[analyzer] MisusedMovedObjectChecker: More precise warning message

Added new enum in order to differentiate the warning messages on "misusing" into
3 categories: function calls, moving an object, copying an object. (At the
moment the checker gives the same message in case of copying and moving.)

Additional test cases added as well.

Differential Revision: https://reviews.llvm.org/D38674

llvm-svn: 316852

1 files changed, 23 insertions, 9 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/MisusedMovedObjectChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MisusedMovedObjectChecker.cpp
index 9d405cd39c5..497978f0781 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MisusedMovedObjectChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MisusedMovedObjectChecker.cpp
@@ -60,6 +60,7 @@ public:
                   const char *NL, const char *Sep) const override;
 
 private:
+  enum MisuseKind {MK_FunCall, MK_Copy, MK_Move};
   class MovedBugVisitor : public BugReporterVisitorImpl<MovedBugVisitor> {
   public:
     MovedBugVisitor(const MemRegion *R) : Region(R), Found(false) {}
@@ -83,7 +84,7 @@ private:
 
   mutable std::unique_ptr<BugType> BT;
   ExplodedNode *reportBug(const MemRegion *Region, const CallEvent &Call,
-                          CheckerContext &C, bool isCopy) const;
+                          CheckerContext &C, MisuseKind MK) const;
   bool isInMoveSafeContext(const LocationContext *LC) const;
   bool isStateResetMethod(const CXXMethodDecl *MethodDec) const;
   bool isMoveSafeMethod(const CXXMethodDecl *MethodDec) const;
@@ -179,7 +180,7 @@ const ExplodedNode *MisusedMovedObjectChecker::getMoveLocation(
 ExplodedNode *MisusedMovedObjectChecker::reportBug(const MemRegion *Region,
                                                    const CallEvent &Call,
                                                    CheckerContext &C,
-                                                   bool isCopy = false) const {
+                                                   MisuseKind MK) const {
   if (ExplodedNode *N = C.generateNonFatalErrorNode()) {
     if (!BT)
       BT.reset(new BugType(this, "Usage of a 'moved-from' object",
@@ -195,10 +196,17 @@ ExplodedNode *MisusedMovedObjectChecker::reportBug(const MemRegion *Region,
 
     // Creating the error message.
     std::string ErrorMessage;
-    if (isCopy)
-      ErrorMessage = "Copying a 'moved-from' object";
-    else
-      ErrorMessage = "Method call on a 'moved-from' object";
+    switch(MK) {
+      case MK_FunCall:
+        ErrorMessage = "Method call on a 'moved-from' object";
+        break;
+      case MK_Copy:
+        ErrorMessage = "Copying a 'moved-from' object";
+        break;
+      case MK_Move:
+        ErrorMessage = "Moving a 'moved-from' object";
+        break;
+    }
     if (const auto DecReg = Region->getAs<DeclRegion>()) {
       const auto *RegionDecl = dyn_cast<NamedDecl>(DecReg->getDecl());
       ErrorMessage += " '" + RegionDecl->getNameAsString() + "'";
@@ -365,7 +373,10 @@ void MisusedMovedObjectChecker::checkPreCall(const CallEvent &Call,
       const RegionState *ArgState = State->get<TrackedRegionMap>(ArgRegion);
       if (ArgState && ArgState->isMoved()) {
         if (!isInMoveSafeContext(LC)) {
-          N = reportBug(ArgRegion, Call, C, /*isCopy=*/true);
+          if(CtorDec->isMoveConstructor())
+            N = reportBug(ArgRegion, Call, C, MK_Move);
+          else
+            N = reportBug(ArgRegion, Call, C, MK_Copy);
           State = State->set<TrackedRegionMap>(ArgRegion,
                                                RegionState::getReported());
         }
@@ -405,7 +416,10 @@ void MisusedMovedObjectChecker::checkPreCall(const CallEvent &Call,
           State->get<TrackedRegionMap>(IC->getArgSVal(0).getAsRegion());
       if (ArgState && ArgState->isMoved() && !isInMoveSafeContext(LC)) {
         const MemRegion *ArgRegion = IC->getArgSVal(0).getAsRegion();
-        N = reportBug(ArgRegion, Call, C, /*isCopy=*/true);
+        if(MethodDecl->isMoveAssignmentOperator())
+          N = reportBug(ArgRegion, Call, C, MK_Move);
+        else
+          N = reportBug(ArgRegion, Call, C, MK_Copy);
         State =
             State->set<TrackedRegionMap>(ArgRegion, RegionState::getReported());
       }
@@ -443,7 +457,7 @@ void MisusedMovedObjectChecker::checkPreCall(const CallEvent &Call,
   if (isInMoveSafeContext(LC))
     return;
 
-  N = reportBug(ThisRegion, Call, C);
+  N = reportBug(ThisRegion, Call, C, MK_FunCall);
   State = State->set<TrackedRegionMap>(ThisRegion, RegionState::getReported());
   C.addTransition(State, N);
 }