Enhance static analyzer diagnostics by introducing a new 'EnhancedBugReporter'

which allows custom checks to register callback creator functions for creating
BugReporterVisitor objects. This allows various checks to include diagnostics
such as 'assuming value is null' with little extra work. Eventually this API
should be refactored to be cleaner and more simple.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79302 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 60 insertions, 12 deletions

diff --git a/include/clang/Analysis/PathSensitive/BugReporter.h b/include/clang/Analysis/PathSensitive/BugReporter.h
index 70eb1da8f2..b99eaee953 100644
--- a/include/clang/Analysis/PathSensitive/BugReporter.h
+++ b/include/clang/Analysis/PathSensitive/BugReporter.h
@@ -244,6 +244,35 @@ public:
   }
 };
   
+class EnhancedBugReport : public RangedBugReport {
+public:
+  typedef void (*VisitorCreator)(BugReporterContext &BRcC, const void *data,
+                                 const ExplodedNode *N);
+  
+private:
+  typedef std::vector<std::pair<VisitorCreator, const void*> > Creators;
+  Creators creators;
+  
+public:
+  EnhancedBugReport(BugType& D, const char* description, ExplodedNode *n)
+   : RangedBugReport(D, description, n) {}
+  
+  EnhancedBugReport(BugType& D, const char *shortDescription,
+                  const char *description, ExplodedNode *n)
+    : RangedBugReport(D, shortDescription, description, n) {}
+  
+  ~EnhancedBugReport() {}
+  
+  void registerInitialVisitors(BugReporterContext& BRC, const ExplodedNode* N) {    
+    for (Creators::iterator I = creators.begin(), E = creators.end(); I!=E; ++I)
+      I->first(BRC, I->second, N);
+  }
+  
+  void addVisitorCreator(VisitorCreator creator, const void *data) {
+    creators.push_back(std::make_pair(creator, data));
+  }
+};
+  
 //===----------------------------------------------------------------------===//
 // BugReporter and friends.
 //===----------------------------------------------------------------------===//
@@ -471,7 +500,7 @@ const Stmt *GetDenomExpr(const ExplodedNode *N);
 const Stmt *GetCalleeExpr(const ExplodedNode *N);
 const Stmt *GetRetValExpr(const ExplodedNode *N);
 
-void registerTrackNullOrUndefValue(BugReporterContext& BRC, const Stmt *S,
+void registerTrackNullOrUndefValue(BugReporterContext& BRC, const void *stmt,
                                    const ExplodedNode* N);
 
 } // end namespace clang::bugreporter
diff --git a/include/clang/Analysis/PathSensitive/Checker.h b/include/clang/Analysis/PathSensitive/Checker.h
index 278f85c160..77373699a2 100644
--- a/include/clang/Analysis/PathSensitive/Checker.h
+++ b/include/clang/Analysis/PathSensitive/Checker.h
@@ -17,6 +17,7 @@
 #include "clang/Analysis/Support/SaveAndRestore.h"
 #include "clang/Analysis/PathSensitive/GRCoreEngine.h"
 #include "clang/Analysis/PathSensitive/GRState.h"
+#include "clang/Analysis/PathSensitive/GRExprEngine.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
 #include "clang/AST/StmtCXX.h"
@@ -67,9 +68,18 @@ public:
   ExplodedNode *&getPredecessor() { return Pred; }
   const GRState *getState() { return B.GetState(Pred); }
   
-  ExplodedNode *generateNode(const Stmt* S,
-                                      const GRState *state) {
-    return B.generateNode(S, state, Pred);
+  ASTContext &getASTContext() {
+    return Eng.getContext();
+  }
+  
+  ExplodedNode *generateNode(const Stmt* S, const GRState *state,
+                             bool markAsSink = false) {    
+    ExplodedNode *node = B.generateNode(S, state, Pred);
+    
+    if (markAsSink && node)
+      node->markAsSink();
+    
+    return node;
   }
   
   void addTransition(ExplodedNode *node) {
diff --git a/lib/Analysis/BugReporter.cpp b/lib/Analysis/BugReporter.cpp
index af4fd384e8..354bafd989 100644
--- a/lib/Analysis/BugReporter.cpp
+++ b/lib/Analysis/BugReporter.cpp
@@ -41,8 +41,8 @@ BugReporterContext::~BugReporterContext() {
 //===----------------------------------------------------------------------===//
 
 static inline const Stmt* GetStmt(ProgramPoint P) {
-  if (const PostStmt* PS = dyn_cast<PostStmt>(&P))
-    return PS->getStmt();
+  if (const StmtPoint* SP = dyn_cast<StmtPoint>(&P))
+    return SP->getStmt();
   else if (const BlockEdge* BE = dyn_cast<BlockEdge>(&P))
     return BE->getSrc()->getTerminator();
   
diff --git a/lib/Analysis/BugReporterVisitors.cpp b/lib/Analysis/BugReporterVisitors.cpp
index 77501bbba2..604542b2c1 100644
--- a/lib/Analysis/BugReporterVisitors.cpp
+++ b/lib/Analysis/BugReporterVisitors.cpp
@@ -189,6 +189,10 @@ public:
       else if (V.isUndef()) {
         os << "Uninitialized value stored to ";
       }
+      else if (isa<nonloc::ConcreteInt>(V)) {
+        os << "The value " << cast<nonloc::ConcreteInt>(V).getValue()
+           << " is assigned to ";
+      }
       else
         return NULL;
       
@@ -296,9 +300,11 @@ static void registerTrackConstraint(BugReporterContext& BRC, SVal Constraint,
 }
 
 void clang::bugreporter::registerTrackNullOrUndefValue(BugReporterContext& BRC,
-                                                       const Stmt *S,
+                                                       const void *data,
                                                        const ExplodedNode* N) {
   
+  const Stmt *S = static_cast<const Stmt*>(data);
+  
   if (!S)
     return;
   
diff --git a/lib/Analysis/GRExprEngineInternalChecks.cpp b/lib/Analysis/GRExprEngineInternalChecks.cpp
index 3c316eb3e9..d22f276a55 100644
--- a/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -583,7 +583,7 @@ public:
       if (stateNull && !stateNotNull) {
         // Generate an error node.  Check for a null node in case
         // we cache out.
-        if (ExplodedNode *errorNode = C.generateNode(CE, stateNull)) {
+        if (ExplodedNode *errorNode = C.generateNode(CE, stateNull, true)) {
                   
           // Lazily allocate the BugType object if it hasn't already been
           // created. Ownership is transferred to the BugReporter object once
@@ -592,12 +592,15 @@ public:
             BT = new BugType("Argument with 'nonnull' attribute passed null",
                              "API");
           
-          RangedBugReport *R =
-            new RangedBugReport(*BT, "Null pointer passed as an argument to a "
-                                "'nonnull' parameter", errorNode);
+          EnhancedBugReport *R =
+            new EnhancedBugReport(*BT,
+                                  "Null pointer passed as an argument to a "
+                                  "'nonnull' parameter", errorNode);
           
           // Highlight the range of the argument that was null.
-          R->addRange((*I)->getSourceRange());
+          const Expr *arg = *I;
+          R->addRange(arg->getSourceRange());
+          R->addVisitorCreator(registerTrackNullOrUndefValue, arg);
           
           // Emit the bug report.
           C.EmitReport(R);