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//-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------
using System;
using System.Linq;
using System.Collections.Generic;
using System.Text;
namespace Microsoft.Boogie
{
public class Model
{
#region Elements and functions (inner classes)
public enum ElementKind
{
Integer,
BitVector,
Boolean,
Uninterpreted
}
abstract public class Element
{
public readonly Model Model;
internal List<FuncTuple> references = new List<FuncTuple>();
public readonly int Id;
public IEnumerable<FuncTuple> References { get { return references; } }
public IEnumerable<FuncTuple> Names {
get {
foreach (var f in references)
if (f.Result == this) yield return f;
}
}
protected Element(Model p) { Model = p; }
public abstract ElementKind Kind { get; }
public virtual int AsInt() { throw new NotImplementedException(); }
}
#region element kinds
public class Uninterpreted : Element
{
public override ElementKind Kind { get { return ElementKind.Uninterpreted; } }
public override string ToString() { return Name; }
internal Uninterpreted(Model p, string n) : base(p) { Name = n; }
public readonly string Name;
}
abstract public class Number : Element
{
protected Number(Model p, string n) : base(p) { Numeral = n; }
public readonly string Numeral;
public override int AsInt() { return int.Parse(Numeral); }
}
public class Integer : Number
{
internal Integer(Model p, string n) : base(p, n) { }
public override ElementKind Kind { get { return ElementKind.Integer; } }
public override string ToString() { return Numeral.ToString(); }
}
public class BitVector : Number
{
internal BitVector(Model p, string n, int sz) : base(p, n) { Size = sz; }
public readonly int Size;
public override ElementKind Kind { get { return ElementKind.BitVector; } }
public override string ToString() { return string.Format("{0}bv{1}", Numeral, Size); }
}
public class Boolean : Element
{
public bool Value;
internal Boolean(Model p, bool v) : base(p) { Value = v; }
public override ElementKind Kind { get { return ElementKind.Boolean; } }
public override string ToString() { return Value ? "true" : "false"; }
}
#endregion
public class Func
{
public readonly Model Model;
public readonly string Name;
public readonly int Arity;
internal readonly List<FuncTuple> apps = new List<FuncTuple>();
public IEnumerable<FuncTuple> Apps { get { return apps; } }
public int AppCount { get { return apps.Count; } }
internal Func(Model p, string n, int a) { Model = p; Name = n; Arity = a; }
public override string ToString()
{
return string.Format("{0}/{1}", Name, Arity);
}
public void SetConstant(Element res)
{
if (Arity != 0 || apps.Count > 0)
throw new ArgumentException();
var t = new FuncTuple(this, res, null);
apps.Add(t);
res.references.Add(t);
}
/// <summary>
/// Return the first application where the argument at position argIdx is elt.
/// </summary>
public FuncTuple AppWithArg(int argIdx, Element elt)
{
foreach (var a in AppsWithArg(argIdx, elt))
return a;
return null;
}
/// <summary>
/// Return the first application with the result elt.
/// </summary>
public FuncTuple AppWithResult(Element elt)
{
foreach (var a in AppsWithResult(elt))
return a;
return null;
}
/// <summary>
/// Return all applications where the argument at position argIdx is elt.
/// </summary>
public IEnumerable<FuncTuple> AppsWithArg(int argIdx, Element elt)
{
foreach (var r in elt.References) {
if (r.Func == this && r.Args[argIdx] == elt)
yield return r;
}
}
/// <summary>
/// Return all applications where the argument at position argIdx0 is elt0 and argument at argIdx1 is elt1.
/// </summary>
public IEnumerable<FuncTuple> AppsWithArgs(int argIdx0, Element elt0, int argIdx1, Element elt1)
{
foreach (var r in elt0.References) {
if (r.Func == this && r.Args[argIdx0] == elt0 && r.Args[argIdx1] == elt1)
yield return r;
}
}
/// <summary>
/// Return all the applications with the result elt.
/// </summary>
public IEnumerable<FuncTuple> AppsWithResult(Element elt)
{
foreach (var r in elt.References) {
if (r.Func == this && r.Result == elt)
yield return r;
}
}
/// <summary>
/// For a nullary function, return its value.
/// </summary>
public Element GetConstant()
{
if (Arity != 0)
throw new ArgumentException();
if (apps.Count == 0)
SetConstant(Model.MkElement("**" + Name));
return apps[0].Result;
}
/// <summary>
/// If all arguments are non-null, and function application for them exists return the value, otherwise return null.
/// </summary>
public Element OptEval(params Element[] args)
{
if (args.Any(a => a == null)) return null;
return TryEval(args);
}
/// <summary>
/// Look for function application with given arguments and return its value or null if no such application exists.
/// </summary>
public Element TryEval(params Element[] args)
{
foreach (var tpl in apps) {
bool same = true;
for (int i = 0; i < args.Length; ++i)
if (tpl.Args[i] != args[i]) {
same = false;
break;
}
if (same) return tpl.Result;
}
return null;
}
/// <summary>
/// Short for TryEval(args) == (Element)true
/// </summary>
public bool IsTrue(params Element[] args)
{
var r = TryEval(args) as Boolean;
return r != null && r.Value;
}
/// <summary>
/// Short for TryEval(args) == (Element)false
/// </summary>
public bool IsFalse(params Element[] args)
{
var r = TryEval(args) as Boolean;
return r != null && !r.Value;
}
public void AddApp(Element res, params Element[] args)
{
if (Arity == 0)
SetConstant(res);
else {
if (args.Length != Arity)
throw new ArgumentException();
var t = new FuncTuple(this, res, (Element[])args.Clone());
apps.Add(t);
var u = new HashSet<Element>();
res.references.Add(t);
u.Add(res);
foreach (var a in args)
if (!u.Contains(a)) {
u.Add(a);
a.references.Add(t);
}
}
}
}
public class FuncTuple
{
static readonly Element[] EmptyArgs = new Element[0];
public readonly Func Func;
public readonly Element Result;
public readonly Element[] Args;
internal FuncTuple(Func func, Element res, Element[] args)
{
if (args == null) Args = EmptyArgs;
else Args = args;
Func = func;
Result = res;
}
public override string ToString()
{
var res = new StringBuilder();
res.Append(Func.Name).Append("(");
for (int i = 0; i < Args.Length; ++i) {
if (i != 0) res.Append(", ");
res.Append(Args[i]);
}
res.Append(") -> ").Append(Result);
return res.ToString();
}
}
#endregion
private List<Func> functions = new List<Func>();
private List<Element> elements = new List<Element>();
private List<CapturedState> states = new List<CapturedState>();
private Dictionary<string, Func> functionsByName = new Dictionary<string, Func>();
private Dictionary<string, Element> elementsByName = new Dictionary<string, Element>();
#region factory methods
Element ConstructElement(string name)
{
if (name.ToLower() == "true") return True;
if (name.ToLower() == "false") return False;
if (name.StartsWith("bv") && name.Length > 4 && Char.IsDigit(name[2]))
name = name.Substring(2);
if (Char.IsDigit(name[0]) || name[0] == '-') {
int col = name.IndexOf("bv");
int szi = -1;
if (name.EndsWith(":int"))
name = name.Substring(0, name.Length - 4);
if (col > 0) {
if (int.TryParse(name.Substring(col + 2), out szi) && szi > 0) {
name = name.Substring(0, col);
} else {
return null;
}
} else if (name.EndsWith("]")) {
col = name.IndexOf("[");
if (col > 0 && int.TryParse(name.Substring(col + 1, name.Length - col - 2), out szi) && szi > 0) {
name = name.Substring(0, col);
} else {
return null;
}
}
for (int i = 1; i < name.Length; ++i)
if (!Char.IsDigit(name[i]))
return null;
if (szi > 0)
return new BitVector(this, name, szi);
else
return new Integer(this, name);
} else if (name[0] == '*' || name.StartsWith("val!") || name.Contains("!val!")) {
return new Uninterpreted(this, name);
} else {
return null;
}
}
public Element TryMkElement(string name)
{
Element res;
if (elementsByName.TryGetValue(name, out res))
return res;
var tmp = ConstructElement(name);
if (tmp == null) return null;
name = tmp.ToString();
if (elementsByName.TryGetValue(name, out res))
return res;
elementsByName.Add(name, tmp);
elements.Add(tmp);
return tmp;
}
public Element MkElement(string name)
{
Element res = TryMkElement(name);
if (res == null)
throw new ArgumentException("invalid element name: '" + name + "'");
return res;
}
public Func MkFunc(string name, int arity)
{
Func res;
if (functionsByName.TryGetValue(name, out res)) {
if (res.Arity != arity)
throw new ArgumentException(string.Format("function '{0}' previously created with arity {1}, now trying to recreate with arity {2}", name, res.Arity, arity));
return res;
}
res = new Func(this, name, arity);
functionsByName.Add(name, res);
functions.Add(res);
return res;
}
#endregion
#region state management
public class CapturedState
{
List<string> vars = new List<string>();
Dictionary<string, Element> valuations = new Dictionary<string, Element>();
readonly CapturedState previous;
public readonly string Name;
public IEnumerable<string> Variables { get { return vars; } }
public IEnumerable<string> AllVariables {
get {
if (previous != null)
return previous.AllVariables.Concat(Variables).Distinct();
else
return Variables;
}
}
public int VariableCount { get { return vars.Count; } }
public bool HasBinding(string varname)
{
return valuations.ContainsKey(varname);
}
public Element TryGet(string varname)
{
CapturedState curr = this;
while (curr != null) {
Element res;
if (curr.valuations.TryGetValue(varname, out res))
return res;
curr = curr.previous;
}
return null;
}
public void AddBinding(string varname, Element value)
{
vars.Add(varname);
valuations.Add(varname, value);
}
internal CapturedState(string name, CapturedState prev)
{
Name = name;
previous = prev;
}
}
public CapturedState MkState(string name)
{
var last = states[states.Count - 1];
var s = new CapturedState(name, last);
states.Add(s);
return s;
}
#endregion
public Model()
{
InitialState = new CapturedState("<initial>", null);
states.Add(InitialState);
True = new Boolean(this, true);
False = new Boolean(this, false);
elements.Add(True);
elements.Add(False);
elementsByName.Add("true", True);
elementsByName.Add("false", False);
}
public IEnumerable<Func> Functions { get { return functions; } }
public IEnumerable<Element> Elements { get { return elements; } }
public IEnumerable<CapturedState> States { get { return states; } }
public readonly Element True, False;
public readonly CapturedState InitialState;
public bool HasFunc(string name)
{
return functionsByName.ContainsKey(name);
}
public Func TryGetFunc(string name)
{
Func res;
if (functionsByName.TryGetValue(name, out res))
return res;
else
return null;
}
public Func GetFunc(string name)
{
Func res = TryGetFunc(name);
if (res == null)
throw new KeyNotFoundException("function '" + name + "' undefined in the model");
return res;
}
public Element GetElement(string name)
{
Element res;
if (elementsByName.TryGetValue(name, out res))
return res;
else
throw new KeyNotFoundException("element '" + name + "' undefined in the model");
}
public void Write(System.IO.TextWriter wr)
{
wr.WriteLine("*** MODEL");
foreach (var f in Functions)
if (f.Arity == 0) {
wr.WriteLine("{0} -> {1}", f.Name, f.GetConstant());
}
foreach (var f in Functions)
if (f.Arity != 0) {
wr.WriteLine("{0} -> {1}", f.Name, "{");
foreach (var app in f.Apps) {
wr.Write(" ");
foreach (var a in app.Args)
wr.Write("{0} ", a);
wr.WriteLine("-> {0}", app.Result);
}
wr.WriteLine("}");
}
foreach (var s in States) {
if (s == InitialState && s.VariableCount == 0)
continue;
wr.WriteLine("*** STATE {0}", s.Name);
foreach (var v in s.Variables)
wr.WriteLine(" {0} -> {1}", v, s.TryGet(v));
wr.WriteLine("*** END_STATE", s.Name);
}
wr.WriteLine("*** END_MODEL");
}
class Parser
{
internal System.IO.TextReader rd;
string lastLine = "";
int lineNo;
bool v1model = false;
Dictionary<string, Element> partitionMapping = new Dictionary<string, Element>(); // only used when v1model is true
internal List<Model> resModels = new List<Model>();
Model currModel;
void BadModel(string msg)
{
throw new ArgumentException(string.Format("Invalid model: {0}, at line {1} ({2})", msg, lineNo, lastLine));
}
static char[] seps = new char[] { ' ' };
string[] GetWords(string line)
{
if (line == null)
return null;
var words = line.Split(seps, StringSplitOptions.RemoveEmptyEntries);
return words;
}
string ReadLine()
{
var l = rd.ReadLine();
if (l != null) {
lineNo++;
lastLine = l;
}
return l;
}
Element GetElt(string name)
{
Element ret;
if (v1model) {
if (!partitionMapping.TryGetValue(name, out ret))
BadModel("undefined partition " + name);
} else {
ret = currModel.TryMkElement(name);
if (ret == null)
BadModel("invalid element name " + name);
}
return ret;
}
void NewModel()
{
v1model = false;
partitionMapping.Clear();
lastLine = "";
currModel = new Model();
resModels.Add(currModel);
}
internal void Run()
{
for (; ; ) {
var line = ReadLine();
if (line == null) break; // end of model, everything fine
if (line == "Counterexample:" || line == "Z3 error model: " || line == "*** MODEL") {
NewModel();
continue;
}
if (line.EndsWith(": Invalid.") || line.EndsWith(": Valid.")|| line.StartsWith("labels:"))
continue;
if (line == "END_OF_MODEL" || line == "." || line == "*** END_MODEL")
continue;
if (line == "partitions:" || line == "function interpretations:") {
v1model = true;
continue;
}
var words = GetWords(line);
if (words.Length == 0) continue;
var lastWord = words[words.Length - 1];
if (currModel == null)
BadModel("model begin marker not found");
if (line.StartsWith("*** STATE ")) {
var name = line.Substring(10);
CapturedState cs;
if (name == "<initial>")
cs = currModel.InitialState;
else
cs = currModel.MkState(name);
for (; ; ) {
var tmpline = ReadLine();
if (tmpline == "*** END_STATE") break;
var tuple = GetWords(tmpline);
if (tuple == null) BadModel("EOF in state table");
if (tuple.Length == 0) continue;
if (tuple.Length != 3 || tuple[1] != "->") BadModel("invalid state tuple definition");
cs.AddBinding(tuple[0], GetElt(tuple[2]));
}
continue;
}
if (v1model && words[0][0] == '*') {
var partName = words[0];
var len = words.Length;
Element elt;
if (len >= 3 && words[len - 2] == "->") {
elt = currModel.TryMkElement(lastWord);
if (elt == null) BadModel("bad parition value " + lastWord);
len -= 2;
} else {
elt = currModel.MkElement(words[0]);
}
partitionMapping.Add(partName, elt);
for (int i = 1; i < len; ++i) {
var name = words[i];
if (i == 1 && name[0] == '{')
name = name.Substring(1);
if (i == len - 1 && name.EndsWith("}"))
name = name.Substring(0, name.Length - 1);
var cnst = currModel.MkFunc(name, 0);
cnst.SetConstant(elt);
}
} else if (words.Length == 3 && words[1] == "->") {
Func fn = null;
var funName = words[0];
if (lastWord == "{") {
for (; ; ) {
var tuple = GetWords(ReadLine());
if (tuple == null) BadModel("EOF in function table");
if (tuple.Length == 0) continue;
if (tuple.Length == 1 && tuple[0] == "}") break;
if (tuple.Length < 3 || tuple[tuple.Length - 2] != "->") BadModel("invalid function tuple definition");
if (tuple[0] == "else") {
if (tuple[tuple.Length - 1].EndsWith("}"))
break;
else
continue;
}
if (fn == null)
fn = currModel.MkFunc(funName, tuple.Length - 2);
var args = new Element[fn.Arity];
for (int i = 0; i < fn.Arity; ++i)
args[i] = GetElt(tuple[i]);
fn.AddApp(GetElt(tuple[tuple.Length - 1]), args);
}
} else {
fn = currModel.MkFunc(funName, 0);
fn.SetConstant(GetElt(lastWord));
}
} else {
BadModel("unidentified line");
}
}
}
}
public static List<Model> ParseModels(System.IO.TextReader rd)
{
var p = new Parser();
p.rd = rd;
p.Run();
return p.resModels;
}
}
}
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