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//
// Analysis.GenericValueAnalysis.cs
//
// Authors:
// Alexander Chebaturkin (chebaturkin@gmail.com)
//
// Copyright (C) 2012 Alexander Chebaturkin
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.IO;
using Mono.CodeContracts.Static.AST;
using Mono.CodeContracts.Static.AST.Visitors;
using Mono.CodeContracts.Static.Analysis.Drivers;
using Mono.CodeContracts.Static.ControlFlow;
using Mono.CodeContracts.Static.DataFlowAnalysis;
using Mono.CodeContracts.Static.DataStructures;
using Mono.CodeContracts.Static.Lattices;
using Mono.CodeContracts.Static.Providers;
using Mono.CodeContracts.Static.Proving;
namespace Mono.CodeContracts.Static.Analysis.Numerical {
static partial class AnalysisFacade {
static partial class Bind<TVar, TExpr> where TExpr : IEquatable<TExpr> where TVar : IEquatable<TVar> {
abstract class GenericValueAnalysis<TDomain> :
ILVisitorBase<APC, TVar, TVar, TDomain, TDomain>,
IAbstractAnalysis<TDomain, TVar>,
IMethodResult<TVar>
where TDomain : IEnvironmentDomain<TDomain, BoxedVariable<TVar>, BoxedExpression> {
readonly IMethodDriver<TExpr, TVar> method_driver;
//readonly string method_name;
protected ConstantEvaluator EvaluatorOfConstants;
protected IFixPointInfo<APC, TDomain> FixPointInfo;
BoxedExpressionDecoder<TVar, TExpr> expression_decoder;
protected GenericValueAnalysis (string methodName,
IMethodDriver<TExpr, TVar> methodDriver)
{
ThresholdDB.Reset ();
BoxedVariable<TVar>.ResetFreshVariableCounter ();
// method_name = methodName;
method_driver = methodDriver;
EvaluatorOfConstants = new ConstantEvaluator (ContextProvider,
MetaDataProvider);
}
protected IExpressionContextProvider<TExpr, TVar> ContextProvider { get { return method_driver.ContextProvider; } }
protected IMetaDataProvider MetaDataProvider { get { return method_driver.MetaDataProvider; } }
protected BoxedExpressionDecoder<TVar, TExpr> ExpressionDecoder
{
get
{
if (expression_decoder == null)
expression_decoder =
new BoxedExpressionDecoder<TVar, TExpr> (
new ValueExpressionDecoder<TVar, TExpr> (
MetaDataProvider,
ContextProvider));
return expression_decoder;
}
}
public IILVisitor<APC, TVar, TVar, TDomain, TDomain> GetVisitor ()
{
return this;
}
public TDomain Join (Pair<APC, APC> edge, TDomain newstate, TDomain prevstate,
out bool weaker, bool widen)
{
TDomain result;
if (!widen) {
result = Join (newstate, prevstate, edge);
weaker = true;
}
else {
result = Widen (newstate, prevstate, edge);
weaker = !result.LessEqual (prevstate);
}
return result;
}
public TDomain ImmutableVersion (TDomain arg)
{
return arg;
}
public TDomain MutableVersion (TDomain arg)
{
return arg.Clone ();
}
public virtual TDomain EdgeConversion (APC @from, APC to, bool isJoinPoint,
IImmutableMap<TVar, Sequence<TVar>>
sourceTargetMap, TDomain state)
{
return state;
}
public bool IsBottom (APC pc, TDomain state)
{
return state.IsBottom;
}
public Predicate<APC> SaveFixPointInfo (IFixPointInfo<APC, TDomain> fixPointInfo)
{
FixPointInfo = fixPointInfo;
return a => false;
}
public void Dump (Pair<TDomain, TextWriter> pair)
{
pair.Value.WriteLine (pair.Key.ToString ());
}
public abstract TDomain TopValue ();
public TDomain BottomValue ()
{
return TopValue ().Bottom;
}
public abstract IFactQuery<BoxedExpression, TVar> FactQuery (
IFixPointInfo<APC, TDomain> fixpoint);
IFactQuery<BoxedExpression, TVar> IMethodAnalysisFixPoint<TVar>.FactQuery { get { return FactQuery (FixPointInfo); } }
public FlatDomain<bool> ValidateExplicitAssertion (APC pc, TVar value)
{
return FlatDomain<bool>.TopValue;
}
public IMethodAnalysis MethodAnalysis { get; set; }
public void ValidateImplicitAssertions (IFactQuery<BoxedExpression, TVar> facts,
List<string> proofResults)
{
}
protected virtual TDomain Widen (TDomain newState, TDomain prevState,
Pair<APC, APC> edge)
{
return newState.Widen (prevState);
}
protected virtual TDomain Join (TDomain newState, TDomain prevState, Pair<APC, APC> edge)
{
return newState.Join (prevState);
}
public override TDomain Assume (APC pc, EdgeTag tag, TVar condition, TDomain data)
{
var boxed = ToBoxedExpression (pc, condition);
if (tag != EdgeTag.False) {
bool value;
if (boxed.IsTrivialCondition (out value))
return !value ? data.Bottom : data;
}
List<int> thresholds;
if (ThresholdDB.TryGetAThreshold (boxed, expression_decoder, out thresholds))
ThresholdDB.Add (thresholds);
TDomain result;
switch (tag) {
case EdgeTag.True:
case EdgeTag.Requires:
case EdgeTag.Assume:
case EdgeTag.Invariant:
result = data.AssumeTrue (boxed);
break;
case EdgeTag.False:
result = data.AssumeFalse (boxed);
break;
default:
result = data;
break;
}
if (tag != EdgeTag.False) {
var abstractType =
ContextProvider.ValueContext.GetType (
ContextProvider.MethodContext.CFG.Post (pc), condition);
if (abstractType.IsNormal () &&
MetaDataProvider.Equal (abstractType.Value,
MetaDataProvider.System_Boolean)) {
var guard =
BoxedExpression.Binary (BinaryOperator.Ceq, boxed,
BoxedExpression.Const (1,
MetaDataProvider
.
System_Int32));
result = result.AssumeTrue (guard);
}
}
return result;
}
public override TDomain Assert (APC pc, EdgeTag tag, TVar condition, TDomain data)
{
var boxed = ToBoxedExpression (pc, condition);
bool result;
if (boxed.IsTrivialCondition (out result))
return result ? data : data.Bottom;
data = data.AssumeTrue (boxed);
var type =
ContextProvider.ValueContext.GetType (
ContextProvider.MethodContext.CFG.Post (pc), condition);
if (type.IsNormal () &&
MetaDataProvider.Equal (type.Value, MetaDataProvider.System_Boolean)) {
var guard =
BoxedExpression.Binary (BinaryOperator.Ceq, boxed,
BoxedExpression.Const (1,
MetaDataProvider.
System_Int32));
data = data.AssumeTrue (guard);
}
return data;
}
public override TDomain DefaultVisit (APC pc, TDomain data)
{
return data;
}
protected BoxedExpression ToBoxedExpression (APC pc, TVar condition)
{
return
BoxedExpression.For (
ContextProvider.ExpressionContext.Refine (pc, condition),
ExpressionDecoder.ExternalDecoder);
}
public IFactQuery<BoxedExpression, TVar> FactQuery ()
{
return FactQuery (FixPointInfo);
}
}
}
}
}
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