From 4aa5e10fcc0b1546ce33c1b60f9cfd6db3e42f81 Mon Sep 17 00:00:00 2001
From: Peter Szecsi <szepet95@gmail.com>
Date: Mon, 21 Aug 2017 16:10:19 +0000
Subject: [StaticAnalyzer] Handle LoopExit CFGElement in the analyzer

This patch adds handling of the LoopExit CFGElements to the StaticAnalyzer.
This is reached by introducing a new ProgramPoint.
Tests will be added in a following commit.

Differential Revision: https://reviews.llvm.org/D35670

llvm-svn: 311344
---
 clang/lib/StaticAnalyzer/Core/CoreEngine.cpp |  6 ++++--
 clang/lib/StaticAnalyzer/Core/ExprEngine.cpp | 25 ++++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 3 deletions(-)

(limited to 'clang/lib/StaticAnalyzer')

diff --git a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
index 4e2866c56f0..e2e9ddf5048 100644
--- a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
@@ -274,7 +274,8 @@ void CoreEngine::dispatchWorkItem(ExplodedNode* Pred, ProgramPoint Loc,
       assert(Loc.getAs<PostStmt>() ||
              Loc.getAs<PostInitializer>() ||
              Loc.getAs<PostImplicitCall>() ||
-             Loc.getAs<CallExitEnd>());
+             Loc.getAs<CallExitEnd>() ||
+             Loc.getAs<LoopExit>());
       HandlePostStmt(WU.getBlock(), WU.getIndex(), Pred);
       break;
   }
@@ -566,7 +567,8 @@ void CoreEngine::enqueueStmtNode(ExplodedNode *N,
 
   // Do not create extra nodes. Move to the next CFG element.
   if (N->getLocation().getAs<PostInitializer>() ||
-      N->getLocation().getAs<PostImplicitCall>()) {
+      N->getLocation().getAs<PostImplicitCall>()||
+      N->getLocation().getAs<LoopExit>()) {
     WList->enqueue(N, Block, Idx+1);
     return;
   }
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 547978ad43c..43b067b6d2b 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -364,8 +364,10 @@ void ExprEngine::processCFGElement(const CFGElement E, ExplodedNode *Pred,
     case CFGElement::TemporaryDtor:
       ProcessImplicitDtor(E.castAs<CFGImplicitDtor>(), Pred);
       return;
-    case CFGElement::LifetimeEnds:
     case CFGElement::LoopExit:
+      ProcessLoopExit(E.castAs<CFGLoopExit>().getLoopStmt(), Pred);
+      return;
+    case CFGElement::LifetimeEnds:
       return;
   }
 }
@@ -510,6 +512,21 @@ void ExprEngine::ProcessStmt(const CFGStmt S,
   Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
 }
 
+void ExprEngine::ProcessLoopExit(const Stmt* S, ExplodedNode *Pred) {
+  PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),
+                                S->getLocStart(),
+                                "Error evaluating end of the loop");
+  ExplodedNodeSet Dst;
+  Dst.Add(Pred);
+  NodeBuilder Bldr(Pred, Dst, *currBldrCtx);
+
+  LoopExit PP(S, Pred->getLocationContext());
+  Bldr.generateNode(PP, Pred->getState(), Pred);
+
+  // Enqueue the new nodes onto the work list.
+  Engine.enqueue(Dst, currBldrCtx->getBlock(), currStmtIdx);
+}
+
 void ExprEngine::ProcessInitializer(const CFGInitializer Init,
                                     ExplodedNode *Pred) {
   const CXXCtorInitializer *BMI = Init.getInitializer();
@@ -2689,6 +2706,12 @@ struct DOTGraphTraits<ExplodedNode*> :
         Out << "Epsilon Point";
         break;
 
+      case ProgramPoint::LoopExitKind: {
+        LoopExit LE = Loc.castAs<LoopExit>();
+        Out << "LoopExit: " << LE.getLoopStmt()->getStmtClassName();
+        break;
+      }
+
       case ProgramPoint::PreImplicitCallKind: {
         ImplicitCallPoint PC = Loc.castAs<ImplicitCallPoint>();
         Out << "PreCall: ";
-- 
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