Move all logic for the null dereference checker from GRExprEngineInternalChecks.cpp to a separate .cpp file.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@85595 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CMakeLists.txt b/lib/Analysis/CMakeLists.txt
index 89c1783..d3bf42b 100644
--- a/lib/Analysis/CMakeLists.txt
+++ b/lib/Analysis/CMakeLists.txt
@@ -28,6 +28,7 @@
   GRState.cpp
   LiveVariables.cpp
   MemRegion.cpp
+  NullDerefChecker.cpp
   PathDiagnostic.cpp
   RangeConstraintManager.cpp
   RegionStore.cpp
diff --git a/lib/Analysis/GRExprEngineInternalChecks.cpp b/lib/Analysis/GRExprEngineInternalChecks.cpp
index 526bc93..81b465e 100644
--- a/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -66,11 +66,6 @@
   for (; I != E; ++I) BR.EmitReport(new BuiltinBugReport(*this, desc.c_str(),
                                                          GetNode(I)));
 }
-void NullDeref::registerInitialVisitors(BugReporterContext& BRC,
-                                        const ExplodedNode* N,
-                                        BuiltinBugReport *R) {
-  registerTrackNullOrUndefValue(BRC, bugreporter::GetDerefExpr(N), N);
-}
 
 class VISIBILITY_HIDDEN NilReceiverStructRet : public BuiltinBug {
 public:
@@ -794,48 +789,8 @@
   return Pred;
 }
 
-ExplodedNode *NullDerefChecker::CheckLocation(const Stmt *S, ExplodedNode *Pred,
-                                        const GRState *state, SVal V,
-                                        GRExprEngine &Eng) {
-  Loc *LV = dyn_cast<Loc>(&V);
-
-  // If the value is not a location, don't touch the node.
-  if (!LV)
-    return Pred;
-
-  const GRState *NotNullState = state->Assume(*LV, true);
-  const GRState *NullState = state->Assume(*LV, false);
-
-  GRStmtNodeBuilder &Builder = Eng.getBuilder();
-  BugReporter &BR = Eng.getBugReporter();
-
-  // The explicit NULL case.
-  if (NullState) {
-    // Use the GDM to mark in the state what lval was null.
-    const SVal *PersistentLV = Eng.getBasicVals().getPersistentSVal(*LV);
-    NullState = NullState->set<GRState::NullDerefTag>(PersistentLV);
-
-    ExplodedNode *N = Builder.generateNode(S, NullState, Pred,
-                                         ProgramPoint::PostNullCheckFailedKind);
-    if (N) {
-      N->markAsSink();
-      
-      if (!NotNullState) { // Explicit null case.
-        if (!BT)
-          BT = new NullDeref();
-        BR.EmitReport(new BuiltinBugReport(*BT,BT->getDescription().c_str(),N));
-        return 0;
-      } else // Implicit null case.
-        ImplicitNullDerefNodes.push_back(N);
-    }
-  }
-
-  if (!NotNullState)
-    return 0;
-  return Builder.generateNode(S, NotNullState, Pred, 
-                              ProgramPoint::PostLocationChecksSucceedKind);
-}
 } // end clang namespace
+
 //===----------------------------------------------------------------------===//
 // Check registration.
 //===----------------------------------------------------------------------===//
diff --git a/lib/Analysis/NullDerefChecker.cpp b/lib/Analysis/NullDerefChecker.cpp
new file mode 100644
index 0000000..2a899d2
--- /dev/null
+++ b/lib/Analysis/NullDerefChecker.cpp
@@ -0,0 +1,76 @@
+//== NullDerefChecker.cpp - Null dereference checker ------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines NullDerefChecker, a builtin check in GRExprEngine that performs
+// checks for null pointers at loads and stores.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/NullDerefChecker.h"
+#include "clang/Analysis/PathSensitive/GRExprEngine.h"
+#include "clang/Analysis/PathSensitive/BugReporter.h"
+
+using namespace clang;
+
+void *NullDerefChecker::getTag() {
+  static int x = 0;
+  return &x;
+}
+
+ExplodedNode *NullDerefChecker::CheckLocation(const Stmt *S, ExplodedNode *Pred,
+                                              const GRState *state, SVal V,
+                                              GRExprEngine &Eng) {
+  Loc *LV = dyn_cast<Loc>(&V);
+  
+    // If the value is not a location, don't touch the node.
+  if (!LV)
+    return Pred;
+  
+  const GRState *NotNullState = state->Assume(*LV, true);
+  const GRState *NullState = state->Assume(*LV, false);
+  
+  GRStmtNodeBuilder &Builder = Eng.getBuilder();
+  BugReporter &BR = Eng.getBugReporter();
+  
+    // The explicit NULL case.
+  if (NullState) {
+      // Use the GDM to mark in the state what lval was null.
+    const SVal *PersistentLV = Eng.getBasicVals().getPersistentSVal(*LV);
+    NullState = NullState->set<GRState::NullDerefTag>(PersistentLV);
+    
+    ExplodedNode *N = Builder.generateNode(S, NullState, Pred,
+                                           ProgramPoint::PostNullCheckFailedKind);
+    if (N) {
+      N->markAsSink();
+      
+      if (!NotNullState) { // Explicit null case.
+        if (!BT)
+          BT = new BuiltinBug(NULL, "Null dereference",
+                              "Dereference of null pointer");
+
+        EnhancedBugReport *R =
+          new EnhancedBugReport(*BT, BT->getDescription().c_str(), N);
+        
+        R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
+                             bugreporter::GetDerefExpr(N));
+        
+        BR.EmitReport(R);
+        
+        return 0;
+      } else // Implicit null case.
+        ImplicitNullDerefNodes.push_back(N);
+    }
+  }
+  
+  if (!NotNullState)
+    return 0;
+
+  return Builder.generateNode(S, NotNullState, Pred, 
+                              ProgramPoint::PostLocationChecksSucceedKind);
+}