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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@253177 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index 8efcd79cbcd04c6e993998eeb61cf16f1471f786..dfce3508e2657ea6940748fb7a894945aac01077 100644 (file)
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -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;
     }