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author | Nico Weber <nicolasweber@gmx.de> | 2014-12-28 02:07:26 +0000 |
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committer | Nico Weber <nicolasweber@gmx.de> | 2014-12-28 02:07:26 +0000 |
commit | 59745e0f880af0e27e0b8e4444b817b39141311d (patch) | |
tree | ec7543bdaa031ae19e9d1c34e117dbe22fad33a9 /docs/InternalsManual.rst | |
parent | fc0695463f61033053a34d36050c6ba7b49bce74 (diff) |
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.)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@224894 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/InternalsManual.rst')
-rw-r--r-- | docs/InternalsManual.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/docs/InternalsManual.rst b/docs/InternalsManual.rst index 50a1943ee2..511e2c61e9 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` 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 @@ 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 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 =================== |