[analyzer]StreamChecker refactoring (NFC).

Reviewers: Szelethus

Reviewed By: Szelethus

Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy, Charusso, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73359

diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index dc6bd4f1544e89a3944c008ece0a6ef710401749..ab4c9fafae1db7b70c4b3eaccc9673fd68ae083d 100644 (file)
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -94,15 +94,15 @@ private:
   void evalFreopen(const CallEvent &Call, CheckerContext &C) const;
   void evalFclose(const CallEvent &Call, CheckerContext &C) const;
   void evalFseek(const CallEvent &Call, CheckerContext &C) const;
-
   void checkArgNullStream(const CallEvent &Call, CheckerContext &C,
                           unsigned ArgI) const;
-  bool checkNullStream(SVal SV, CheckerContext &C,
-                       ProgramStateRef &State) const;
-  void checkFseekWhence(SVal SV, CheckerContext &C,
-                        ProgramStateRef &State) const;
-  bool checkDoubleClose(const CallEvent &Call, CheckerContext &C,
-                        ProgramStateRef &State) const;
+
+  ProgramStateRef checkNullStream(SVal SV, CheckerContext &C,
+                                  ProgramStateRef State) const;
+  ProgramStateRef checkFseekWhence(SVal SV, CheckerContext &C,
+                                   ProgramStateRef State) const;
+  ProgramStateRef checkDoubleClose(const CallEvent &Call, CheckerContext &C,
+                                   ProgramStateRef State) const;
 };
 
 } // end anonymous namespace
@@ -176,9 +176,8 @@ void StreamChecker::evalFreopen(const CallEvent &Call,
     return;
   // Do not allow NULL as passed stream pointer.
   // This is not specified in the man page but may crash on some system.
-  checkNullStream(*StreamVal, C, State);
-  // Check if error was generated.
-  if (C.isDifferent())
+  State = checkNullStream(*StreamVal, C, State);
+  if (!State)
     return;
 
   SymbolRef StreamSym = StreamVal->getAsSymbol();
@@ -208,7 +207,8 @@ void StreamChecker::evalFreopen(const CallEvent &Call,
 
 void StreamChecker::evalFclose(const CallEvent &Call, CheckerContext &C) const {
   ProgramStateRef State = C.getState();
-  if (checkDoubleClose(Call, C, State))
+  State = checkDoubleClose(Call, C, State);
+  if (State)
     C.addTransition(State);
 }
 
@@ -219,30 +219,31 @@ void StreamChecker::evalFseek(const CallEvent &Call, CheckerContext &C) const {
 
   ProgramStateRef State = C.getState();
 
-  bool StateChanged = checkNullStream(Call.getArgSVal(0), C, State);
-  // Check if error was generated.
-  if (C.isDifferent())
+  State = checkNullStream(Call.getArgSVal(0), C, State);
+  if (!State)
     return;
 
-  // Check the legality of the 'whence' argument of 'fseek'.
-  checkFseekWhence(State->getSVal(AE2, C.getLocationContext()), C, State);
+  State =
+      checkFseekWhence(State->getSVal(AE2, C.getLocationContext()), C, State);
+  if (!State)
+    return;
 
-  if (!C.isDifferent() && StateChanged)
-    C.addTransition(State);
+  C.addTransition(State);
 }
 
 void StreamChecker::checkArgNullStream(const CallEvent &Call, CheckerContext &C,
                                        unsigned ArgI) const {
   ProgramStateRef State = C.getState();
-  if (checkNullStream(Call.getArgSVal(ArgI), C, State))
+  State = checkNullStream(Call.getArgSVal(ArgI), C, State);
+  if (State)
     C.addTransition(State);
 }
 
-bool StreamChecker::checkNullStream(SVal SV, CheckerContext &C,
-                                    ProgramStateRef &State) const {
+ProgramStateRef StreamChecker::checkNullStream(SVal SV, CheckerContext &C,
+                                               ProgramStateRef State) const {
   Optional<DefinedSVal> DV = SV.getAs<DefinedSVal>();
   if (!DV)
-    return false;
+    return State;
 
   ConstraintManager &CM = C.getConstraintManager();
   ProgramStateRef StateNotNull, StateNull;
@@ -256,26 +257,22 @@ bool StreamChecker::checkNullStream(SVal SV, CheckerContext &C,
       C.emitReport(std::make_unique<PathSensitiveBugReport>(
           *BT_nullfp, BT_nullfp->getDescription(), N));
     }
-    return false;
-  }
-
-  if (StateNotNull) {
-    State = StateNotNull;
-    return true;
+    return nullptr;
   }
 
-  return false;
+  return StateNotNull;
 }
 
-void StreamChecker::checkFseekWhence(SVal SV, CheckerContext &C,
-                                     ProgramStateRef &State) const {
+// Check the legality of the 'whence' argument of 'fseek'.
+ProgramStateRef StreamChecker::checkFseekWhence(SVal SV, CheckerContext &C,
+                                                ProgramStateRef State) const {
   Optional<nonloc::ConcreteInt> CI = SV.getAs<nonloc::ConcreteInt>();
   if (!CI)
-    return;
+    return State;
 
   int64_t X = CI->getValue().getSExtValue();
   if (X >= 0 && X <= 2)
-    return;
+    return State;
 
   if (ExplodedNode *N = C.generateNonFatalErrorNode(State)) {
     if (!BT_illegalwhence)
@@ -285,20 +282,24 @@ void StreamChecker::checkFseekWhence(SVal SV, CheckerContext &C,
                          "SEEK_SET, SEEK_END, or SEEK_CUR."));
     C.emitReport(std::make_unique<PathSensitiveBugReport>(
         *BT_illegalwhence, BT_illegalwhence->getDescription(), N));
+    return nullptr;
   }
+
+  return State;
 }
 
-bool StreamChecker::checkDoubleClose(const CallEvent &Call, CheckerContext &C,
-                                     ProgramStateRef &State) const {
+ProgramStateRef StreamChecker::checkDoubleClose(const CallEvent &Call,
+                                                CheckerContext &C,
+                                                ProgramStateRef State) const {
   SymbolRef Sym = Call.getArgSVal(0).getAsSymbol();
   if (!Sym)
-    return false;
+    return State;
 
   const StreamState *SS = State->get<StreamMap>(Sym);
 
   // If the file stream is not tracked, return.
   if (!SS)
-    return false;
+    return State;
 
   // Check: Double close a File Descriptor could cause undefined behaviour.
   // Conforming to man-pages
@@ -311,14 +312,16 @@ bool StreamChecker::checkDoubleClose(const CallEvent &Call, CheckerContext &C,
                                    " closed. Cause undefined behaviour."));
       C.emitReport(std::make_unique<PathSensitiveBugReport>(
           *BT_doubleclose, BT_doubleclose->getDescription(), N));
+      return nullptr;
     }
-    return false;
+
+    return State;
   }
 
   // Close the File Descriptor.
   State = State->set<StreamMap>(Sym, StreamState::getClosed());
 
-  return true;
+  return State;
 }
 
 void StreamChecker::checkDeadSymbols(SymbolReaper &SymReaper,