tree 79baf682b230d0b318d0b6942f4b016ed13853b3
parent 48bd7b72b8911147ec9bdeaa8ebb211543fd23a9
author Argyrios Kyrtzidis <akyrtzi@gmail.com> 1358353178 +0000
committer Argyrios Kyrtzidis <akyrtzi@gmail.com> 1358353178 +0000

[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