[Analyzer] Replace `CXXSelfAssignmentBRVisitor` with `NoteTags`

The `cplusplus.SelfAssignment` checker has a visitor that is added
to every `BugReport` to mark the to branch of the self assignment
operator with e.g. `rhs == *this` and `rhs != *this`. With the new
`NoteTag` feature this visitor is not needed anymore. Instead the
checker itself marks the two branches using the `NoteTag`s.

Differential Revision: https://reviews.llvm.org/D62479

llvm-svn: 361818

1 files changed, 18 insertions, 2 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/CXXSelfAssignmentChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CXXSelfAssignmentChecker.cpp
index 1233849b173..01f5b9c889e 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CXXSelfAssignmentChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CXXSelfAssignmentChecker.cpp
@@ -50,10 +50,26 @@ void CXXSelfAssignmentChecker::checkBeginFunction(CheckerContext &C) const {
       State->getSVal(SVB.getCXXThis(MD, LCtx->getStackFrame()));
   auto Param = SVB.makeLoc(State->getRegion(MD->getParamDecl(0), LCtx));
   auto ParamVal = State->getSVal(Param);
+
   ProgramStateRef SelfAssignState = State->bindLoc(Param, ThisVal, LCtx);
-  C.addTransition(SelfAssignState);
+  const NoteTag *SelfAssignTag =
+    C.getNoteTag([MD](BugReport &BR) -> std::string {
+        SmallString<256> Msg;
+        llvm::raw_svector_ostream Out(Msg);
+        Out << "Assuming " << MD->getParamDecl(0)->getName() << " == *this";
+        return Out.str();
+      });
+  C.addTransition(SelfAssignState, SelfAssignTag);
+
   ProgramStateRef NonSelfAssignState = State->bindLoc(Param, ParamVal, LCtx);
-  C.addTransition(NonSelfAssignState);
+  const NoteTag *NonSelfAssignTag =
+    C.getNoteTag([MD](BugReport &BR) -> std::string {
+        SmallString<256> Msg;
+        llvm::raw_svector_ostream Out(Msg);
+        Out << "Assuming " << MD->getParamDecl(0)->getName() << " != *this";
+        return Out.str();
+      });
+  C.addTransition(NonSelfAssignState, NonSelfAssignTag);
 }
 
 void ento::registerCXXSelfAssignmentChecker(CheckerManager &Mgr) {