reset-assertions: Remove all non-global symbols in the parser (#5229)

Fixes #5163. When `:global-declarations` is disabled (the default), then
`(reset-assertions)` should remove all declared and defined symbols. Before
this commit, we would remove the defined function from `SmtEngine` but the
parser would not remove it from its symbol table because the symbol was defined
at (what it considered) level 0. Level 0, however, is reserved for global
symbols that we never want to remove.

This commit adds an additional global `pushScope()`/`popScope()`, similar to
what we have in `SmtEngine`. As a result, user-defined symbols are now defined
at level 1 and get removed from the `SymbolTable` when `(reset-assertions)` is
called. The commit also makes sure that symbols defined by the logic are
asserted at level 0, so that they are not removed by `(reset-assertions)`. It
adds a flag to `defineType` to ignore duplicate definitions because some
symbols are defined by multiple logics, which leads to a failing assertion when
inserting them both at level 0 in the hashmap of the `SymbolTable`. E.g.
strings and integer arithmetic both define `Int`. The commit also fixes
existing unit tests that fail with these stricter semantics of
`(reset-assertions)`.

Signed-off-by: Andres Noetzli <noetzli@amazon.com>

11 files changed, 52 insertions, 31 deletions

diff --git a/src/parser/parser.cpp b/src/parser/parser.cpp
index 31ab49158..e58172b92 100644
--- a/src/parser/parser.cpp
+++ b/src/parser/parser.cpp
@@ -291,8 +291,14 @@ void Parser::defineVar(const std::string& name,
 
 void Parser::defineType(const std::string& name,
                         const api::Sort& type,
-                        bool levelZero)
+                        bool levelZero,
+                        bool skipExisting)
 {
+  if (skipExisting && isDeclared(name, SYM_SORT))
+  {
+    assert(api::Sort(d_solver, d_symtab->lookupType(name)) == type);
+    return;
+  }
   d_symtab->bindType(name, type.getType(), levelZero);
   assert(isDeclared(name, SYM_SORT));
 }
diff --git a/src/parser/parser.h b/src/parser/parser.h
index d478163b8..8e8080bc3 100644
--- a/src/parser/parser.h
+++ b/src/parser/parser.h
@@ -531,11 +531,15 @@ public:
    * @param name The name of the type
    * @param type The type that should be associated with the name
    * @param levelZero If true, the type definition is considered global and
-   *                  cannot be removed by poppoing the user context
+   *                  cannot be removed by popping the user context
+   * @param skipExisting If true, the type definition is ignored if the same
+   *                     symbol has already been defined. It is assumed that
+   *                     the definition is the exact same as the existing one.
    */
   void defineType(const std::string& name,
                   const api::Sort& type,
-                  bool levelZero = false);
+                  bool levelZero = false,
+                  bool skipExisting = false);
 
   /**
    * Create a new (parameterized) type definition.
diff --git a/src/parser/smt2/smt2.cpp b/src/parser/smt2/smt2.cpp
index b9b7de149..a226f7cbf 100644
--- a/src/parser/smt2/smt2.cpp
+++ b/src/parser/smt2/smt2.cpp
@@ -37,12 +37,11 @@ Smt2::Smt2(api::Solver* solver, Input* input, bool strictMode, bool parseOnly)
       d_logicSet(false),
       d_seenSetLogic(false)
 {
-  if (!strictModeEnabled())
-  {
-    addCoreSymbols();
-  }
+  pushScope(true);
 }
 
+Smt2::~Smt2() { popScope(); }
+
 void Smt2::addArithmeticOperators() {
   addOperator(api::PLUS, "+");
   addOperator(api::MINUS, "-");
@@ -288,9 +287,9 @@ void Smt2::addSepOperators() {
 
 void Smt2::addCoreSymbols()
 {
-  defineType("Bool", d_solver->getBooleanSort());
-  defineVar("true", d_solver->mkTrue());
-  defineVar("false", d_solver->mkFalse());
+  defineType("Bool", d_solver->getBooleanSort(), true, true);
+  defineVar("true", d_solver->mkTrue(), true, true);
+  defineVar("false", d_solver->mkFalse(), true, true);
   addOperator(api::AND, "and");
   addOperator(api::DISTINCT, "distinct");
   addOperator(api::EQUAL, "=");
@@ -472,10 +471,7 @@ void Smt2::reset() {
   operatorKindMap.clear();
   d_lastNamedTerm = std::pair<api::Term, std::string>();
   this->Parser::reset();
-
-  if( !strictModeEnabled() ) {
-    addCoreSymbols();
-  }
+  pushScope(true);
 }
 
 void Smt2::resetAssertions() {
@@ -483,6 +479,7 @@ void Smt2::resetAssertions() {
   while (this->scopeLevel() > 0) {
     this->popScope();
   }
+  pushScope(true);
 }
 
 Smt2::SynthFunFactory::SynthFunFactory(
@@ -604,7 +601,7 @@ Command* Smt2::setLogic(std::string name, bool fromCommand)
 
   if(d_logic.isTheoryEnabled(theory::THEORY_ARITH)) {
     if(d_logic.areIntegersUsed()) {
-      defineType("Int", d_solver->getIntegerSort());
+      defineType("Int", d_solver->getIntegerSort(), true, true);
       addArithmeticOperators();
       addOperator(api::INTS_DIVISION, "div");
       addOperator(api::INTS_MODULUS, "mod");
@@ -614,7 +611,7 @@ Command* Smt2::setLogic(std::string name, bool fromCommand)
 
     if (d_logic.areRealsUsed())
     {
-      defineType("Real", d_solver->getRealSort());
+      defineType("Real", d_solver->getRealSort(), true, true);
       addArithmeticOperators();
       addOperator(api::DIVISION, "/");
       if (!strictModeEnabled())
@@ -663,7 +660,7 @@ Command* Smt2::setLogic(std::string name, bool fromCommand)
 
   if(d_logic.isTheoryEnabled(theory::THEORY_DATATYPES)) {
     const std::vector<api::Sort> types;
-    defineType("Tuple", d_solver->mkTupleSort(types));
+    defineType("Tuple", d_solver->mkTupleSort(types), true, true);
     addDatatypesOperators();
   }
 
@@ -708,9 +705,9 @@ Command* Smt2::setLogic(std::string name, bool fromCommand)
     addOperator(api::BAG_TO_SET, "bag.to_set");
   }
   if(d_logic.isTheoryEnabled(theory::THEORY_STRINGS)) {
-    defineType("String", d_solver->getStringSort());
-    defineType("RegLan", d_solver->getRegExpSort());
-    defineType("Int", d_solver->getIntegerSort());
+    defineType("String", d_solver->getStringSort(), true, true);
+    defineType("RegLan", d_solver->getRegExpSort(), true, true);
+    defineType("Int", d_solver->getIntegerSort(), true, true);
 
     if (getLanguage() == language::input::LANG_SMTLIB_V2_6
         || getLanguage() == language::input::LANG_SYGUS_V2)
@@ -735,11 +732,11 @@ Command* Smt2::setLogic(std::string name, bool fromCommand)
   }
 
   if (d_logic.isTheoryEnabled(theory::THEORY_FP)) {
-    defineType("RoundingMode", d_solver->getRoundingModeSort());
-    defineType("Float16", d_solver->mkFloatingPointSort(5, 11));
-    defineType("Float32", d_solver->mkFloatingPointSort(8, 24));
-    defineType("Float64", d_solver->mkFloatingPointSort(11, 53));
-    defineType("Float128", d_solver->mkFloatingPointSort(15, 113));
+    defineType("RoundingMode", d_solver->getRoundingModeSort(), true, true);
+    defineType("Float16", d_solver->mkFloatingPointSort(5, 11), true, true);
+    defineType("Float32", d_solver->mkFloatingPointSort(8, 24), true, true);
+    defineType("Float64", d_solver->mkFloatingPointSort(11, 53), true, true);
+    defineType("Float128", d_solver->mkFloatingPointSort(15, 113), true, true);
 
     defineVar("RNE", d_solver->mkRoundingMode(api::ROUND_NEAREST_TIES_TO_EVEN));
     defineVar("roundNearestTiesToEven",
diff --git a/src/parser/smt2/smt2.h b/src/parser/smt2/smt2.h
index a698b9633..5fcf49637 100644
--- a/src/parser/smt2/smt2.h
+++ b/src/parser/smt2/smt2.h
@@ -73,6 +73,8 @@ class Smt2 : public Parser
        bool parseOnly = false);
 
  public:
+  ~Smt2();
+
   /**
    * Add core theory symbols to the parser state.
    */
diff --git a/src/preprocessing/passes/ho_elim.cpp b/src/preprocessing/passes/ho_elim.cpp
index 34645b441..445cac18e 100644
--- a/src/preprocessing/passes/ho_elim.cpp
+++ b/src/preprocessing/passes/ho_elim.cpp
@@ -33,8 +33,8 @@ HoElim::HoElim(PreprocessingPassContext* preprocContext)
 Node HoElim::eliminateLambdaComplete(Node n, std::map<Node, Node>& newLambda)
 {
   NodeManager* nm = NodeManager::currentNM();
-  std::unordered_map<TNode, Node, TNodeHashFunction>::iterator it;
-  std::vector<TNode> visit;
+  std::unordered_map<Node, Node, TNodeHashFunction>::iterator it;
+  std::vector<Node> visit;
   TNode cur;
   visit.push_back(n);
   do
@@ -148,7 +148,7 @@ Node HoElim::eliminateHo(Node n)
 {
   Trace("ho-elim-assert") << "Ho-elim assertion: " << n << std::endl;
   NodeManager* nm = NodeManager::currentNM();
-  std::unordered_map<TNode, Node, TNodeHashFunction>::iterator it;
+  std::unordered_map<Node, Node, NodeHashFunction>::iterator it;
   std::map<Node, Node> preReplace;
   std::map<Node, Node>::iterator itr;
   std::vector<TNode> visit;
@@ -319,7 +319,7 @@ PreprocessingPassResult HoElim::applyInternal(
   {
     std::map<Node, Node> lproc = newLambda;
     newLambda.clear();
-    for (const std::pair<Node, Node>& l : lproc)
+    for (const std::pair<const Node, Node>& l : lproc)
     {
       Node lambda = l.second;
       std::vector<Node> vars;
diff --git a/src/preprocessing/passes/ho_elim.h b/src/preprocessing/passes/ho_elim.h
index 1a3142b39..2edc96074 100644
--- a/src/preprocessing/passes/ho_elim.h
+++ b/src/preprocessing/passes/ho_elim.h
@@ -112,7 +112,7 @@ class HoElim : public PreprocessingPass
    * Stores the set of nodes we have current visited and their results
    * in steps [1] and [2] of this pass.
    */
-  std::unordered_map<TNode, Node, TNodeHashFunction> d_visited;
+  std::unordered_map<Node, Node, NodeHashFunction> d_visited;
   /**
    * Stores the mapping from functions f to their corresponding function H(f)
    * in the encoding for step [2] of this pass.
diff --git a/test/regress/CMakeLists.txt b/test/regress/CMakeLists.txt
index cc5c911ff..1eca91a5a 100644
--- a/test/regress/CMakeLists.txt
+++ b/test/regress/CMakeLists.txt
@@ -644,6 +644,7 @@ set(regress_0_tests
   regress0/parser/declarefun-emptyset-uf.smt2
   regress0/parser/force_logic_set_logic.smt2
   regress0/parser/force_logic_success.smt2
+  regress0/parser/issue5163.smt2
   regress0/parser/shadow_fun_symbol_all.smt2
   regress0/parser/shadow_fun_symbol_nirat.smt2
   regress0/parser/strings20.smt2
diff --git a/test/regress/regress0/parser/issue5163.smt2 b/test/regress/regress0/parser/issue5163.smt2
new file mode 100644
index 000000000..8bb7c382f
--- /dev/null
+++ b/test/regress/regress0/parser/issue5163.smt2
@@ -0,0 +1,10 @@
+; SCRUBBER: grep -o "Symbol a is not declared"
+; EXPECT: Symbol a is not declared
+; EXIT: 1
+(set-logic ALL)
+(define-fun a () Bool false)
+(reset-assertions)
+(declare-const x Int)
+(assert (and (= (+ x x) 0) true))
+(assert a)
+(check-sat)
diff --git a/test/regress/regress0/smtlib/issue4077.smt2 b/test/regress/regress0/smtlib/issue4077.smt2
index 76a37886b..6ce3f4b01 100644
--- a/test/regress/regress0/smtlib/issue4077.smt2
+++ b/test/regress/regress0/smtlib/issue4077.smt2
@@ -3,6 +3,7 @@
 
 ; Use a quantified logic to make sure that TheoryEngine creates a master
 ; equality engine
+(set-option :global-declarations true)
 (set-logic BV)
 (declare-const x (_ BitVec 4))
 (push)
diff --git a/test/regress/regress0/smtlib/reset-assertions1.smt2 b/test/regress/regress0/smtlib/reset-assertions1.smt2
index 7b4006c5d..244b0ecd9 100644
--- a/test/regress/regress0/smtlib/reset-assertions1.smt2
+++ b/test/regress/regress0/smtlib/reset-assertions1.smt2
@@ -1,5 +1,6 @@
 ; EXPECT: unsat
 ; EXPECT: sat
+(set-option :global-declarations true)
 (set-logic QF_BV)
 (declare-fun v0 () (_ BitVec 4))
 (set-option :produce-models true)
diff --git a/test/regress/regress1/sygus/interpol_cosa_1.smt2 b/test/regress/regress1/sygus/interpol_cosa_1.smt2
index 583f94ed4..7e349996d 100644
--- a/test/regress/regress1/sygus/interpol_cosa_1.smt2
+++ b/test/regress/regress1/sygus/interpol_cosa_1.smt2
@@ -12,7 +12,6 @@
 (declare-fun clk@1 () (_ BitVec 1))
 (declare-fun a@1 () (_ BitVec 16))
 (declare-fun b@1 () (_ BitVec 16))
-(reset-assertions)
 (declare-fun cfg@0 () (_ BitVec 1))
 (declare-fun witness_0@0 () Bool)
 (declare-fun counter@0 () (_ BitVec 16))