Extend comments for problems and future directions.

llvm-svn: 188035
diff --git a/clang-tools-extra/modularize/Modularize.cpp b/clang-tools-extra/modularize/Modularize.cpp
index ea7d2d5..6a4c4fd 100644
--- a/clang-tools-extra/modularize/Modularize.cpp
+++ b/clang-tools-extra/modularize/Modularize.cpp
@@ -70,7 +70,7 @@
 //             ^

 //   Macro defined here.

 //

-// See PreprocessorTracker.cpp for additional details.

+// See PreprocessorTracker.cpp for additional details.
 //
 // Current problems:
 //
@@ -86,6 +86,14 @@
 //
 // 3. There seem to be a lot of spurious "not always provided" messages,
 // and many duplicates of these.
+//
+// 4. There are some legitimate uses of preprocessor macros that
+// modularize will flag as errors, such as repeatedly #include'ing
+// a file and using interleaving defined/undefined macros
+// to change declarations in the included file.  Is there a way
+// to address this?  Maybe have modularize accept a list of macros
+// to ignore.  Otherwise you can just exclude the file, after checking
+// for legitimate errors.
 //

 // Future directions:
 //
@@ -105,7 +113,12 @@
 // 4. Check for correct and consistent usage of extern "C" {} and other
 // directives. Warn about #include inside extern "C" {}.
 //
-// 5. What else?
+// 5. To support headers that depend on other headers to be included first
+// add support for a dependency list to the header list input.
+// I.e.: header.h: dependent1.h dependent2.h
+// (Implement using clang's "-include" option"?)
+//
+// 6. What else?
 //
 // General clean-up and refactoring:
 //