3 files changed, 173 insertions, 1 deletions
diff --git a/docs/CommandGuide/clang.rst b/docs/CommandGuide/clang.rst
index 16bb09f3c740b..d440d915d686d 100644
--- a/docs/CommandGuide/clang.rst
+++ b/docs/CommandGuide/clang.rst
@@ -98,10 +98,129 @@ Language Selection and Mode Options
 
  Treat subsequent input files as having type language.
 
-.. option:: -std=<language>
+.. option:: -std=<standard>
 
  Specify the language standard to compile for.
 
+ Supported values for the C language are:
+
+  | ``c89``
+  | ``c90``
+  | ``iso9899:1990``
+
+   ISO C 1990
+
+  | ``iso9899:199409``
+
+   ISO C 1990 with amendment 1
+
+  | ``gnu89``
+  | ``gnu90``
+
+   ISO C 1990 with GNU extensions
+
+  | ``c99``
+  | ``iso9899:1999``
+
+   ISO C 1999
+
+  | ``gnu99``
+
+   ISO C 1999 with GNU extensions
+
+  | ``c11``
+  | ``iso9899:2011``
+
+   ISO C 2011
+
+  | ``gnu11``
+
+   ISO C 2011 with GNU extensions
+
+  | ``c17``
+  | ``iso9899:2017``
+
+   ISO C 2017
+
+  | ``gnu17``
+
+   ISO C 2017 with GNU extensions
+
+ The default C language standard is ``gnu11``, except on PS4, where it is
+ ``gnu99``.
+
+ Supported values for the C++ language are:
+
+  | ``c++98``
+  | ``c++03``
+
+   ISO C++ 1998 with amendments
+
+  | ``gnu++98``
+  | ``gnu++03``
+
+   ISO C++ 1998 with amendments and GNU extensions
+
+  | ``c++11``
+
+   ISO C++ 2011 with amendments
+
+  | ``gnu++11``
+
+    ISO C++ 2011 with amendments and GNU extensions
+
+  | ``c++14``
+
+   ISO C++ 2014 with amendments
+
+  | ``gnu++14``
+
+   ISO C++ 2014 with amendments and GNU extensions
+
+  | ``c++17``
+
+   ISO C++ 2017 with amendments
+
+  | ``gnu++17``
+
+   ISO C++ 2017 with amendments and GNU extensions
+
+  | ``c++2a``
+
+   Working draft for ISO C++ 2020
+
+  | ``gnu++2a``
+
+   Working draft for ISO C++ 2020 with GNU extensions
+
+ The default C++ language standard is ``gnu++14``.
+
+ Supported values for the OpenCL language are:
+
+  | ``cl1.0``
+
+   OpenCL 1.0
+
+  | ``cl1.1``
+
+   OpenCL 1.1
+
+  | ``cl1.2``
+
+   OpenCL 1.2
+
+  | ``cl2.0``
+
+   OpenCL 2.0
+
+ The default OpenCL language standard is ``cl1.0``.
+
+ Supported values for the CUDA language are:
+
+  | ``cuda``
+
+   NVIDIA CUDA(tm)
+
 .. option:: -stdlib=<library>
 
  Specify the C++ standard library to use; supported options are libstdc++ and
diff --git a/docs/CommandGuide/diagtool.rst b/docs/CommandGuide/diagtool.rst
new file mode 100644
index 0000000000000..59417f71f69d7
--- /dev/null
+++ b/docs/CommandGuide/diagtool.rst
@@ -0,0 +1,52 @@
+diagtool - clang diagnostics tool
+=================================
+
+SYNOPSIS
+--------
+
+:program:`diagtool` *command* [*args*]
+
+DESCRIPTION
+-----------
+
+:program:`diagtool` is a combination of four tool for dealing with diagnostics in :program:`clang`.
+
+SUBCOMMANDS
+-----------
+
+:program:`diagtool` is separated into several subcommands each tailored to a
+different purpose. A brief summary of each command follows, with more detail in
+the sections that follow.
+
+  * :ref:`find_diagnostic_id` - Print the id of the given diagnostic.
+  * :ref:`list_warnings` - List warnings and their corresponding flags.
+  * :ref:`show_enabled` - Show which warnings are enabled for a given command line.
+  * :ref:`tree` - Show warning flags in a tree view.
+
+.. _find_diagnostic_id:
+
+find-diagnostic-id
+~~~~~~~~~~~~~~~~~~
+
+:program:`diagtool` find-diagnostic-id *diagnostic-name*
+
+.. _list_warnings:
+
+list-warnings
+~~~~~~~~~~~~~
+
+:program:`diagtool` list-warnings
+
+.. _show_enabled:
+
+show-enabled
+~~~~~~~~~~~~
+
+:program:`diagtool` show-enabled [*options*] *filename ...*
+
+.. _tree:
+
+tree
+~~~~
+
+:program:`diagtool` tree [*diagnostic-group*]
diff --git a/docs/CommandGuide/index.rst b/docs/CommandGuide/index.rst
index 826ed97119805..83a91182e9ca6 100644
--- a/docs/CommandGuide/index.rst
+++ b/docs/CommandGuide/index.rst
@@ -15,3 +15,4 @@ Basic Commands
    :maxdepth: 1
 
    clang
+   diagtool