[analyzer] fix regression in analyzer of NOT actually aborting on Stmts it doesn't understand. We registered

as aborted, but didn't treat such cases as sinks in the ExplodedGraph.

Along the way, add basic support for CXXCatchStmt, expanding the set of code we actually analyze (hopefully correctly).

Fixes: <rdar://problem/10892489>
llvm-svn: 152468

9 files changed, 140 insertions, 28 deletions

diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
index 5714a7edde0..e7d6cd6d2c9 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
@@ -27,6 +27,7 @@
 namespace clang {
 
 class AnalysisDeclContextManager;
+class CXXCatchStmt;
 class CXXConstructExpr;
 class CXXDeleteExpr;
 class CXXNewExpr;
@@ -339,6 +340,9 @@ public:
   void VisitIncrementDecrementOperator(const UnaryOperator* U,
                                        ExplodedNode *Pred,
                                        ExplodedNodeSet &Dst);
+  
+  void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
+                         ExplodedNodeSet &Dst);
 
   void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 
                         ExplodedNodeSet & Dst);
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
index 6d1da6e445d..4ad36f9dbb1 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
@@ -145,16 +145,16 @@ public:
   // Forwarding methods to SymbolManager.
 
   const SymbolConjured* getConjuredSymbol(const Stmt *stmt,
-					  const LocationContext *LCtx,
-					  QualType type,
+                                          const LocationContext *LCtx,
+                                          QualType type,
                                           unsigned visitCount,
                                           const void *symbolTag = 0) {
     return SymMgr.getConjuredSymbol(stmt, LCtx, type, visitCount, symbolTag);
   }
 
   const SymbolConjured* getConjuredSymbol(const Expr *expr,
-					  const LocationContext *LCtx,
-					  unsigned visitCount,
+                                          const LocationContext *LCtx,
+                                          unsigned visitCount,
                                           const void *symbolTag = 0) {
     return SymMgr.getConjuredSymbol(expr, LCtx, visitCount, symbolTag);
   }
@@ -173,13 +173,18 @@ public:
   /// conjured symbols should be used sparingly.
   DefinedOrUnknownSVal getConjuredSymbolVal(const void *symbolTag,
                                             const Expr *expr,
-					    const LocationContext *LCtx,
-					    unsigned count);
+                                            const LocationContext *LCtx,
+                                            unsigned count);
   DefinedOrUnknownSVal getConjuredSymbolVal(const void *symbolTag,
                                             const Expr *expr,
-					    const LocationContext *LCtx,
-					    QualType type,
+                                            const LocationContext *LCtx,
+                                            QualType type,
                                             unsigned count);
+  
+  DefinedOrUnknownSVal getConjuredSymbolVal(const Stmt *stmt,
+                                            const LocationContext *LCtx,
+                                            QualType type,
+                                            unsigned visitCount);
 
   DefinedOrUnknownSVal getDerivedRegionValueSymbolVal(
       SymbolRef parentSymbol, const TypedValueRegion *region);
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index f50cc31e9d8..e19381dcd81 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -2620,9 +2620,18 @@ CFGBlock *CFGBuilder::VisitCXXCatchStmt(CXXCatchStmt *CS) {
   CFGBlock *CatchBlock = Block;
   if (!CatchBlock)
     CatchBlock = createBlock();
-
+  
+  // CXXCatchStmt is more than just a label.  They have semantic meaning
+  // as well, as they implicitly "initialize" the catch variable.  Add
+  // it to the CFG as a CFGElement so that the control-flow of these
+  // semantics gets captured.
+  appendStmt(CatchBlock, CS);
+
+  // Also add the CXXCatchStmt as a label, to mirror handling of regular
+  // labels.
   CatchBlock->setLabel(CS);
 
+  // Bail out if the CFG is bad.
   if (badCFG)
     return 0;
 
diff --git a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
index a350757a0f1..326ecbfbfbc 100644
--- a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
@@ -335,6 +335,19 @@ void CoreEngine::HandleBlockExit(const CFGBlock * B, ExplodedNode *Pred) {
         HandleBranch(cast<ChooseExpr>(Term)->getCond(), Term, B, Pred);
         return;
 
+      case Stmt::CXXTryStmtClass: {
+        // Generate a node for each of the successors.
+        // Our logic for EH analysis can certainly be improved.
+        for (CFGBlock::const_succ_iterator it = B->succ_begin(),
+             et = B->succ_end(); it != et; ++it) {
+          if (const CFGBlock *succ = *it) {
+            generateNode(BlockEdge(B, succ, Pred->getLocationContext()),
+                         Pred->State, Pred);
+          }
+        }
+        return;
+      }
+        
       case Stmt::DoStmtClass:
         HandleBranch(cast<DoStmt>(Term)->getCond(), Term, B, Pred);
         return;
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 63027175cad..d9f98394441 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -23,6 +23,7 @@
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/ParentMap.h"
 #include "clang/AST/StmtObjC.h"
+#include "clang/AST/StmtCXX.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/SourceManager.h"
@@ -481,10 +482,8 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
   switch (S->getStmtClass()) {
     // C++ and ARC stuff we don't support yet.
     case Expr::ObjCIndirectCopyRestoreExprClass:
-    case Stmt::CXXCatchStmtClass:
     case Stmt::CXXDependentScopeMemberExprClass:
     case Stmt::CXXPseudoDestructorExprClass:
-    case Stmt::CXXThrowExprClass:
     case Stmt::CXXTryStmtClass:
     case Stmt::CXXTypeidExprClass:
     case Stmt::CXXUuidofExprClass:
@@ -505,7 +504,8 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::SEHExceptStmtClass:
     case Stmt::LambdaExprClass:
     case Stmt::SEHFinallyStmtClass: {
-      const ExplodedNode *node = Bldr.generateNode(S, Pred, Pred->getState());
+      const ExplodedNode *node = Bldr.generateNode(S, Pred, Pred->getState(),
+                                                   /* sink */ true);
       Engine.addAbortedBlock(node, currentBuilderContext->getBlock());
       break;
     }
@@ -600,8 +600,13 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::OpaqueValueExprClass:
     case Stmt::AsTypeExprClass:
     case Stmt::AtomicExprClass:
-        // Fall through.
+      // Fall through.
 
+    // Currently all handling of 'throw' just falls to the CFG.  We
+    // can consider doing more if necessary.
+    case Stmt::CXXThrowExprClass:
+      // Fall through.
+      
     // Cases we intentionally don't evaluate, since they don't need
     // to be explicitly evaluated.
     case Stmt::AddrLabelExprClass:
@@ -720,6 +725,13 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
       Bldr.addNodes(Dst);
       break;
     }
+    
+    case Stmt::CXXCatchStmtClass: {
+      Bldr.takeNodes(Pred);
+      VisitCXXCatchStmt(cast<CXXCatchStmt>(S), Pred, Dst);
+      Bldr.addNodes(Dst);
+      break;
+    }
 
     case Stmt::CXXTemporaryObjectExprClass:
     case Stmt::CXXConstructExprClass: {
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
index fa0245145cb..72ab48ec008 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
@@ -16,6 +16,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h"
 #include "clang/AST/DeclCXX.h"
+#include "clang/AST/StmtCXX.h"
 
 using namespace clang;
 using namespace ento;
@@ -340,6 +341,20 @@ void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE,
   Bldr.generateNode(CDE, Pred, state);
 }
 
+void ExprEngine::VisitCXXCatchStmt(const CXXCatchStmt *CS,
+                                   ExplodedNode *Pred,
+                                   ExplodedNodeSet &Dst) {
+  const VarDecl *VD = CS->getExceptionDecl();
+  const LocationContext *LCtx = Pred->getLocationContext();
+  SVal V = svalBuilder.getConjuredSymbolVal(CS, LCtx, VD->getType(),
+                                 currentBuilderContext->getCurrentBlockCount());
+  ProgramStateRef state = Pred->getState();
+  state = state->bindLoc(state->getLValue(VD, LCtx), V);
+
+  StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
+  Bldr.generateNode(CS, Pred, state);
+}
+
 void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
                                     ExplodedNodeSet &Dst) {
   StmtNodeBuilder Bldr(Pred, Dst, *currentBuilderContext);
diff --git a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
index 6f5eb375f48..9e97f5e7d12 100644
--- a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -106,19 +106,21 @@ SValBuilder::getRegionValueSymbolVal(const TypedValueRegion* region) {
   return nonloc::SymbolVal(sym);
 }
 
-DefinedOrUnknownSVal SValBuilder::getConjuredSymbolVal(const void *symbolTag,
-                                                       const Expr *expr,
-						       const LocationContext *LCtx,
-                                                       unsigned count) {
+DefinedOrUnknownSVal
+SValBuilder::getConjuredSymbolVal(const void *symbolTag,
+                                  const Expr *expr,
+                                  const LocationContext *LCtx,
+                                  unsigned count) {
   QualType T = expr->getType();
   return getConjuredSymbolVal(symbolTag, expr, LCtx, T, count);
 }
 
-DefinedOrUnknownSVal SValBuilder::getConjuredSymbolVal(const void *symbolTag,
-                                                       const Expr *expr,
-						       const LocationContext *LCtx,
-                                                       QualType type,
-                                                       unsigned count) {
+DefinedOrUnknownSVal
+SValBuilder::getConjuredSymbolVal(const void *symbolTag,
+                                  const Expr *expr,
+                                  const LocationContext *LCtx,
+                                  QualType type,
+                                  unsigned count) {
   if (!SymbolManager::canSymbolicate(type))
     return UnknownVal();
 
@@ -130,6 +132,23 @@ DefinedOrUnknownSVal SValBuilder::getConjuredSymbolVal(const void *symbolTag,
   return nonloc::SymbolVal(sym);
 }
 
+
+DefinedOrUnknownSVal
+SValBuilder::getConjuredSymbolVal(const Stmt *stmt,
+                                  const LocationContext *LCtx,
+                                  QualType type,
+                                  unsigned visitCount) {
+  if (!SymbolManager::canSymbolicate(type))
+    return UnknownVal();
+
+  SymbolRef sym = SymMgr.getConjuredSymbol(stmt, LCtx, type, visitCount);
+  
+  if (Loc::isLocType(type))
+    return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));
+  
+  return nonloc::SymbolVal(sym);
+}
+
 DefinedSVal SValBuilder::getMetadataSymbolVal(const void *symbolTag,
                                               const MemRegion *region,
                                               const Expr *expr, QualType type,
diff --git a/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp b/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
index 2402e0072e5..20804dbfaf8 100644
--- a/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
+++ b/clang/test/Analysis/auto-obj-dtors-cfg-output.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-checker=debug.DumpCFG -cfg-add-implicit-dtors %s 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-checker=debug.DumpCFG -cfg-add-implicit-dtors %s > %t 2>&1
+// RUN: FileCheck --input-file=%t %s
 // XPASS: *
 
 class A {
@@ -323,6 +324,15 @@ void test_catch_copy() {
 // CHECK:    Succs (2): B3 B2
 // CHECK:  [B0 (EXIT)]
 // CHECK:    Preds (1): B1
+// CHECK:  [B2 (ENTRY)]
+// CHECK:    Succs (1): B1
+// CHECK:  [B1]
+// CHECK:    1: 1
+// CHECK:    2: return [B1.1];
+// CHECK:    Preds (1): B2
+// CHECK:    Succs (1): B0
+// CHECK:  [B0 (EXIT)]
+// CHECK:    Preds (1): B1
 // CHECK:  [B9 (ENTRY)]
 // CHECK:    Succs (1): B8
 // CHECK:  [B1]
@@ -824,6 +834,8 @@ void test_catch_copy() {
 // CHECK:    Succs (2): B2 B0
 // CHECK:  [B2]
 // CHECK:   catch (const A &e):
+// CHECK:    1: catch (const A &e) {
+// CHECK: }
 // CHECK:    Preds (1): B1
 // CHECK:    Succs (1): B0
 // CHECK:  [B0 (EXIT)]
@@ -835,10 +847,10 @@ void test_catch_copy() {
 // CHECK:    Succs (2): B2 B0
 // CHECK:  [B2]
 // CHECK:   catch (A e):
-// CHECK:    1: .~A() (Implicit destructor)
+// CHECK:    1: catch (A e) {
+// CHECK: }
+// CHECK:    2: [B2.1].~A() (Implicit destructor)
 // CHECK:    Preds (1): B1
 // CHECK:    Succs (1): B0
 // CHECK:  [B0 (EXIT)]
 // CHECK:    Preds (3): B2 B1 B3
-
-
diff --git a/clang/test/Analysis/misc-ps-region-store.cpp b/clang/test/Analysis/misc-ps-region-store.cpp
index b00a8f2d6ee..9fa0b860f2a 100644
--- a/clang/test/Analysis/misc-ps-region-store.cpp
+++ b/clang/test/Analysis/misc-ps-region-store.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -triple i386-apple-darwin9 -analyze -analyzer-checker=core,experimental.core -analyzer-store=region -verify -fblocks -analyzer-opt-analyze-nested-blocks %s
-// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -analyze -analyzer-checker=core,experimental.core -analyzer-store=region -verify -fblocks   -analyzer-opt-analyze-nested-blocks %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -analyze -analyzer-checker=core,experimental.core -analyzer-store=region -verify -fblocks -analyzer-opt-analyze-nested-blocks %s -fexceptions -fcxx-exceptions
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 -analyze -analyzer-checker=core,experimental.core -analyzer-store=region -verify -fblocks   -analyzer-opt-analyze-nested-blocks %s -fexceptions -fcxx-exceptions
 
 // Test basic handling of references.
 char &test1_aux();
@@ -506,3 +506,26 @@ void TestNullThis::test() {
   field = 2; // no-warning
 }
 
+// Test handling of 'catch' exception variables, and not warning
+// about uninitialized values.
+enum MyEnum { MyEnumValue };
+MyEnum rdar10892489() {
+  try {
+      throw MyEnumValue;
+  } catch (MyEnum e) {
+      return e; // no-warning
+  }
+  return MyEnumValue;
+}
+
+MyEnum rdar10892489_positive() {
+  try {
+    throw MyEnumValue;
+  } catch (MyEnum e) {
+    int *p = 0;
+    *p = 0xDEADBEEF; // expected-warning {{null}}
+    return e;
+  }
+  return MyEnumValue;
+}
+