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//-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using Microsoft.Contracts;
using Microsoft.Boogie.VCExprAST;
namespace Microsoft.Boogie.Z3
{
// Visitor for collecting the occurring function symbols in a VCExpr,
// and for creating the corresponding declarations that can be fed into
// Z3
// (should this be rather done by Context.DeclareFunction? right now,
// the TypeErasure visitor introduces new function symbols that are
// not passed to this method)
public class TypeDeclCollector : BoundVarTraversingVCExprVisitor<bool, bool> {
private readonly UniqueNamer! Namer;
private readonly bool NativeBv;
public TypeDeclCollector(UniqueNamer! namer, bool nativeBv) {
this.Namer = namer;
this.NativeBv = nativeBv;
AllDecls = new List<string!> ();
IncDecls = new List<string!> ();
KnownFunctions = new Dictionary<Function!, bool> ();
KnownVariables = new Dictionary<VCExprVar!, bool> ();
KnownTypes = new Dictionary<Type!, bool> ();
KnownBvOps = new Dictionary<string!, bool> ();
}
internal TypeDeclCollector(UniqueNamer! namer, TypeDeclCollector! coll) {
this.Namer = namer;
this.NativeBv = coll.NativeBv;
AllDecls = new List<string!> (coll.AllDecls);
IncDecls = new List<string!> (coll.IncDecls);
KnownFunctions = new Dictionary<Function!, bool> (coll.KnownFunctions);
KnownVariables = new Dictionary<VCExprVar!, bool> (coll.KnownVariables);
KnownTypes = new Dictionary<Type!, bool> (coll.KnownTypes);
KnownBvOps = new Dictionary<string!, bool> (coll.KnownBvOps);
}
// not used
protected override bool StandardResult(VCExpr! node, bool arg) {
return true;
}
private readonly List<string!>! AllDecls;
private readonly List<string!>! IncDecls;
private readonly IDictionary<Function!, bool>! KnownFunctions;
private readonly IDictionary<VCExprVar!, bool>! KnownVariables;
// bitvector types have to be registered as well
private readonly IDictionary<Type!, bool>! KnownTypes;
// the names of registered BvConcatOps and BvExtractOps
private readonly IDictionary<string!, bool>! KnownBvOps;
public List<string!>! AllDeclarations { get {
List<string!>! res = new List<string!> ();
res.AddRange(AllDecls);
return res;
} }
public List<string!>! GetNewDeclarations() {
List<string!>! res = new List<string!> ();
res.AddRange(IncDecls);
IncDecls.Clear();
return res;
}
private void AddDeclaration(string! decl) {
AllDecls.Add(decl);
IncDecls.Add(decl);
}
public void Collect(VCExpr! expr) {
Traverse(expr, true);
}
///////////////////////////////////////////////////////////////////////////
private static string! TypeToString(Type! t) {
return SimplifyLikeExprLineariser.TypeToString(t);
}
private void RegisterType(Type! type)
{
if (!type.IsBv || !NativeBv) return;
if (!KnownTypes.ContainsKey(type)) {
int bits = type.BvBits;
string name = TypeToString(type);
AddDeclaration("(DEFTYPE " + name + " :BUILTIN BitVec " + bits + ")");
// If we add the BUILTIN then the conversion axiom does not work
AddDeclaration("(DEFOP " + name + "_to_int " + name + " $int)"); // :BUILTIN bv2int $int)");
AddDeclaration("(DEFOP $make_bv" + bits + " $int " + name + " :BUILTIN int2bv " + bits + ")");
string! expr = "($make_bv" + bits + " (" + name + "_to_int x))";
AddDeclaration("(BG_PUSH (FORALL (x :TYPE " + name + ") (PATS "
+ expr + ") (QID bvconv" + bits + ") (EQ " + expr + " x)))");
KnownTypes.Add(type, true);
}
}
public override bool Visit(VCExprNAry! node, bool arg) {
// there are a couple of cases where operators have to be
// registered by generating appropriate Z3 statements
if (node.Op is VCExprBvConcatOp) {
//
if (NativeBv) {
RegisterType(node[0].Type);
RegisterType(node[1].Type);
RegisterType(node.Type);
string name = SimplifyLikeExprLineariser.BvConcatOpName(node);
if (!KnownBvOps.ContainsKey(name)) {
AddDeclaration("(DEFOP " + name +
" " + TypeToString(node[0].Type) +
" " + TypeToString(node[1].Type) +
" " + TypeToString(node.Type) +
" :BUILTIN concat)");
KnownBvOps.Add(name, true);
}
}
//
} else if (node.Op is VCExprBvExtractOp) {
//
if (NativeBv) {
RegisterType(node[0].Type);
RegisterType(node.Type);
VCExprBvExtractOp! op = (VCExprBvExtractOp)node.Op;
string name = SimplifyLikeExprLineariser.BvExtractOpName(node);
if (!KnownBvOps.ContainsKey(name)) {
AddDeclaration("(DEFOP " + name +
" " + TypeToString(node[0].Type) +
" " + TypeToString(node.Type) +
" :BUILTIN extract " +
(op.End - 1) + " " + op.Start + ")");
KnownBvOps.Add(name, true);
}
}
//
} else {
//
VCExprBoogieFunctionOp op = node.Op as VCExprBoogieFunctionOp;
if (op != null && !KnownFunctions.ContainsKey(op.Func)) {
Function! f = op.Func;
string! printedName = Namer.GetName(f, f.Name);
string! decl = "(DEFOP " + SimplifyLikeExprLineariser.MakeIdPrintable(printedName);
foreach (Variable! v in f.InParams) {
decl += " " + TypeToString(v.TypedIdent.Type);
RegisterType(v.TypedIdent.Type);
}
assert f.OutParams.Length == 1;
foreach (Variable! v in f.OutParams) {
decl += " " + TypeToString(v.TypedIdent.Type);
RegisterType(v.TypedIdent.Type);
}
string? builtin = ExtractBuiltin(f);
if (builtin != null)
decl += " :BUILTIN " + builtin;
decl += ")";
AddDeclaration(decl);
KnownFunctions.Add(f, true);
}
//
}
return base.Visit(node, arg);
}
private string? ExtractBuiltin(Function! f) {
if (NativeBv) {
return f.FindStringAttribute("bvbuiltin");
} else {
return null;
}
}
public override bool Visit(VCExprVar! node, bool arg) {
if (!BoundTermVars.Contains(node) && !KnownVariables.ContainsKey(node)) {
RegisterType(node.Type);
string! printedName = Namer.GetName(node, node.Name);
string! decl =
"(DEFOP " + SimplifyLikeExprLineariser.MakeIdPrintable(printedName)
+ " " + TypeToString(node.Type) + ")";
AddDeclaration(decl);
KnownVariables.Add(node, true);
}
return base.Visit(node, arg);
}
}
}
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