[cfe-commits] r38727 - /cfe/cfe/trunk/README.txt

[sabre at cs.uiuc.edu]

Author: sabre
Date: Wed Jul 11 11:24:08 2007
New Revision: 38727

URL: http://llvm.org/viewvc/llvm-project?rev=38727&view=rev
Log:
Add some notes

Modified:
    cfe/cfe/trunk/README.txt

Modified: cfe/cfe/trunk/README.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/cfe/trunk/README.txt?rev=38727&r1=38726&r2=38727&view=diff

==============================================================================
--- cfe/cfe/trunk/README.txt (original)
+++ cfe/cfe/trunk/README.txt Wed Jul 11 11:24:08 2007
@@ -36,6 +36,27 @@
 
 III. Missing Functionality
 
+File Manager:
+ * We currently do a lot of stat'ing for files that don't exist, particularly
+   when lots of -I paths exist (e.g. see the <iostream> example, check for
+   failures in stat in FileManager::getFile).  It would be far better to make
+   the following changes:
+     1. FileEntry contains a sys::Path instead of a std::string for Name.
+     2. sys::Path contains timestamp and size, lazily computed.  Eliminate from
+        FileEntry.
+     3. File UIDs are created on request, not when files are opened.
+   These changes make it possible to efficiently have FileEntry objects for
+   files that exist on the file system, but have not been used yet.
+   
+   Once this is done:
+     1. DirectoryEntry gets a boolean value "has read entries".  When false, not
+        all entries in the directory are in the file mgr, when true, they are.
+     2. Instead of stat'ing the file in FileManager::getFile, check to see if 
+        the dir has been read.  If so, fail immediately, if not, read the dir,
+        then retry.
+     3. Reading the dir uses the getdirentries syscall, creating an FileEntry
+        for all files found.
+
 Lexer:
  * Source character mapping.  GCC supports ASCII and UTF-8.
    See GCC options: -ftarget-charset and -ftarget-wide-charset.