[clang] [clang][analyzer] Add StreamChecker note tags for "indeterminate stream position". (PR #83288)

[via cfe-commits]

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@@ -607,6 +564,103 @@ class StreamChecker : public Checker<check::PreCall, eval::Call,
                                                 CheckerContext &C);
 };
 
+struct StreamOperationEvaluator {
+  SValBuilder &SVB;
+  const ASTContext &ACtx;
+
+  SymbolRef StreamSym;
+  const StreamState *SS = nullptr;
+  const CallExpr *CE = nullptr;
+  StreamErrorState NewES;
+
+  StreamOperationEvaluator(CheckerContext &C)
+      : SVB(C.getSValBuilder()), ACtx(C.getASTContext()) {
+    ;
+  }
+
+  bool Init(const FnDescription *Desc, const CallEvent &Call, CheckerContext &C,
+            ProgramStateRef State) {
+    StreamSym = getStreamArg(Desc, Call).getAsSymbol();
+    if (!StreamSym)
+      return false;
+    SS = State->get<StreamMap>(StreamSym);
+    if (!SS)
+      return false;
+    NewES = SS->ErrorState;
+    CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
+    if (!CE)
+      return false;
+
+    assertStreamStateOpened(SS);
+
+    return true;
+  }
+
+  bool isStreamEof() const { return SS->ErrorState == ErrorFEof; }
+
+  NonLoc getZeroVal(const CallEvent &Call) {
+    return *SVB.makeZeroVal(Call.getResultType()).getAs<NonLoc>();
+  }
+
+  ProgramStateRef setStreamState(ProgramStateRef State,
+                                 const StreamState &NewSS) {
+    NewES = NewSS.ErrorState;
+    return State->set<StreamMap>(StreamSym, NewSS);
+  }
+
+  ProgramStateRef makeAndBindRetVal(ProgramStateRef State, CheckerContext &C) {
+    NonLoc RetVal = makeRetVal(C, CE).castAs<NonLoc>();
+    return State->BindExpr(CE, C.getLocationContext(), RetVal);
+  }
+
+  ProgramStateRef bindReturnValue(ProgramStateRef State, CheckerContext &C,
+                                  uint64_t Val) {
+    return State->BindExpr(CE, C.getLocationContext(),
+                           SVB.makeIntVal(Val, CE->getCallReturnType(ACtx)));
+  }
+
+  ProgramStateRef bindReturnValue(ProgramStateRef State, CheckerContext &C,
+                                  SVal Val) {
+    return State->BindExpr(CE, C.getLocationContext(), Val);
+  }
+
+  ProgramStateRef bindNullReturnValue(ProgramStateRef State,
+                                      CheckerContext &C) {
+    return State->BindExpr(CE, C.getLocationContext(),
+                           C.getSValBuilder().makeNullWithType(CE->getType()));
+  }
+
+  ProgramStateRef assumeBinOpNN(ProgramStateRef State,
+                                BinaryOperator::Opcode Op, NonLoc LHS,
+                                NonLoc RHS) {
+    auto Cond = SVB.evalBinOpNN(State, Op, LHS, RHS, SVB.getConditionType())
+                    .getAs<DefinedOrUnknownSVal>();
+    if (!Cond)
+      return nullptr;
+    return State->assume(*Cond, true);
+  }
+
+  ConstraintManager::ProgramStatePair
+  makeRetValAndAssumeDual(ProgramStateRef State, CheckerContext &C) {
+    DefinedSVal RetVal = makeRetVal(C, CE);
+    State = State->BindExpr(CE, C.getLocationContext(), RetVal);
+    return C.getConstraintManager().assumeDual(State, RetVal);
+  }
+
+  const NoteTag *getStreamErrorNoteTag(const StreamChecker *Ch,
----------------
NagyDonat wrote:

It's a bit misleading that the name of this function refers to "Error" while it can place both the "Eof" and the "Error" note tags (depending on the situation). Try to find a more neutral name like `getStreamStateNoteTag` (or something better -- `State` is neutral between `Error` and `Eof`, but is an overused word).

https://github.com/llvm/llvm-project/pull/83288