[analyzer] This patch removes passing around of const-invalidation vs regular-invalidation info by passing around a datastructure that maps regions and symbols to the type of invalidation they experience. This simplifies the code and would allow to associate more different invalidation types in the future.

With this patch things like preserving contents of regions (either hi- or low-level ones) or processing of the only top-level region can be implemented easily without passing around extra parameters.

This patch is a first step towards adequate modeling of memcpy() by the CStringChecker checker and towards eliminating of majority of false-positives produced by the NewDeleteLeaks checker.

llvm-svn: 191342

1 files changed, 37 insertions, 51 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
index 50186fbaa5a..bc998d80ec1 100644
--- a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -349,7 +349,6 @@ private:
   /// regions.
   void populateWorkList(invalidateRegionsWorker &W,
                         ArrayRef<SVal> Values,
-                        bool IsArrayOfConstRegions,
                         InvalidatedRegions *TopLevelRegions);
 
 public:
@@ -395,15 +394,13 @@ public:
 
   StoreRef invalidateRegions(Store store,
                              ArrayRef<SVal> Values,
-                             ArrayRef<SVal> ConstValues,
                              const Expr *E, unsigned Count,
                              const LocationContext *LCtx,
                              const CallEvent *Call,
                              InvalidatedSymbols &IS,
-                             InvalidatedSymbols &ConstIS,
+                             RegionAndSymbolInvalidationTraits &ITraits,
                              InvalidatedRegions *Invalidated,
-                             InvalidatedRegions *InvalidatedTopLevel,
-                             InvalidatedRegions *InvalidatedTopLevelConst);
+                             InvalidatedRegions *InvalidatedTopLevel);
 
   bool scanReachableSymbols(Store S, const MemRegion *R,
                             ScanReachableSymbols &Callbacks);
@@ -648,7 +645,7 @@ template <typename DERIVED>
 class ClusterAnalysis  {
 protected:
   typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
-  typedef llvm::PointerIntPair<const MemRegion *, 1, bool> WorkListElement;
+  typedef const MemRegion * WorkListElement;
   typedef SmallVector<WorkListElement, 10> WorkList;
 
   llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
@@ -720,18 +717,17 @@ public:
     return true;
   }
 
-  bool AddToWorkList(const MemRegion *R, bool Flag = false) {
+  bool AddToWorkList(const MemRegion *R) {
     const MemRegion *BaseR = R->getBaseRegion();
-    return AddToWorkList(WorkListElement(BaseR, Flag), getCluster(BaseR));
+    return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
   }
 
   void RunWorkList() {
     while (!WL.empty()) {
       WorkListElement E = WL.pop_back_val();
-      const MemRegion *BaseR = E.getPointer();
+      const MemRegion *BaseR = E;
 
-      static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR),
-                                                E.getInt());
+      static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
     }
   }
 
@@ -951,7 +947,7 @@ class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
   unsigned Count;
   const LocationContext *LCtx;
   InvalidatedSymbols &IS;
-  InvalidatedSymbols &ConstIS;
+  RegionAndSymbolInvalidationTraits &ITraits;
   StoreManager::InvalidatedRegions *Regions;
 public:
   invalidateRegionsWorker(RegionStoreManager &rm,
@@ -960,16 +956,15 @@ public:
                           const Expr *ex, unsigned count,
                           const LocationContext *lctx,
                           InvalidatedSymbols &is,
-                          InvalidatedSymbols &inConstIS,
+                          RegionAndSymbolInvalidationTraits &ITraitsIn,
                           StoreManager::InvalidatedRegions *r,
                           GlobalsFilterKind GFK)
     : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b, GFK),
-      Ex(ex), Count(count), LCtx(lctx), IS(is), ConstIS(inConstIS), Regions(r){}
+      Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r){}
 
   /// \param IsConst Specifies if the region we are invalidating is constant.
   /// If it is, we invalidate all subregions, but not the base region itself.
-  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C,
-                    bool IsConst);
+  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
   void VisitBinding(SVal V);
 };
 }
@@ -1000,14 +995,18 @@ void invalidateRegionsWorker::VisitBinding(SVal V) {
 }
 
 void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
-                                           const ClusterBindings *C,
-                                           bool IsConst) {
+                                           const ClusterBindings *C) {
+
+  bool PreserveRegionsContents = 
+      ITraits.hasTrait(baseR, 
+                       RegionAndSymbolInvalidationTraits::TK_PreserveContents);
+
   if (C) {
     for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
       VisitBinding(I.getData());
 
-    // Invalidate the contents of a non-const base region.
-    if (!IsConst)
+    // Invalidate regions contents.
+    if (!PreserveRegionsContents)
       B = B.remove(baseR);
   }
 
@@ -1039,18 +1038,11 @@ void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
   }
 
   // Symbolic region?
-  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
-    SymbolRef RegionSym = SR->getSymbol();
-
-    // Mark that symbol touched by the invalidation.
-    if (IsConst)
-      ConstIS.insert(RegionSym);
-    else
-      IS.insert(RegionSym);
-  }
+  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
+    IS.insert(SR->getSymbol());
 
-  // Nothing else should be done for a const region.
-  if (IsConst)
+  // Nothing else should be done in the case when we preserve regions context.
+  if (PreserveRegionsContents)
     return;
 
   // Otherwise, we have a normal data region. Record that we touched the region.
@@ -1059,7 +1051,7 @@ void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
 
   if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
     // Invalidate the region by setting its default value to
-    // conjured symbol. The type of the symbol is irrelavant.
+    // conjured symbol. The type of the symbol is irrelevant.
     DefinedOrUnknownSVal V =
       svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
     B = B.addBinding(baseR, BindingKey::Default, V);
@@ -1081,7 +1073,7 @@ void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
 
   if (T->isStructureOrClassType()) {
     // Invalidate the region by setting its default value to
-    // conjured symbol. The type of the symbol is irrelavant.
+    // conjured symbol. The type of the symbol is irrelevant.
     DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
                                                           Ctx.IntTy, Count);
     B = B.addBinding(baseR, BindingKey::Default, V);
@@ -1130,7 +1122,6 @@ RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
 
 void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
                                           ArrayRef<SVal> Values,
-                                          bool IsArrayOfConstRegions,
                                           InvalidatedRegions *TopLevelRegions) {
   for (ArrayRef<SVal>::iterator I = Values.begin(),
                                 E = Values.end(); I != E; ++I) {
@@ -1145,7 +1136,7 @@ void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
         // Note: the last argument is false here because these are
         // non-top-level regions.
         if (const MemRegion *R = (*I).getAsRegion())
-          W.AddToWorkList(R, /*IsConst=*/ false);
+          W.AddToWorkList(R);
       }
       continue;
     }
@@ -1153,7 +1144,7 @@ void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
     if (const MemRegion *R = V.getAsRegion()) {
       if (TopLevelRegions)
         TopLevelRegions->push_back(R);
-      W.AddToWorkList(R, /*IsConst=*/ IsArrayOfConstRegions);
+      W.AddToWorkList(R);
       continue;
     }
   }
@@ -1161,16 +1152,14 @@ void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
 
 StoreRef
 RegionStoreManager::invalidateRegions(Store store,
-                                      ArrayRef<SVal> Values,
-                                      ArrayRef<SVal> ConstValues,
-                                      const Expr *Ex, unsigned Count,
-                                      const LocationContext *LCtx,
-                                      const CallEvent *Call,
-                                      InvalidatedSymbols &IS,
-                                      InvalidatedSymbols &ConstIS,
-                                      InvalidatedRegions *TopLevelRegions,
-                                      InvalidatedRegions *TopLevelConstRegions,
-                                      InvalidatedRegions *Invalidated) {
+                                     ArrayRef<SVal> Values,
+                                     const Expr *Ex, unsigned Count,
+                                     const LocationContext *LCtx,
+                                     const CallEvent *Call,
+                                     InvalidatedSymbols &IS,
+                                     RegionAndSymbolInvalidationTraits &ITraits,
+                                     InvalidatedRegions *TopLevelRegions,
+                                     InvalidatedRegions *Invalidated) {
   GlobalsFilterKind GlobalsFilter;
   if (Call) {
     if (Call->isInSystemHeader())
@@ -1182,17 +1171,14 @@ RegionStoreManager::invalidateRegions(Store store,
   }
 
   RegionBindingsRef B = getRegionBindings(store);
-  invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ConstIS,
+  invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
                             Invalidated, GlobalsFilter);
 
   // Scan the bindings and generate the clusters.
   W.GenerateClusters();
 
   // Add the regions to the worklist.
-  populateWorkList(W, Values, /*IsArrayOfConstRegions*/ false,
-                   TopLevelRegions);
-  populateWorkList(W, ConstValues, /*IsArrayOfConstRegions*/ true,
-                   TopLevelConstRegions);
+  populateWorkList(W, Values, TopLevelRegions);
 
   W.RunWorkList();