[analyzer] PthreadLock: add printState().

[NoQ]

Summary

The self-debugging method to add dumps of the checker's internal state to program state dumps and exploded graphs.

I'm looking into enabling this checker by default, so more patches would follow.

lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp

class PthreadLockChecker
   enum LockingSemantics {
     NotApplicable = 0,
     PthreadSemantics,
     XNUSemantics
   };
 public:
   void checkPostStmt(const CallExpr *CE, CheckerContext &C) const;
   void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+  void printState(raw_ostream &Out, ProgramStateRef State,
+                  const char *NL, const char *Sep) const override;
 
   void AcquireLock(CheckerContext &C, const CallExpr *CE, SVal lock,
                    bool isTryLock, enum LockingSemantics semantics) const;
 
   void ReleaseLock(CheckerContext &C, const CallExpr *CE, SVal lock) const;
   void DestroyLock(CheckerContext &C, const CallExpr *CE, SVal Lock,
                    enum LockingSemantics semantics) const;
   void InitLock(CheckerContext &C, const CallExpr *CE, SVal Lock) const;
if (retZero.isConstrainedFalse()) {
     state = state->set<LockMap>(lockR, LockState::getDestroyed());
 
   // Removing the map entry (lockR, sym) from DestroyRetVal as the lock state is
   // now resolved.
   state = state->remove<DestroyRetVal>(lockR);
   return state;
 }
 
+void PthreadLockChecker::printState(raw_ostream &Out, ProgramStateRef State,
+                                    const char *NL, const char *Sep) const {
+  LockMapTy LM = State->get<LockMap>();
+  if (!LM.isEmpty()) {
+    Out << Sep << "Mutex states:" << NL;
+    for (auto I : LM) {
+      I.first->dumpToStream(Out);
+      if (I.second.isLocked())
+        Out << ": locked";
+      else if (I.second.isUnlocked())
+        Out << ": unlocked";
+      else if (I.second.isDestroyed())
+        Out << ": destroyed";
+      else if (I.second.isUntouchedAndPossiblyDestroyed())
+        Out << ": not tracked, possibly destroyed";
+      else if (I.second.isUnlockedAndPossiblyDestroyed())
+        Out << ": unlocked, possibly destroyed";
+      Out << NL;
+    }
+  }
+
+  LockSetTy LS = State->get<LockSet>();
+  if (!LS.isEmpty()) {
+    Out << Sep << "Mutex lock order:" << NL;
+    for (auto I: LS) {
+      I->dumpToStream(Out);
+      Out << NL;
+    }
+  }
+
+  // TODO: Dump destroyed mutex symbols?
+}
+
 void PthreadLockChecker::AcquireLock(CheckerContext &C, const CallExpr *CE,
                                      SVal lock, bool isTryLock,
                                      enum LockingSemantics semantics) const {
 
   const MemRegion *lockR = lock.getAsRegion();
   if (!lockR)
     return;