Add stub sections about Parse, Sema, CodeGen to the internals manual.
I'd be interested if the paragraph on Parse not knowing much about AST is
something folks agree with. I think this used to be true after rjmccall removed
the Action interface in r112244 and I believe it's still true, but I'm not sure.
(For example, ParseOpenMP.cpp does include AST/StmtOpenMP.h. Other than that,
Parse not using AST nodes much seems to be still true, though.)
llvm-svn: 224894
diff --git a/clang/docs/InternalsManual.rst b/clang/docs/InternalsManual.rst
index 50a1943..511e2c6 100644
--- a/clang/docs/InternalsManual.rst
+++ b/clang/docs/InternalsManual.rst
@@ -784,9 +784,24 @@
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` library. However, the Parser still
+accesses AST objects only through opaque types like ``ExprResult`` and
+``StmtResult``. Only ::ref::`Sema` looks at the AST node contents of these
+wrappers.
+
+.. _AST:
+
The AST Library
===============
@@ -1582,6 +1597,23 @@
* ``__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 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` as input and produces `LLVM IR code
+<//llvm.org/docs/LangRef.html>`_ from it.
+
How to change Clang
===================