common/autoconf/toolchain.m4

rev 977 : JDK-8019470: Changes needed to compile JDK8 on MacOS with clang compiler
Reviewed-by:

*** 94,105 ****
--- 94,124 ----
        [the toolchain type (or family) to use, use '--help' to show possible values @<:@platform dependent@:>@])])
  
    # Use indirect variable referencing
    toolchain_var_name=VALID_TOOLCHAINS_$OPENJDK_BUILD_OS
    VALID_TOOLCHAINS=${!toolchain_var_name}
+ 
+   if test "x$OPENJDK_TARGET_OS" = xmacosx; then
+     # On Mac OS X, default toolchain to clang after Xcode 5
+     XCODE_VERSION_OUTPUT=`xcodebuild -version 2>&1 | $HEAD -n 1`
+     $ECHO "$XCODE_VERSION_OUTPUT" | $GREP "Xcode " > /dev/null
+     if test $? -ne 0; then
+       AC_MSG_ERROR([Failed to determine Xcode version.])
+     fi
+     XCODE_MAJOR_VERSION=`$ECHO $XCODE_VERSION_OUTPUT | \
+         $SED -e 's/^Xcode \(@<:@1-9@:>@@<:@0-9.@:>@*\)/\1/' | \
+         $CUT -f 1 -d .`
+     AC_MSG_NOTICE([Xcode major version: $XCODE_MAJOR_VERSION])
+     if test $XCODE_MAJOR_VERSION -ge 5; then
+         DEFAULT_TOOLCHAIN="clang"
+     else
+         DEFAULT_TOOLCHAIN="gcc"
+     fi
+   else
      # First toolchain type in the list is the default
      DEFAULT_TOOLCHAIN=${VALID_TOOLCHAINS%% *}
+   fi
    
    if test "x$with_toolchain_type" = xlist; then
      # List all toolchains
      AC_MSG_NOTICE([The following toolchains are valid on this platform:])
      for toolchain in $VALID_TOOLCHAINS; do