From 41c8ba80de74c45e5ca0987c0f36a27f6e02bb43 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Thu, 15 Jan 2009 02:19:31 +0000
Subject: [PATCH] Deallocate the BasePaths structure that we allocate for
 LookupResult.

llvm-svn: 62250
---
 clang/lib/Sema/Sema.h         | 14 ++++++++++++--
 clang/lib/Sema/SemaLookup.cpp | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index eb718f7f1ad1..cf9f8502c722 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -638,7 +638,11 @@ public:
       /// by the LookupResult. Last is non-zero to indicate that the
       /// ambiguity is caused by two names found in base class
       /// subobjects of different types.
-      AmbiguousLookup
+      AmbiguousLookup,
+
+      /// We've moved from this object. There should not be any
+      /// attempts to look at its state.
+      Dead
     } StoredKind;
 
     /// The first lookup result, whose contents depend on the kind of
@@ -706,7 +710,9 @@ public:
       AmbiguousBaseSubobjects
     };
 
-    LookupResult() : StoredKind(SingleDecl), First(0), Last(0), Context(0) { }
+    LookupResult() : StoredKind(Dead), First(0), Last(0), Context(0) { }
+
+    LookupResult(const LookupResult& Other);
 
     LookupResult(ASTContext &Context, Decl *D) 
       : StoredKind(SingleDecl), First(reinterpret_cast<uintptr_t>(D)),
@@ -725,6 +731,10 @@ public:
         Last(DifferentSubobjectTypes? 1 : 0),
         Context(&Context) { }
 
+    ~LookupResult();
+
+    LookupResult& operator=(const LookupResult& Other);
+
     LookupKind getKind() const;
 
     /// @brief Determine whether name look found something.
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index b85824382bf4..cc9a36ced223 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -127,6 +127,15 @@ bool Sema::LookupCriteria::isLookupResult(Decl *D) const {
   return false;
 }
 
+/// @brief Moves the name-lookup results from Other to the
+/// newly-constructed LookupResult.
+Sema::LookupResult::LookupResult(const LookupResult& Other) 
+  : StoredKind(Other.StoredKind), First(Other.First), Last(Other.Last),
+    Context(Other.Context) {
+  Other.StoredKind = Dead;
+}
+
+/// @brief Moves the name-lookup results from Other to this LookupResult.
 Sema::LookupResult::LookupResult(ASTContext &Context, 
                                  IdentifierResolver::iterator F, 
                                  IdentifierResolver::iterator L)
@@ -167,6 +176,25 @@ Sema::LookupResult::LookupResult(ASTContext &Context,
   Last = 0;
 }
 
+Sema::LookupResult::~LookupResult() {
+  if (StoredKind == AmbiguousLookup)
+    delete getBasePaths();
+}
+
+Sema::LookupResult& Sema::LookupResult::operator=(const LookupResult& Other) {
+  if (StoredKind == AmbiguousLookup)
+    delete getBasePaths();
+
+  StoredKind = Other.StoredKind;
+  First = Other.First;
+  Last = Other.Last;
+  Context = Other.Context;
+
+  Other.StoredKind = Dead;
+  return *this;
+}
+
+
 /// @brief Determine the result of name lookup.
 Sema::LookupResult::LookupKind Sema::LookupResult::getKind() const {
   switch (StoredKind) {
@@ -179,6 +207,10 @@ Sema::LookupResult::LookupKind Sema::LookupResult::getKind() const {
 
   case AmbiguousLookup:
     return Last? AmbiguousBaseSubobjectTypes : AmbiguousBaseSubobjects;
+
+  case Dead:
+    assert(false && "Attempt to look at a dead LookupResult");
+    break;
   }
 
   // We can't ever get here.
@@ -217,6 +249,9 @@ Decl *Sema::LookupResult::getAsDecl() const {
     assert(false && 
            "Name lookup returned an ambiguity that could not be handled");
     break;
+
+  case Dead:
+    assert(false && "Attempt to look at a dead LookupResult");
   }
 
   return 0;