tree c9a3838dd8bb8eda8c958dfd28ef7f74c61a66f2
parent 8d7f5481a0eeb4c0508202a4bd2b754cfa93c4fe
author Douglas Gregor <dgregor@apple.com> 1239316064 +0000
committer Douglas Gregor <dgregor@apple.com> 1239316064 +0000

Implementation of pre-compiled headers (PCH) based on lazy
de-serialization of abstract syntax trees.

PCH support serializes the contents of the abstract syntax tree (AST)
to a bitstream. When the PCH file is read, declarations are serialized
as-needed. For example, a declaration of a variable "x" will be
deserialized only when its VarDecl can be found by a client, e.g.,
based on name lookup for "x" or traversing the entire contents of the
owner of "x".

This commit provides the framework for serialization and (lazy)
deserialization, along with support for variable and typedef
declarations (along with several kinds of types). More
declarations/types, along with important auxiliary structures (source
manager, preprocessor, etc.), will follow.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68732 91177308-0d34-0410-b5e6-96231b3b80d8