1 files changed, 33 insertions, 4 deletions
diff --git a/docs/InternalsManual.rst b/docs/InternalsManual.rst
index 8e047db..502cae4 100644
--- a/docs/InternalsManual.rst
+++ b/docs/InternalsManual.rst
@@ -784,9 +784,24 @@ buffer uses this idiom and is subsequently ``#include``'d, the preprocessor can
 simply check to see whether the guarding condition is defined or not.  If so,
 the preprocessor can completely ignore the include of the header.
 
+.. _Parser:
+
 The Parser Library
 ==================
 
+This library contains a recursive-descent parser that polls tokens from the
+preprocessor and notifies a client of the parsing progress.
+
+Historically, the parser used to talk to an abstract ``Action`` interface that
+had virtual methods for parse events, for example ``ActOnBinOp()``.  When Clang
+grew C++ support, the parser stopped supporting general ``Action`` clients --
+it now always talks to the :ref:`Sema libray <Sema>`.  However, the Parser
+still accesses AST objects only through opaque types like ``ExprResult`` and
+``StmtResult``.  Only :ref:`Sema <Sema>` looks at the AST node contents of these
+wrappers.
+
+.. _AST:
+
 The AST Library
 ===============
 
@@ -1396,10 +1411,7 @@ body by single call to a static class method:
 .. code-block:: c++
 
   Stmt *FooBody = ...
-  CFG *FooCFG = CFG::buildCFG(FooBody);
-
-It is the responsibility of the caller of ``CFG::buildCFG`` to ``delete`` the
-returned ``CFG*`` when the CFG is no longer needed.
+  std::unique_ptr<CFG> FooCFG = CFG::buildCFG(FooBody);
 
 Along with providing an interface to iterate over its ``CFGBlocks``, the
 ``CFG`` class also provides methods that are useful for debugging and
@@ -1585,6 +1597,23 @@ interacts with constant evaluation:
 * ``__builtin_strlen`` and ``strlen``: These are constant folded as integer
   constant expressions if the argument is a string literal.
 
+.. _Sema:
+
+The Sema Library
+================
+
+This library is called by the :ref:`Parser library <Parser>` during parsing to
+do semantic analysis of the input.  For valid programs, Sema builds an AST for
+parsed constructs.
+
+.. _CodeGen:
+
+The CodeGen Library
+===================
+
+CodeGen takes an :ref:`AST <AST>` as input and produces `LLVM IR code
+<//llvm.org/docs/LangRef.html>`_ from it.
+
 How to change Clang
 ===================