[analyzer] StackFrameContext: Add NodeBuilderContext::blockCount() to its profile

Summary:
It allows discriminating between stack frames of the same call that is
called multiple times in a loop.

Thanks to Artem Dergachev for the great idea!

Reviewed By: NoQ

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65587

llvm-svn: 367608

4 files changed, 23 insertions, 20 deletions

diff --git a/clang/lib/Analysis/AnalysisDeclContext.cpp b/clang/lib/Analysis/AnalysisDeclContext.cpp
index b6a429ff49e..5ecb3ff470a 100644
--- a/clang/lib/Analysis/AnalysisDeclContext.cpp
+++ b/clang/lib/Analysis/AnalysisDeclContext.cpp
@@ -310,8 +310,10 @@ BodyFarm &AnalysisDeclContextManager::getBodyFarm() { return FunctionBodyFarm; }
 
 const StackFrameContext *
 AnalysisDeclContext::getStackFrame(LocationContext const *Parent, const Stmt *S,
-                               const CFGBlock *Blk, unsigned Idx) {
-  return getLocationContextManager().getStackFrame(this, Parent, S, Blk, Idx);
+                                   const CFGBlock *Blk, unsigned BlockCount,
+                                   unsigned Idx) {
+  return getLocationContextManager().getStackFrame(this, Parent, S, Blk,
+                                                   BlockCount, Idx);
 }
 
 const BlockInvocationContext *
@@ -359,7 +361,8 @@ void LocationContext::ProfileCommon(llvm::FoldingSetNodeID &ID,
 }
 
 void StackFrameContext::Profile(llvm::FoldingSetNodeID &ID) {
-  Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block, Index);
+  Profile(ID, getAnalysisDeclContext(), getParent(), CallSite, Block,
+          BlockCount, Index);
 }
 
 void ScopeContext::Profile(llvm::FoldingSetNodeID &ID) {
@@ -392,18 +395,16 @@ LocationContextManager::getLocationContext(AnalysisDeclContext *ctx,
   return L;
 }
 
-const StackFrameContext*
-LocationContextManager::getStackFrame(AnalysisDeclContext *ctx,
-                                      const LocationContext *parent,
-                                      const Stmt *s,
-                                      const CFGBlock *blk, unsigned idx) {
+const StackFrameContext *LocationContextManager::getStackFrame(
+    AnalysisDeclContext *ctx, const LocationContext *parent, const Stmt *s,
+    const CFGBlock *blk, unsigned blockCount, unsigned idx) {
   llvm::FoldingSetNodeID ID;
-  StackFrameContext::Profile(ID, ctx, parent, s, blk, idx);
+  StackFrameContext::Profile(ID, ctx, parent, s, blk, blockCount, idx);
   void *InsertPos;
   auto *L =
    cast_or_null<StackFrameContext>(Contexts.FindNodeOrInsertPos(ID, InsertPos));
   if (!L) {
-    L = new StackFrameContext(ctx, parent, s, blk, idx, ++NewID);
+    L = new StackFrameContext(ctx, parent, s, blk, blockCount, idx, ++NewID);
     Contexts.InsertNode(L, InsertPos);
   }
   return L;
diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index a5f7500e630..b6f551d4920 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -191,7 +191,8 @@ AnalysisDeclContext *CallEvent::getCalleeAnalysisDeclContext() const {
   return ADC;
 }
 
-const StackFrameContext *CallEvent::getCalleeStackFrame() const {
+const StackFrameContext *
+CallEvent::getCalleeStackFrame(unsigned BlockCount) const {
   AnalysisDeclContext *ADC = getCalleeAnalysisDeclContext();
   if (!ADC)
     return nullptr;
@@ -217,11 +218,12 @@ const StackFrameContext *CallEvent::getCalleeStackFrame() const {
         break;
   assert(Idx < Sz);
 
-  return ADC->getManager()->getStackFrame(ADC, LCtx, E, B, Idx);
+  return ADC->getManager()->getStackFrame(ADC, LCtx, E, B, BlockCount, Idx);
 }
 
-const VarRegion *CallEvent::getParameterLocation(unsigned Index) const {
-  const StackFrameContext *SFC = getCalleeStackFrame();
+const VarRegion *CallEvent::getParameterLocation(unsigned Index,
+                                                 unsigned BlockCount) const {
+  const StackFrameContext *SFC = getCalleeStackFrame(BlockCount);
   // We cannot construct a VarRegion without a stack frame.
   if (!SFC)
     return nullptr;
@@ -322,7 +324,7 @@ ProgramStateRef CallEvent::invalidateRegions(unsigned BlockCount,
     if (getKind() != CE_CXXAllocator)
       if (isArgumentConstructedDirectly(Idx))
         if (auto AdjIdx = getAdjustedParameterIndex(Idx))
-          if (const VarRegion *VR = getParameterLocation(*AdjIdx))
+          if (const VarRegion *VR = getParameterLocation(*AdjIdx, BlockCount))
             ValuesToInvalidate.push_back(loc::MemRegionVal(VR));
   }
 
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
index 1cbd09ea579..10c8cb1a9ee 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
@@ -323,7 +323,8 @@ std::pair<ProgramStateRef, SVal> ExprEngine::prepareForObjectConstruction(
       CallEventManager &CEMgr = getStateManager().getCallEventManager();
       SVal V = UnknownVal();
       auto getArgLoc = [&](CallEventRef<> Caller) -> Optional<SVal> {
-        const LocationContext *FutureSFC = Caller->getCalleeStackFrame();
+        const LocationContext *FutureSFC =
+            Caller->getCalleeStackFrame(currBldrCtx->blockCount());
         // Return early if we are unable to reliably foresee
         // the future stack frame.
         if (!FutureSFC)
@@ -342,7 +343,7 @@ std::pair<ProgramStateRef, SVal> ExprEngine::prepareForObjectConstruction(
         // because this-argument is implemented as a normal argument in
         // operator call expressions but not in operator declarations.
         const VarRegion *VR = Caller->getParameterLocation(
-            *Caller->getAdjustedParameterIndex(Idx));
+            *Caller->getAdjustedParameterIndex(Idx), currBldrCtx->blockCount());
         if (!VR)
           return None;
 
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
index b935e3afe34..345d4d817de 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
@@ -451,9 +451,8 @@ bool ExprEngine::inlineCall(const CallEvent &Call, const Decl *D,
   // Construct a new stack frame for the callee.
   AnalysisDeclContext *CalleeADC = AMgr.getAnalysisDeclContext(D);
   const StackFrameContext *CalleeSFC =
-    CalleeADC->getStackFrame(ParentOfCallee, CallE,
-                             currBldrCtx->getBlock(),
-                             currStmtIdx);
+      CalleeADC->getStackFrame(ParentOfCallee, CallE, currBldrCtx->getBlock(),
+                               currBldrCtx->blockCount(), currStmtIdx);
 
   CallEnter Loc(CallE, CalleeSFC, CurLC);