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//===-- AssignmentValidatingSolver.cpp ------------------------------------===//
//
// The KLEE Symbolic Virtual Machine
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "klee/Expr/Constraints.h"
#include "klee/Expr/Assignment.h"
#include "klee/Solver/Solver.h"
#include "klee/Solver/SolverImpl.h"
#include <memory>
#include <utility>
#include <vector>
namespace klee {
class AssignmentValidatingSolver : public SolverImpl {
private:
std::unique_ptr<Solver> solver;
void dumpAssignmentQuery(const Query &query, const Assignment &assignment);
public:
AssignmentValidatingSolver(std::unique_ptr<Solver> solver)
: solver(std::move(solver)) {}
bool computeValidity(const Query &, Solver::Validity &result);
bool computeTruth(const Query &, bool &isValid);
bool computeValue(const Query &, ref<Expr> &result);
bool computeInitialValues(const Query &,
const std::vector<const Array *> &objects,
std::vector<std::vector<unsigned char> > &values,
bool &hasSolution);
SolverRunStatus getOperationStatusCode();
char *getConstraintLog(const Query &);
void setCoreSolverTimeout(time::Span timeout);
};
// TODO: use computeInitialValues for all queries for more stress testing
bool AssignmentValidatingSolver::computeValidity(const Query &query,
Solver::Validity &result) {
return solver->impl->computeValidity(query, result);
}
bool AssignmentValidatingSolver::computeTruth(const Query &query,
bool &isValid) {
return solver->impl->computeTruth(query, isValid);
}
bool AssignmentValidatingSolver::computeValue(const Query &query,
ref<Expr> &result) {
return solver->impl->computeValue(query, result);
}
bool AssignmentValidatingSolver::computeInitialValues(
const Query &query, const std::vector<const Array *> &objects,
std::vector<std::vector<unsigned char> > &values, bool &hasSolution) {
bool success =
solver->impl->computeInitialValues(query, objects, values, hasSolution);
if (!hasSolution)
return success;
// Use `_allowFreeValues` so that if we are missing an assignment
// we can't compute a constant and flag this as a problem.
Assignment assignment(objects, values, /*_allowFreeValues=*/true);
// Check computed assignment satisfies query
for (const auto &constraint : query.constraints) {
ref<Expr> constraintEvaluated = assignment.evaluate(constraint);
ConstantExpr *CE = dyn_cast<ConstantExpr>(constraintEvaluated);
if (CE == NULL) {
llvm::errs() << "Constraint did not evalaute to a constant:\n";
llvm::errs() << "Constraint:\n" << constraint << "\n";
llvm::errs() << "Evaluated Constraint:\n" << constraintEvaluated << "\n";
llvm::errs() << "Assignment:\n";
assignment.dump();
dumpAssignmentQuery(query, assignment);
abort();
}
if (CE->isFalse()) {
llvm::errs() << "Constraint evaluated to false when using assignment\n";
llvm::errs() << "Constraint:\n" << constraint << "\n";
llvm::errs() << "Assignment:\n";
assignment.dump();
dumpAssignmentQuery(query, assignment);
abort();
}
}
ref<Expr> queryExprEvaluated = assignment.evaluate(query.expr);
ConstantExpr *CE = dyn_cast<ConstantExpr>(queryExprEvaluated);
if (CE == NULL) {
llvm::errs() << "Query expression did not evalaute to a constant:\n";
llvm::errs() << "Expression:\n" << query.expr << "\n";
llvm::errs() << "Evaluated expression:\n" << queryExprEvaluated << "\n";
llvm::errs() << "Assignment:\n";
assignment.dump();
dumpAssignmentQuery(query, assignment);
abort();
}
// KLEE queries are validity queries. A counter example to
// ∀ x constraints(x) → query(x)
// exists therefore
// ¬∀ x constraints(x) → query(x)
// Which is equivalent to
// ∃ x constraints(x) ∧ ¬ query(x)
// This means for the assignment we get back query expression should evaluate
// to false.
if (CE->isTrue()) {
llvm::errs()
<< "Query Expression evaluated to true when using assignment\n";
llvm::errs() << "Expression:\n" << query.expr << "\n";
llvm::errs() << "Assignment:\n";
assignment.dump();
dumpAssignmentQuery(query, assignment);
abort();
}
return success;
}
void AssignmentValidatingSolver::dumpAssignmentQuery(
const Query &query, const Assignment &assignment) {
// Create a Query that is augmented with constraints that
// enforce the given assignment.
auto constraints = assignment.createConstraintsFromAssignment();
// Add Constraints from `query`
for (const auto &constraint : query.constraints)
constraints.push_back(constraint);
Query augmentedQuery(constraints, query.expr);
// Ask the solver for the log for this query.
char *logText = solver->getConstraintLog(augmentedQuery);
llvm::errs() << "Query with assignment as constraints:\n" << logText << "\n";
free(logText);
}
SolverImpl::SolverRunStatus
AssignmentValidatingSolver::getOperationStatusCode() {
return solver->impl->getOperationStatusCode();
}
char *AssignmentValidatingSolver::getConstraintLog(const Query &query) {
return solver->impl->getConstraintLog(query);
}
void AssignmentValidatingSolver::setCoreSolverTimeout(time::Span timeout) {
return solver->impl->setCoreSolverTimeout(timeout);
}
std::unique_ptr<Solver>
createAssignmentValidatingSolver(std::unique_ptr<Solver> s) {
return std::make_unique<Solver>(
std::make_unique<AssignmentValidatingSolver>(std::move(s)));
}
}
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