Correctly determine libc.so 'OUTPUT_FORMAT' when cross-compiling.

Commit 87d583c6e8 replaces the sed script
with an "objdump -f" invocation to determine the 'OUTPUT_FORMAT' bit of
the libc.so linker script.

However, when cross-compiling, for example from x86_64-linux-gnu to
aarch64-linux-gnu, "objdump -f" would report the wrong
format ("elf64-little").  Conversely, "aarch64-linux-gnu-objdump -f"
reports "elf64-littleaarch64" as expected.

This patch changes 'configure.ac' to use AC_CHECK_TOOL rather than
'$CC -print-prog-name=objdump' to determine the value of the OBJDUMP
variable.  That way, OBJDUMP is set to TRIPLET-objdump when
cross-compiling for TRIPLET.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Ludovic Courtès 2021-07-01 23:00:19 +02:00 committed by Carlos O'Donell
parent 8c77e26ba8
commit 361d6454c0
3 changed files with 94 additions and 5 deletions

2
aclocal.m4 vendored
View File

@ -122,8 +122,6 @@ AS=`$CC -print-prog-name=as`
LD=`$CC -print-prog-name=$LDNAME`
AR=`$CC -print-prog-name=ar`
AC_SUBST(AR)
OBJDUMP=`$CC -print-prog-name=objdump`
AC_SUBST(OBJDUMP)
OBJCOPY=`$CC -print-prog-name=objcopy`
AC_SUBST(OBJCOPY)
GPROF=`$CC -print-prog-name=gprof`

96
configure vendored
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@ -649,7 +649,6 @@ LD
AS
GPROF
OBJCOPY
OBJDUMP
AR
LN_S
INSTALL_DATA
@ -685,6 +684,7 @@ sysheaders
ac_ct_CXX
CXXFLAGS
CXX
OBJDUMP
READELF
CPP
cross_compiling
@ -2963,6 +2963,98 @@ else
READELF="$ac_cv_prog_READELF"
fi
if test -n "$ac_tool_prefix"; then
# Extract the first word of "${ac_tool_prefix}objdump", so it can be a program name with args.
set dummy ${ac_tool_prefix}objdump; ac_word=$2
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
$as_echo_n "checking for $ac_word... " >&6; }
if ${ac_cv_prog_OBJDUMP+:} false; then :
$as_echo_n "(cached) " >&6
else
if test -n "$OBJDUMP"; then
ac_cv_prog_OBJDUMP="$OBJDUMP" # Let the user override the test.
else
as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in $PATH
do
IFS=$as_save_IFS
test -z "$as_dir" && as_dir=.
for ac_exec_ext in '' $ac_executable_extensions; do
if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
ac_cv_prog_OBJDUMP="${ac_tool_prefix}objdump"
$as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
break 2
fi
done
done
IFS=$as_save_IFS
fi
fi
OBJDUMP=$ac_cv_prog_OBJDUMP
if test -n "$OBJDUMP"; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $OBJDUMP" >&5
$as_echo "$OBJDUMP" >&6; }
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
fi
if test -z "$ac_cv_prog_OBJDUMP"; then
ac_ct_OBJDUMP=$OBJDUMP
# Extract the first word of "objdump", so it can be a program name with args.
set dummy objdump; ac_word=$2
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
$as_echo_n "checking for $ac_word... " >&6; }
if ${ac_cv_prog_ac_ct_OBJDUMP+:} false; then :
$as_echo_n "(cached) " >&6
else
if test -n "$ac_ct_OBJDUMP"; then
ac_cv_prog_ac_ct_OBJDUMP="$ac_ct_OBJDUMP" # Let the user override the test.
else
as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in $PATH
do
IFS=$as_save_IFS
test -z "$as_dir" && as_dir=.
for ac_exec_ext in '' $ac_executable_extensions; do
if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
ac_cv_prog_ac_ct_OBJDUMP="objdump"
$as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
break 2
fi
done
done
IFS=$as_save_IFS
fi
fi
ac_ct_OBJDUMP=$ac_cv_prog_ac_ct_OBJDUMP
if test -n "$ac_ct_OBJDUMP"; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_OBJDUMP" >&5
$as_echo "$ac_ct_OBJDUMP" >&6; }
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
if test "x$ac_ct_OBJDUMP" = x; then
OBJDUMP="false"
else
case $cross_compiling:$ac_tool_warned in
yes:)
{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
ac_tool_warned=yes ;;
esac
OBJDUMP=$ac_ct_OBJDUMP
fi
else
OBJDUMP="$ac_cv_prog_OBJDUMP"
fi
# We need the C++ compiler only for testing.
ac_ext=cpp
@ -4580,8 +4672,6 @@ AS=`$CC -print-prog-name=as`
LD=`$CC -print-prog-name=$LDNAME`
AR=`$CC -print-prog-name=ar`
OBJDUMP=`$CC -print-prog-name=objdump`
OBJCOPY=`$CC -print-prog-name=objcopy`
GPROF=`$CC -print-prog-name=gprof`

View File

@ -52,6 +52,7 @@ fi
AC_SUBST(cross_compiling)
AC_PROG_CPP
AC_CHECK_TOOL(READELF, readelf, false)
AC_CHECK_TOOL(OBJDUMP, objdump, false)
# We need the C++ compiler only for testing.
AC_PROG_CXX