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z3/src/interp/iz3interp.cpp
2017-05-19 16:21:57 -07:00

574 lines
18 KiB
C++
Executable file

/*++
Copyright (c) 2011 Microsoft Corporation
Module Name:
iz3interp.cpp
Abstract:
Interpolation based on proof translation.
Author:
Ken McMillan (kenmcmil)
Revision History:
--*/
/* Copyright 2011 Microsoft Research. */
#ifdef _WINDOWS
#pragma warning(disable:4996)
#pragma warning(disable:4800)
#pragma warning(disable:4267)
#pragma warning(disable:4101)
#endif
#include <algorithm>
#include <stdio.h>
#include <fstream>
#include <sstream>
#include <set>
#include <iostream>
#include "iz3profiling.h"
#include "iz3translate.h"
#include "iz3proof.h"
#include "iz3hash.h"
#include "iz3interp.h"
#include"scoped_proof.h"
using namespace stl_ext;
#if 1
struct frame_reducer : public iz3mgr {
int frames;
hash_map<ast,int> frame_map;
std::vector<int> assertions_map;
std::vector<int> orig_parents_copy;
std::vector<bool> used_frames;
frame_reducer(const iz3mgr &other)
: iz3mgr(other) {}
void get_proof_assumptions_rec(z3pf proof, hash_set<ast> &memo, std::vector<bool> &used_frames){
if(memo.find(proof) != memo.end())return;
memo.insert(proof);
pfrule dk = pr(proof);
if(dk == PR_ASSERTED){
ast con = conc(proof);
if(frame_map.find(con) != frame_map.end()){ // false for theory facts
int frame = frame_map[con];
used_frames[frame] = true;
}
}
else {
unsigned nprems = num_prems(proof);
for(unsigned i = 0; i < nprems; i++){
z3pf arg = prem(proof,i);
get_proof_assumptions_rec(arg,memo,used_frames);
}
}
}
void get_frames(const std::vector<std::vector<ast> >&z3_preds,
const std::vector<int> &orig_parents,
std::vector<std::vector<ast> >&assertions,
std::vector<int> &parents,
z3pf proof){
frames = z3_preds.size();
orig_parents_copy = orig_parents;
for(unsigned i = 0; i < z3_preds.size(); i++)
for(unsigned j = 0; j < z3_preds[i].size(); j++)
frame_map[z3_preds[i][j]] = i;
used_frames.resize(frames);
hash_set<ast> memo;
get_proof_assumptions_rec(proof,memo,used_frames);
std::vector<int> assertions_back_map(frames);
// if multiple children of a tree node are used, we can't delete it
std::vector<int> used_children;
for(int i = 0; i < frames; i++)
used_children.push_back(0);
for(int i = 0; i < frames; i++)
if(orig_parents[i] != SHRT_MAX)
if(used_frames[i] || used_children[i]){
if(used_children[i] > 1)
used_frames[i] = true;
used_children[orig_parents[i]]++;
}
for(unsigned i = 0; i < z3_preds.size(); i++)
if(used_frames[i] || i == z3_preds.size() - 1){
assertions.push_back(z3_preds[i]);
assertions_map.push_back(i);
assertions_back_map[i] = assertions.size() - 1;
}
if(orig_parents.size()){
parents.resize(assertions.size());
for(unsigned i = 0; i < assertions.size(); i++){
int p = orig_parents[assertions_map[i]];
while(p != SHRT_MAX && !used_frames[p])
p = orig_parents[p];
parents[i] = p == SHRT_MAX ? p : assertions_back_map[p];
}
}
// std::cout << "used frames = " << frames << "\n";
}
void fix_interpolants(std::vector<ast> &interpolants){
std::vector<ast> unfixed = interpolants;
interpolants.resize(frames - 1);
for(int i = 0; i < frames - 1; i++)
interpolants[i] = mk_true();
for(unsigned i = 0; i < unfixed.size(); i++)
interpolants[assertions_map[i]] = unfixed[i];
for(int i = 0; i < frames-2; i++){
int p = orig_parents_copy.size() == 0 ? i+1 : orig_parents_copy[i];
if(p < frames - 1 && !used_frames[p])
interpolants[p] = mk_and(interpolants[i],interpolants[p]);
}
}
};
#else
struct frame_reducer {
frame_reducer(context _ctx){
}
void get_frames(const std::vector<ast> &z3_preds,
const std::vector<int> &orig_parents,
std::vector<ast> &assertions,
std::vector<int> &parents,
ast proof){
assertions = z3_preds;
parents = orig_parents;
}
void fix_interpolants(std::vector<ast> &interpolants){
}
};
#endif
template<class T>
struct killme {
T *p;
killme(){p = 0;}
void set(T *_p) {p = _p;}
~killme(){
if(p)
delete p;
}
};
class iz3interp : public iz3base {
public:
killme<iz3secondary> sp_killer;
killme<iz3translation> tr_killer;
bool is_linear(std::vector<int> &parents){
for(int i = 0; i < ((int)parents.size())-1; i++)
if(parents[i] != i+1)
return false;
return true;
}
void test_secondary(const std::vector<ast> &cnsts,
const std::vector<int> &parents,
std::vector<ast> &interps
){
throw iz3_exception("secondary interpolating prover not supported");
}
void proof_to_interpolant(z3pf proof,
const std::vector<std::vector<ast> > &cnsts,
const std::vector<int> &parents,
std::vector<ast> &interps,
const std::vector<ast> &theory,
interpolation_options_struct *options = 0
){
#if 0
test_secondary(cnsts,parents,interps);
return;
#endif
profiling::timer_start("Interpolation prep");
// get rid of frames not used in proof
std::vector<std::vector<ast> > cnsts_vec;
std::vector<int> parents_vec;
frame_reducer fr(*this);
fr.get_frames(cnsts,parents,cnsts_vec,parents_vec,proof);
int num = cnsts_vec.size();
std::vector<ast> interps_vec(num-1);
// if this is really a sequence problem, we can make it easier
if(is_linear(parents_vec))
parents_vec.clear();
// secondary prover no longer supported
iz3secondary *sp = NULL;
#define BINARY_INTERPOLATION
#ifndef BINARY_INTERPOLATION
// create a translator
iz3translation *tr = iz3translation::create(*this,sp,cnsts_vec,parents_vec,theory);
tr_killer.set(tr);
// set the translation options, if needed
if(options)
for(hash_map<std::string,std::string>::iterator it = options->map.begin(), en = options->map.end(); it != en; ++it)
tr->set_option(it->first, it->second);
// create a proof object to hold the translation
iz3proof pf(tr);
profiling::timer_stop("Interpolation prep");
// translate into an interpolatable proof
profiling::timer_start("Proof translation");
try {
tr->translate(proof,pf);
}
catch (const char *msg) {
throw interpolation_failure(msg);
}
catch (const iz3translation::unsupported &) {
throw interpolation_error();
}
catch (const iz3proof::proof_error &) {
throw interpolation_error();
}
profiling::timer_stop("Proof translation");
// translate the proof into interpolants
profiling::timer_start("Proof interpolation");
for(int i = 0; i < num-1; i++){
interps_vec[i] = pf.interpolate(tr->range_downward(i),tr->weak_mode());
interps_vec[i] = tr->quantify(interps_vec[i],tr->range_downward(i));
}
profiling::timer_stop("Proof interpolation");
#else
iz3base the_base(*this,cnsts_vec,parents_vec,theory);
profiling::timer_stop("Interpolation prep");
for(int i = 0; i < num-1; i++){
range rng = the_base.range_downward(i);
std::vector<std::vector<ast> > cnsts_vec_vec(2);
for(unsigned j = 0; j < cnsts_vec.size(); j++){
bool is_A = the_base.in_range(j,rng);
for(unsigned k = 0; k < cnsts_vec[j].size(); k++)
cnsts_vec_vec[is_A ? 0 : 1].push_back(cnsts_vec[j][k]);
}
killme<iz3translation> tr_killer_i;
iz3translation *tr = iz3translation::create(*this,sp,cnsts_vec_vec,std::vector<int>(),theory);
tr_killer_i.set(tr);
// set the translation options, if needed
if(options)
for(hash_map<std::string,std::string>::iterator it = options->map.begin(), en = options->map.end(); it != en; ++it)
tr->set_option(it->first, it->second);
// create a proof object to hold the translation
iz3proof pf(tr);
// translate into an interpolatable proof
profiling::timer_start("Proof translation");
try {
tr->translate(proof,pf);
}
catch (const char *msg) {
throw interpolation_failure(msg);
}
catch (const iz3translation::unsupported &) {
throw interpolation_error();
}
catch (const iz3proof::proof_error &) {
throw interpolation_error();
}
profiling::timer_stop("Proof translation");
// translate the proof into interpolants
profiling::timer_start("Proof interpolation");
interps_vec[i] = pf.interpolate(tr->range_downward(0),tr->weak_mode());
interps_vec[i] = tr->quantify(interps_vec[i],tr->range_downward(0));
profiling::timer_stop("Proof interpolation");
}
#endif
// put back in the removed frames
fr.fix_interpolants(interps_vec);
interps = interps_vec;
}
void proof_to_interpolant(z3pf proof,
std::vector<ast> &cnsts,
const std::vector<int> &parents,
std::vector<ast> &interps,
const std::vector<ast> &theory,
interpolation_options_struct *options = 0
){
std::vector<std::vector<ast> > cnsts_vec(cnsts.size());
for(unsigned i = 0; i < cnsts.size(); i++)
cnsts_vec[i].push_back(cnsts[i]);
proof_to_interpolant(proof,cnsts_vec,parents,interps,theory,options);
}
// same as above, but represents the tree using an ast
void proof_to_interpolant(const z3pf &proof,
const std::vector<ast> &_cnsts,
const ast &tree,
std::vector<ast> &interps,
interpolation_options_struct *options = 0
){
std::vector<int> pos_map;
// convert to the parents vector representation
to_parents_vec_representation(_cnsts, tree, cnsts, parents, theory, pos_map);
//use the parents vector representation to compute interpolant
proof_to_interpolant(proof,cnsts,parents,interps,theory,options);
// get the interps for the tree positions
std::vector<ast> _interps = interps;
interps.resize(pos_map.size());
for(unsigned i = 0; i < pos_map.size(); i++){
unsigned j = pos_map[i];
interps[i] = j < _interps.size() ? _interps[j] : mk_false();
}
}
bool has_interp(hash_map<ast,bool> &memo, const ast &t){
if(memo.find(t) != memo.end())
return memo[t];
bool res = false;
if(op(t) == Interp)
res = true;
else if(op(t) == And){
int nargs = num_args(t);
for(int i = 0; i < nargs; i++)
res |= has_interp(memo, arg(t,i));
}
memo[t] = res;
return res;
}
void collect_conjuncts(std::vector<ast> &cnsts, hash_map<ast,bool> &memo, const ast &t){
if(!has_interp(memo,t))
cnsts.push_back(t);
else {
int nargs = num_args(t);
for(int i = 0; i < nargs; i++)
collect_conjuncts(cnsts, memo, arg(t,i));
}
}
void assert_conjuncts(solver &s, std::vector<ast> &cnsts, const ast &t){
hash_map<ast,bool> memo;
collect_conjuncts(cnsts,memo,t);
for(unsigned i = 0; i < cnsts.size(); i++)
s.assert_expr(to_expr(cnsts[i].raw()));
}
void get_proof_assumptions(z3pf proof, std::vector<ast> &cnsts, hash_set<ast> &memo){
if(memo.find(proof) != memo.end())return;
memo.insert(proof);
pfrule dk = pr(proof);
if(dk == PR_ASSERTED)
cnsts.push_back(conc(proof));
else {
unsigned nprems = num_prems(proof);
for(unsigned i = 0; i < nprems; i++){
z3pf arg = prem(proof,i);
get_proof_assumptions(arg,cnsts,memo);
}
}
}
iz3interp(ast_manager &_m_manager)
: iz3base(_m_manager) {}
};
void iz3interpolate(ast_manager &_m_manager,
ast *proof,
const ptr_vector<ast> &cnsts,
const ::vector<int> &parents,
ptr_vector<ast> &interps,
const ptr_vector<ast> &theory,
interpolation_options_struct * options)
{
iz3interp itp(_m_manager);
if(options)
options->apply(itp);
std::vector<iz3mgr::ast> _cnsts(cnsts.size());
std::vector<int> _parents(parents.size());
std::vector<iz3mgr::ast> _interps;
std::vector<iz3mgr::ast> _theory(theory.size());
for(unsigned i = 0; i < cnsts.size(); i++)
_cnsts[i] = itp.cook(cnsts[i]);
for(unsigned i = 0; i < parents.size(); i++)
_parents[i] = parents[i];
for(unsigned i = 0; i < theory.size(); i++)
_theory[i] = itp.cook(theory[i]);
iz3mgr::ast _proof = itp.cook(proof);
itp.proof_to_interpolant(_proof,_cnsts,_parents,_interps,_theory,options);
interps.resize(_interps.size());
for(unsigned i = 0; i < interps.size(); i++)
interps[i] = itp.uncook(_interps[i]);
}
void iz3interpolate(ast_manager &_m_manager,
ast *proof,
const ::vector<ptr_vector<ast> > &cnsts,
const ::vector<int> &parents,
ptr_vector<ast> &interps,
const ptr_vector<ast> &theory,
interpolation_options_struct * options)
{
iz3interp itp(_m_manager);
if(options)
options->apply(itp);
std::vector<std::vector<iz3mgr::ast> > _cnsts(cnsts.size());
std::vector<int> _parents(parents.size());
std::vector<iz3mgr::ast> _interps;
std::vector<iz3mgr::ast> _theory(theory.size());
for(unsigned i = 0; i < cnsts.size(); i++)
for(unsigned j = 0; j < cnsts[i].size(); j++)
_cnsts[i].push_back(itp.cook(cnsts[i][j]));
for(unsigned i = 0; i < parents.size(); i++)
_parents[i] = parents[i];
for(unsigned i = 0; i < theory.size(); i++)
_theory[i] = itp.cook(theory[i]);
iz3mgr::ast _proof = itp.cook(proof);
itp.proof_to_interpolant(_proof,_cnsts,_parents,_interps,_theory,options);
interps.resize(_interps.size());
for(unsigned i = 0; i < interps.size(); i++)
interps[i] = itp.uncook(_interps[i]);
}
void iz3interpolate(ast_manager &_m_manager,
ast *proof,
const ptr_vector<ast> &cnsts,
ast *tree,
ptr_vector<ast> &interps,
interpolation_options_struct * options)
{
iz3interp itp(_m_manager);
if(options)
options->apply(itp);
std::vector<iz3mgr::ast> _cnsts(cnsts.size());
std::vector<iz3mgr::ast> _interps;
for(unsigned i = 0; i < cnsts.size(); i++)
_cnsts[i] = itp.cook(cnsts[i]);
iz3mgr::ast _proof = itp.cook(proof);
iz3mgr::ast _tree = itp.cook(tree);
// if consts isn't provided, we can reconstruct it
if(_cnsts.empty()){
hash_set<iz3mgr::ast> memo;
itp.get_proof_assumptions(_proof,_cnsts,memo);
}
itp.proof_to_interpolant(_proof,_cnsts,_tree,_interps,options);
interps.resize(_interps.size());
for(unsigned i = 0; i < interps.size(); i++)
interps[i] = itp.uncook(_interps[i]);
}
lbool iz3interpolate(ast_manager &_m_manager,
solver &s,
ast *tree,
ptr_vector<ast> &cnsts,
ptr_vector<ast> &interps,
model_ref &m,
interpolation_options_struct * options)
{
iz3interp itp(_m_manager);
if(options)
options->apply(itp);
iz3mgr::ast _tree = itp.cook(tree);
std::vector<iz3mgr::ast> _cnsts;
itp.assert_conjuncts(s,_cnsts,_tree);
profiling::timer_start("solving");
lbool res = s.check_sat(0,0);
profiling::timer_stop("solving");
if(res == l_false){
ast *proof = s.get_proof();
iz3mgr::ast _proof = itp.cook(proof);
std::vector<iz3mgr::ast> _interps;
itp.proof_to_interpolant(_proof,_cnsts,_tree,_interps,options);
interps.resize(_interps.size());
for(unsigned i = 0; i < interps.size(); i++)
interps[i] = itp.uncook(_interps[i]);
}
else if(m){
s.get_model(m);
}
cnsts.resize(_cnsts.size());
for(unsigned i = 0; i < cnsts.size(); i++)
cnsts[i] = itp.uncook(_cnsts[i]);
return res;
}
void interpolation_options_struct::apply(iz3base &b){
for(stl_ext::hash_map<std::string,std::string>::iterator it = map.begin(), en = map.end();
it != en;
++it)
b.set_option((*it).first,(*it).second);
}
// On linux and mac, unlimit stack space so we get recursion
#if defined(_WINDOWS) || defined(_CYGWIN)
#else
#include <sys/time.h>
#include <sys/resource.h>
class iz3stack_unlimiter {
public:
iz3stack_unlimiter() {
struct rlimit rl = {RLIM_INFINITY, RLIM_INFINITY};
setrlimit(RLIMIT_STACK, &rl);
// nothing to be done if above fails
}
};
// initializing this will unlimit stack
iz3stack_unlimiter the_iz3stack_unlimiter;
#endif