Makes symbols static

Conflicts:
	svm-partition-trace-symb/src/main/java/com/lexicalscope/svm/partition/trace/symb/tree/GoalTree.java
	svm-partition-trace-symb/src/test/java/com/lexicalscope/svm/partition/trace/symb/tree/TestGoalTree.java

Author: drognanar

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/EqStrategy.java

@@ -13,9 +13,9 @@ public final class EqStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value == 0) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/GeStrategy.java

@@ -13,9 +13,9 @@ public final class GeStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value >= 0) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/GtStrategy.java

@@ -13,9 +13,9 @@ public final class GtStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value > 0) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpEqStrategy.java

@@ -22,8 +22,8 @@ public final class ICmpEqStrategy implements BinarySBranchOp {
 
    private BoolSymbol pConditionSymbol(final int value1, final int value2) {
       if (value1 == value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpGeStrategy.java

@@ -17,8 +17,8 @@ public final class ICmpGeStrategy implements BinarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value1, final Integer value2) {
       if (value1 >= value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpGtStrategy.java

@@ -17,8 +17,8 @@ public final class ICmpGtStrategy implements BinarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value1, final Integer value2) {
       if (value1 > value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpLeStrategy.java

@@ -17,8 +17,8 @@ public final class ICmpLeStrategy implements BinarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value1, final Integer value2) {
       if (value1 <= value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpLtStrategy.java

@@ -17,8 +17,8 @@ public final class ICmpLtStrategy implements BinarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value1, final Integer value2) {
       if (value1 < value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/ICmpNeStrategy.java

@@ -21,8 +21,8 @@ public final class ICmpNeStrategy implements BinarySBranchOp {
 
    private BoolSymbol pConditionSymbol(final int value1, final int value2) {
       if (value1 != value2) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/LeStrategy.java

@@ -13,9 +13,9 @@ public final class LeStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value <= 0) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/LtStrategy.java

@@ -13,9 +13,9 @@ public final class LtStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value < 0) {
-         return new TrueSymbol();
+         return TrueSymbol.TT;
       }
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/predicates/NeStrategy.java

@@ -13,9 +13,9 @@ public final class NeStrategy implements UnarySBranchOp {
 
    @Override public BoolSymbol conditionSymbol(final Integer value) {
       if(value == 0) {
-         return new FalseSymbol();
+         return FalseSymbol.FF;
       }
-      return new TrueSymbol();
+      return TrueSymbol.TT;
    }
 
    @Override public String toString() {

svm-jinstruction-symb/src/main/java/com/lexicalscope/svm/z3/FeasibilityChecker.java

@@ -42,8 +42,8 @@ public FeasibilityChecker() {
          throw new RuntimeException("could not enable warning messages", e);
       }
       //Log.open("test.log");
-      satisfiableCache.put(new TrueSymbol(), true);
-      satisfiableCache.put(new FalseSymbol(), false);
+      satisfiableCache.put(TrueSymbol.TT, true);
+      satisfiableCache.put(FalseSymbol.FF, false);
 
       final HashMap<String, String> cfg = new HashMap<String, String>();
       cfg.put("model", "true");

svm-jinstruction-symb/src/test/java/com/lexicalscope/svm/j/instruction/symbolic/ops/array/TestArrayTheory.java

@@ -23,7 +23,7 @@ public class TestArrayTheory {
    private final FeasibilityChecker feasbilityChecker = new FeasibilityChecker();
 
    private final StateBuilder state = new StateBuilder();
-   private final BoolSymbol pc = new TrueSymbol();
+   private final BoolSymbol pc = TrueSymbol.TT;
 
    @Test public void storeAndSelectAtSymbolicIndex() throws Exception {
       final ITerminalSymbol indexSymbol = state.intSymbol();

svm-jsymbols/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/pc/PcBuilder.java

@@ -57,10 +57,10 @@ public static BoolSymbol or(final BoolSymbol left, final BoolSymbol right) {
    }
 
    public static BoolSymbol truth() {
-      return new TrueSymbol();
+      return TrueSymbol.TT;
    }
 
    public static BoolSymbol falsity() {
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 }

svm-jsymbols/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/symbols/FalseSymbol.java

@@ -2,6 +2,10 @@
 
 
 public class FalseSymbol implements BoolSymbol {
+   public static FalseSymbol FF = new FalseSymbol();
+
+   private FalseSymbol() { }
+
    @Override public boolean isTT() {
       return false;
    }
@@ -27,14 +31,6 @@ public class FalseSymbol implements BoolSymbol {
    }
 
    @Override public BoolSymbol not() {
-      return new TrueSymbol();
-   }
-
-   @Override public int hashCode() {
-      return FalseSymbol.class.hashCode();
-   }
-
-   @Override public boolean equals(final Object obj) {
-      return obj != null && obj.getClass().equals(this.getClass());
+      return TrueSymbol.TT;
    }
 }

svm-jsymbols/src/main/java/com/lexicalscope/svm/j/instruction/symbolic/symbols/TrueSymbol.java

@@ -2,6 +2,10 @@
 
 
 public final class TrueSymbol implements BoolSymbol {
+   public static TrueSymbol TT = new TrueSymbol();
+
+   private TrueSymbol() {}
+
    @Override public boolean isTT() {
       return true;
    }
@@ -23,18 +27,10 @@ public final class TrueSymbol implements BoolSymbol {
    }
 
    @Override public BoolSymbol not() {
-      return new FalseSymbol();
+      return FalseSymbol.FF;
    }
 
    @Override public String toString() {
       return "TT";
    }
-
-   @Override public int hashCode() {
-      return TrueSymbol.class.hashCode();
-   }
-
-   @Override public boolean equals(final Object obj) {
-      return obj != null && obj.getClass().equals(this.getClass());
-   }
 }

svm-jvm-symb/src/main/java/com/lexicalscope/svm/vm/symb/SymbVmFactory.java

@@ -31,7 +31,7 @@ public static JvmBuilder symbolicVmBuilder(
                         .useNatives(SymbolicNativeMethods.natives())
                         .instructionFactory(instructionFactory)
                         .heapFactory(heapFactory)
-                        .meta(PC, new TrueSymbol())
+                        .meta(PC, TrueSymbol.TT)
                         .meta(TERMINATION, false)
                         .meta(SC, 0));
         return vmBuilder;