[libclang] In ASTUnit::Parse copy the CompilerInvocation object instead of

modifying directly for the preamble.

This avoids an awful, hard to find, bug where "PreprocessorOpts.DisablePCHValidation = true"
would be persistent for subsequent reparses of the translation unit which would result
in defines, present in command-line but not in the PCH, being ignored.

Fixes rdar://9615399.

llvm-svn: 139512

1 files changed, 5 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 03efd5bc645..09aee487234 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2595,7 +2595,11 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
   // Here comes stuff that we only do once the entire chain is loaded.
   
   // Check the predefines buffers.
-  if (!DisableValidation && Type != MK_Module && CheckPredefinesBuffers())
+  if (!DisableValidation && Type != MK_Module && Type != MK_Preamble &&
+      // FIXME: CheckPredefinesBuffers also sets the SuggestedPredefines;
+      // if DisableValidation is true, defines that were set on command-line
+      // but not in the PCH file will not be added to SuggestedPredefines.
+      CheckPredefinesBuffers())
     return IgnorePCH;
 
   // Initialization of keywords and pragmas occurs before the