Clean up ownership of 'AttributeList' objects in Parser. Apparently

we would just leak them all over the place, with no clear ownership of
these objects at all.  AttributeList objects would get leaked on both
error and non-error paths.

Note: I introduced the usage of llvm::OwningPtr<AttributeList> to
manage these objects, which is particularly useful for methods with
multiple return sites.  In at least one method I used them even when
they weren't strictly necessary because it clarified the ownership
semantics and made the code easier to read.  Should the excessive
'take()' and 'reset()' calls become a performance issue we can always
re-evaluate.

Note+1: I believe I have not introduced any double-frees, but it would
be nice for someone to review this.

This fixes <rdar://problem/7635046>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95847 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 6 deletions

diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index ef65204e8c..3757ee2f6d 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -786,15 +786,15 @@ Parser::DeclPtrTy Parser::ParseObjCMethodDecl(SourceLocation mLoc,
   llvm::SmallVector<Declarator, 8> CargNames;
   if (Tok.isNot(tok::colon)) {
     // If attributes exist after the method, parse them.
-    AttributeList *MethodAttrs = 0;
+    llvm::OwningPtr<AttributeList> MethodAttrs;
     if (getLang().ObjC2 && Tok.is(tok::kw___attribute))
-      MethodAttrs = ParseGNUAttributes();
+      MethodAttrs.reset(ParseGNUAttributes());
 
     Selector Sel = PP.getSelectorTable().getNullarySelector(SelIdent);
     DeclPtrTy Result
          = Actions.ActOnMethodDeclaration(mLoc, Tok.getLocation(),
                                           mType, IDecl, DSRet, ReturnType, Sel,
-                                          0, CargNames, MethodAttrs,
+                                          0, CargNames, MethodAttrs.get(),
                                           MethodImplKind);
     PD.complete(Result);
     return Result;
@@ -862,9 +862,9 @@ Parser::DeclPtrTy Parser::ParseObjCMethodDecl(SourceLocation mLoc,
 
   // FIXME: Add support for optional parmameter list...
   // If attributes exist after the method, parse them.
-  AttributeList *MethodAttrs = 0;
+  llvm::OwningPtr<AttributeList> MethodAttrs;
   if (getLang().ObjC2 && Tok.is(tok::kw___attribute))
-    MethodAttrs = ParseGNUAttributes();
+    MethodAttrs.reset(ParseGNUAttributes());
 
   if (KeyIdents.size() == 0)
     return DeclPtrTy();
@@ -873,9 +873,16 @@ Parser::DeclPtrTy Parser::ParseObjCMethodDecl(SourceLocation mLoc,
   DeclPtrTy Result
        = Actions.ActOnMethodDeclaration(mLoc, Tok.getLocation(),
                                         mType, IDecl, DSRet, ReturnType, Sel,
-                                        &ArgInfos[0], CargNames, MethodAttrs,
+                                        &ArgInfos[0], CargNames,
+                                        MethodAttrs.get(),
                                         MethodImplKind, isVariadic);
   PD.complete(Result);
+  
+  // Delete referenced AttributeList objects.
+  for (llvm::SmallVectorImpl<Action::ObjCArgInfo>::iterator
+       I = ArgInfos.begin(), E = ArgInfos.end(); I != E; ++I)
+    delete I->ArgAttrs;
+  
   return Result;
 }