예제 #1
0
 // Look up a previously instantiated SubSequence relationship.
 public static SubSequence find(PptSlice ppt) {
   Assert.assertTrue(ppt.arity() == 2);
   for (Invariant inv : ppt.invs) {
     if (inv instanceof SubSequence) return (SubSequence) inv;
   }
   return null;
 }
 // Look up a previously instantiated invariant.
 public static EltwiseIntEqual find(PptSlice ppt) {
   Assert.assertTrue(ppt.arity() == 1);
   for (Invariant inv : ppt.invs) {
     if (inv instanceof EltwiseIntEqual) return (EltwiseIntEqual) inv;
   }
   return null;
 }
예제 #3
0
    /**
     * process the sample by checking it against each existing invariant and issuing an error if any
     * invariant is falsified or weakened.
     */
    public void process_sample(PptMap all_ppts, PptTopLevel ppt, ValueTuple vt, Integer nonce) {

      this.all_ppts = all_ppts;

      debug.fine("processing sample from: " + ppt.name);

      // Add orig and derived variables
      FileIO.add_orig_variables(ppt, vt.vals, vt.mods, nonce);
      FileIO.add_derived_variables(ppt, vt.vals, vt.mods);

      // Intern the sample
      vt = new ValueTuple(vt.vals, vt.mods);

      // If this is an enter point, just remember it for later
      if (ppt.ppt_name.isEnterPoint()) {
        Assert.assertTrue(nonce != null);
        if (dir_file != null) {
          // Yoav: I had to do a hack to handle the case that several dtrace files are concatenated
          // together,
          // and Sung's dtrace files have unterminated calls, and when concatenating two files you
          // can have the same nonce.
          // So I have to remove the nonce found from the call_map
          call_map.remove(nonce);
        } else Assert.assertTrue(call_map.get(nonce) == null);
        call_map.put(nonce, new EnterCall(ppt, vt));
        debug.fine("Skipping enter sample");
        return;
      }

      // If this is an exit point, process the saved enter point
      if (ppt.ppt_name.isExitPoint()) {
        Assert.assertTrue(nonce != null);
        EnterCall ec = call_map.get(nonce);
        if (ec != null) {
          call_map.remove(nonce);
          debug.fine("Processing enter sample from " + ec.ppt.name);
          add(ec.ppt, ec.vt);
        } else { // didn't find the enter
          if (!quiet)
            System.out.printf("couldn't find enter for nonce %d at ppt %s\n", nonce, ppt.name());
          return;
        }
      }

      add(ppt, vt);
    }
예제 #4
0
 public boolean isSameFormula(Invariant inv) {
   Assert.assertTrue(inv instanceof SubSequence);
   return (true);
 }
예제 #5
0
  /**
   * Returns true if the two original variables are related in a way that makes subsequence or
   * subset detection not informative.
   */
  public static boolean isObviousSubSequenceDynamically(
      Invariant inv, VarInfo subvar, VarInfo supervar) {

    VarInfo[] vis = {subvar, supervar};

    ProglangType rep1 = subvar.rep_type;
    ProglangType rep2 = supervar.rep_type;
    if (!(((rep1 == ProglangType.INT_ARRAY) && (rep2 == ProglangType.INT_ARRAY))
        || ((rep1 == ProglangType.DOUBLE_ARRAY) && (rep2 == ProglangType.DOUBLE_ARRAY))
        || ((rep1 == ProglangType.STRING_ARRAY) && (rep2 == ProglangType.STRING_ARRAY))))
      return false;

    if (debug.isLoggable(Level.FINE)) {
      debug.fine(
          "Checking isObviousSubSequenceDynamically " + subvar.name() + " in " + supervar.name());
    }

    Object[] di = isObviousSubSequence(subvar, supervar);
    if (di[1] != null) {
      inv.log("ObvSubSeq- true from isObviousSubSequence: " + di[1]);
      return true;
    }
    debug.fine("  not isObviousSubSequence(statically)");

    PptTopLevel ppt_parent = subvar.ppt;

    // If the elements of supervar are always the same (EltOneOf),
    // we aren't going to learn anything new from this invariant,
    // since each sequence should have an EltOneOf over it.
    if (false) {
      PptSlice1 slice = ppt_parent.findSlice(supervar);
      if (slice == null) {
        System.out.println("No slice: parent =" + ppt_parent);
      } else {
        System.out.println("Slice var =" + slice.var_infos[0]);
        for (Invariant superinv : slice.invs) {
          System.out.println("Inv = " + superinv);
          if (superinv instanceof EltOneOf) {
            EltOneOf eltinv = (EltOneOf) superinv;
            if (eltinv.num_elts() > 0) {
              inv.log(" obvious because of " + eltinv.format());
              return true;
            }
          }
        }
      }
    }

    // Obvious if subvar is always just []
    if (true) {
      PptSlice1 slice = ppt_parent.findSlice(subvar);
      if (slice != null) {
        for (Invariant subinv : slice.invs) {
          if (subinv instanceof OneOfSequence) {
            OneOfSequence seqinv = (OneOfSequence) subinv;
            if (seqinv.num_elts() == 1) {
              Object elt = seqinv.elt();
              if (elt instanceof long[] && ((long[]) elt).length == 0) {
                Debug.log(
                    debug, inv.getClass(), inv.ppt, vis, "ObvSubSeq- True from subvar being []");
                return true;
              }
              if (elt instanceof double[] && ((double[]) elt).length == 0) {
                inv.log("ObvSubSeq- True from subvar being []");
                return true;
              }
            }
          }
        }
      }
    }

    // Check for a[0..i] subseq a[0..j] but i < j.
    VarInfo subvar_super = subvar.isDerivedSubSequenceOf();
    VarInfo supervar_super = supervar.isDerivedSubSequenceOf();

    if (subvar_super != null && subvar_super == supervar_super) {
      // both sequences are derived from the same supersequence
      if ((subvar.derived instanceof SequenceScalarSubsequence
              || subvar.derived instanceof SequenceScalarArbitrarySubsequence)
          && (supervar.derived instanceof SequenceScalarSubsequence
              || supervar.derived instanceof SequenceScalarArbitrarySubsequence)) {
        VarInfo sub_left_var = null,
            sub_right_var = null,
            super_left_var = null,
            super_right_var = null;
        // I'm careful not to access foo_shift unless foo_var has been set
        // to a non-null value, but Java is too stupid to recognize that.
        int sub_left_shift = 42,
            sub_right_shift = 69,
            super_left_shift = 1492,
            super_right_shift = 1776;
        if (subvar.derived instanceof SequenceScalarSubsequence) {
          SequenceScalarSubsequence sub = (SequenceScalarSubsequence) subvar.derived;
          if (sub.from_start) {
            sub_right_var = sub.sclvar();
            sub_right_shift = sub.index_shift;
          } else {
            sub_left_var = sub.sclvar();
            sub_left_shift = sub.index_shift;
          }
        } else if (subvar.derived instanceof SequenceScalarArbitrarySubsequence) {
          SequenceScalarArbitrarySubsequence sub =
              (SequenceScalarArbitrarySubsequence) subvar.derived;
          sub_left_var = sub.startvar();
          sub_left_shift = (sub.left_closed ? 0 : 1);
          sub_right_var = sub.endvar();
          sub_right_shift = (sub.right_closed ? 0 : -1);
        } else {
          Assert.assertTrue(false);
        }
        if (supervar.derived instanceof SequenceScalarSubsequence) {
          SequenceScalarSubsequence super_ = (SequenceScalarSubsequence) supervar.derived;
          if (super_.from_start) {
            super_right_var = super_.sclvar();
            super_right_shift = super_.index_shift;
          } else {
            super_left_var = super_.sclvar();
            super_left_shift = super_.index_shift;
          }
        } else if (supervar.derived instanceof SequenceScalarArbitrarySubsequence) {
          SequenceScalarArbitrarySubsequence super_ =
              (SequenceScalarArbitrarySubsequence) supervar.derived;
          super_left_var = super_.startvar();
          super_left_shift = (super_.left_closed ? 0 : 1);
          super_right_var = super_.endvar();
          super_right_shift = (super_.right_closed ? 0 : -1);
        } else {
          Assert.assertTrue(false);
        }
        boolean left_included, right_included;
        if (super_left_var == null) left_included = true;
        else if (sub_left_var == null) // we know super_left_var != null here
        left_included = false;
        else
          left_included =
              VarInfo.compare_vars(
                  super_left_var, super_left_shift, sub_left_var, sub_left_shift, true /* <= */);
        if (super_right_var == null) right_included = true;
        else if (sub_right_var == null) // we know super_right_var != null here
        right_included = false;
        else
          right_included =
              VarInfo.compare_vars(
                  super_right_var,
                  super_right_shift,
                  sub_right_var,
                  sub_right_shift,
                  false /* >= */);
        //         System.out.println("Is " + subvar.name() + " contained in "
        //                            + supervar.name()
        //                            + "? left: " + left_included + ", right: "
        //                            + right_included);
        if (left_included && right_included) {
          inv.log("ObvSubSeq- True a[0..i] subseq a[0..j] and i < j");
          return true;
        }
      } else if ((subvar.derived instanceof SequenceStringSubsequence)
          && (supervar.derived instanceof SequenceStringSubsequence)) {
        // Copied from just above
        SequenceStringSubsequence sss1 = (SequenceStringSubsequence) subvar.derived;
        SequenceStringSubsequence sss2 = (SequenceStringSubsequence) supervar.derived;
        VarInfo index1 = sss1.sclvar();
        int shift1 = sss1.index_shift;
        boolean start1 = sss1.from_start;
        VarInfo index2 = sss2.sclvar();
        int shift2 = sss2.index_shift;
        boolean start2 = sss2.from_start;
        if (start1 == start2)
          if (VarInfo.compare_vars(index1, shift1, index2, shift2, start1)) {
            inv.log("True from comparing indices");
            return true;
          }
      } else {
        Assert.assertTrue(
            false,
            "how can this happen? "
                + subvar.name()
                + " "
                + subvar.derived.getClass()
                + " "
                + supervar.name()
                + " "
                + supervar.derived.getClass());
      }
    }

    // Also need to check A[0..i] subseq A[0..j] via compare_vars.

    // A subseq B[0..n] => A subseq B

    List<Derivation> derivees = supervar.derivees();
    // For each variable derived from supervar ("B")
    for (Derivation der : derivees) {
      // System.out.println("  ... der = " + der.getVarInfo().name() + " " + der);
      if (der instanceof SequenceScalarSubsequence) {
        // If that variable is "B[0..n]"
        VarInfo supervar_part = der.getVarInfo();
        // Get the canonical version; being equal to it is good enough.
        if (supervar_part.get_equalitySet_leader() == subvar) {
          Debug.log(debug, inv.getClass(), inv.ppt, vis, "ObvSubSeq- True from canonical leader");
          return true;
        }

        if (supervar_part.isCanonical()) {
          if (subvar == supervar_part) {
            System.err.println(
                "Error: variables "
                    + subvar.name()
                    + " and "
                    + supervar_part.name()
                    + " are identical.  Canonical");
            System.err.println(subvar.isCanonical());
            System.err.println(supervar_part.isCanonical());
            throw new Error();
          }

          // Check to see if there is a subsequence over the supervar
          if (ppt_parent.is_subsequence(subvar, supervar_part)) {
            if (Debug.logOn())
              inv.log(
                  "ObvSubSeq- true from A subseq B[0..n] "
                      + subvar.name()
                      + "/"
                      + supervar_part.name());
            return (true);
          }
        }
      }
    }
    return false;
  }
예제 #6
0
  /**
   * @return Array "a" such that a[0] is a valid discardCode and a[1] is a valid discardString. If
   *     the Invariant is not an obvious subsequence, both are null
   */
  public static Object[] isObviousSubSequence(VarInfo subvar, VarInfo supervar) {
    // Must typecheck since this could be called with non sequence variables in
    // some methods.
    ProglangType rep1 = subvar.rep_type;
    ProglangType rep2 = supervar.rep_type;
    if (!(((rep1 == ProglangType.INT_ARRAY) && (rep2 == ProglangType.INT_ARRAY))
        || ((rep1 == ProglangType.DOUBLE_ARRAY) && (rep2 == ProglangType.DOUBLE_ARRAY))
        || ((rep1 == ProglangType.STRING_ARRAY) && (rep2 == ProglangType.STRING_ARRAY)))) {
      return new Object[] {null, null};
    }

    if (debug.isLoggable(Level.FINE)) {
      debug.fine("isObviousSubSequence " + subvar.name() + "in " + supervar.name());
    }

    // Standard discard reason/string
    DiscardCode discardCode = DiscardCode.obvious;
    String discardString = subvar.name() + " obvious subset/subsequence of " + supervar.name();

    // For unions and intersections, it probably doesn't make sense to
    // do subsequence or subset detection.  This is mainly to prevent
    // invariants of the form (x subset of union(x, y)) but this means
    // we also miss those of the form (z subset of union(x,y)) which
    // might be useful.  Subsequence, however, seems totally useless
    // on unions and intersections.
    if (supervar.derived instanceof SequenceScalarIntersection
        || supervar.derived instanceof SequenceScalarUnion
        || subvar.derived instanceof SequenceScalarIntersection
        || subvar.derived instanceof SequenceScalarUnion) {
      discardCode = DiscardCode.obvious;
      discardString =
          "Invariants involving subsets/subsequences of unions/intersections" + "are suppressed";
      debug.fine("  returning true because of union or intersection");
      return new Object[] {discardCode, discardString};
    }

    if (subvar.derived instanceof SequencesPredicate) {
      // It's not useful that predicate(x[], b[]) is a subsequence or subset
      // of x[]
      SequencesPredicate derived = (SequencesPredicate) subvar.derived;
      if (derived.var1().equals(supervar)) {
        discardCode = DiscardCode.obvious;
        discardString = subvar.name() + " is derived from " + supervar.name();
        debug.fine("  returning true because of predicate slicing");
        return new Object[] {discardCode, discardString + " [pred slicing]"};
      }
    }

    VarInfo subvar_super = subvar.isDerivedSubSequenceOf();
    if (subvar_super == null) {
      // If it's not a union, intersection or a subsequence, it's not obvious
      debug.fine("  returning false because subvar_super == null");
      return new Object[] {null, null};
    }

    if (subvar_super == supervar) {
      // System.out.println("SubSequence.isObviousDerived(" + subvar.name() + ", " + supervar.name +
      // ") = true");
      // System.out.println("  details: subvar_super=" + subvar_super.name + "; supervar_super=" +
      // supervar.isDerivedSubSequenceOf() == null ? "null" :
      // supervar.isDerivedSubSequenceOf().name);
      discardCode = DiscardCode.obvious;
      discardString = subvar.name() + "==" + supervar.name();
      debug.fine("  returning true because subvar_super == supervar");
      return new Object[] {discardCode, discardString + " [subvar_super == supervar]"};
    }

    // a[i+a..j+b] cmp a[i+c..j+d]
    VarInfo supervar_super = supervar.isDerivedSubSequenceOf();
    // we know subvar_super != null due to check above
    if (subvar_super == supervar_super) {
      // both sequences are derived from the same supersequence
      if ((subvar.derived instanceof SequenceScalarSubsequence
              || subvar.derived instanceof SequenceScalarArbitrarySubsequence)
          && (supervar.derived instanceof SequenceScalarSubsequence
              || supervar.derived instanceof SequenceScalarArbitrarySubsequence)) {
        // In "A[i..j] subseq B[k..l]": i=sub_left_var, j=sub_right_var,
        //  k=super_left_var, l=super_right_var.
        VarInfo sub_left_var = null,
            sub_right_var = null,
            super_left_var = null,
            super_right_var = null;
        // I'm careful not to access foo_shift unless foo_var has been set
        // to a non-null value, but Java is too stupid to recognize that.
        int sub_left_shift = 42,
            sub_right_shift = 69,
            super_left_shift = 1492,
            super_right_shift = 1776;
        if (subvar.derived instanceof SequenceScalarSubsequence) {
          SequenceScalarSubsequence sub = (SequenceScalarSubsequence) subvar.derived;
          if (sub.from_start) {
            sub_right_var = sub.sclvar();
            sub_right_shift = sub.index_shift;
          } else {
            sub_left_var = sub.sclvar();
            sub_left_shift = sub.index_shift;
          }
        } else if (subvar.derived instanceof SequenceScalarArbitrarySubsequence) {
          SequenceScalarArbitrarySubsequence sub =
              (SequenceScalarArbitrarySubsequence) subvar.derived;
          sub_left_var = sub.startvar();
          sub_left_shift = (sub.left_closed ? 0 : 1);
          sub_right_var = sub.endvar();
          sub_right_shift = (sub.right_closed ? 0 : -1);
        } else {
          Assert.assertTrue(false);
        }
        if (supervar.derived instanceof SequenceScalarSubsequence) {
          SequenceScalarSubsequence super_ = (SequenceScalarSubsequence) supervar.derived;
          if (super_.from_start) {
            super_right_var = super_.sclvar();
            super_right_shift = super_.index_shift;
          } else {
            super_left_var = super_.sclvar();
            super_left_shift = super_.index_shift;
          }
        } else if (supervar.derived instanceof SequenceScalarArbitrarySubsequence) {
          SequenceScalarArbitrarySubsequence super_ =
              (SequenceScalarArbitrarySubsequence) supervar.derived;
          super_left_var = super_.startvar();
          super_left_shift = (super_.left_closed ? 0 : 1);
          super_right_var = super_.endvar();
          super_right_shift = (super_.right_closed ? 0 : -1);
        } else {
          Assert.assertTrue(false);
        }
        boolean left_included = false, right_included = false;
        if (super_left_var == null) left_included = true;
        if (super_left_var == sub_left_var) {
          if (super_left_shift < sub_left_shift) left_included = true;
        }
        if (super_right_var == null) right_included = true;
        if (super_right_var == sub_right_var) {
          if (super_right_shift > sub_right_shift) right_included = true;
        }
        if (left_included && right_included) {
          discardCode = DiscardCode.obvious;
          discardString = subvar.name() + " obvious subset/subsequence of " + supervar.name();
          return new Object[] {discardCode, discardString + " [obvious]"};
        }
      } else if ((subvar.derived instanceof SequenceStringSubsequence)
          && (supervar.derived instanceof SequenceStringSubsequence)) {
        // Copied from (an old version) just above
        // XXX I think this code is dead; why isn't it just produced
        // from the above by macro expansion? -smcc
        SequenceStringSubsequence sss1 = (SequenceStringSubsequence) subvar.derived;
        SequenceStringSubsequence sss2 = (SequenceStringSubsequence) supervar.derived;
        VarInfo index1 = sss1.sclvar();
        int shift1 = sss1.index_shift;
        boolean start1 = sss1.from_start;
        VarInfo index2 = sss2.sclvar();
        int shift2 = sss2.index_shift;
        boolean start2 = sss2.from_start;
        if (index1 == index2) {
          if (start1 == true && start2 == true) {
            if (shift1 <= shift2) return new Object[] {discardCode, discardString + " [shift1]"};
          } else if (start1 == false && start2 == false) {
            if (shift1 >= shift2) return new Object[] {discardCode, discardString + " [shift2]"};
          }
        }
      } else {
        Assert.assertTrue(
            false,
            "how can this happen? "
                + subvar.name()
                + " "
                + subvar.derived.getClass()
                + " "
                + supervar.name()
                + " "
                + supervar.derived.getClass());
      }
    }

    return new Object[] {null, null};
  }
예제 #7
0
    private void add(PptTopLevel ppt, ValueTuple vt) {
      // Add the sample to any splitters
      if (ppt.has_splitters()) {
        for (PptSplitter ppt_split : ppt.splitters) {
          PptConditional ppt_cond = ppt_split.choose_conditional(vt);
          if (ppt_cond != null) add(ppt_cond, vt);
          else debug.fine(": sample doesn't pick conditional");
        }
      }

      // if this is a numbered exit, apply to the combined exit as well
      if (!(ppt instanceof PptConditional) && ppt.ppt_name.isNumberedExitPoint()) {
        PptTopLevel parent = all_ppts.get(ppt.ppt_name.makeExit());
        if (parent != null) {
          parent.get_missingOutOfBounds(ppt, vt);
          add(parent, vt);
        }
      }

      // If the point has no variables, skip it
      if (ppt.var_infos.length == 0) return;

      // We should have received sample here before, or there is nothing
      // to check.
      // Yoav added: It can be that the different dtrace and inv files have different program points
      if (false && ppt.num_samples() <= 0)
        Assert.assertTrue(
            ppt.num_samples() > 0,
            "ppt " + ppt.name + " has 0 samples and " + ppt.var_infos.length + " variables");

      // Loop through each slice
      slice_loop:
      for (Iterator<PptSlice> i = ppt.views_iterator(); i.hasNext(); ) {
        PptSlice slice = i.next();
        if (debug_detail.isLoggable(Level.FINE))
          debug_detail.fine(
              ": processing slice " + slice + "vars: " + Debug.toString(slice.var_infos, vt));

        // If any variables are missing, skip this slice
        for (int j = 0; j < slice.var_infos.length; j++) {
          VarInfo v = slice.var_infos[j];
          int mod = vt.getModified(v);
          if (v.isMissing(vt)) {
            if (debug_detail.isLoggable(Level.FINE))
              debug_detail.fine(": : Skipping slice, " + v.name() + " missing");
            continue slice_loop;
          }
          if (v.missingOutOfBounds()) {
            if (debug_detail.isLoggable(Level.FINE))
              debug.fine(": : Skipping slice, " + v.name() + " out of bounds");
            continue slice_loop;
          }
        }

        // Loop through each invariant
        for (Invariant inv : slice.invs) {
          if (debug_detail.isLoggable(Level.FINE))
            debug_detail.fine(": : Processing invariant: " + inv);
          if (!inv.isActive()) {
            if (debug_detail.isLoggable(Level.FINE))
              debug_detail.fine(": : skipped non-active " + inv);
            continue;
          }

          // Yoav added
          if (!activeInvariants.contains(inv)) {
            // System.out.printf ("skipping invariant %s:%s\n", inv.ppt.name(),
            //                   inv.format());
            continue;
          }

          // String invRep = invariant2str(ppt, inv);
          testedInvariants.add(inv);

          InvariantStatus status = inv.add_sample(vt, 1);
          sample_cnt++;
          if (status != InvariantStatus.NO_CHANGE) {
            LineNumberReader lnr = FileIO.data_trace_state.reader;
            String line = (lnr == null) ? "?" : String.valueOf(lnr.getLineNumber());
            if (!quiet) {
              output_stream.println(
                  "At ppt "
                      + ppt.name
                      + ", Invariant '"
                      + inv.format()
                      + "' invalidated by sample "
                      + Debug.toString(slice.var_infos, vt)
                      + "at line "
                      + line
                      + " in file "
                      + FileIO.data_trace_state.filename);
            }
            failedInvariants.add(inv);
            activeInvariants.remove(inv);
            error_cnt++;
          }
        }
      }
    }