2ALIGN
/* GNU_PROPERTY_X86_ISA_1_NEEDED */
.long 0xc0008002 /* pr_type. */
.long 3f - 2f /* pr_datasz. */
2:
.long 0x1
3:
.p2align P2ALIGN
4:
EOF
cat > conftest2.S <<EOF
#ifdef __LP64__
# define P2ALIGN 3
#else
# define P2ALIGN 2
#endif
.section ".note.gnu.property", "a"
.p2align P2ALIGN
.long 1f - 0f /* name length. */
.long 4f - 1f /* data length. */
/* NT_GNU_PROPERTY_TYPE_0 */
.long 5 /* note type. */
0:
.asciz "GNU" /* vendor name. */
1:
.p2align P2ALIGN
/* GNU_PROPERTY_X86_ISA_1_NEEDED */
.long 0xc0008002 /* pr_type. */
.long 3f - 2f /* pr_datasz. */
2:
.long 0x2
3:
.p2align P2ALIGN
4:
EOF
libc_cv_include_x86_isa_level=no
if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; }; then
count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
if test "$count" = 1; then
libc_cv_include_x86_isa_level=yes
fi
fi
rm -f conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_include_x86_isa_level" >&5
$as_echo "$libc_cv_include_x86_isa_level" >&6; }
if test $libc_cv_include_x86_isa_level = yes; then
$as_echo "#define INCLUDE_X86_ISA_LEVEL 1" >>confdefs.h
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for LAHF/SAHF instruction support" >&5
$as_echo_n "checking for LAHF/SAHF instruction support... " >&6; }
if ${libc_cv_have_x86_lahf_sahf+:} false; then :
$as_echo_n "(cached) " >&6
else
libc_cv_have_x86_lahf_sahf=no
if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -fverbose-asm -S -o - -x c /dev/null'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; } | grep -q "\-msahf"; then
libc_cv_have_x86_lahf_sahf=yes
fi
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_have_x86_lahf_sahf" >&5
$as_echo "$libc_cv_have_x86_lahf_sahf" >&6; }
if test $libc_cv_have_x86_lahf_sahf = yes; then
$as_echo "#define HAVE_X86_LAHF_SAHF 1" >>confdefs.h
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for MOVBE instruction support" >&5
$as_echo_n "checking for MOVBE instruction support... " >&6; }
if ${libc_cv_have_x86_movbe+:} false; then :
$as_echo_n "(cached) " >&6
else
libc_cv_have_x86_movbe=no
if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -fverbose-asm -S -o - -x c /dev/null'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; } | grep -q "\-mmovbe"; then
libc_cv_have_x86_movbe=yes
fi
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_have_x86_movbe" >&5
$as_echo "$libc_cv_have_x86_movbe" >&6; }
if test $libc_cv_have_x86_movbe = yes; then
$as_echo "#define HAVE_X86_MOVBE 1" >>confdefs.h
fi
fi
config_vars="$config_vars
enable-x86-isa-level = $libc_cv_include_x86_isa_level"