2 Commits

Author	SHA1	Message	Date
Robert Widmann	61203921f5	Diagnose clobbering clang's VFS with our own ... There are three modes of concern here: 1) User provides -vfsoverlay but not -Xcc -ivfsoverlay Recommended behavior. 2) User provides -Xcc -ivfsoverlay but not -vfsoverlay Legacy behavior. Clang will handle setup for the VFS. 3) User provides both -vfsoverlay and -Xcc -ivfsoverlay Unsupported. We will ignore the clang VFS overlays and substitute our own. We will also pop a warning about this.	2018-07-31 15:11:52 -07:00
Robert Widmann	0e58b7fd14	Plumbing for a Virtual File System ... Adds the -vfsoverlay frontend option that enables the user to pass VFS overlay YAML files to Swift. These files define a (potentially many-layered) virtual mapping on which we predicate a VFS. Switch all input-based memory buffer reads in the Frontend to the new FileSystem-based approach.	2018-07-31 13:16:14 -07:00