Deserialize macro history when we deserialize an identifier that has

macro history.

When deserializing macro history, we arrange history such that the
macros that have definitions (that haven't been #undef'd) and are
visible come at the beginning of the list, which is what the
preprocessor and other clients of Preprocessor::getMacroInfo()
expect. If additional macro definitions become visible later, they'll
be moved toward the front of the list. Note that it's possible to have
ambiguities, but we don't diagnose them yet.

There is a partially-implemented design decision here that, if a
particular identifier has been defined or #undef'd within the
translation unit, that definition (or #undef) hides any macro
definitions that come from imported modules. There's still a little
work to do to ensure that the right #undef'ing happens.

Additionally, we'll need to scope the update records for #undefs, so
they only kick in when the submodule containing that update record
becomes visible.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165682 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 2 deletions

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 12b99af6e0..2c0814c910 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -517,8 +517,12 @@ public:
   MacroInfo *getMacroInfoHistory(IdentifierInfo *II) const;
 
   /// \brief Specify a macro for this identifier.
-  void setMacroInfo(IdentifierInfo *II, MacroInfo *MI,
-                    bool LoadedFromAST = false);
+  void setMacroInfo(IdentifierInfo *II, MacroInfo *MI);
+  /// \brief Add a MacroInfo that was loaded from an AST file.
+  void addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI);
+  /// \brief Make the given MacroInfo, that was loaded from an AST file and
+  /// previously hidden, visible.
+  void makeLoadedMacroInfoVisible(IdentifierInfo *II, MacroInfo *MI);
   /// \brief Undefine a macro for this identifier.
   void clearMacroInfo(IdentifierInfo *II);