Improved error reporting in IdempotentOperationChecker

- SourceRange highlighting is only given for the relevant side of the operator (assignments give both)
- Added PostVisitBinaryOperator hook to retrieve the ExplodedNode for an operator
- Added a BugReporterVisitor to display the last store to every VarDecl in a Stmt
- Changed bug reporting to use the new BugReporterVisitor

llvm-svn: 112839

1 files changed, 37 insertions, 0 deletions

diff --git a/clang/lib/Checker/BugReporterVisitors.cpp b/clang/lib/Checker/BugReporterVisitors.cpp
index cddc86ee9dc..91cf349107c 100644
--- a/clang/lib/Checker/BugReporterVisitors.cpp
+++ b/clang/lib/Checker/BugReporterVisitors.cpp
@@ -419,3 +419,40 @@ public:
 void clang::bugreporter::registerNilReceiverVisitor(BugReporterContext &BRC) {
   BRC.addVisitor(new NilReceiverVisitor());
 }
+
+// Registers every VarDecl inside a Stmt with a last store vistor.
+void clang::bugreporter::registerVarDeclsLastStore(BugReporterContext &BRC,
+                                                   const void *stmt,
+                                                   const ExplodedNode *N) {
+  const Stmt *S = static_cast<const Stmt *>(stmt);
+
+  std::deque<const Stmt *> WorkList;
+
+  WorkList.push_back(S);
+
+  while (!WorkList.empty()) {
+    const Stmt *Head = WorkList.front();
+    WorkList.pop_front();
+
+    GRStateManager &StateMgr = BRC.getStateManager();
+    const GRState *state = N->getState();
+
+    if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(Head)) {
+      if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
+        const VarRegion *R =
+        StateMgr.getRegionManager().getVarRegion(VD, N->getLocationContext());
+
+        // What did we load?
+        SVal V = state->getSVal(S);
+
+        if (isa<loc::ConcreteInt>(V) || isa<nonloc::ConcreteInt>(V)) {
+          ::registerFindLastStore(BRC, R, V);
+        }
+      }
+    }
+
+    for (Stmt::const_child_iterator I = Head->child_begin();
+        I != Head->child_end(); ++I)
+      WorkList.push_back(*I);
+  }
+}