string Z3Solver::ToString(u32 Verbosity) const
{
if (Ctx != Z3Ctx::NullPtr && Solver != nullptr) {
return string(Z3_solver_to_string(*Ctx, Solver));
} else {
return "nullsolver";
}
}
bool Z3SolverImpl::validateZ3Model(::Z3_solver &theSolver, ::Z3_model &theModel) {
bool success = true;
::Z3_ast_vector constraints =
Z3_solver_get_assertions(builder->ctx, theSolver);
Z3_ast_vector_inc_ref(builder->ctx, constraints);
unsigned size = Z3_ast_vector_size(builder->ctx, constraints);
for (unsigned index = 0; index < size; ++index) {
Z3ASTHandle constraint = Z3ASTHandle(
Z3_ast_vector_get(builder->ctx, constraints, index), builder->ctx);
::Z3_ast rawEvaluatedExpr;
bool successfulEval =
Z3_model_eval(builder->ctx, theModel, constraint,
/*model_completion=*/Z3_TRUE, &rawEvaluatedExpr);
assert(successfulEval && "Failed to evaluate model");
// Use handle to do ref-counting.
Z3ASTHandle evaluatedExpr(rawEvaluatedExpr, builder->ctx);
Z3SortHandle sort =
Z3SortHandle(Z3_get_sort(builder->ctx, evaluatedExpr), builder->ctx);
assert(Z3_get_sort_kind(builder->ctx, sort) == Z3_BOOL_SORT &&
"Evaluated expression has wrong sort");
Z3_lbool evaluatedValue =
Z3_get_bool_value(builder->ctx, evaluatedExpr);
if (evaluatedValue != Z3_L_TRUE) {
llvm::errs() << "Validating model failed:\n"
<< "The expression:\n";
constraint.dump();
llvm::errs() << "evaluated to \n";
evaluatedExpr.dump();
llvm::errs() << "But should be true\n";
success = false;
}
}
if (!success) {
llvm::errs() << "Solver state:\n" << Z3_solver_to_string(builder->ctx, theSolver) << "\n";
llvm::errs() << "Model:\n" << Z3_model_to_string(builder->ctx, theModel) << "\n";
}
Z3_ast_vector_dec_ref(builder->ctx, constraints);
return success;
}
bool Z3SolverImpl::internalRunSolver(
const Query &query, const std::vector<const Array *> *objects,
std::vector<std::vector<unsigned char> > *values, bool &hasSolution) {
TimerStatIncrementer t(stats::queryTime);
// NOTE: Z3 will switch to using a slower solver internally if push/pop are
// used so for now it is likely that creating a new solver each time is the
// right way to go until Z3 changes its behaviour.
//
// TODO: Investigate using a custom tactic as described in
// https://github.com/klee/klee/issues/653
Z3_solver theSolver = Z3_mk_solver(builder->ctx);
Z3_solver_inc_ref(builder->ctx, theSolver);
Z3_solver_set_params(builder->ctx, theSolver, solverParameters);
runStatusCode = SOLVER_RUN_STATUS_FAILURE;
for (ConstraintManager::const_iterator it = query.constraints.begin(),
ie = query.constraints.end();
it != ie; ++it) {
Z3_solver_assert(builder->ctx, theSolver, builder->construct(*it));
}
++stats::queries;
if (objects)
++stats::queryCounterexamples;
Z3ASTHandle z3QueryExpr =
Z3ASTHandle(builder->construct(query.expr), builder->ctx);
// KLEE Queries are validity queries i.e.
// ∀ X Constraints(X) → query(X)
// but Z3 works in terms of satisfiability so instead we ask the
// negation of the equivalent i.e.
// ∃ X Constraints(X) ∧ ¬ query(X)
Z3_solver_assert(
builder->ctx, theSolver,
Z3ASTHandle(Z3_mk_not(builder->ctx, z3QueryExpr), builder->ctx));
if (dumpedQueriesFile) {
*dumpedQueriesFile << "; start Z3 query\n";
*dumpedQueriesFile << Z3_solver_to_string(builder->ctx, theSolver);
*dumpedQueriesFile << "(check-sat)\n";
*dumpedQueriesFile << "(reset)\n";
*dumpedQueriesFile << "; end Z3 query\n\n";
dumpedQueriesFile->flush();
}
::Z3_lbool satisfiable = Z3_solver_check(builder->ctx, theSolver);
runStatusCode = handleSolverResponse(theSolver, satisfiable, objects, values,
hasSolution);
Z3_solver_dec_ref(builder->ctx, theSolver);
// Clear the builder's cache to prevent memory usage exploding.
// By using ``autoClearConstructCache=false`` and clearning now
// we allow Z3_ast expressions to be shared from an entire
// ``Query`` rather than only sharing within a single call to
// ``builder->construct()``.
builder->clearConstructCache();
if (runStatusCode == SolverImpl::SOLVER_RUN_STATUS_SUCCESS_SOLVABLE ||
runStatusCode == SolverImpl::SOLVER_RUN_STATUS_SUCCESS_UNSOLVABLE) {
if (hasSolution) {
++stats::queriesInvalid;
} else {
++stats::queriesValid;
}
return true; // success
}
return false; // failed
}