Make 'LangOptions' in CompilerInvocation a heap-allocated, reference counted object. I discovered that llvm::RefCountedBase<T> has

a bug where the reference count is copied in the copy constructor, which means that there were cases when the CompilerInvocation
objects created by ASTUnit were actually leaked.  When I fixed that bug locally, it showed that a whole bunch of code assumed
that the LangOptions object that was part of CompilerInvocation was still alive.  By making it heap-allocated and reference counted,
we can keep it around after the CompilerInvocation object goes away.

As part of this change, change CompilerInvocation:getLangOptions() to return a pointer, acting as another clue that this
object may outlive the CompilerInvocation object.

This commit doesn't fix the CompilerInvocation leak itself.  That will come when I commit the fix to llvm::RefCountedBase<T> to
mainline LLVM.

llvm-svn: 144930

1 files changed, 3 insertions, 2 deletions

diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index e2544027b5a..c59f2d16d28 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1041,6 +1041,7 @@ bool ASTUnit::Parse(llvm::MemoryBuffer *OverrideMainBuffer) {
 
   // Configure the various subsystems.
   // FIXME: Should we retain the previous file manager?
+  LangOpts = &Clang->getLangOpts();
   FileSystemOpts = Clang->getFileSystemOpts();
   FileMgr = new FileManager(FileSystemOpts);
   SourceMgr = new SourceManager(getDiagnostics(), *FileMgr);
@@ -1247,7 +1248,7 @@ ASTUnit::ComputePreamble(CompilerInvocation &Invocation,
   }
   
   return std::make_pair(Buffer, Lexer::ComputePreamble(Buffer,
-                                                       Invocation.getLangOpts(),
+                                                       *Invocation.getLangOpts(),
                                                        MaxLines));
 }
 
@@ -2230,7 +2231,7 @@ void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
   FrontendOpts.CodeCompletionAt.Column = Column;
 
   // Set the language options appropriately.
-  LangOpts = CCInvocation->getLangOpts();
+  LangOpts = *CCInvocation->getLangOpts();
 
   llvm::OwningPtr<CompilerInstance> Clang(new CompilerInstance());