Merge branch '1.2.x'

3 files changed, 64 insertions, 4 deletions

diff --git a/src/theory/uf/symmetry_breaker.cpp b/src/theory/uf/symmetry_breaker.cpp
index fcb6c3cd5..f5d7f9235 100644
--- a/src/theory/uf/symmetry_breaker.cpp
+++ b/src/theory/uf/symmetry_breaker.cpp
@@ -52,6 +52,8 @@ namespace CVC4 {
 namespace theory {
 namespace uf {
 
+using namespace ::CVC4::context;
+
 SymmetryBreaker::Template::Template() :
   d_template(),
   d_sets(),
@@ -165,7 +167,10 @@ void SymmetryBreaker::Template::reset() {
   d_reps.clear();
 }
 
-SymmetryBreaker::SymmetryBreaker() :
+SymmetryBreaker::SymmetryBreaker(context::Context* context) :
+  ContextNotifyObj(context),
+  d_assertionsToRerun(context),
+  d_rerunningAssertions(false),
   d_phi(),
   d_phiSet(),
   d_permutations(),
@@ -175,6 +180,31 @@ SymmetryBreaker::SymmetryBreaker() :
   d_termEqs() {
 }
 
+class SBGuard {
+  bool& d_ref;
+  bool d_old;
+public:
+  SBGuard(bool& b) : d_ref(b), d_old(b) {}
+  ~SBGuard() { Debug("uf") << "reset to " << d_old << std::endl; d_ref = d_old; }
+};/* class SBGuard */
+
+void SymmetryBreaker::rerunAssertionsIfNecessary() {
+  if(d_rerunningAssertions || !d_phi.empty() || d_assertionsToRerun.empty()) {
+    return;
+  }
+
+  SBGuard g(d_rerunningAssertions);
+  d_rerunningAssertions = true;
+
+  Debug("ufsymm") << "UFSYMM: rerunning assertions..." << std::endl;
+  for(CDList<Node>::const_iterator i = d_assertionsToRerun.begin();
+      i != d_assertionsToRerun.end();
+      ++i) {
+    assertFormula(*i);
+  }
+  Debug("ufsymm") << "UFSYMM: DONE rerunning assertions..." << std::endl;
+}
+
 Node SymmetryBreaker::norm(TNode phi) {
   Node n = Rewriter::rewrite(phi);
   return normInternal(n);
@@ -254,6 +284,10 @@ Node SymmetryBreaker::normInternal(TNode n) {
 }
 
 void SymmetryBreaker::assertFormula(TNode phi) {
+  rerunAssertionsIfNecessary();
+  if(!d_rerunningAssertions) {
+    d_assertionsToRerun.push_back(phi);
+  }
   // use d_phi, put into d_permutations
   Debug("ufsymm") << "UFSYMM assertFormula(): phi is " << phi << endl;
   d_phi.push_back(phi);
@@ -322,6 +356,7 @@ void SymmetryBreaker::clear() {
 }
 
 void SymmetryBreaker::apply(std::vector<Node>& newClauses) {
+  rerunAssertionsIfNecessary();
   guessPermutations();
   Debug("ufsymm") << "UFSYMM =====================================================" << endl
                   << "UFSYMM have " << d_permutations.size() << " permutation sets" << endl;
diff --git a/src/theory/uf/symmetry_breaker.h b/src/theory/uf/symmetry_breaker.h
index cf54b62c2..d04da048a 100644
--- a/src/theory/uf/symmetry_breaker.h
+++ b/src/theory/uf/symmetry_breaker.h
@@ -50,13 +50,15 @@
 
 #include "expr/node.h"
 #include "expr/node_builder.h"
+#include "context/context.h"
+#include "context/cdlist.h"
 #include "util/statistics_registry.h"
 
 namespace CVC4 {
 namespace theory {
 namespace uf {
 
-class SymmetryBreaker {
+class SymmetryBreaker : public context::ContextNotifyObj {
 
   class Template {
     Node d_template;
@@ -92,6 +94,19 @@ public:
 
 private:
 
+  /**
+   * This class wasn't initially built to be incremental.  It should
+   * be attached to a UserContext so that it clears everything when
+   * a pop occurs.  This "assertionsToRerun" is a set of assertions to
+   * feed back through assertFormula() when we started getting things
+   * again.  It's not just a matter of effectiveness, but also soundness;
+   * if some assertions (still in scope) are not seen by a symmetry-breaking
+   * round, then some symmetries that don't actually exist might be broken,
+   * leading to unsound results!
+   */
+  context::CDList<Node> d_assertionsToRerun;
+  bool d_rerunningAssertions;
+
   std::vector<Node> d_phi;
   std::set<TNode> d_phiSet;
   Permutations d_permutations;
@@ -101,6 +116,7 @@ private:
   TermEqs d_termEqs;
 
   void clear();
+  void rerunAssertionsIfNecessary();
 
   void guessPermutations();
   bool invariantByPermutations(const Permutation& p);
@@ -140,9 +156,17 @@ private:
                  d_initNormalizationTimer,
                  "theory::uf::symmetry_breaker::timers::initNormalization");
 
+protected:
+
+  void contextNotifyPop() {
+    Debug("ufsymm") << "UFSYMM: clearing state due to pop" << std::endl;
+    clear();
+  }
+
 public:
 
-  SymmetryBreaker();
+  SymmetryBreaker(context::Context* context);
+  ~SymmetryBreaker() throw() {}
   void assertFormula(TNode phi);
   void apply(std::vector<Node>& newClauses);
 
diff --git a/src/theory/uf/theory_uf.cpp b/src/theory/uf/theory_uf.cpp
index 69a963360..41935984f 100644
--- a/src/theory/uf/theory_uf.cpp
+++ b/src/theory/uf/theory_uf.cpp
@@ -38,7 +38,8 @@ TheoryUF::TheoryUF(context::Context* c, context::UserContext* u, OutputChannel&
   d_conflict(c, false),
   d_literalsToPropagate(c),
   d_literalsToPropagateIndex(c, 0),
-  d_functionsTerms(c)
+  d_functionsTerms(c),
+  d_symb(u)
 {
   // The kinds we are treating as function application in congruence
   d_equalityEngine.addFunctionKind(kind::APPLY_UF);