[PCH/Modules] Change how macro [re]definitions are de/serialized.

Previously we would serialize the macro redefinitions as a list, part of
the identifier, and try to chain them together across modules individually
without having the info that they were already chained at definition time.

Change this by serializing the macro redefinition chain and then try
to synthesize the chain parts across modules. This allows us to correctly
pinpoint when 2 different definitions are ambiguous because they came from
unrelated modules.

Fixes bogus "ambiguous expansion of macro" warning when a macro in a PCH
is redefined without undef'ing it first.

rdar://13016031

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172620 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 2 deletions

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 1789e81b0a..e7bd0dfeec 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -525,8 +525,7 @@ public:
   /// \brief Specify a macro for this identifier.
   void setMacroInfo(IdentifierInfo *II, MacroInfo *MI);
   /// \brief Add a MacroInfo that was loaded from an AST file.
-  void addLoadedMacroInfo(IdentifierInfo *II, MacroInfo *MI,
-                          MacroInfo *Hint = 0);
+  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);