tree fee8c776b8591a09c1387bcc7dd3bd1bccb14e7e
parent f1410802d1c9e7ff72b2818ad91fd85283abc6bf
author Argyrios Kyrtzidis <akyrtzi@gmail.com> 1288824323 +0000
committer Argyrios Kyrtzidis <akyrtzi@gmail.com> 1288824323 +0000

Implement -working-directory.

When -working-directory is passed in command line, file paths are resolved relative to the specified directory.
This helps both when using libclang (where we can't require the user to actually change the working directory)
and to help reproduce test cases when the reproduction work comes along.

--FileSystemOptions is introduced which controls how file system operations are performed (currently it just contains
 the working directory value if set).
--FileSystemOptions are passed around to various interfaces that perform file operations.
--Opening & reading the content of files should be done only through FileManager. This is useful in general since
 file operations will be abstracted in the future for the reproduction mechanism.

FileSystemOptions is independent of FileManager so that we can have multiple translation units sharing the same
FileManager but with different FileSystemOptions.

Addresses rdar://8583824.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118203 91177308-0d34-0410-b5e6-96231b3b80d8