Make SymbolicRegion subclass TypedRegion, for symbols usually have types, so

do the symblic regions associated with them and we need them to be typed.

Current SymbolicRegion::getRValueType() method is very restricting. It may be
modified when we are more clear about what could be the types of symblic
regions.

BasicConstraintManager::Assume() is changed due to that now SymblicRegion is a
subclass of SubRegion.
 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63844 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 75 insertions, 48 deletions

diff --git a/include/clang/Analysis/PathSensitive/MemRegion.h b/include/clang/Analysis/PathSensitive/MemRegion.h
index 8a62eff7a9..ba08e38387 100644
--- a/include/clang/Analysis/PathSensitive/MemRegion.h
+++ b/include/clang/Analysis/PathSensitive/MemRegion.h
@@ -38,10 +38,11 @@ class MemRegionManager;
 /// MemRegion - The root abstract class for all memory regions.
 class MemRegion : public llvm::FoldingSetNode {
 public:
-  enum Kind { MemSpaceRegionKind, SymbolicRegionKind,
+  enum Kind { MemSpaceRegionKind,
               AllocaRegionKind,
               // Typed regions.
               BEG_TYPED_REGIONS,
+               SymbolicRegionKind,
                CompoundLiteralRegionKind,
                StringRegionKind, ElementRegionKind,
                AnonTypedRegionKind,
@@ -103,7 +104,7 @@ public:
   bool isSubRegionOf(const MemRegion* R) const;
 
   static bool classof(const MemRegion* R) {
-    return R->getKind() > SymbolicRegionKind;
+    return R->getKind() > MemSpaceRegionKind;
   }
 };
   
@@ -135,32 +136,6 @@ public:
   }
 };    
   
-/// SymbolicRegion - A special, "non-concrete" region. Unlike other region
-///  clases, SymbolicRegion represents a region that serves as an alias for
-///  either a real region, a NULL pointer, etc.  It essentially is used to
-///  map the concept of symbolic values into the domain of regions.  Symbolic
-///  regions do not need to be typed.
-class SymbolicRegion : public MemRegion {
-protected:
-  const SymbolRef sym;
-
-public:
-  SymbolicRegion(const SymbolRef s) : MemRegion(SymbolicRegionKind), sym(s) {}
-    
-  SymbolRef getSymbol() const {
-    return sym;
-  }
-    
-  void Profile(llvm::FoldingSetNodeID& ID) const;
-  static void ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym);
-  
-  void print(llvm::raw_ostream& os) const;
-  
-  static bool classof(const MemRegion* R) {
-    return R->getKind() == SymbolicRegionKind;
-  }
-};  
-
 /// TypedRegion - An abstract class representing regions that are typed.
 class TypedRegion : public SubRegion {
 protected:
@@ -188,6 +163,37 @@ public:
   }
 };
 
+/// SymbolicRegion - A special, "non-concrete" region. Unlike other region
+///  clases, SymbolicRegion represents a region that serves as an alias for
+///  either a real region, a NULL pointer, etc.  It essentially is used to
+///  map the concept of symbolic values into the domain of regions.  Symbolic
+///  regions do not need to be typed.
+class SymbolicRegion : public TypedRegion {
+protected:
+  const SymbolRef sym;
+  const SymbolManager& SymMgr;
+
+public:
+  SymbolicRegion(const SymbolRef s, const SymbolManager& mgr, MemRegion* sreg) 
+    : TypedRegion(sreg, SymbolicRegionKind), sym(s), SymMgr(mgr) {}
+    
+  SymbolRef getSymbol() const {
+    return sym;
+  }
+
+  QualType getRValueType(ASTContext& C) const;
+
+  void Profile(llvm::FoldingSetNodeID& ID) const;
+
+  static void ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym);
+  
+  void print(llvm::raw_ostream& os) const;
+  
+  static bool classof(const MemRegion* R) {
+    return R->getKind() == SymbolicRegionKind;
+  }
+};  
+
 /// StringRegion - Region associated with a StringLiteral.
 class StringRegion : public TypedRegion {
   friend class MemRegionManager;
@@ -492,7 +498,7 @@ public:
   getCompoundLiteralRegion(const CompoundLiteralExpr* CL);  
   
   /// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
-  SymbolicRegion* getSymbolicRegion(const SymbolRef sym);
+  SymbolicRegion* getSymbolicRegion(const SymbolRef sym, const SymbolManager&);
 
   StringRegion* getStringRegion(const StringLiteral* Str);
 
diff --git a/lib/Analysis/BasicConstraintManager.cpp b/lib/Analysis/BasicConstraintManager.cpp
index 0c98bf6450..58c4727d51 100644
--- a/lib/Analysis/BasicConstraintManager.cpp
+++ b/lib/Analysis/BasicConstraintManager.cpp
@@ -165,17 +165,14 @@ const GRState* BasicConstraintManager::AssumeAux(const GRState* St, Loc Cond,
     // FIXME: Should this go into the storemanager?
     
     const MemRegion* R = cast<loc::MemRegionVal>(Cond).getRegion();
-    
-    while (R) {
-      if (const SubRegion* SubR = dyn_cast<SubRegion>(R)) {
-        R = SubR->getSuperRegion();
-        continue;
-      }
-      else if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R))
+    const SubRegion* SubR = dyn_cast<SubRegion>(R);
+
+    while (SubR) {
+      // FIXME: now we only find the first symbolic region.
+      if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(SubR))
         return AssumeAux(St, loc::SymbolVal(SymR->getSymbol()), Assumption,
                                             isFeasible);
-      
-      break;
+      SubR = dyn_cast<SubRegion>(SubR->getSuperRegion());
     }
     
     // FALL-THROUGH.
diff --git a/lib/Analysis/BasicStore.cpp b/lib/Analysis/BasicStore.cpp
index 2feea594b8..ad542b884a 100644
--- a/lib/Analysis/BasicStore.cpp
+++ b/lib/Analysis/BasicStore.cpp
@@ -173,7 +173,8 @@ SVal BasicStoreManager::getLValueField(const GRState* St, SVal Base,
   
   switch(BaseL.getSubKind()) {
     case loc::SymbolValKind:
-      BaseR = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(&BaseL)->getSymbol());
+      BaseR = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(&BaseL)->getSymbol(),
+                                      StateMgr.getSymbolManager());
       break;
       
     case loc::GotoLabelKind:
@@ -218,7 +219,8 @@ SVal BasicStoreManager::getLValueElement(const GRState* St, SVal Base,
       // Create a region to represent this symbol.
       // FIXME: In the future we may just use symbolic regions instead of
       //  SymbolVals to reason about symbolic memory chunks.
-      const MemRegion* SymR = MRMgr.getSymbolicRegion(Sym);
+      const MemRegion* SymR = MRMgr.getSymbolicRegion(Sym, 
+                                                  StateMgr.getSymbolManager());
       // Layered a typed region on top of this.
       QualType T = StateMgr.getSymbolManager().getType(Sym);
       BaseR = MRMgr.getAnonTypedRegion(T, SymR);
diff --git a/lib/Analysis/MemRegion.cpp b/lib/Analysis/MemRegion.cpp
index 82f4423541..e41c5f937b 100644
--- a/lib/Analysis/MemRegion.cpp
+++ b/lib/Analysis/MemRegion.cpp
@@ -107,6 +107,28 @@ void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
   ElementRegion::ProfileRegion(ID, Index, superRegion);
 }
 
+//===----------------------------------------------------------------------===//
+// getLValueType() and getRValueType()
+//===----------------------------------------------------------------------===//
+
+QualType SymbolicRegion::getRValueType(ASTContext& C) const {
+  const SymbolData& data = SymMgr.getSymbolData(sym);
+
+  // FIXME: We could use the SymbolManager::getType() directly. But that
+  // would hide the assumptions we made here. What is the type of a symbolic
+  // region is unclear for other cases.
+
+  // For now we assume the symbol is a typed region rvalue.
+  const TypedRegion* R 
+    = cast<TypedRegion>(cast<SymbolRegionRValue>(data).getRegion());
+
+  // Assume the region rvalue has a pointer type, only then we could have a
+  // symbolic region associated with it.
+  PointerType* PTy = cast<PointerType>(R->getRValueType(C).getTypePtr());
+
+  return PTy->getPointeeType();
+}
+
 QualType ElementRegion::getRValueType(ASTContext& C) const {
   // Strip off typedefs from the ArrayRegion's RvalueType.
   QualType T = getArrayRegion()->getRValueType(C)->getDesugaredType();
@@ -119,10 +141,6 @@ QualType ElementRegion::getRValueType(ASTContext& C) const {
   return T;
 }
 
-//===----------------------------------------------------------------------===//
-// getLValueType() and getRValueType()
-//===----------------------------------------------------------------------===//
-
 QualType StringRegion::getRValueType(ASTContext& C) const {
   return Str->getType();
 }
@@ -308,7 +326,8 @@ MemRegionManager::getElementRegion(SVal Idx, const TypedRegion* superRegion){
 }
 
 /// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
-SymbolicRegion* MemRegionManager::getSymbolicRegion(const SymbolRef sym) {
+SymbolicRegion* MemRegionManager::getSymbolicRegion(const SymbolRef sym,
+                                                    const SymbolManager& mgr) {
   
   llvm::FoldingSetNodeID ID;
   SymbolicRegion::ProfileRegion(ID, sym);
@@ -319,7 +338,8 @@ SymbolicRegion* MemRegionManager::getSymbolicRegion(const SymbolRef sym) {
   
   if (!R) {
     R = (SymbolicRegion*) A.Allocate<SymbolicRegion>();
-    new (R) SymbolicRegion(sym);
+    // SymbolicRegion's storage class is usually unknown.
+    new (R) SymbolicRegion(sym, mgr, getUnknownRegion());
     Regions.InsertNode(R, InsertPos);
   }
   
diff --git a/lib/Analysis/RegionStore.cpp b/lib/Analysis/RegionStore.cpp
index 8d36d10a8a..e640087acb 100644
--- a/lib/Analysis/RegionStore.cpp
+++ b/lib/Analysis/RegionStore.cpp
@@ -312,7 +312,8 @@ SVal RegionStoreManager::getLValueField(const GRState* St, SVal Base,
     break;
 
   case loc::SymbolValKind:
-    BaseR = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(&BaseL)->getSymbol());
+    BaseR = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(&BaseL)->getSymbol(),
+                                    StateMgr.getSymbolManager());
     break;
   
   case loc::GotoLabelKind:
@@ -701,7 +702,8 @@ Store RegionStoreManager::Remove(Store store, Loc L) {
   if (isa<loc::MemRegionVal>(L))
     R = cast<loc::MemRegionVal>(L).getRegion();
   else if (isa<loc::SymbolVal>(L))
-    R = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(L).getSymbol());
+    R = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(L).getSymbol(),
+                                StateMgr.getSymbolManager());
   
   if (R) {
     RegionBindingsTy B = GetRegionBindings(store);