[cfe-dev] patch for improving Clang's virtual file handling

[Douglas Gregor]

Hi Zhanyong,

Your patch looks good to me. Did you consider using the functionality in llvm::sys::path to handle the parsing of path names, rather than hand-coding string algorithm such as

+void FileManager::addAncestorsAsVirtualDirs(llvm::StringRef Path) {
+  size_t SlashPos = Path.size();
+
+  // Find the beginning of the last segment in Path.
+  while (SlashPos != 0 && !IS_DIR_SEPARATOR_CHAR(Path[SlashPos-1]))
+    --SlashPos;
+
+  // Ignore repeated //'s.
+  while (SlashPos != 0 && IS_DIR_SEPARATOR_CHAR(Path[SlashPos-1]))
+    --SlashPos;
+
+  if (SlashPos == 0)
+    return;

?

	- Doug

On Feb 7, 2011, at 2:17 PM, Zhanyong Wan (λx.x x) wrote:

> Hi, Doug,
> 
> Per our chat, please review the attached patch Manuel and I wrote for
> improving Clang's virtual file handling.  I also uploaded the patch to
> http://codereview.appspot.com/4126060 to make it easier to comment on
> the individual lines.
> 
> This patch contains:
> 
> - making some of the existing comments more accurate in the presence
> of virtual files/directories.
> 
> - renaming some private data members of FileManager to match their roles better.
> 
> - creating 'DirectorEntry's for the parent directories of virtual
> files, such that we can tell whether two virtual files are from the
> same directory.  This is useful for injecting virtual files whose
> directories don't exist in the real file system.
> 
> - minor clean-ups and adding comments for class
> FileManager::UniqueDirContainer and FileManager::UniqueFileContainer.
> 
> - adding statistics on virtual files to FileManager::PrintStats().
> 
> I didn't add new tests, but all existing tests pass.  I plan to add
> the tests in a new patch, as I'm still figuring out how to do that.
> 
> Thanks a lot!
> -- 
> Zhanyong
> <virtual-dir.patch>