[analyzer] Malloc: Utter the name of the leaked variable.

Specifically, we use the last store of the leaked symbol in the leak diagnostic.
(No support for struct fields since the malloc checker doesn't track those
yet.)

+ Infrastructure to track the regions used in store evaluations.
This approach is more precise than iterating the store to
obtain the region bound to the symbol, which is used in RetainCount
checker. The region corresponds to what is uttered in the code in the
last store and we do not rely on the store implementation to support
this functionality.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153212 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 3 deletions

diff --git a/include/clang/Analysis/ProgramPoint.h b/include/clang/Analysis/ProgramPoint.h
index 78a4f8928b..413b3cf4ea 100644
--- a/include/clang/Analysis/ProgramPoint.h
+++ b/include/clang/Analysis/ProgramPoint.h
@@ -76,6 +76,7 @@ protected:
 protected:
   const void *getData1() const { return Data.first; }
   const void *getData2() const { return Data.second; }
+  void setData2(const void *d) { Data.second = d; }
 
 public:
   /// Create a new ProgramPoint object that is the same as the original
@@ -195,7 +196,7 @@ public:
 class PostStmt : public StmtPoint {
 protected:
   PostStmt(const Stmt *S, const void *data, Kind k, const LocationContext *L,
-           const ProgramPointTag *tag =0)
+           const ProgramPointTag *tag = 0)
     : StmtPoint(S, data, k, L, tag) {}
 
 public:
@@ -270,15 +271,29 @@ public:
   }
 };
 
+/// \class Represents a program point after a store evaluation.
 class PostStore : public PostStmt {
 public:
-  PostStore(const Stmt *S, const LocationContext *L,
+  /// Construct the post store point.
+  /// \param Loc can be used to store the information about the location 
+  /// used in the form it was uttered in the code.
+  PostStore(const Stmt *S, const LocationContext *L, const void *Loc,
             const ProgramPointTag *tag = 0)
-    : PostStmt(S, PostStoreKind, L, tag) {}
+    : PostStmt(S, PostStoreKind, L, tag) {
+    assert(getData2() == 0);
+    setData2(Loc);
+  }
 
   static bool classof(const ProgramPoint* Location) {
     return Location->getKind() == PostStoreKind;
   }
+  
+  /// \brief Returns the information about the location used in the store,
+  /// how it was uttered in the code.
+  const void *getLocationValue() const {
+    return getData2();
+  }
+
 };
 
 class PostLValue : public PostStmt {