Remove DeclGroupOwningRef, since we intend for declarations to be owned

by DeclContexts (always) rather than by statements. 

DeclContext currently goes out of its way to avoid destroying any
Decls that might be owned by a DeclGroupOwningRef. However, in an
error-recovery situation, a failure in a declaration statement can
cause all of the decls in a DeclGroupOwningRef to be destroyed after
they've already be added into the DeclContext. Hence, DeclContext is
left with already-destroyed declarations, and bad things happen. This
problem was causing failures that showed up as assertions on x86 Linux
in test/Parser/objc-forcollection-neg-2.m.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64474 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 7 insertions, 59 deletions

diff --git a/lib/AST/CFG.cpp b/lib/AST/CFG.cpp
index 2ea8388287..e08a00b8a5 100644
--- a/lib/AST/CFG.cpp
+++ b/lib/AST/CFG.cpp
@@ -379,11 +379,8 @@ CFGBlock* CFGBuilder::WalkAST(Stmt* Terminator, bool AlwaysAddStmt = false) {
                        ? 8 : llvm::AlignOf<DeclStmt>::Alignment;
           
           // Allocate the DeclStmt using the BumpPtrAllocator.  It will
-          // get automatically freed with the CFG.  Note that even though
-          // we are using a DeclGroupOwningRef that wraps a singe Decl*,
-          // that Decl* will not get deallocated because the destroy method
-          // of DG is never called.
-          DeclGroupOwningRef DG(*I);
+          // get automatically freed with the CFG. 
+          DeclGroupRef DG(*I);
           Decl* D = *I;
           void* Mem = cfg->getAllocator().Allocate(sizeof(DeclStmt), A);
           
diff --git a/lib/AST/DeclGroup.cpp b/lib/AST/DeclGroup.cpp
index e7f84e1f46..35cb6d3bc6 100644
--- a/lib/AST/DeclGroup.cpp
+++ b/lib/AST/DeclGroup.cpp
@@ -7,7 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-//  This file defines the DeclGroup, DeclGroupRef, and OwningDeclGroup classes.
+//  This file defines the DeclGroup and DeclGroupRef classes.
 //
 //===----------------------------------------------------------------------===//
 
@@ -36,7 +36,7 @@ void DeclGroup::Emit(llvm::Serializer& S) const {
 }
 
 /// Read - Deserialize a DeclGroup from Bitcode.
-DeclGroup* DeclGroup::Create(llvm::Deserializer& D, ASTContext& C) {
+DeclGroup* DeclGroup::Read(llvm::Deserializer& D, ASTContext& C) {
   unsigned NumDecls = (unsigned) D.ReadInt();
   unsigned size = sizeof(DeclGroup) + sizeof(Decl*) * NumDecls;
   unsigned alignment = llvm::AlignOf<DeclGroup>::Alignment;  
@@ -54,32 +54,10 @@ DeclGroup::DeclGroup(unsigned numdecls, Decl** decls) : NumDecls(numdecls) {
 }
 
 void DeclGroup::Destroy(ASTContext& C) {
-  Decl** Decls = (Decl**) (this + 1);
-  
-  for (unsigned i = 0; i < NumDecls; ++i)
-    Decls[i]->Destroy(C);
-  
   this->~DeclGroup();
   C.Deallocate((void*) this);
 }
 
-DeclGroupOwningRef::~DeclGroupOwningRef() {
-  assert (D == 0 && "Destroy method not called.");
-}
-
-void DeclGroupOwningRef::Destroy(ASTContext& C) {
-  if (!D)
-    return;
-  
-  if (getKind() == DeclKind)
-    D->Destroy(C);
-  else    
-    reinterpret_cast<DeclGroup*>(reinterpret_cast<uintptr_t>(D) &
-                                 ~Mask)->Destroy(C);
-  
-  D = 0;
-}
-
 void DeclGroupRef::Emit(llvm::Serializer& S) const {
   if (getKind() == DeclKind) {
     S.EmitBool(false);
@@ -98,28 +76,3 @@ DeclGroupRef DeclGroupRef::ReadVal(llvm::Deserializer& D) {
   
   return DeclGroupRef(D.ReadPtr<DeclGroup>());
 }
-
-void DeclGroupOwningRef::Emit(llvm::Serializer& S) const {
-  if (getKind() == DeclKind) {
-    S.EmitBool(false);
-    S.EmitOwnedPtr(D);
-  }
-  else {
-    S.EmitBool(true);
-    S.EmitOwnedPtr(reinterpret_cast<DeclGroup*>(reinterpret_cast<uintptr_t>(D)
-                                                & ~Mask));        
-  }
-}
-
-DeclGroupOwningRef& DeclGroupOwningRef::Read(llvm::Deserializer& Dezr, 
-                                             ASTContext& C) {
-  
-  if (!Dezr.ReadBool())
-    D = Dezr.ReadOwnedPtr<Decl>(C);
-  else {
-    uintptr_t x = reinterpret_cast<uintptr_t>(Dezr.ReadOwnedPtr<DeclGroup>(C));
-    D = reinterpret_cast<Decl*>(x | DeclGroupKind);
-  }
-  
-  return *this;
-}
diff --git a/lib/AST/Stmt.cpp b/lib/AST/Stmt.cpp
index 49c8c80509..b85a67e689 100644
--- a/lib/AST/Stmt.cpp
+++ b/lib/AST/Stmt.cpp
@@ -58,7 +58,6 @@ void Stmt::Destroy(ASTContext& C) {
 }
 
 void DeclStmt::Destroy(ASTContext& C) {
-  DG.Destroy(C);
   this->~DeclStmt();
   C.Deallocate((void *)this);
 }
diff --git a/lib/AST/StmtSerialization.cpp b/lib/AST/StmtSerialization.cpp
index 5a6e49cb3e..22ce8183fd 100644
--- a/lib/AST/StmtSerialization.cpp
+++ b/lib/AST/StmtSerialization.cpp
@@ -550,8 +550,7 @@ void DeclStmt::EmitImpl(Serializer& S) const {
 DeclStmt* DeclStmt::CreateImpl(Deserializer& D, ASTContext& C) {
   SourceLocation StartLoc = SourceLocation::ReadVal(D);
   SourceLocation EndLoc = SourceLocation::ReadVal(D); 
-  DeclGroupOwningRef DG;
-  return new DeclStmt(DG.Read(D, C), StartLoc, EndLoc);
+  return new DeclStmt(DeclGroupRef::ReadVal(D), StartLoc, EndLoc);
 }
 
 void DeclRefExpr::EmitImpl(Serializer& S) const {
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index dd505f6967..bfa1c5e6d0 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -58,11 +58,11 @@ Sema::OwningStmtResult Sema::ActOnDeclStmt(DeclTy *decl,
   assert (!decls.empty());
 
   if (decls.size() == 1) {
-    DeclGroupOwningRef DG(*decls.begin());                      
+    DeclGroupRef DG(*decls.begin());                      
     return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
   }
   else {
-    DeclGroupOwningRef DG(DeclGroup::Create(Context, decls.size(), &decls[0]));
+    DeclGroupRef DG(DeclGroup::Create(Context, decls.size(), &decls[0]));
     return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc));
   }
 }