diff -r 099891b1d86f -r 85635b5bf0a6 common/autoconf/flags.m4
--- a/common/autoconf/flags.m4	Wed Jul 05 19:32:12 2017 +0200
+++ b/common/autoconf/flags.m4	Tue Feb 25 23:38:52 2014 -0800
@@ -148,6 +148,26 @@
       SET_SHARED_LIBRARY_NAME='-Xlinker -soname=[$]1'
       SET_SHARED_LIBRARY_MAPFILE='-Xlinker -version-script=[$]1'
     fi
+  elif test "x$TOOLCHAIN_TYPE" = xclang; then
+    PICFLAG=''
+    C_FLAG_REORDER=''
+    CXX_FLAG_REORDER=''
+
+    if test "x$OPENJDK_TARGET_OS" = xmacosx; then
+      # Linking is different on MacOSX
+      SHARED_LIBRARY_FLAGS="-dynamiclib -compatibility_version 1.0.0 -current_version 1.0.0 $PICFLAG"
+      SET_EXECUTABLE_ORIGIN='-Xlinker -rpath -Xlinker @loader_path/.'
+      SET_SHARED_LIBRARY_ORIGIN="$SET_EXECUTABLE_ORIGIN"
+      SET_SHARED_LIBRARY_NAME='-Xlinker -install_name -Xlinker @rpath/[$]1'
+      SET_SHARED_LIBRARY_MAPFILE=''
+    else
+      # Default works for linux, might work on other platforms as well.
+      SHARED_LIBRARY_FLAGS='-shared'
+      SET_EXECUTABLE_ORIGIN='-Xlinker -rpath -Xlinker \$$$$ORIGIN[$]1'
+      SET_SHARED_LIBRARY_ORIGIN="-Xlinker -z -Xlinker origin $SET_EXECUTABLE_ORIGIN"
+      SET_SHARED_LIBRARY_NAME='-Xlinker -soname=[$]1'
+      SET_SHARED_LIBRARY_MAPFILE='-Xlinker -version-script=[$]1'
+    fi
   elif test "x$TOOLCHAIN_TYPE" = xsolstudio; then
     PICFLAG="-KPIC"
     C_FLAG_REORDER='-xF'
@@ -242,6 +262,8 @@
   # Generate make dependency files
   if test "x$TOOLCHAIN_TYPE" = xgcc; then
     C_FLAG_DEPS="-MMD -MF"
+  elif test "x$TOOLCHAIN_TYPE" = xclang; then
+    C_FLAG_DEPS="-MMD -MF"
   elif test "x$TOOLCHAIN_TYPE" = xsolstudio; then
     C_FLAG_DEPS="-xMMD -xMF"
   elif test "x$TOOLCHAIN_TYPE" = xxlc; then
@@ -260,6 +282,9 @@
       CFLAGS_DEBUG_SYMBOLS="-g"
       CXXFLAGS_DEBUG_SYMBOLS="-g"
     fi
+  elif test "x$TOOLCHAIN_TYPE" = xclang; then
+    CFLAGS_DEBUG_SYMBOLS="-g"
+    CXXFLAGS_DEBUG_SYMBOLS="-g"
   elif test "x$TOOLCHAIN_TYPE" = xsolstudio; then
     CFLAGS_DEBUG_SYMBOLS="-g -xs"
     CXXFLAGS_DEBUG_SYMBOLS="-g0 -xs"
@@ -315,6 +340,20 @@
         C_O_FLAG_NORM="-O2"
         C_O_FLAG_NONE="-O0"
       fi
+    elif test "x$TOOLCHAIN_TYPE" = xclang; then
+      if test "x$OPENJDK_TARGET_OS" = xmacosx; then
+        # On MacOSX we optimize for size, something
+        # we should do for all platforms?
+        C_O_FLAG_HIGHEST="-Os"
+        C_O_FLAG_HI="-Os"
+        C_O_FLAG_NORM="-Os"
+        C_O_FLAG_NONE=""
+      else
+        C_O_FLAG_HIGHEST="-O3"
+        C_O_FLAG_HI="-O3"
+        C_O_FLAG_NORM="-O2"
+        C_O_FLAG_NONE="-O0"
+      fi
     elif test "x$TOOLCHAIN_TYPE" = xxlc; then
       C_O_FLAG_HIGHEST="-O3"
       C_O_FLAG_HI="-O3 -qstrict"