Fix PR 7475 by enhancing the static analyzer to also invalidate bindings for non-static global variables

when calling a function/method whose impact on global variables we cannot accurately estimate.
This change introduces two new MemSpaceRegions that divide up the memory space of globals, and causes
RegionStore and BasicStore to consult a binding to the NonStaticGlobalsMemSpaceRegion when lazily
determining the value of a global.

llvm-svn: 107423

1 files changed, 78 insertions, 44 deletions

diff --git a/clang/lib/Checker/MemRegion.cpp b/clang/lib/Checker/MemRegion.cpp
index 575458c9dc7..66d2a419148 100644
--- a/clang/lib/Checker/MemRegion.cpp
+++ b/clang/lib/Checker/MemRegion.cpp
@@ -29,22 +29,22 @@ template<typename RegionTy> struct MemRegionManagerTrait;
 
 template <typename RegionTy, typename A1>
 RegionTy* MemRegionManager::getRegion(const A1 a1) {
-  
+
   const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
   MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1);
-  
+
   llvm::FoldingSetNodeID ID;
   RegionTy::ProfileRegion(ID, a1, superRegion);
   void* InsertPos;
   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
                                                                    InsertPos));
-  
+
   if (!R) {
     R = (RegionTy*) A.Allocate<RegionTy>();
     new (R) RegionTy(a1, superRegion);
     Regions.InsertNode(R, InsertPos);
   }
-  
+
   return R;
 }
 
@@ -56,72 +56,72 @@ RegionTy* MemRegionManager::getSubRegion(const A1 a1,
   void* InsertPos;
   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
                                                                    InsertPos));
-  
+
   if (!R) {
     R = (RegionTy*) A.Allocate<RegionTy>();
     new (R) RegionTy(a1, superRegion);
     Regions.InsertNode(R, InsertPos);
   }
-  
+
   return R;
 }
 
 template <typename RegionTy, typename A1, typename A2>
 RegionTy* MemRegionManager::getRegion(const A1 a1, const A2 a2) {
-  
+
   const typename MemRegionManagerTrait<RegionTy>::SuperRegionTy *superRegion =
   MemRegionManagerTrait<RegionTy>::getSuperRegion(*this, a1, a2);
-  
+
   llvm::FoldingSetNodeID ID;
   RegionTy::ProfileRegion(ID, a1, a2, superRegion);
   void* InsertPos;
   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
                                                                    InsertPos));
-  
+
   if (!R) {
     R = (RegionTy*) A.Allocate<RegionTy>();
     new (R) RegionTy(a1, a2, superRegion);
     Regions.InsertNode(R, InsertPos);
   }
-  
+
   return R;
 }
 
 template <typename RegionTy, typename A1, typename A2>
 RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2,
                                          const MemRegion *superRegion) {
-  
+
   llvm::FoldingSetNodeID ID;
   RegionTy::ProfileRegion(ID, a1, a2, superRegion);
   void* InsertPos;
   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
                                                                    InsertPos));
-  
+
   if (!R) {
     R = (RegionTy*) A.Allocate<RegionTy>();
     new (R) RegionTy(a1, a2, superRegion);
     Regions.InsertNode(R, InsertPos);
   }
-  
+
   return R;
 }
 
 template <typename RegionTy, typename A1, typename A2, typename A3>
 RegionTy* MemRegionManager::getSubRegion(const A1 a1, const A2 a2, const A3 a3,
                                          const MemRegion *superRegion) {
-  
+
   llvm::FoldingSetNodeID ID;
   RegionTy::ProfileRegion(ID, a1, a2, a3, superRegion);
   void* InsertPos;
   RegionTy* R = cast_or_null<RegionTy>(Regions.FindNodeOrInsertPos(ID,
                                                                    InsertPos));
-  
+
   if (!R) {
     R = (RegionTy*) A.Allocate<RegionTy>();
     new (R) RegionTy(a1, a2, a3, superRegion);
     Regions.InsertNode(R, InsertPos);
   }
-  
+
   return R;
 }
 
@@ -183,6 +183,11 @@ void StackSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
   ID.AddPointer(getStackFrame());
 }
 
+void StaticGlobalSpaceRegion::Profile(llvm::FoldingSetNodeID &ID) const {
+  ID.AddInteger((unsigned)getKind());
+  ID.AddPointer(getCodeRegion());
+}
+
 void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
                                  const StringLiteral* Str,
                                  const MemRegion* superRegion) {
@@ -226,7 +231,7 @@ void CXXThisRegion::ProfileRegion(llvm::FoldingSetNodeID &ID,
 void CXXThisRegion::Profile(llvm::FoldingSetNodeID &ID) const {
   CXXThisRegion::ProfileRegion(ID, ThisPointerTy, superRegion);
 }
-                                  
+
 void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl* D,
                                const MemRegion* superRegion, Kind k) {
   ID.AddInteger((unsigned) k);
@@ -412,7 +417,7 @@ const REG *MemRegionManager::LazyAllocate(REG*& region, ARG a) {
     region = (REG*) A.Allocate<REG>();
     new (region) REG(this, a);
   }
-  
+
   return region;
 }
 
@@ -442,8 +447,18 @@ MemRegionManager::getStackArgumentsRegion(const StackFrameContext *STC) {
   return R;
 }
 
-const GlobalsSpaceRegion *MemRegionManager::getGlobalsRegion() {
-  return LazyAllocate(globals);
+const GlobalsSpaceRegion
+*MemRegionManager::getGlobalsRegion(const CodeTextRegion *CR) {
+  if (!CR)
+    return LazyAllocate(globals);
+
+  StaticGlobalSpaceRegion *&R = StaticsGlobalSpaceRegions[CR];
+  if (R)
+    return R;
+
+  R = A.Allocate<StaticGlobalSpaceRegion>();
+  new (R) StaticGlobalSpaceRegion(this, CR);
+  return R;
 }
 
 const HeapSpaceRegion *MemRegionManager::getHeapRegion() {
@@ -462,7 +477,7 @@ const MemSpaceRegion *MemRegionManager::getCodeRegion() {
 // Constructing regions.
 //===----------------------------------------------------------------------===//
 
-const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str) {
+const StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str){
   return getSubRegion<StringRegion>(Str, getGlobalsRegion());
 }
 
@@ -470,7 +485,9 @@ const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
                                                 const LocationContext *LC) {
   const MemRegion *sReg = 0;
 
-  if (D->hasLocalStorage()) {    
+  if (D->hasGlobalStorage() && !D->isStaticLocal())
+    sReg = getGlobalsRegion();
+  else {
     // FIXME: Once we implement scope handling, we will need to properly lookup
     // 'D' to the proper LocationContext.
     const DeclContext *DC = D->getDeclContext();
@@ -479,15 +496,32 @@ const VarRegion* MemRegionManager::getVarRegion(const VarDecl *D,
     if (!STC)
       sReg = getUnknownRegion();
     else {
-      sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
-            ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
-            : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
+      if (D->hasLocalStorage()) {
+        sReg = isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)
+               ? static_cast<const MemRegion*>(getStackArgumentsRegion(STC))
+               : static_cast<const MemRegion*>(getStackLocalsRegion(STC));
+      }
+      else {
+        assert(D->isStaticLocal());
+        const Decl *D = STC->getDecl();
+        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+          sReg = getGlobalsRegion(getFunctionTextRegion(FD));
+        else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
+          const BlockTextRegion *BTR =
+            getBlockTextRegion(BD,
+                     C.getCanonicalType(BD->getSignatureAsWritten()->getType()),
+                     STC->getAnalysisContext());
+          sReg = getGlobalsRegion(BTR);
+        }
+        else {
+          // FIXME: For ObjC-methods, we need a new CodeTextRegion.  For now
+          // just use the main global memspace.
+          sReg = getGlobalsRegion();
+        }
+      }
     }
   }
-  else {
-    sReg = getGlobalsRegion();
-  }
-  
+
   return getSubRegion<VarRegion>(D, sReg);
 }
 
@@ -500,10 +534,10 @@ const BlockDataRegion *
 MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
                                      const LocationContext *LC) {
   const MemRegion *sReg = 0;
-  
-  if (LC) {    
+
+  if (LC) {
     // FIXME: Once we implement scope handling, we want the parent region
-    // to be the scope.  
+    // to be the scope.
     const StackFrameContext *STC = LC->getCurrentStackFrame();
     assert(STC);
     sReg = getStackLocalsRegion(STC);
@@ -520,9 +554,9 @@ MemRegionManager::getBlockDataRegion(const BlockTextRegion *BC,
 const CompoundLiteralRegion*
 MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr* CL,
                                            const LocationContext *LC) {
-  
+
   const MemRegion *sReg = 0;
-  
+
   if (CL->isFileScope())
     sReg = getGlobalsRegion();
   else {
@@ -530,7 +564,7 @@ MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr* CL,
     assert(STC);
     sReg = getStackLocalsRegion(STC);
   }
-  
+
   return getSubRegion<CompoundLiteralRegion>(CL, sReg);
 }
 
@@ -749,24 +783,24 @@ void BlockDataRegion::LazyInitializeReferencedVars() {
   AnalysisContext *AC = getCodeRegion()->getAnalysisContext();
   AnalysisContext::referenced_decls_iterator I, E;
   llvm::tie(I, E) = AC->getReferencedBlockVars(BC->getDecl());
-  
+
   if (I == E) {
     ReferencedVars = (void*) 0x1;
     return;
   }
-    
+
   MemRegionManager &MemMgr = *getMemRegionManager();
   llvm::BumpPtrAllocator &A = MemMgr.getAllocator();
   BumpVectorContext BC(A);
-  
+
   typedef BumpVector<const MemRegion*> VarVec;
   VarVec *BV = (VarVec*) A.Allocate<VarVec>();
   new (BV) VarVec(BC, E - I);
-  
+
   for ( ; I != E; ++I) {
     const VarDecl *VD = *I;
     const VarRegion *VR = 0;
-    
+
     if (!VD->getAttr<BlocksAttr>() && VD->hasLocalStorage())
       VR = MemMgr.getVarRegion(VD, this);
     else {
@@ -776,11 +810,11 @@ void BlockDataRegion::LazyInitializeReferencedVars() {
         VR = MemMgr.getVarRegion(VD, MemMgr.getUnknownRegion());
       }
     }
-    
+
     assert(VR);
     BV->push_back(VR, BC);
   }
-  
+
   ReferencedVars = BV;
 }
 
@@ -790,7 +824,7 @@ BlockDataRegion::referenced_vars_begin() const {
 
   BumpVector<const MemRegion*> *Vec =
     static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
-  
+
   return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
                                                    NULL : Vec->begin());
 }
@@ -801,7 +835,7 @@ BlockDataRegion::referenced_vars_end() const {
 
   BumpVector<const MemRegion*> *Vec =
     static_cast<BumpVector<const MemRegion*>*>(ReferencedVars);
-  
+
   return BlockDataRegion::referenced_vars_iterator(Vec == (void*) 0x1 ?
                                                    NULL : Vec->end());
 }