[analyzer] Add LocationContext as a parameter to checkRegionChanges

This patch adds LocationContext to checkRegionChanges and removes
wantsRegionChangeUpdate as it was unused.

A patch by Krzysztof Wiśniewski!

Differential Revision: https://reviews.llvm.org/D27090

llvm-svn: 291869

clang/include/clang/StaticAnalyzer/Core/Checker.h

@@ -321,9 +321,11 @@ class RegionChanges {
                       const InvalidatedSymbols *invalidated,
                       ArrayRef<const MemRegion *> Explicits,
                       ArrayRef<const MemRegion *> Regions,
+                      const LocationContext *LCtx,
                       const CallEvent *Call) {
-    return ((const CHECKER *)checker)->checkRegionChanges(state, invalidated,
-                                                      Explicits, Regions, Call);
+    return ((const CHECKER *) checker)->checkRegionChanges(state, invalidated,
+                                                           Explicits, Regions,
+                                                           LCtx, Call);
   }
 
 public:

clang/include/clang/StaticAnalyzer/Core/CheckerManager.h

@@ -338,6 +338,7 @@ class CheckerManager {
                               const InvalidatedSymbols *invalidated,
                               ArrayRef<const MemRegion *> ExplicitRegions,
                               ArrayRef<const MemRegion *> Regions,
+                              const LocationContext *LCtx,
                               const CallEvent *Call);
 
   /// \brief Run checkers when pointers escape.
@@ -443,10 +444,11 @@ class CheckerManager {
   typedef CheckerFn<void (ProgramStateRef,SymbolReaper &)> CheckLiveSymbolsFunc;
 
   typedef CheckerFn<ProgramStateRef (ProgramStateRef,
-                                const InvalidatedSymbols *symbols,
-                                ArrayRef<const MemRegion *> ExplicitRegions,
-                                ArrayRef<const MemRegion *> Regions,
-                                const CallEvent *Call)>
+                                     const InvalidatedSymbols *symbols,
+                                     ArrayRef<const MemRegion *> ExplicitRegions,
+                                     ArrayRef<const MemRegion *> Regions,
+                                     const LocationContext *LCtx,
+                                     const CallEvent *Call)>
       CheckRegionChangesFunc;
 
   typedef CheckerFn<ProgramStateRef (ProgramStateRef,

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h

@@ -293,6 +293,7 @@ class ExprEngine : public SubEngine {
                        const InvalidatedSymbols *invalidated,
                        ArrayRef<const MemRegion *> ExplicitRegions,
                        ArrayRef<const MemRegion *> Regions,
+                       const LocationContext *LCtx,
                        const CallEvent *Call) override;
 
   /// printState - Called by ProgramStateManager to print checker-specific data.
@@ -522,7 +523,9 @@ class ExprEngine : public SubEngine {
 
   /// Call PointerEscape callback when a value escapes as a result of bind.
   ProgramStateRef processPointerEscapedOnBind(ProgramStateRef State,
-                                              SVal Loc, SVal Val) override;
+                                              SVal Loc,
+                                              SVal Val,
+                                              const LocationContext *LCtx) override;
   /// Call PointerEscape callback when a value escapes as a result of
   /// region invalidation.
   /// \param[in] ITraits Specifies invalidation traits for regions/symbols.

clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h

@@ -229,11 +229,12 @@ class ProgramState : public llvm::FoldingSetNode {
 
   ProgramStateRef bindLoc(Loc location,
                           SVal V,
+                          const LocationContext *LCtx,
                           bool notifyChanges = true) const;
 
-  ProgramStateRef bindLoc(SVal location, SVal V) const;
+  ProgramStateRef bindLoc(SVal location, SVal V, const LocationContext *LCtx) const;
 
-  ProgramStateRef bindDefault(SVal loc, SVal V) const;
+  ProgramStateRef bindDefault(SVal loc, SVal V, const LocationContext *LCtx) const;
 
   ProgramStateRef killBinding(Loc LV) const;
 
@@ -681,9 +682,9 @@ ProgramState::assumeInclusiveRange(DefinedOrUnknownSVal Val,
       this, Val.castAs<NonLoc>(), From, To);
 }
 
-inline ProgramStateRef ProgramState::bindLoc(SVal LV, SVal V) const {
+inline ProgramStateRef ProgramState::bindLoc(SVal LV, SVal V, const LocationContext *LCtx) const {
   if (Optional<Loc> L = LV.getAs<Loc>())
-    return bindLoc(*L, V);
+    return bindLoc(*L, V, LCtx);
   return this;
 }
 

clang/include/clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h

@@ -131,17 +131,19 @@ class SubEngine {
                        const InvalidatedSymbols *invalidated,
                        ArrayRef<const MemRegion *> ExplicitRegions,
                        ArrayRef<const MemRegion *> Regions,
+                       const LocationContext *LCtx,
                        const CallEvent *Call) = 0;
 
 
   inline ProgramStateRef 
   processRegionChange(ProgramStateRef state,
-                      const MemRegion* MR) {
-    return processRegionChanges(state, nullptr, MR, MR, nullptr);
+                      const MemRegion* MR,
+                      const LocationContext *LCtx) {
+    return processRegionChanges(state, nullptr, MR, MR, LCtx, nullptr);
   }
 
   virtual ProgramStateRef
-  processPointerEscapedOnBind(ProgramStateRef State, SVal Loc, SVal Val) = 0;
+  processPointerEscapedOnBind(ProgramStateRef State, SVal Loc, SVal Val, const LocationContext *LCtx) = 0;
 
   virtual ProgramStateRef
   notifyCheckersOfPointerEscape(ProgramStateRef State,

clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp

@@ -68,6 +68,7 @@ class CStringChecker : public Checker< eval::Call,
                        const InvalidatedSymbols *,
                        ArrayRef<const MemRegion *> ExplicitRegions,
                        ArrayRef<const MemRegion *> Regions,
+                       const LocationContext *LCtx,
                        const CallEvent *Call) const;
 
   typedef void (CStringChecker::*FnCheck)(CheckerContext &,
@@ -1943,8 +1944,12 @@ void CStringChecker::evalStrsep(CheckerContext &C, const CallExpr *CE) const {
     // Overwrite the search string pointer. The new value is either an address
     // further along in the same string, or NULL if there are no more tokens.
     State = State->bindLoc(*SearchStrLoc,
-                           SVB.conjureSymbolVal(getTag(), CE, LCtx, CharPtrTy,
-                                                C.blockCount()));
+                           SVB.conjureSymbolVal(getTag(),
+                                                CE,
+                                                LCtx,
+                                                CharPtrTy,
+                                                C.blockCount()),
+                           LCtx);
   } else {
     assert(SearchStrVal.isUnknown());
     // Conjure a symbolic value. It's the best we can do.
@@ -2116,6 +2121,7 @@ CStringChecker::checkRegionChanges(ProgramStateRef state,
                                    const InvalidatedSymbols *,
                                    ArrayRef<const MemRegion *> ExplicitRegions,
                                    ArrayRef<const MemRegion *> Regions,
+                                   const LocationContext *LCtx,
                                    const CallEvent *Call) const {
   CStringLengthTy Entries = state->get<CStringLength>();
   if (Entries.isEmpty())

clang/lib/StaticAnalyzer/Checkers/CXXSelfAssignmentChecker.cpp

@@ -51,9 +51,9 @@ void CXXSelfAssignmentChecker::checkBeginFunction(CheckerContext &C) const {
       State->getSVal(SVB.getCXXThis(MD, LCtx->getCurrentStackFrame()));
   auto Param = SVB.makeLoc(State->getRegion(MD->getParamDecl(0), LCtx));
   auto ParamVal = State->getSVal(Param);
-  ProgramStateRef SelfAssignState = State->bindLoc(Param, ThisVal);
+  ProgramStateRef SelfAssignState = State->bindLoc(Param, ThisVal, LCtx);
   C.addTransition(SelfAssignState);
-  ProgramStateRef NonSelfAssignState = State->bindLoc(Param, ParamVal);
+  ProgramStateRef NonSelfAssignState = State->bindLoc(Param, ParamVal, LCtx);
   C.addTransition(NonSelfAssignState);
 }
 

clang/lib/StaticAnalyzer/Checkers/CheckerDocumentation.cpp

@@ -231,14 +231,6 @@ class CheckerDocumentation : public Checker< check::PreStmt<ReturnStmt>,
   /// check::LiveSymbols
   void checkLiveSymbols(ProgramStateRef State, SymbolReaper &SR) const {}
 
-  /// \brief Called to determine if the checker currently needs to know if when
-  /// contents of any regions change.
-  ///
-  /// Since it is not necessarily cheap to compute which regions are being
-  /// changed, this allows the analyzer core to skip the more expensive
-  /// #checkRegionChanges when no checkers are tracking any state.
-  bool wantsRegionChangeUpdate(ProgramStateRef St) const { return true; }
-
   /// \brief Called when the contents of one or more regions change.
   ///
   /// This can occur in many different ways: an explicit bind, a blanket
@@ -255,18 +247,18 @@ class CheckerDocumentation : public Checker< check::PreStmt<ReturnStmt>,
   ///        by this change. For a simple bind, this list will be the same as
   ///        \p ExplicitRegions, since a bind does not affect the contents of
   ///        anything accessible through the base region.
+  /// \param LCtx LocationContext that is useful for getting various contextual
+  ///        info, like callstack, CFG etc.
   /// \param Call The opaque call triggering this invalidation. Will be 0 if the
   ///        change was not triggered by a call.
   ///
-  /// Note that this callback will not be invoked unless
-  /// #wantsRegionChangeUpdate returns \c true.
-  ///
   /// check::RegionChanges
   ProgramStateRef
     checkRegionChanges(ProgramStateRef State,
                        const InvalidatedSymbols *Invalidated,
                        ArrayRef<const MemRegion *> ExplicitRegions,
                        ArrayRef<const MemRegion *> Regions,
+                       const LocationContext *LCtx,
                        const CallEvent *Call) const {
     return State;
   }

clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp

@@ -1154,7 +1154,7 @@ ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
   State = State->BindExpr(CE, C.getLocationContext(), RetVal);
 
   // Fill the region with the initialization value.
-  State = State->bindDefault(RetVal, Init);
+  State = State->bindDefault(RetVal, Init, LCtx);
 
   // Set the region's extent equal to the Size parameter.
   const SymbolicRegion *R =

clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp

@@ -2661,6 +2661,7 @@ class RetainCountChecker
                      const InvalidatedSymbols *invalidated,
                      ArrayRef<const MemRegion *> ExplicitRegions,
                      ArrayRef<const MemRegion *> Regions,
+                     const LocationContext* LCtx,
                      const CallEvent *Call) const;
 
   void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
@@ -3647,7 +3648,7 @@ void RetainCountChecker::checkBind(SVal loc, SVal val, const Stmt *S,
       // same state.
       SVal StoredVal = state->getSVal(regionLoc->getRegion());
       if (StoredVal != val)
-        escapes = (state == (state->bindLoc(*regionLoc, val)));
+        escapes = (state == (state->bindLoc(*regionLoc, val, C.getLocationContext())));
     }
     if (!escapes) {
       // Case 4: We do not currently model what happens when a symbol is
@@ -3714,10 +3715,11 @@ ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state,
 
 ProgramStateRef
 RetainCountChecker::checkRegionChanges(ProgramStateRef state,
-                                    const InvalidatedSymbols *invalidated,
-                                    ArrayRef<const MemRegion *> ExplicitRegions,
-                                    ArrayRef<const MemRegion *> Regions,
-                                    const CallEvent *Call) const {
+                                       const InvalidatedSymbols *invalidated,
+                                       ArrayRef<const MemRegion *> ExplicitRegions,
+                                       ArrayRef<const MemRegion *> Regions,
+                                       const LocationContext *LCtx,
+                                       const CallEvent *Call) const {
   if (!invalidated)
     return state;
 

clang/lib/StaticAnalyzer/Core/CheckerManager.cpp

@@ -521,17 +521,19 @@ void CheckerManager::runCheckersForDeadSymbols(ExplodedNodeSet &Dst,
 /// \brief Run checkers for region changes.
 ProgramStateRef
 CheckerManager::runCheckersForRegionChanges(ProgramStateRef state,
-                                    const InvalidatedSymbols *invalidated,
-                                    ArrayRef<const MemRegion *> ExplicitRegions,
-                                    ArrayRef<const MemRegion *> Regions,
-                                    const CallEvent *Call) {
+                                            const InvalidatedSymbols *invalidated,
+                                            ArrayRef<const MemRegion *> ExplicitRegions,
+                                            ArrayRef<const MemRegion *> Regions,
+                                            const LocationContext *LCtx,
+                                            const CallEvent *Call) {
   for (unsigned i = 0, e = RegionChangesCheckers.size(); i != e; ++i) {
     // If any checker declares the state infeasible (or if it starts that way),
     // bail out.
     if (!state)
       return nullptr;
     state = RegionChangesCheckers[i](state, invalidated,
-                                     ExplicitRegions, Regions, Call);
+                                     ExplicitRegions, Regions,
+                                     LCtx, Call);
   }
   return state;
 }

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -254,7 +254,7 @@ ExprEngine::createTemporaryRegionIfNeeded(ProgramStateRef State,
       break;
     case SubobjectAdjustment::MemberPointerAdjustment:
       // FIXME: Unimplemented.
-      State->bindDefault(Reg, UnknownVal());
+      State->bindDefault(Reg, UnknownVal(), LC);
       return State;
     }
   }
@@ -265,7 +265,7 @@ ExprEngine::createTemporaryRegionIfNeeded(ProgramStateRef State,
                                           currBldrCtx->blockCount());
   // Bind the value of the expression to the sub-object region, and then bind
   // the sub-object region to our expression.
-  State = State->bindLoc(Reg, V);
+  State = State->bindLoc(Reg, V, LC);
   State = State->BindExpr(Result, LC, Reg);
   return State;
 }
@@ -286,9 +286,11 @@ ExprEngine::processRegionChanges(ProgramStateRef state,
                                  const InvalidatedSymbols *invalidated,
                                  ArrayRef<const MemRegion *> Explicits,
                                  ArrayRef<const MemRegion *> Regions,
+                                 const LocationContext *LCtx,
                                  const CallEvent *Call) {
   return getCheckerManager().runCheckersForRegionChanges(state, invalidated,
-                                                      Explicits, Regions, Call);
+                                                         Explicits, Regions,
+                                                         LCtx, Call);
 }
 
 void ExprEngine::printState(raw_ostream &Out, ProgramStateRef State,
@@ -2165,7 +2167,9 @@ class CollectReachableSymbolsCallback final : public SymbolVisitor {
 // (3) We are binding to a MemRegion with stack storage that the store
 //     does not understand.
 ProgramStateRef ExprEngine::processPointerEscapedOnBind(ProgramStateRef State,
-                                                        SVal Loc, SVal Val) {
+                                                        SVal Loc,
+                                                        SVal Val,
+                                                        const LocationContext *LCtx) {
   // Are we storing to something that causes the value to "escape"?
   bool escapes = true;
 
@@ -2181,7 +2185,7 @@ ProgramStateRef ExprEngine::processPointerEscapedOnBind(ProgramStateRef State,
       // same state.
       SVal StoredVal = State->getSVal(regionLoc->getRegion());
       if (StoredVal != Val)
-        escapes = (State == (State->bindLoc(*regionLoc, Val)));
+        escapes = (State == (State->bindLoc(*regionLoc, Val, LCtx)));
     }
   }
 
@@ -2278,7 +2282,7 @@ void ExprEngine::evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE,
     const ProgramPoint L = PostStore(StoreE, LC, /*Loc*/nullptr,
                                      /*tag*/nullptr);
     ProgramStateRef state = Pred->getState();
-    state = processPointerEscapedOnBind(state, location, Val);
+    state = processPointerEscapedOnBind(state, location, Val, LC);
     Bldr.generateNode(L, state, Pred);
     return;
   }
@@ -2288,13 +2292,13 @@ void ExprEngine::evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE,
     ExplodedNode *PredI = *I;
     ProgramStateRef state = PredI->getState();
 
-    state = processPointerEscapedOnBind(state, location, Val);
+    state = processPointerEscapedOnBind(state, location, Val, LC);
 
     // When binding the value, pass on the hint that this is a initialization.
     // For initializations, we do not need to inform clients of region
     // changes.
     state = state->bindLoc(location.castAs<Loc>(),
-                           Val, /* notifyChanges = */ !atDeclInit);
+                           Val, LC, /* notifyChanges = */ !atDeclInit);
 
     const MemRegion *LocReg = nullptr;
     if (Optional<loc::MemRegionVal> LocRegVal =
@@ -2520,7 +2524,7 @@ void ExprEngine::VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
     assert (!X.getAs<NonLoc>());  // Should be an Lval, or unknown, undef.
 
     if (Optional<Loc> LV = X.getAs<Loc>())
-      state = state->bindLoc(*LV, UnknownVal());
+      state = state->bindLoc(*LV, UnknownVal(), Pred->getLocationContext());
   }
 
   Bldr.generateNode(A, Pred, state);

clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp

@@ -227,12 +227,13 @@ void ExprEngine::VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
 
       if (capturedR != originalR) {
         SVal originalV;
+        const LocationContext *LCtx = Pred->getLocationContext();
         if (copyExpr) {
-          originalV = State->getSVal(copyExpr, Pred->getLocationContext());
+          originalV = State->getSVal(copyExpr, LCtx);
         } else {
           originalV = State->getSVal(loc::MemRegionVal(originalR));
         }
-        State = State->bindLoc(loc::MemRegionVal(capturedR), originalV);
+        State = State->bindLoc(loc::MemRegionVal(capturedR), originalV, LCtx);
       }
     }
   }
@@ -534,7 +535,7 @@ void ExprEngine::VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
   } else {
     assert(isa<InitListExpr>(Init));
     Loc CLLoc = State->getLValue(CL, LCtx);
-    State = State->bindLoc(CLLoc, V);
+    State = State->bindLoc(CLLoc, V, LCtx);
 
     if (CL->isGLValue())
       V = CLLoc;

clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp

@@ -317,7 +317,7 @@ void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE,
         // actually make things worse. Placement new makes this tricky as well,
         // since it's then possible to be initializing one part of a multi-
         // dimensional array.
-        State = State->bindDefault(loc::MemRegionVal(Target), ZeroVal);
+        State = State->bindDefault(loc::MemRegionVal(Target), ZeroVal, LCtx);
         Bldr.generateNode(CE, *I, State, /*tag=*/nullptr,
                           ProgramPoint::PreStmtKind);
       }
@@ -572,7 +572,7 @@ void ExprEngine::VisitCXXCatchStmt(const CXXCatchStmt *CS,
   SVal V = svalBuilder.conjureSymbolVal(CS, LCtx, VD->getType(),
                                         currBldrCtx->blockCount());
   ProgramStateRef state = Pred->getState();
-  state = state->bindLoc(state->getLValue(VD, LCtx), V);
+  state = state->bindLoc(state->getLValue(VD, LCtx), V, LCtx);
 
   StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
   Bldr.generateNode(CS, Pred, state);
@@ -627,7 +627,7 @@ void ExprEngine::VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
       InitVal = State->getSVal(SizeExpr, LocCtxt);
     }
 
-    State = State->bindLoc(FieldLoc, InitVal);
+    State = State->bindLoc(FieldLoc, InitVal, LocCtxt);
   }
 
   // Decay the Loc into an RValue, because there might be a