Rework the (de-)serialization of macros, as stored in

MacroInfo*. Instead of simply dumping an offset into the current file,
give each macro definition a proper ID with all of the standard
modules-remapping facilities. Additionally, when a macro is modified
in a subsequent AST file (e.g., #undef'ing a macro loaded from another
module or from a precompiled header), provide a macro update record
rather than rewriting the entire macro definition. This gives us
greater consistency with the way we handle declarations, and ties
together macro definitions much more cleanly.

Note that we're still not actually deserializing macro history (we
never were), but it's far easy to do properly now.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165560 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 1 deletions

diff --git a/include/clang/Serialization/ASTBitCodes.h b/include/clang/Serialization/ASTBitCodes.h
index 57d896ee41..a0c62bb296 100644
--- a/include/clang/Serialization/ASTBitCodes.h
+++ b/include/clang/Serialization/ASTBitCodes.h
@@ -126,7 +126,13 @@ namespace clang {
 
     /// \brief The number of predefined identifier IDs.
     const unsigned int NUM_PREDEF_IDENT_IDS = 1;
+
+    /// \brief An ID number that refers to a macro in an AST file.
+    typedef uint32_t MacroID;
     
+    /// \brief The number of predefined macro IDs.
+    const unsigned int NUM_PREDEF_MACRO_IDS = 1;
+
     /// \brief An ID number that refers to an ObjC selector in an AST file.
     typedef uint32_t SelectorID;
 
@@ -472,7 +478,18 @@ namespace clang {
       ///
       /// This array can only be interpreted properly using the Objective-C
       /// categories map.
-      OBJC_CATEGORIES = 54
+      OBJC_CATEGORIES = 54,
+
+      /// \brief Record code for the table of offsets of each macro ID.
+      ///
+      /// The offset table contains offsets into the blob stored in
+      /// the preprocessor block. Each offset points to the corresponding
+      /// macro definition.
+      MACRO_OFFSET = 55,
+
+      /// \brief Record of updates for a macro that was modified after
+      /// being deserialized.
+      MACRO_UPDATES = 56
     };
 
     /// \brief Record types used within a source manager block.