[PATCH] Some infrastructure work for virtual file system (now on phab)

Ben Langmuir blangmuir at apple.com
Fri Feb 14 07:15:19 PST 2014



================
Comment at: lib/Basic/VirtualFileSystem.cpp:62-83
@@ +61,24 @@
+
+ErrorOr<AbstractFileSystem::Status>
+AbstractFileSystem::status(AbstractFileSystem::FileDescriptor FD) {
+  // FIXME: when we support virtual files, use information from the FD to lookup
+  // which AbstractFileSystem to perform this operation on.
+  return getRealFileSystem()->statusOfOpenFile(FD);
+}
+
+error_code AbstractFileSystem::getBufferForFile(
+    FileDescriptor FD, const llvm::Twine &Name,
+    llvm::OwningPtr<llvm::MemoryBuffer> &Result, int64_t FileSize,
+    bool RequiresNullTerminator) {
+  // FIXME: when we support virtual files, use information from the FD to lookup
+  // which AbstractFileSystem to perform this operation on.
+  return getRealFileSystem()->getBufferForOpenFile(FD, Name, Result, FileSize,
+                                                   RequiresNullTerminator);
+}
+
+error_code AbstractFileSystem::close(AbstractFileSystem::FileDescriptor FD) {
+  // FIXME: when we support virtual files, use information from the FD to lookup
+  // which AbstractFileSystem to perform this operation on.
+  return getRealFileSystem()->closeOpenFile(FD);
+}
+
----------------
Ben Langmuir wrote:
> Manuel Klimek wrote:
> > I'd have expected this->*OpenFile(...) calls in those methods.
> These methods take a file descriptor as a parameter, so the file is already open.
Oh sorry, I think I misunderstood your comment.

The reason we don't call this->*OpenFile in here is that the FileDescriptor object (when we create one) should give us the AbstractFileSystem that we need to call the method on.  If we have a virtual file system composed of several AbstractFileSystems overlaid on top of each other, we shouldn't have to search for which file system owns the open file, since by opening it we already figured that out and can save it in the file descriptor.


http://llvm-reviews.chandlerc.com/D2745



More information about the cfe-commits mailing list