r253177 - [Basic] Use a bitfield in SLocEntry for clarity. NFC.

[Vedant Kumar via cfe-commits]

Author: vedantk
Date: Sun Nov 15 18:11:58 2015
New Revision: 253177

URL: http://llvm.org/viewvc/llvm-project?rev=253177&view=rev
Log:
[Basic] Use a bitfield in SLocEntry for clarity. NFC.

Modified:
    cfe/trunk/include/clang/Basic/SourceManager.h

Modified: cfe/trunk/include/clang/Basic/SourceManager.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/SourceManager.h?rev=253177&r1=253176&r2=253177&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/SourceManager.h (original)
+++ cfe/trunk/include/clang/Basic/SourceManager.h Sun Nov 15 18:11:58 2015
@@ -388,15 +388,16 @@ namespace SrcMgr {
   /// SourceManager keeps an array of these objects, and they are uniquely
   /// identified by the FileID datatype.
   class SLocEntry {
-    unsigned Offset;   // low bit is set for expansion info.
+    unsigned Offset : 31;
+    unsigned IsExpansion : 1;
     union {
       FileInfo File;
       ExpansionInfo Expansion;
     };
   public:
-    unsigned getOffset() const { return Offset >> 1; }
+    unsigned getOffset() const { return Offset; }
 
-    bool isExpansion() const { return Offset & 1; }
+    bool isExpansion() const { return IsExpansion; }
     bool isFile() const { return !isExpansion(); }
 
     const FileInfo &getFile() const {
@@ -410,15 +411,19 @@ namespace SrcMgr {
     }
 
     static SLocEntry get(unsigned Offset, const FileInfo &FI) {
+      assert(!(Offset & (1 << 31)) && "Offset is too large");
       SLocEntry E;
-      E.Offset = Offset << 1;
+      E.Offset = Offset;
+      E.IsExpansion = false;
       E.File = FI;
       return E;
     }
 
     static SLocEntry get(unsigned Offset, const ExpansionInfo &Expansion) {
+      assert(!(Offset & (1 << 31)) && "Offset is too large");
       SLocEntry E;
-      E.Offset = (Offset << 1) | 1;
+      E.Offset = Offset;
+      E.IsExpansion = true;
       E.Expansion = Expansion;
       return E;
     }