Merge remote-tracking branch 'upstream/master'

16 files changed, 311 insertions, 21 deletions

diff --git a/scripts/addToolVersion.sh b/scripts/addToolVersion.sh
index 3cbf712..806ecca 100755
--- a/scripts/addToolVersion.sh
+++ b/scripts/addToolVersion.sh
@@ -44,7 +44,7 @@ doHelp() {
             add experimental obsolete version 2.3.5 and stable current versions 2.6.1
             and 2.6.2 to glibc, add stable obsolete version 3.3.3 to gcc:
               ${myname} --glibc -x -o 2.3.5 -s -c 2.6.1 2.6.2 --gcc -o 3.3.3
-        EOF
+EOF
 }
 
 # Extract field $3 from version $1 with separator $2
@@ -61,7 +61,7 @@ getVersionField() {
 # $tool         : tool name
 # $tool_prefix  : tool directory prefix
 # $EXP          : set to non empty if experimental, to empty otherwise
-# #OBS          : set to non empty if obsolete, to empty otherwise
+# OBS           : set to non empty if obsolete, to empty otherwise
 # $1            : version string to add
 addToolVersion() {
     local version="$1"
@@ -124,7 +124,7 @@ addToolVersion() {
             ver_p=$(getVersionField "${version}" . 3)
             if [ ${ver_M} -eq 2 -a ${ver_m} -eq 26 ]; then
                 SedExpr1="${SedExpr1}\n    select BINUTILS_2_26_or_later"
-            if [ ${ver_M} -eq 2 -a ${ver_m} -eq 25 -a ${ver_p} -eq 1 ]; then
+            elif [ ${ver_M} -eq 2 -a ${ver_m} -eq 25 -a ${ver_p} -eq 1 ]; then
                 SedExpr1="${SedExpr1}\n    select BINUTILS_2_25_1_or_later"
             elif [ ${ver_M} -eq 2 -a ${ver_m} -eq 25 -a -z ${ver_p} ]; then
                 SedExpr1="${SedExpr1}\n    select BINUTILS_2_25_or_later"
@@ -139,7 +139,7 @@ addToolVersion() {
             ver_M=$(getVersionField "${version}" . 1)
             ver_m=$(getVersionField "${version}" . 2)
             ver_p=$(getVersionField "${version}" . 3)
-            elif [  ${ver_M} -eq 0 -a ${ver_m} -eq 9 -a ${ver_p} -eq 33 ]; then
+            if [  ${ver_M} -eq 0 -a ${ver_m} -eq 9 -a ${ver_p} -eq 33 ]; then
                 SedExpr1="${SedExpr1}\n    select LIBC_UCLIBC_0_9_33_2_or_later"
             fi
             ;;
diff --git a/scripts/build/arch/alpha.sh b/scripts/build/arch/alpha.sh
index cf6d40d..ffceae3 100644
--- a/scripts/build/arch/alpha.sh
+++ b/scripts/build/arch/alpha.sh
@@ -4,3 +4,14 @@ CT_DoArchTupleValues () {
     # The architecture part of the tuple:
     CT_TARGET_ARCH="${CT_ARCH}${CT_ARCH_SUFFIX:-${CT_ARCH_ALPHA_VARIANT}}"
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/arm.sh b/scripts/build/arch/arm.sh
index 5f6ce2f..338392c 100644
--- a/scripts/build/arch/arm.sh
+++ b/scripts/build/arch/arm.sh
@@ -39,3 +39,14 @@ CT_DoArchTupleValues() {
         CT_TARGET_SYS="${CT_TARGET_SYS}hf"
     fi
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/m68k.sh b/scripts/build/arch/m68k.sh
index bf26d1b..a6eb010 100644
--- a/scripts/build/arch/m68k.sh
+++ b/scripts/build/arch/m68k.sh
@@ -3,3 +3,14 @@
 CT_DoArchTupleValues() {
     :
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/microblaze.sh b/scripts/build/arch/microblaze.sh
index 456a6e3..93ecc9a 100644
--- a/scripts/build/arch/microblaze.sh
+++ b/scripts/build/arch/microblaze.sh
@@ -19,3 +19,14 @@ CT_DoArchTupleValues () {
     esac
 
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/mips.sh b/scripts/build/arch/mips.sh
index 4d732be..68ad4fa 100644
--- a/scripts/build/arch/mips.sh
+++ b/scripts/build/arch/mips.sh
@@ -14,3 +14,14 @@ CT_DoArchTupleValues() {
     CT_ARCH_ABI_CFLAG="-mabi=${CT_ARCH_mips_ABI}"
     CT_ARCH_WITH_ABI="--with-abi=${CT_ARCH_mips_ABI}"
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/powerpc.sh b/scripts/build/arch/powerpc.sh
index fbc3120..77bbc8a 100644
--- a/scripts/build/arch/powerpc.sh
+++ b/scripts/build/arch/powerpc.sh
@@ -26,3 +26,44 @@ CT_DoArchTupleValues () {
         CT_ARCH_CC_EXTRA_CONFIG="--enable-e500_double"
     fi
 }
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    local m32=false
+    local m64=false
+    local mlittle=false
+    local mbig=false
+
+    for m in "${multi_flags[@]}"; do
+        case "$m" in
+            -m32)     m32=true ;;
+            -m64)     m64=true ;;
+            -mbig)    mbig=true ;;
+            -mlittle) mlittle=true ;;
+        esac
+    done
+
+    # Fix up bitness
+    case "${target}" in
+        powerpc-*)      $m64 && target=${target/#powerpc-/powerpc64-} ;;
+        powerpcle-*)    $m64 && target=${target/#powerpcle-/powerpc64le-} ;;
+        powerpc64-*)    $m32 && target=${target/#powerpc64-/powerpc-} ;;
+        powerpc64le-*)  $m32 && target=${target/#powerpc64le-/powerpcle-} ;;
+    esac
+
+    # Fix up endianness
+    case "${target}" in
+        powerpc-*)      $mlittle && target=${target/#powerpc-/powerpcle-} ;;
+        powerpcle-*)    $mbig && target=${target/#powerpcle-/powerpc-} ;;
+        powerpc64-*)    $mlittle && target=${target/#powerpc64-/powerpc64le-} ;;
+        powerpc64le-*)  $mbig && target=${target/#powerpc64le-/powerpc64-} ;;
+    esac
+
+    # return the target
+    echo "${target}"
+}
diff --git a/scripts/build/arch/s390.sh b/scripts/build/arch/s390.sh
index b4b8078..e303420 100644
--- a/scripts/build/arch/s390.sh
+++ b/scripts/build/arch/s390.sh
@@ -6,3 +6,30 @@ CT_DoArchTupleValues() {
         CT_TARGET_ARCH="s390x${CT_ARCH_SUFFIX}"
     fi
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    local m31=false
+    local m64=false
+
+    for m in "${multi_flags[@]}"; do
+        case "${multi_flags}" in
+            -m64) m64=true ;;
+            -m31) m31=true ;;
+        esac
+    done
+
+    # Fix bitness
+    case "${target}" in
+        s390-*)   $m64 && target=${target/#s390-/s390x-} ;;
+        s390x-*)  $m31 && target=${target/#s390x-/s390-} ;;
+    esac
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/sh.sh b/scripts/build/arch/sh.sh
index 7780e40..e7f4f1a 100644
--- a/scripts/build/arch/sh.sh
+++ b/scripts/build/arch/sh.sh
@@ -35,3 +35,14 @@ CT_DoArchTupleValues () {
     esac
     CT_ARCH_FLOAT_CFLAG=
 }
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
+}
diff --git a/scripts/build/arch/sparc.sh b/scripts/build/arch/sparc.sh
index e3e7491..2d3baa3 100644
--- a/scripts/build/arch/sparc.sh
+++ b/scripts/build/arch/sparc.sh
@@ -2,4 +2,28 @@
 CT_DoArchTupleValues() {
     # That's the only thing to override
     CT_TARGET_ARCH="sparc${target_bits_64}${CT_ARCH_SUFFIX}"
+
+    # By default, sparc64-*-linux is configured with -mcpu=v9. However,
+    # according to https://sourceware.org/ml/libc-alpha/2005-12/msg00027.html,
+    # "There is no Linux sparc64 port that runs on non-UltraSPARC-I+ ISA CPUs."
+    # There is a patch that would change the default to -mcpu=ultrasparc for
+    # sparc64-*-linux configuration: https://patchwork.ozlabs.org/patch/409424/
+    # but that patch has not been integrated (yet). One concern raised about
+    # this patch was that -mcpu=ultrasparc can suboptimally schedule instructions
+    # for newer SPARC CPUs. So, override to -mcpu=ultrasparc and warn the user.
+    if [ "${CT_KERNEL}" = "linux" -a "${CT_ARCH_64}" = "y" -a -z "${CT_ARCH_CPU}" ]; then
+        CT_DoLog WARN "Setting CPU to UltraSPARC-I for sparc64-linux. Set CT_ARCH_CPU if a different CPU is desired."
+        CT_ARCH_WITH_CPU="--with-cpu=ultrasparc"
+    fi
+}
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    echo "${target}"
 }
diff --git a/scripts/build/arch/x86.sh b/scripts/build/arch/x86.sh
index 69407db..ca0f08b 100644
--- a/scripts/build/arch/x86.sh
+++ b/scripts/build/arch/x86.sh
@@ -20,4 +20,51 @@ CT_DoArchTupleValues() {
         esac
     fi
     CT_TARGET_ARCH="${CT_TARGET_ARCH}${CT_ARCH_SUFFIX}"
+
+    # Shouldn't be possible to specify this (CT_TARGET_SYS is not specified by the user,
+    # it is computed by scripts/functions from libc choices). But trap if such invalid
+    # values ever come from the caller:
+    case "${CT_TARGET_ARCH}-${CT_TARGET_SYS}" in
+        i[34567]86-gnux32)
+            CT_DoLog ERROR "Invalid CT_TARGET: i[34567]86-<vendor>-<os>-gnux32 is invalid."
+            CT_DoLog ERROR "CT_TARGET: ${CT_TARGET}"
+            CT_Abort "Go read: https://wiki.debian.org/Multiarch/Tuples"
+            ;;
+    esac
+}
+
+#------------------------------------------------------------------------------
+# Get multilib architecture-specific target
+# Usage: CT_DoArchMultilibTarget "multilib flags" "target tuple"
+CT_DoArchMultilibTarget ()
+{
+    local target="${1}"; shift
+    local -a multi_flags=( "$@" )
+
+    local bit32=false
+    local bit64=false
+    local abi_dflt=false
+    local abi_x32=false
+
+    for m in "${multi_flags[@]}"; do
+        case "$m" in
+            -m32)  bit32=true; abi_dflt=true;;
+            -m64)  bit64=true; abi_dflt=true;;
+            -mx32) bit64=true; abi_x32=true;;
+        esac
+    done
+
+    # Fix up architecture.
+    case "${target}" in
+        x86_64-*)      $bit32 && target=${target/#x86_64-/i386-} ;;
+        i[34567]86-*)  $bit64 && target=${target/#i[34567]86-/x86_64-} ;;
+    esac
+
+    # Fix up the ABI part.
+    case "${target}" in
+        *x32) $abi_dflt && target=${target/%x32} ;;
+        *)    $abi_x32  && target=${target}x32 ;;
+    esac
+
+    echo "${target}"
 }
diff --git a/scripts/build/cc/100-gcc.sh b/scripts/build/cc/100-gcc.sh
index 7085a90..7bb3610 100644
--- a/scripts/build/cc/100-gcc.sh
+++ b/scripts/build/cc/100-gcc.sh
@@ -403,10 +403,20 @@ do_gcc_core_backend() {
         extra_config+=("--with-system-zlib")
     fi
 
-    # Some versions of gcc have a deffective --enable-multilib.
-    # Since that's the default, only pass --disable-multilib.
+    # Some versions of gcc have a defective --enable-multilib.
+    # Since that's the default, only pass --disable-multilib. For multilib,
+    # also enable multiarch. Without explicit --enable-multiarch, pass-1
+    # compiler is configured as multilib/no-multiarch and pass-2/final
+    # are multilib/multiarch (because gcc autodetects multiarch based on
+    # multiple instances of crt*.o in the install directory - which do
+    # not exist in pass-1).
     if [ "${CT_MULTILIB}" != "y" ]; then
         extra_config+=("--disable-multilib")
+    else
+        extra_config+=("--enable-multiarch")
+        if [ -n "${CT_CC_GCC_MULTILIB_LIST}" ]; then
+            extra_config+=("--with-multilib-list=${CT_CC_GCC_MULTILIB_LIST}")
+        fi
     fi
 
     CT_DoLog DEBUG "Extra config passed: '${extra_config[*]}'"
@@ -880,10 +890,15 @@ do_gcc_backend() {
         extra_config+=("--with-system-zlib")
     fi
 
-    # Some versions of gcc have a deffective --enable-multilib.
+    # Some versions of gcc have a defective --enable-multilib.
     # Since that's the default, only pass --disable-multilib.
     if [ "${CT_MULTILIB}" != "y" ]; then
         extra_config+=("--disable-multilib")
+    else
+        extra_config+=("--enable-multiarch")
+        if [ -n "${CT_CC_GCC_MULTILIB_LIST}" ]; then
+            extra_config+=("--with-multilib-list=${CT_CC_GCC_MULTILIB_LIST}")
+        fi
     fi
 
     CT_DoLog DEBUG "Extra config passed: '${extra_config[*]}'"
diff --git a/scripts/build/debug/300-gdb.sh b/scripts/build/debug/300-gdb.sh
index 418e85c..ee4753e 100644
--- a/scripts/build/debug/300-gdb.sh
+++ b/scripts/build/debug/300-gdb.sh
@@ -69,7 +69,11 @@ do_debug_gdb_build() {
 
         cross_extra_config=("${extra_config[@]}")
         cross_extra_config+=("--with-expat")
-        cross_extra_config+=("--with-libexpat-prefix=${CT_HOST_COMPLIBS_DIR}")
+        # NOTE: DO NOT USE --with-libexpat-prefix (until GDB configure is smarter)!!!
+        # It conflicts with a static build: GDB's configure script will find the shared
+        # version of expat and will attempt to link that, despite the -static flag.
+        # The link will fail, and configure will abort with "expat missing or unusable"
+        # message.
         case "${CT_THREADS}" in
             none)   cross_extra_config+=("--disable-threads");;
             *)      cross_extra_config+=("--enable-threads");;
@@ -88,17 +92,24 @@ do_debug_gdb_build() {
             cross_extra_config+=("--disable-nls")
         fi
 
-        CC_for_gdb=
-        LD_for_gdb=
+        CC_for_gdb="${CT_HOST}-gcc ${CT_CFLAGS_FOR_HOST} ${CT_LDFLAGS_FOR_HOST}"
+        LD_for_gdb="${CT_HOST}-ld ${CT_LDFLAGS_FOR_HOST}"
         if [ "${CT_GDB_CROSS_STATIC}" = "y" ]; then
-            CC_for_gdb="${CT_HOST}-gcc -static"
-            LD_for_gdb="${CT_HOST}-ld -static"
+            CC_for_gdb+=" -static"
+            LD_for_gdb+=" -static"
         fi
 
-    # Disable binutils options when building from the binutils-gdb repo.
-    cross_extra_config+=("--disable-binutils")
-    cross_extra_config+=("--disable-ld")
-    cross_extra_config+=("--disable-gas")
+        # Fix up whitespace. Some older GDB releases (e.g. 6.8a) get confused if there
+        # are multiple consecutive spaces: sub-configure scripts replace them with a
+        # single space and then complain that $CC value changed from that in
+        # the master directory.
+        CC_for_gdb=`echo $CC_for_gdb`
+        LD_for_gdb=`echo $LD_for_gdb`
+
+        # Disable binutils options when building from the binutils-gdb repo.
+        cross_extra_config+=("--disable-binutils")
+        cross_extra_config+=("--disable-ld")
+        cross_extra_config+=("--disable-gas")
 
         CT_DoLog DEBUG "Extra config passed: '${cross_extra_config[*]}'"
 
@@ -162,6 +173,11 @@ do_debug_gdb_build() {
         fi
 
         native_extra_config+=("--with-expat")
+        # NOTE: DO NOT USE --with-libexpat-prefix (until GDB configure is smarter)!!!
+        # It conflicts with a static build: GDB's configure script will find the shared
+        # version of expat and will attempt to link that, despite the -static flag.
+        # The link will fail, and configure will abort with "expat missing or unusable"
+        # message.
 
         CT_DoLog EXTRA "Configuring native gdb"
 
diff --git a/scripts/build/libc/glibc.sh b/scripts/build/libc/glibc.sh
index 0a09cbd..472acad 100644
--- a/scripts/build/libc/glibc.sh
+++ b/scripts/build/libc/glibc.sh
@@ -73,6 +73,7 @@ do_libc_backend() {
     local multi_dir
     local multi_flags
     local extra_dir
+    local target
     local libc_headers libc_startfiles libc_full
     local hdr
     local arg
@@ -136,11 +137,36 @@ do_libc_backend() {
 
         CT_mkdir_pushd "${CT_BUILD_DIR}/build-libc-${libc_mode}${extra_dir//\//_}"
 
+        target=$( CT_DoMultilibTarget "${CT_TARGET}" ${extra_flags} )
+        case "${target}" in
+            # SPARC quirk: glibc 2.23 and newer dropped support for SPARCv8 and
+            # earlier (corresponding pthread barrier code is missing). Until this
+            # support is reintroduced, configure as sparcv9.
+            sparc-*)
+                if [ "${CT_LIBC_GLIBC_2_23_or_later}" = y ]; then
+                    target=${target/#sparc-/sparcv9-}
+                fi
+                ;;
+            # x86 quirk: architecture name is i386, but glibc expects i[4567]86 - to
+            # indicate the desired optimization. If it was a multilib variant of x86_64,
+            # then it targets at least NetBurst a.k.a. i786, but we'll follow arch/x86.sh
+            # and set the optimization to i686. Otherwise, replace with the most
+            # conservative choice, i486.
+            i386-*)
+                if [ "${CT_TARGET_ARCH}" = "x86_64" ]; then
+                    target=${target/#i386-/i686-}
+                else
+                    target=${target/#i386-/i486-}
+                fi
+                ;;
+        esac
+
         do_libc_backend_once extra_dir="${extra_dir}"               \
                              extra_flags="${extra_flags}"           \
                              libc_headers="${libc_headers}"         \
                              libc_startfiles="${libc_startfiles}"   \
-                             libc_full="${libc_full}"
+                             libc_full="${libc_full}"               \
+                             target="${target}"
 
         CT_Popd
 
@@ -179,6 +205,7 @@ do_libc_backend() {
 #   libc_full           : Build full libc                       : bool      : n
 #   extra_flags         : Extra CFLAGS to use (for multilib)    : string    : (empty)
 #   extra_dir           : Extra subdir for multilib             : string    : (empty)
+#   target              : Build libc using this target (for multilib) : string : ${CT_TARGET}
 do_libc_backend_once() {
     local libc_headers
     local libc_startfiles
@@ -192,12 +219,17 @@ do_libc_backend_once() {
     local glibc_cflags
     local float_extra
     local endian_extra
+    local target
     local arg
 
     for arg in "$@"; do
         eval "${arg// /\\ }"
     done
 
+    if [ "${target}" = "" ]; then
+        target="${CT_TARGET}"
+    fi
+
     CT_DoLog EXTRA "Configuring C library"
 
     case "${CT_LIBC}" in
@@ -273,12 +305,12 @@ do_libc_backend_once() {
                      |${sed} -r -e '/^(.*[[:space:]])?-(E[BL]|m((big|little)(-endian)?|e?[bl]))([[:space:]].*)?$/!d;' \
                                 -e 's//\2/;'    \
                    )"
+    # If extra_flags contained an endianness option, no need to add it again. Otherwise,
+    # add the option from the configuration.
     case "${endian_extra}" in
         EB|mbig-endian|mbig|meb|mb)
-            extra_cc_args="${extra_cc_args} ${endian_extra}"
             ;;
         EL|mlittle-endian|mlittle|mel|ml)
-            extra_cc_args="${extra_cc_args} ${endian_extra}"
             ;;
         "") extra_cc_args="${extra_cc_args} ${CT_ARCH_ENDIAN_OPT}"
             ;;
@@ -341,7 +373,7 @@ do_libc_backend_once() {
     "${src_dir}/configure"                                          \
         --prefix=/usr                                               \
         --build=${CT_BUILD}                                         \
-        --host=${CT_TARGET}                                         \
+        --host=${target}                                            \
         --cache-file="$(pwd)/config.cache"                          \
         --without-cvs                                               \
         --disable-profile                                           \
@@ -443,7 +475,8 @@ do_libc_backend_once() {
             # However, since we will never actually execute its code,
             # it doesn't matter what it contains.  So, treating '/dev/null'
             # as a C source file, we produce a dummy 'libc.so' in one step
-            CT_DoExecLog ALL "${cross_cc}" -nostdlib        \
+            CT_DoExecLog ALL "${cross_cc}" ${extra_flags}   \
+                                           -nostdlib        \
                                            -nostartfiles    \
                                            -shared          \
                                            -x c /dev/null   \
diff --git a/scripts/crosstool-NG.sh.in b/scripts/crosstool-NG.sh.in
index 9297e3b..3c193c3 100644
--- a/scripts/crosstool-NG.sh.in
+++ b/scripts/crosstool-NG.sh.in
@@ -509,6 +509,8 @@ if [ -z "${CT_RESTART}" ]; then
     CT_CFLAGS_FOR_HOST+=" ${CT_EXTRA_CFLAGS_FOR_HOST}"
     CT_LDFLAGS_FOR_HOST=
     CT_LDFLAGS_FOR_HOST+=" ${CT_EXTRA_LDFLAGS_FOR_HOST}"
+    CT_CFLAGS_FOR_HOST+=" -I${CT_HOST_COMPLIBS_DIR}/include"
+    CT_LDFLAGS_FOR_HOST+=" -L${CT_HOST_COMPLIBS_DIR}/lib"
     CT_DoLog DEBUG "CFLAGS for host compiler: '${CT_CFLAGS_FOR_HOST}'"
     CT_DoLog DEBUG "LDFLAGS for host compiler: '${CT_LDFLAGS_FOR_HOST}'"
 
diff --git a/scripts/functions b/scripts/functions
index 70c1ba6..62d264e 100644
--- a/scripts/functions
+++ b/scripts/functions
@@ -1305,6 +1305,25 @@ CT_DoBuildTargetTuple() {
     CT_ARCH_TARGET_LDFLAGS="${CT_ARCH_TARGET_LDFLAGS} ${CT_ARCH_ENDIAN_LDFLAG}"
 }
 
+# This function determines the target tuple for a given set of compiler
+# flags, using either GCC's multiarch feature (if supported; if not,
+# GCC prints nothing and exits with status 0), falling back to calling
+# the architecture-specific functions.
+CT_DoMultilibTarget() {
+    local target="$1"; shift
+    local -a multi_flags=( "$@" )
+    local gcc_multiarch
+
+    gcc_multiarch=$( "${CT_TARGET}-gcc" -print-multiarch "${multi_flags[@]}" )
+    if [ -n "${gcc_multiarch}" ]; then
+        echo "${gcc_multiarch}"
+        return
+    fi
+
+    # Fall back to arch-specific guesswork
+    CT_DoArchMultilibTarget "${target}" "${multi_flags[@]}"
+}
+
 # This function does pause the build until the user strikes "Return"
 # Usage: CT_DoPause [optional_message]
 CT_DoPause() {