Genericize the existing logic for removing duplicate header dirs to apply

the "system dirs win over user dirs" logic to framework and headermap
search locations as well as normal directories.  This means that
clang t.m -F/System/Library/Frameworks  will treat /System/Library/Frameworks
as a system directory not a user directory.  If you use -v, the difference is:

Before:
ignoring nonexistent directory "/usr/libdata/gcc41"
ignoring duplicate framework "/System/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:

After:
ignoring nonexistent directory "/usr/libdata/gcc41"
ignoring duplicate directory "/System/Library/Frameworks"
  as it is a non-system directory that duplicates a system directory
#include "..." search starts here:
#include <...> search starts here:

This fixes rdar://6566429.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64060 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Driver/InitHeaderSearch.cpp

@@ -284,54 +284,63 @@ static void RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
       // If this isn't the first time we've seen this dir, remove it.
       if (SeenDirs.insert(SearchList[i].getDir()))
         continue;
-      
-      // If we have a normal #include dir that is shadowed later in the chain
-      // by a system include dir, we actually want to ignore the user's request
-      // and drop the user dir... keeping the system dir.  This is weird, but
-      // required to emulate GCC's search path correctly.
-      //
-      // Since dupes of system dirs are rare, just rescan to find the original
-      // that we're nuking instead of using a DenseMap.
-      if (SearchList[i].getDirCharacteristic() != SrcMgr::C_User) {
-        // Find the dir that this is the same of.
-        unsigned FirstDir;
-        for (FirstDir = 0; ; ++FirstDir) {
-          assert(FirstDir != i && "Didn't find dupe?");
-          if (SearchList[FirstDir].getDir() == SearchList[i].getDir())
-            break;
-        }
-        
-        // If the first dir in the search path is a non-system dir, zap it
-        // instead of the system one.
-        if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
-          DirToRemove = FirstDir;
-      }
-      
-      if (Verbose) {
-        fprintf(stderr, "ignoring duplicate directory \"%s\"\n",
-                SearchList[i].getDir()->getName());
-        if (DirToRemove != i)
-          fprintf(stderr, "  as it is a non-system directory that duplicates"
-                  " a system directory\n");
-      }
     } else if (SearchList[i].isFramework()) {
       // If this isn't the first time we've seen this framework dir, remove it.
       if (SeenFrameworkDirs.insert(SearchList[i].getFrameworkDir()))
         continue;
-      
-      if (Verbose)
-        fprintf(stderr, "ignoring duplicate framework \"%s\"\n",
-                SearchList[i].getFrameworkDir()->getName());
-      
     } else {
       assert(SearchList[i].isHeaderMap() && "Not a headermap or normal dir?");
       // If this isn't the first time we've seen this headermap, remove it.
       if (SeenHeaderMaps.insert(SearchList[i].getHeaderMap()))
         continue;
+    }
+    
+    // If we have a normal #include dir/framework/headermap that is shadowed
+    // later in the chain by a system include location, we actually want to
+    // ignore the user's request and drop the user dir... keeping the system
+    // dir.  This is weird, but required to emulate GCC's search path correctly.
+    //
+    // Since dupes of system dirs are rare, just rescan to find the original
+    // that we're nuking instead of using a DenseMap.
+    if (SearchList[i].getDirCharacteristic() != SrcMgr::C_User) {
+      // Find the dir that this is the same of.
+      unsigned FirstDir;
+      for (FirstDir = 0; ; ++FirstDir) {
+        assert(FirstDir != i && "Didn't find dupe?");
+        
+        // If these are different lookup types, then they can't be the dupe.
+        if (SearchList[FirstDir].getLookupType() !=
+            SearchList[i].getLookupType())
+          continue;
+        
+        bool isSame;
+        if (SearchList[i].isNormalDir())
+          isSame = SearchList[FirstDir].getDir() == SearchList[i].getDir();
+        else if (SearchList[i].isFramework())
+          isSame = SearchList[FirstDir].getFrameworkDir() ==
+                   SearchList[i].getFrameworkDir();
+        else {
+          assert(SearchList[i].isHeaderMap() && "Not a headermap or normal dir?");
+          isSame = SearchList[FirstDir].getHeaderMap() ==
+            SearchList[i].getHeaderMap();
+        }
+        
+        if (isSame)
+          break;
+      }
       
-      if (Verbose)
-        fprintf(stderr, "ignoring duplicate directory \"%s\"\n",
-                SearchList[i].getDir()->getName());
+      // If the first dir in the search path is a non-system dir, zap it
+      // instead of the system one.
+      if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
+        DirToRemove = FirstDir;
+    }
+
+    if (Verbose) {
+      fprintf(stderr, "ignoring duplicate directory \"%s\"\n", 
+              SearchList[i].getName());
+      if (DirToRemove != i)
+        fprintf(stderr, "  as it is a non-system directory that duplicates"
+                " a system directory\n");
     }
     
     // This is reached if the current entry is a duplicate.  Remove the