acx.m4: Fix fastcompare support for new-bootstrap.

[thirdparty/gcc.git] / config / acx.m4

# Autoconf M4 include file defining utility macros for complex Canadian
# cross builds.

dnl ####
dnl # _GCC_TOPLEV_NONCANONICAL_BUILD
dnl # $build_alias or canonical $build if blank.
dnl # Used when we would use $build_alias, but empty is not OK.
AC_DEFUN([_GCC_TOPLEV_NONCANONICAL_BUILD],
[AC_REQUIRE([AC_CANONICAL_BUILD]) []dnl
case ${build_alias} in
  "") build_noncanonical=${build} ;;
  *) build_noncanonical=${build_alias} ;;
esac
]) []dnl # _GCC_TOPLEV_NONCANONICAL_BUILD

dnl ####
dnl # _GCC_TOPLEV_NONCANONICAL_HOST
dnl # $host_alias, or $build_noncanonical if blank.
dnl # Used when we would use $host_alias, but empty is not OK.
AC_DEFUN([_GCC_TOPLEV_NONCANONICAL_HOST],
[AC_REQUIRE([_GCC_TOPLEV_NONCANONICAL_BUILD]) []dnl
case ${host_alias} in
  "") host_noncanonical=${build_noncanonical} ;;
  *) host_noncanonical=${host_alias} ;;
esac
]) []dnl # _GCC_TOPLEV_NONCANONICAL_HOST

dnl ####
dnl # _GCC_TOPLEV_NONCANONICAL_TARGET
dnl # $target_alias or $host_noncanonical if blank.
dnl # Used when we would use $target_alias, but empty is not OK.
AC_DEFUN([_GCC_TOPLEV_NONCANONICAL_TARGET],
[AC_REQUIRE([_GCC_TOPLEV_NONCANONICAL_HOST]) []dnl
case ${target_alias} in
  "") target_noncanonical=${host_noncanonical} ;;
  *) target_noncanonical=${target_alias} ;;
esac
]) []dnl # _GCC_TOPLEV_NONCANONICAL_TARGET

dnl ####
dnl # GCC_TOPLEV_SUBDIRS
dnl # GCC & friends build 'build', 'host', and 'target' tools.  These must
dnl # be separated into three well-known subdirectories of the build directory:
dnl # build_subdir, host_subdir, and target_subdir.  The values are determined
dnl # here so that they can (theoretically) be changed in the future.  They
dnl # were previously reproduced across many different files.
dnl #
dnl # This logic really amounts to very little with autoconf 2.13; it will
dnl # amount to a lot more with autoconf 2.5x.
AC_DEFUN([GCC_TOPLEV_SUBDIRS],
[AC_REQUIRE([_GCC_TOPLEV_NONCANONICAL_TARGET]) []dnl
AC_REQUIRE([_GCC_TOPLEV_NONCANONICAL_BUILD]) []dnl
# Prefix 'build-' so this never conflicts with target_subdir.
build_subdir="build-${build_noncanonical}"
# Not really a subdirectory, but here for completeness.
host_subdir=.
# No prefix.
target_subdir=${target_noncanonical}
AC_SUBST([build_subdir]) []dnl
AC_SUBST([host_subdir]) []dnl
AC_SUBST([target_subdir]) []dnl
]) []dnl # GCC_TOPLEV_SUBDIRS


####
# _NCN_TOOL_PREFIXES:  Some stuff that oughtta be done in AC_CANONICAL_SYSTEM 
# or AC_INIT.
# These demand that AC_CANONICAL_SYSTEM be called beforehand.
AC_DEFUN([_NCN_TOOL_PREFIXES],
[ncn_tool_prefix=
test -n "$host_alias" && ncn_tool_prefix=$host_alias-
ncn_target_tool_prefix=
test -n "$target_alias" && ncn_target_tool_prefix=$target_alias-
]) []dnl # _NCN_TOOL_PREFIXES

####
# NCN_CHECK_TARGET_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
# Like AC_CHECK_TOOL, but tries a prefix of the target, not the host.
# Code is pretty much lifted from autoconf2.53.

AC_DEFUN([NCN_CHECK_TARGET_TOOL],
[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
if test -n "$ncn_target_tool_prefix"; then
  AC_CHECK_PROG([$1], [${ncn_target_tool_prefix}$2], 
                [${ncn_target_tool_prefix}$2], , [$4])
fi
if test -z "$ac_cv_prog_$1" ; then
  ncn_cv_$1=$$1
  AC_CHECK_PROG([ncn_cv_$1], [$2], [$2], [$3], [$4])
  $1=$ncn_cv_$1
else
  $1="$ac_cv_prog_$1"
fi
]) []dnl # NCN_CHECK_TARGET_TOOL


####
# NCN_STRICT_CHECK_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
# Like AC_CHECK_TOOL, but requires the prefix if build!=host.

AC_DEFUN([NCN_STRICT_CHECK_TOOL],
[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
if test -n "$ncn_tool_prefix"; then
  AC_CHECK_PROG([$1], [${ncn_tool_prefix}$2], 
                [${ncn_tool_prefix}$2], , [$4])
fi
if test -z "$ac_cv_prog_$1" ; then
  if test $build = $host ; then
    ncn_cv_$1=$$1
    AC_CHECK_PROG([ncn_cv_$1], [$2], [$2], [ifelse([$3],[],[$2],[$3])], [$4]) 
    $1=$ncn_cv_$1
  else
    $1="ifelse([$3],[],[${ncn_tool_prefix}$2],[$3])"
  fi
else
  $1="$ac_cv_prog_$1"
fi
]) []dnl # NCN_STRICT_CHECK_TOOL


####
# NCN_STRICT_CHECK_TARGET_TOOL(variable, prog-to-check-for,[value-if-not-found],[path])
# Like NCN_CHECK_TARGET_TOOL, but requires the prefix if build!=target.

AC_DEFUN([NCN_STRICT_CHECK_TARGET_TOOL],
[AC_REQUIRE([_NCN_TOOL_PREFIXES]) []dnl
if test -n "$ncn_target_tool_prefix"; then
  AC_CHECK_PROG([$1], [${ncn_target_tool_prefix}$2], 
                [${ncn_target_tool_prefix}$2], , [$4])
fi
if test -z "$ac_cv_prog_$1" ; then
  if test $build = $target ; then
    ncn_cv_$1=$$1
    AC_CHECK_PROG([ncn_cv_$1], [$2], [$2], [ifelse([$3],[],[$2],[$3])], [$4]) 
    $1=$ncn_cv_$1
  else
    $1="ifelse([$3],[],[${ncn_target_tool_prefix}$2],[$3])"
  fi
else
  $1="$ac_cv_prog_$1"
fi
]) []dnl # NCN_STRICT_CHECK_TARGET_TOOL

###
# AC_PROG_CPP_WERROR
# Used for autoconf 2.5x to force AC_PREPROC_IFELSE to reject code which
# triggers warnings from the preprocessor.  Will be in autoconf 2.58.
# For now, using this also overrides header checks to use only the
# preprocessor (matches 2.13 behavior; matching 2.58's behavior is a
# bit harder from here).
# Eventually autoconf will default to checking headers with the compiler
# instead, and we'll have to do this differently.

AC_DEFUN([AC_PROG_CPP_WERROR],
[AC_REQUIRE([AC_PROG_CPP])dnl
m4_define([AC_CHECK_HEADER],m4_defn([_AC_CHECK_HEADER_OLD]))
ac_c_preproc_warn_flag=yes])# AC_PROG_CPP_WERROR

# Test for GNAT.
# We require the gnatbind program, and a compiler driver that
# understands Ada.  We use the user's CC setting, already found.
#
# Sets the shell variable have_gnat to yes or no as appropriate, and
# substitutes GNATBIND.
AC_DEFUN([ACX_PROG_GNAT],
[AC_REQUIRE([AC_CHECK_TOOL_PREFIX])
AC_REQUIRE([AC_PROG_CC])
AC_CHECK_TOOL(GNATBIND, gnatbind, no)
AC_CACHE_CHECK([whether compiler driver understands Ada],
		 acx_cv_cc_gcc_supports_ada,
[cat >conftest.adb <<EOF
procedure conftest is begin null; end conftest;
EOF
acx_cv_cc_gcc_supports_ada=no
# There is a bug in old released versions of GCC which causes the
# driver to exit successfully when the appropriate language module
# has not been installed.  This is fixed in 2.95.4, 3.0.2, and 3.1.
# Therefore we must check for the error message as well as an
# unsuccessful exit.
# Other compilers, like HP Tru64 UNIX cc, exit successfully when
# given a .adb file, but produce no object file.  So we must check
# if an object file was really produced to guard against this.
errors=`(${CC} -c conftest.adb) 2>&1 || echo failure`
if test x"$errors" = x && test -f conftest.$ac_objext; then
  acx_cv_cc_gcc_supports_ada=yes
  break
fi
rm -f conftest.*])

if test x$GNATBIND != xno && test x$acx_cv_cc_gcc_supports_ada != xno; then
  have_gnat=yes
else
  have_gnat=no
fi
])

dnl 'make compare' can be significantly faster, if cmp itself can
dnl skip bytes instead of using tail.  The test being performed is
dnl "if cmp --ignore-initial=2 t1 t2 && ! cmp --ignore-initial=1 t1 t2"
dnl but we need to sink errors and handle broken shells.  We also test
dnl for the parameter format "cmp file1 file2 skip1 skip2" which is
dnl accepted by cmp on some systems.
AC_DEFUN([ACX_PROG_CMP_IGNORE_INITIAL],
[AC_CACHE_CHECK([how to compare bootstrapped objects], gcc_cv_prog_cmp_skip,
[ echo abfoo >t1
  echo cdfoo >t2
  gcc_cv_prog_cmp_skip='tail +16c $$f1 > tmp-foo1; tail +16c $$f2 > tmp-foo2; cmp tmp-foo1 tmp-foo2'
  if cmp t1 t2 2 2 > /dev/null 2>&1; then
    if cmp t1 t2 1 1 > /dev/null 2>&1; then
      :
    else
      gcc_cv_prog_cmp_skip='cmp $$f1 $$f2 16 16'
    fi
  fi
  if cmp --ignore-initial=2 t1 t2 > /dev/null 2>&1; then
    if cmp --ignore-initial=1 t1 t2 > /dev/null 2>&1; then
      :
    else
      gcc_cv_prog_cmp_skip='cmp --ignore-initial=16 $$f1 $$f2'
    fi
  fi
  rm t1 t2
])
do_compare="$gcc_cv_prog_cmp_skip"
AC_SUBST(do_compare)
])