[analyzer] Invalidate regions indirectly accessible through const pointers.

In this case, the value of 'x' may be changed after the call to indirectAccess:

  struct Wrapper {
    int *ptr;
  };

  void indirectAccess(const Wrapper &w);

  void test() {
    int x = 42;
    Wrapper w = { x };

    clang_analyzer_eval(x == 42); // TRUE
    indirectAccess(w);
    clang_analyzer_eval(x == 42); // UNKNOWN
  }

This is important for modelling return-by-value objects in C++, to show
that the contents of the struct are escaping in the return copy-constructor.

<rdar://problem/13239826>

llvm-svn: 177570

1 files changed, 12 insertions, 8 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
index 64205f8d998..3e47dcef2bf 100644
--- a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
@@ -140,30 +140,34 @@ ProgramStateRef ProgramState::bindDefault(SVal loc, SVal V) const {
            new_state;
 }
 
+typedef ArrayRef<const MemRegion *> RegionList;
+
 ProgramStateRef 
-ProgramState::invalidateRegions(ArrayRef<const MemRegion *> Regions,
+ProgramState::invalidateRegions(RegionList Regions,
                                 const Expr *E, unsigned Count,
                                 const LocationContext *LCtx,
                                 bool CausedByPointerEscape,
                                 InvalidatedSymbols *IS,
-                                const CallEvent *Call) const {
+                                const CallEvent *Call,
+                                RegionList ConstRegions) const {
   if (!IS) {
     InvalidatedSymbols invalidated;
     return invalidateRegionsImpl(Regions, E, Count, LCtx,
                                  CausedByPointerEscape,
-                                 invalidated, Call);
+                                 invalidated, Call, ConstRegions);
   }
   return invalidateRegionsImpl(Regions, E, Count, LCtx, CausedByPointerEscape,
-                               *IS, Call);
+                               *IS, Call, ConstRegions);
 }
 
 ProgramStateRef 
-ProgramState::invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions,
+ProgramState::invalidateRegionsImpl(RegionList Regions,
                                     const Expr *E, unsigned Count,
                                     const LocationContext *LCtx,
                                     bool CausedByPointerEscape,
                                     InvalidatedSymbols &IS,
-                                    const CallEvent *Call) const {
+                                    const CallEvent *Call,
+                                    RegionList ConstRegions) const {
   ProgramStateManager &Mgr = getStateManager();
   SubEngine* Eng = Mgr.getOwningEngine();
  
@@ -171,7 +175,7 @@ ProgramState::invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions,
     StoreManager::InvalidatedRegions Invalidated;
     const StoreRef &newStore
       = Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS,
-                                        Call, &Invalidated);
+                                        Call, ConstRegions, &Invalidated);
 
     ProgramStateRef newState = makeWithStore(newStore);
 
@@ -184,7 +188,7 @@ ProgramState::invalidateRegionsImpl(ArrayRef<const MemRegion *> Regions,
 
   const StoreRef &newStore =
     Mgr.StoreMgr->invalidateRegions(getStore(), Regions, E, Count, LCtx, IS,
-                                    Call, NULL);
+                                    Call, ConstRegions, NULL);
   return makeWithStore(newStore);
 }