arch/all: Add common function to return multilib target

This code was abstracted out of Cody P Schafer's multilib patch.
It doesn't seem right having architecture dependent code in a
specific libc implementation script. So this patch breaks it out into
scripts/build/arch/<arch>.sh in a function:

  multilib_target_to_build="$(CT_DoArchMultilibTarget 'multi_flags'
'target-in')"

Note that this function gets called on each multilib variant with
different sets of compiler flags supplied in 'multi_flags'. The caller
will first filter the flags so that there is no conflicting flags (e.g.,
no '-m32 -m64') supplied.

Changed by Alexey Neyman:
- make option analysis check specific option rather than match global
  options string as a whole. Moreover, old code did not handle multiple
  options in the same multilib, e.g. '-m64 -mlittle'.
- fixed substitutions in powerpc.sh (*le variants did not match the
  pattern in the shell parameter expansion)
- make s390.sh actually apply the flags it gathered from the options.
- straighten the spaghetti in x86.sh by setting two flags, arch & abi.
  Also, do not depend on "gnu" being the last part - we can have
  '*-uclibcx32', for example.

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
Signed-off-by: Ray Donnelly <ray.donnelly@gmail.com>
Signed-off-by: Alexey Neyman <stilor@att.net>

1 files changed, 27 insertions, 0 deletions

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}"
+}