diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index 08e4420..fbeec27 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -704,8 +704,8 @@
   }
 
   // If we have any Fix-Its, make sure that all of the Fix-Its point into
-  // source locations that aren't macro instantiations. If any point into
-  // macro instantiations, remove all of the Fix-Its.
+  // source locations that aren't macro expansions. If any point into macro
+  // expansions, remove all of the Fix-Its.
   for (unsigned I = 0, N = Diag.NumFixItHints; I != N; ++I) {
     const FixItHint &FixIt = Diag.FixItHints[I];
     if (FixIt.RemoveRange.isInvalid() ||
diff --git a/lib/Basic/SourceLocation.cpp b/lib/Basic/SourceLocation.cpp
index a13bbc5..6e4f3e6 100644
--- a/lib/Basic/SourceLocation.cpp
+++ b/lib/Basic/SourceLocation.cpp
@@ -48,7 +48,7 @@
       OS << "<invalid>";
       return;
     }
-    // The instantiation and spelling pos is identical for file locs.
+    // The macro expansion and spelling pos is identical for file locs.
     OS << PLoc.getFilename() << ':' << PLoc.getLine()
        << ':' << PLoc.getColumn();
     return;
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 886b23b..f2903e9 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -39,9 +39,8 @@
     delete Buffer.getPointer();
 }
 
-/// getSizeBytesMapped - Returns the number of bytes actually mapped for
-///  this ContentCache.  This can be 0 if the MemBuffer was not actually
-///  instantiated.
+/// getSizeBytesMapped - Returns the number of bytes actually mapped for this
+/// ContentCache. This can be 0 if the MemBuffer was not actually expanded.
 unsigned ContentCache::getSizeBytesMapped() const {
   return Buffer.getPointer() ? Buffer.getPointer()->getBufferSize() : 0;
 }
@@ -401,7 +400,7 @@
   if (LineTable)
     LineTable->clear();
 
-  // Use up FileID #0 as an invalid instantiation.
+  // Use up FileID #0 as an invalid expansion.
   NextLocalOffset = 0;
   // The highest possible offset is 2^31-1, so CurrentLoadedOffset starts at
   // 2^31.
@@ -480,7 +479,7 @@
 }
 
 //===----------------------------------------------------------------------===//
-// Methods to create new FileID's and instantiations.
+// Methods to create new FileID's and macro expansions.
 //===----------------------------------------------------------------------===//
 
 /// createFileID - Create a new FileID for the specified ContentCache and
@@ -638,8 +637,8 @@
   assert(SLocOffset < NextLocalOffset && "Bad function choice");
 
   // After the first and second level caches, I see two common sorts of
-  // behavior: 1) a lot of searched FileID's are "near" the cached file location
-  // or are "near" the cached instantiation location.  2) others are just
+  // behavior: 1) a lot of searched FileID's are "near" the cached file
+  // location or are "near" the cached expansion location. 2) others are just
   // completely random and may be a very long way away.
   //
   // To handle this, we do a linear search for up to 8 steps to catch #1 quickly
@@ -667,8 +666,8 @@
     if (I->getOffset() <= SLocOffset) {
       FileID Res = FileID::get(int(I - LocalSLocEntryTable.begin()));
 
-      // If this isn't an instantiation, remember it.  We have good locality
-      // across FileID lookups.
+      // If this isn't an expansion, remember it.  We have good locality across
+      // FileID lookups.
       if (!I->isExpansion())
         LastFileIDLookup = Res;
       NumLinearScans += NumProbes+1;
@@ -811,8 +810,7 @@
 std::pair<FileID, unsigned>
 SourceManager::getDecomposedExpansionLocSlowCase(
                                              const SrcMgr::SLocEntry *E) const {
-  // If this is an instantiation record, walk through all the instantiation
-  // points.
+  // If this is an expansion record, walk through all the expansion points.
   FileID FID;
   SourceLocation Loc;
   unsigned Offset;
@@ -830,8 +828,7 @@
 std::pair<FileID, unsigned>
 SourceManager::getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
                                                 unsigned Offset) const {
-  // If this is an instantiation record, walk through all the instantiation
-  // points.
+  // If this is an expansion record, walk through all the expansion points.
   FileID FID;
   SourceLocation Loc;
   do {
@@ -857,11 +854,11 @@
 }
 
 
-/// getImmediateExpansionRange - Loc is required to be an instantiation
-/// location.  Return the start/end of the instantiation information.
+/// getImmediateExpansionRange - Loc is required to be an expansion location.
+/// Return the start/end of the expansion information.
 std::pair<SourceLocation,SourceLocation>
 SourceManager::getImmediateExpansionRange(SourceLocation Loc) const {
-  assert(Loc.isMacroID() && "Not an instantiation loc!");
+  assert(Loc.isMacroID() && "Not a macro expansion loc!");
   const ExpansionInfo &Expansion = getSLocEntry(getFileID(Loc)).getExpansion();
   return Expansion.getExpansionLocRange();
 }
@@ -875,7 +872,7 @@
   std::pair<SourceLocation,SourceLocation> Res =
     getImmediateExpansionRange(Loc);
 
-  // Fully resolve the start and end locations to their ultimate instantiation
+  // Fully resolve the start and end locations to their ultimate expansion
   // points.
   while (!Res.first.isFileID())
     Res.first = getImmediateExpansionRange(Res.first).first;
@@ -1217,12 +1214,12 @@
 /// or GNU line marker directives.  This provides a view on the data that a
 /// user should see in diagnostics, for example.
 ///
-/// Note that a presumed location is always given as the instantiation point
-/// of an instantiation location, not at the spelling location.
+/// Note that a presumed location is always given as the expansion point of an
+/// expansion location, not at the spelling location.
 PresumedLoc SourceManager::getPresumedLoc(SourceLocation Loc) const {
   if (Loc.isInvalid()) return PresumedLoc();
 
-  // Presumed locations are always for instantiation points.
+  // Presumed locations are always for expansion points.
   std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
 
   bool Invalid = false;
@@ -1456,10 +1453,10 @@
   return getLocForStartOfFile(FirstFID).getFileLocWithOffset(FilePos + Col - 1);
 }
 
-/// Given a decomposed source location, move it up the include/instantiation
-/// stack to the parent source location.  If this is possible, return the
-/// decomposed version of the parent in Loc and return false.  If Loc is the
-/// top-level entry, return true and don't modify it.
+/// Given a decomposed source location, move it up the include/expansion stack
+/// to the parent source location.  If this is possible, return the decomposed
+/// version of the parent in Loc and return false.  If Loc is the top-level
+/// entry, return true and don't modify it.
 static bool MoveUpIncludeHierarchy(std::pair<FileID, unsigned> &Loc,
                                    const SourceManager &SM) {
   SourceLocation UpperLoc;
@@ -1486,10 +1483,10 @@
   if (LHS == RHS)
     return false;
 
-  // If both locations are macro instantiations, the order of their offsets
-  // reflect the order that the tokens, pointed to by these locations, were
-  // instantiated (during parsing each token that is instantiated by a macro,
-  // expands the SLocEntries).
+  // If both locations are macro expansions, the order of their offsets reflect
+  // the order that the tokens, pointed to by these locations, were expanded
+  // (during parsing each token that is expanded by a macro, expands the
+  // SLocEntries).
 
   std::pair<FileID, unsigned> LOffs = getDecomposedLoc(LHS);
   std::pair<FileID, unsigned> ROffs = getDecomposedLoc(RHS);