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

3 files changed, 26 insertions, 10 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());
 
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index ea2c3bd6c6b..838a0675f28 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -987,11 +987,11 @@ static void compileModule(CompilerInstance &ImportingInstance,
 
   // For any options that aren't intended to affect how a module is built,
   // reset them to their default values.
-  Invocation->getLangOpts().resetNonModularOptions();
+  Invocation->getLangOpts()->resetNonModularOptions();
   Invocation->getPreprocessorOpts().resetNonModularOptions();
 
   // Note the name of the module we're building.
-  Invocation->getLangOpts().CurrentModule = ModuleName;
+  Invocation->getLangOpts()->CurrentModule = ModuleName;
 
   // Note that this module is part of the module build path, so that we
   // can detect cycles in the module graph.
@@ -1004,7 +1004,7 @@ static void compileModule(CompilerInstance &ImportingInstance,
   FrontendOpts.DisableFree = false;
   FrontendOpts.Inputs.clear();
   FrontendOpts.Inputs.push_back(
-    std::make_pair(getSourceInputKindFromOptions(Invocation->getLangOpts()),
+    std::make_pair(getSourceInputKindFromOptions(*Invocation->getLangOpts()),
                                                  UmbrellaHeader));
 
   Invocation->getDiagnosticOpts().VerifyDiagnostics = 0;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 1fd967ffcc3..13be408141c 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -30,6 +30,21 @@
 #include "llvm/Support/Path.h"
 using namespace clang;
 
+//===----------------------------------------------------------------------===//
+// Initialization.
+//===----------------------------------------------------------------------===//
+
+CompilerInvocation::CompilerInvocation()
+  : LangOpts(new LangOptions()) {}
+
+void CompilerInvocation::setLangOpts(LangOptions *LOpts) {
+  LangOpts = LOpts;
+}
+
+//===----------------------------------------------------------------------===//
+// Utility functions.
+//===----------------------------------------------------------------------===//
+
 static const char *getAnalysisStoreName(AnalysisStores Kind) {
   switch (Kind) {
   default:
@@ -892,7 +907,7 @@ void CompilerInvocation::toArgs(std::vector<std::string> &Res) {
   FileSystemOptsToArgs(getFileSystemOpts(), Res);
   FrontendOptsToArgs(getFrontendOpts(), Res);
   HeaderSearchOptsToArgs(getHeaderSearchOpts(), Res);
-  LangOptsToArgs(getLangOpts(), Res);
+  LangOptsToArgs(*getLangOpts(), Res);
   PreprocessorOptsToArgs(getPreprocessorOpts(), Res);
   PreprocessorOutputOptsToArgs(getPreprocessorOutputOpts(), Res);
   TargetOptsToArgs(getTargetOpts(), Res);
@@ -1982,9 +1997,9 @@ void CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
   ParseCodeGenArgs(Res.getCodeGenOpts(), *Args, DashX, Diags);
   ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), *Args);
   if (DashX != IK_AST && DashX != IK_LLVM_IR) {
-    ParseLangArgs(Res.getLangOpts(), *Args, DashX, Diags);
+    ParseLangArgs(*Res.getLangOpts(), *Args, DashX, Diags);
     if (Res.getFrontendOpts().ProgramAction == frontend::RewriteObjC)
-      Res.getLangOpts().ObjCExceptions = 1;
+      Res.getLangOpts()->ObjCExceptions = 1;
   }
   // FIXME: ParsePreprocessorArgs uses the FileManager to read the contents of
   // PCH file and find the original header name. Remove the need to do that in
@@ -2057,9 +2072,9 @@ std::string CompilerInvocation::getModuleHash() const {
   
   // Extend the signature with the language options
 #define LANGOPT(Name, Bits, Default, Description) \
-  Signature.add(LangOpts.Name, Bits);
+  Signature.add(LangOpts->Name, Bits);
 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
-  Signature.add(static_cast<unsigned>(LangOpts.get##Name()), Bits);
+  Signature.add(static_cast<unsigned>(LangOpts->get##Name()), Bits);
 #define BENIGN_LANGOPT(Name, Bits, Default, Description)
 #define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
 #include "clang/Basic/LangOptions.def"