Driver help output for --sysroot.

[Iain Sandoe]

Is there some reason we don't want to own up to having the --sysroot option ?

If not - then how about the following?
Iain


diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 9d4ff4d..17c720e 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1491,7 +1491,9 @@ def _signed_char : Flag<["--"], "signed-char">, Alias<fsigned_char>;
 def _std : Separate<["--"], "std">, Alias<std_EQ>;
 def _stdlib : Separate<["--"], "stdlib">, Alias<stdlib_EQ>;
 def _sysroot_EQ : Joined<["--"], "sysroot=">;
-def _sysroot : Separate<["--"], "sysroot">, Alias<_sysroot_EQ>;
+def _sysroot : Separate<["--"], "sysroot">, Alias<_sysroot_EQ>,
+  HelpText<"Use <dir> as the root directory for headers and libraries">,
+  MetaVarName<"<dir>">;
 def _target_help : Flag<["--"], "target-help">;
 def _trace_includes : Flag<["--"], "trace-includes">, Alias<H>;
 def _undefine_macro_EQ : Joined<["--"], "undefine-macro=">, Alias<U>;