+dnl Allow a specific Clang compiler to be used with this LLVM config.
+AC_ARG_WITH(clang,
+ AS_HELP_STRING([--with-clang],
+ [Specify location of clang compiler (default is --with-built-clang)]),
+ [],[with_clang=default])
+
+dnl Enable use of the built Clang.
+AC_ARG_WITH(built-clang,
+ AS_HELP_STRING([--with-built-clang],
+ [Use the compiled Clang as the LLVM compiler (default=check)]),
+ [],[with_built_clang=check])
+
+dnl Select the Clang compiler option.
+dnl
+dnl If --with-clang is given, always honor that; otherwise honor
+dnl --with-built-clang, or check if we have the clang sources.
+AC_MSG_CHECKING([clang compiler])
+WITH_CLANGPATH=""
+WITH_BUILT_CLANG=0
+if test "$with_clang" != "default"; then
+ WITH_CLANGPATH="$with_clang"
+ if ! test -x "$WITH_CLANGPATH"; then
+ AC_MSG_ERROR([invalid --with-clang, path does not specify an executable])
+ fi
+elif test "$with_built_clang" = "yes"; then
+ WITH_BUILT_CLANG=1
+elif test "$with_built_clang" = "no"; then
+ WITH_BUILT_CLANG=0
+else
+ if test "$with_built_clang" != "check"; then
+ AC_MSG_ERROR([invalid value for --with-built-clang.])
+ fi
+
+ if test -f ${srcdir}/tools/clang/README.txt; then
+ WITH_BUILT_CLANG=1
+ fi
+fi
+
+if ! test -z "$WITH_CLANGPATH"; then
+ AC_MSG_RESULT([$WITH_CLANGPATH])
+ WITH_CLANGXXPATH=`"$WITH_CLANGPATH" --print-prog-name=clang++`
+elif test "$WITH_BUILT_CLANG" = "1"; then
+ AC_MSG_RESULT([built])
+else
+ AC_MSG_RESULT([none])
+fi
+AC_SUBST(CLANGPATH,$WITH_CLANGPATH)
+AC_SUBST(CLANGXXPATH,$WITH_CLANGXXPATH)
+AC_SUBST(ENABLE_BUILT_CLANG,$WITH_BUILT_CLANG)
+