[cfe-commits] [PATCH] Clean up CXX Base Specifiers in AST reader

[Douglas Gregor]

On Jul 21, 2011, at 11:51 AM, Jonathan Turner wrote:

> Cleaning up more of the ID situation in the AST reader.  This patch relaxes and generalizes how CXX base specifiers are identified and loaded by using a ContinuousRangeMap.   

+  typedef ContinuousRangeMap<serialization::CXXBaseSpecifiersID,
+                             std::pair<PerFileData *,
+                                              std::pair<uint64_t, int32_t> >, 4>
+  GlobalCXXBaseSpecifiersMapType;

Usually, once we hit nested pairs, it's better just to introduce a named structure… however, I have a different comment that addresses the problem.

@@ -787,6 +797,9 @@
   /// \brief The total number of method pool entries in the selector table.
   unsigned TotalNumMethodPoolEntries;
 
+  /// Number of CXX base specifiers currently loaded
+  unsigned TotalCXXBaseSizeInBits;
+
   /// Number of lexical decl contexts read/total.
   unsigned NumLexicalDeclContextsRead, TotalLexicalDeclContexts;
 
The comment here is incorrect, and I think this should be a uint64_t.

More importantly, the idea of keeping track of the # of bits loaded applies more generally. For example, note how ASTReader::LoadMacroDefinition() does a global -> local mapping on a bit offset. 

So, I suggest making two ContinuousRangeMaps: one for actually mapping the base specifier IDs (for indexing purposes) and another for mapping from global bit numbers (a uint64_t) to local bit numbers. Loading a CXXBaseSpecifier will look in both maps (which is fine), and the second map will be useful in other places as well.


	- Doug