[analyzer] Make sure IDC works for ‘NSContainer value/key is nil’ checks.

Register the nil tracking visitors with the region and refactor trackNullOrUndefValue a bit.

Also adds the cast and paren stripping before checking if the value is an OpaqueValueExpr
or ExprWithCleanups.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178093 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 23 insertions, 14 deletions

diff --git a/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp b/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
index fb43964a89..533a324e75 100644
--- a/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
+++ b/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
@@ -139,6 +139,7 @@ void NilArgChecker::WarnIfNilArg(CheckerContext &C,
 
     BugReport *R = new BugReport(*BT, os.str(), N);
     R->addRange(msg.getArgSourceRange(Arg));
+    bugreporter::trackNullOrUndefValue(N, msg.getArgExpr(Arg), *R);
     C.emitReport(R);
   }
 }
diff --git a/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp b/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
index 737285823f..4539d85cca 100644
--- a/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ b/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -781,31 +781,39 @@ static const MemRegion *getLocationRegionIfReference(const Expr *E,
   return 0;
 }
 
-bool bugreporter::trackNullOrUndefValue(const ExplodedNode *N,
-                                        const Stmt *S,
-                                        BugReport &report, bool IsArg) {
-  if (!S || !N)
-    return false;
-
-  if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(S))
-    S = EWC->getSubExpr();
-  if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(S))
-    S = OVE->getSourceExpr();
-
-  // Peel off the ternary operator.
+static const Expr *peelOffOuterExpr(const Stmt *S,
+                                    const ExplodedNode *N) {
   if (const Expr *Ex = dyn_cast<Expr>(S)) {
     Ex = Ex->IgnoreParenCasts();
+    if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(Ex))
+      return EWC->getSubExpr();
+    if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Ex))
+      return OVE->getSourceExpr();
+
+    // Peel off the ternary operator.
     if (const ConditionalOperator *CO = dyn_cast<ConditionalOperator>(Ex)) {
       ProgramStateRef State = N->getState();
       SVal CondVal = State->getSVal(CO->getCond(), N->getLocationContext());
       if (State->isNull(CondVal).isConstrainedTrue()) {
-        S = CO->getTrueExpr();
+        return CO->getTrueExpr();
       } else {
         assert(State->isNull(CondVal).isConstrainedFalse());
-        S =  CO->getFalseExpr();
+        return CO->getFalseExpr();
       }
     }
   }
+  return 0;
+}
+
+bool bugreporter::trackNullOrUndefValue(const ExplodedNode *N,
+                                        const Stmt *S,
+                                        BugReport &report, bool IsArg) {
+  if (!S || !N)
+    return false;
+
+  if (const Expr *Ex = peelOffOuterExpr(S, N)) {
+    S = Ex;
+  }
 
   const Expr *Inner = 0;
   if (const Expr *Ex = dyn_cast<Expr>(S)) {