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//-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using Microsoft.Cci;
using Microsoft.Cci.MetadataReader;
using Microsoft.Cci.MutableCodeModel;
using Microsoft.Cci.Contracts;
using Microsoft.Cci.ILToCodeModel;
using Bpl = Microsoft.Boogie;
using System.IO;
using System.Reflection;
namespace BytecodeTranslator {
/// <summary>
/// A heap representation that uses a separate global variable for each
/// field. Each global variable is a map from int to T where T is the
/// type of the field.
/// </summary>
public class SplitFieldsHeap : Heap {
/// <summary>
/// Prelude text for which access to the ASTs is not needed
/// </summary>
private readonly string InitialPreludeText =
@"type Struct = [Field]Box;
type HeapType = [Ref,Field]Box;
var $Heap: HeapType;
var $Alloc: [Ref] bool;
procedure {:inline 1} Alloc() returns (x: Ref)
modifies $Alloc;
{
assume $Alloc[x] == false && x != null;
$Alloc[x] := true;
}
axiom (forall x : Field :: $DefaultStruct[x] == $DefaultBox);
axiom Box2Int($DefaultBox) == 0;
axiom Box2Bool($DefaultBox) == false;
axiom Box2Ref($DefaultBox) == null;
axiom Box2Struct($DefaultBox) == $DefaultStruct;
axiom (forall x: int :: { Int2Box(x) } Box2Int(Int2Box(x)) == x );
axiom (forall x: bool :: { Bool2Box(x) } Box2Bool(Bool2Box(x)) == x );
axiom (forall x: Ref :: { Ref2Box(x) } Box2Ref(Ref2Box(x)) == x );
axiom (forall x: Struct :: { Struct2Box(x) } Box2Struct(Struct2Box(x)) == x );
procedure {:inline 1} System.Object.GetType(this: Ref) returns ($result: Ref)
{
$result := $TypeOf($DynamicType(this));
}
axiom (forall t: Type :: $DynamicType($TypeOf(t)) == t);
function $ThreadDelegate(Ref) : Ref;
procedure {:inline 1} System.Threading.Thread.#ctor$System.Threading.ParameterizedThreadStart(this: Ref, start$in: Ref)
{
assume $ThreadDelegate(this) == start$in;
}
procedure {:inline 1} System.Threading.Thread.Start$System.Object(this: Ref, parameter$in: Ref)
{
call {:async} System.Threading.ParameterizedThreadStart.Invoke$System.Object($ThreadDelegate(this), parameter$in);
}
";
private Sink sink;
public override bool MakeHeap(Sink sink, out Heap heap, out Bpl.Program/*?*/ program) {
heap = this;
program = null;
this.sink = sink;
string prelude = this.InitialPreludeText + this.DelegateEncodingText;
var b = RepresentationFor.ParsePrelude(prelude, this, out program);
if (b) {
this.BoxType = new Bpl.CtorType(this.BoxTypeDecl.tok, this.BoxTypeDecl, new Bpl.TypeSeq());
this.FieldType = new Bpl.CtorType(this.FieldTypeDecl.tok, this.FieldTypeDecl, new Bpl.TypeSeq());
this.TypeType = new Bpl.CtorType(this.TypeTypeDecl.tok, this.TypeTypeDecl, new Bpl.TypeSeq());
this.RefType = new Bpl.CtorType(this.RefTypeDecl.tok, this.RefTypeDecl, new Bpl.TypeSeq());
this.RealType = new Bpl.CtorType(this.RealTypeDecl.tok, this.RealTypeDecl, new Bpl.TypeSeq());
}
return b;
}
/// <summary>
/// Creates a fresh BPL variable to represent <paramref name="field"/>, deciding
/// on its type based on the heap representation.
/// </summary>
public override Bpl.Variable CreateFieldVariable(IFieldReference field) {
Bpl.Variable v;
string fieldname = TypeHelper.GetTypeName(field.ContainingType) + "." + field.Name.Value;
fieldname = TranslationHelper.TurnStringIntoValidIdentifier(fieldname);
Bpl.IToken tok = field.Token();
Bpl.Type t = this.sink.CciTypeToBoogie(field.Type.ResolvedType);
if (field.IsStatic) {
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, t);
v = new Bpl.GlobalVariable(tok, tident);
}
else {
Bpl.Type mt = new Bpl.MapType(tok, new Bpl.TypeVariableSeq(), new Bpl.TypeSeq(this.RefType), t);
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, mt);
v = new Bpl.GlobalVariable(tok, tident);
}
return v;
}
public override Bpl.Variable CreateEventVariable(IEventDefinition e) {
Bpl.Variable v;
string eventName = TypeHelper.GetTypeName(e.ContainingType) + "." + e.Name.Value;
eventName = TranslationHelper.TurnStringIntoValidIdentifier(eventName);
Bpl.IToken tok = e.Token();
Bpl.Type t = this.sink.CciTypeToBoogie(e.Type.ResolvedType);
if (e.Adder.ResolvedMethod.IsStatic) {
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, eventName, t);
v = new Bpl.GlobalVariable(tok, tident);
}
else {
Bpl.Type mt = new Bpl.MapType(tok, new Bpl.TypeVariableSeq(), new Bpl.TypeSeq(this.RefType), t);
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, eventName, mt);
v = new Bpl.GlobalVariable(tok, tident);
}
return v;
}
/// <summary>
/// Returns the (typed) BPL expression that corresponds to the value of the field
/// <paramref name="f"/> belonging to the object <paramref name="o"/> (which must be non-null).
/// </summary>
/// <param name="o">The expression that represents the object to be dereferenced.
/// </param>
/// <param name="f">The field that is used to dereference the object <paramref name="o"/>.
/// </param>
public override Bpl.Expr ReadHeap(Bpl.Expr/*?*/ o, Bpl.Expr f, AccessType accessType, Bpl.Type unboxType) {
if (accessType == AccessType.Struct)
return Unbox(f.tok, unboxType, Bpl.Expr.Select(o, f));
else if (accessType == AccessType.Heap)
return Bpl.Expr.Select(f, o);
else
return Unbox(f.tok, unboxType, Bpl.Expr.Select(Bpl.Expr.Select(Bpl.Expr.Ident(ArrayContentsVariable), o), f));
}
/// <summary>
/// Returns the BPL command that corresponds to assigning the value <paramref name="value"/>
/// to the field <paramref name="f"/> of the object <paramref name="o"/> (which should be non-null).
/// </summary>
public override Bpl.Cmd WriteHeap(Bpl.IToken tok, Bpl.Expr/*?*/ o, Bpl.Expr f, Bpl.Expr value, AccessType accessType, Bpl.Type boxType) {
Debug.Assert(o != null);
if (accessType == AccessType.Struct)
return Bpl.Cmd.MapAssign(tok, (Bpl.IdentifierExpr)o, f, Box(f.tok, boxType, value));
else if (accessType == AccessType.Heap)
return Bpl.Cmd.MapAssign(tok, (Bpl.IdentifierExpr)f, o, value);
else
return TranslationHelper.BuildAssignCmd(Bpl.Expr.Ident(ArrayContentsVariable), Bpl.Expr.Store(Bpl.Expr.Ident(ArrayContentsVariable), o, Bpl.Expr.Store(Bpl.Expr.Select(Bpl.Expr.Ident(ArrayContentsVariable), o), f, Box(f.tok, boxType, value))));
}
}
/// <summary>
/// A heap representation that uses Boogie (in-line) functions
/// for all heap reads and writes. That way the decision about
/// how to exactly represent the heap is made in the Prelude.
/// </summary>
public class GeneralHeap : Heap {
#region Fields
[RepresentationFor("$Heap", "var $Heap: HeapType;", true)]
private Bpl.Variable HeapVariable = null;
[RepresentationFor("Read", "function {:inline true} Read(H:HeapType, o:Ref, f:Field): Box { H[o, f] }")]
private Bpl.Function Read = null;
[RepresentationFor("Write", "function {:inline true} Write(H:HeapType, o:Ref, f:Field, v:Box): HeapType { H[o,f := v] }")]
private Bpl.Function Write = null;
/// <summary>
/// Prelude text for which access to the ASTs is not needed
/// </summary>
private readonly string InitialPreludeText =
@"type Struct = [Field]Box;
type HeapType = [Ref,Field]Box;
var $Alloc: [Ref] bool;
procedure {:inline 1} Alloc() returns (x: Ref)
modifies $Alloc;
{
assume $Alloc[x] == false && x != null;
$Alloc[x] := true;
}
axiom (forall x : Field :: $DefaultStruct[x] == $DefaultBox);
axiom Box2Int($DefaultBox) == 0;
axiom Box2Bool($DefaultBox) == false;
axiom Box2Ref($DefaultBox) == null;
axiom Box2Struct($DefaultBox) == $DefaultStruct;
axiom (forall x: int :: { Int2Box(x) } Box2Int(Int2Box(x)) == x );
axiom (forall x: bool :: { Bool2Box(x) } Box2Bool(Bool2Box(x)) == x );
axiom (forall x: Ref :: { Ref2Box(x) } Box2Ref(Ref2Box(x)) == x );
axiom (forall x: Struct :: { Struct2Box(x) } Box2Struct(Struct2Box(x)) == x );
procedure {:inline 1} System.Object.GetType(this: Ref) returns ($result: Ref)
{
$result := $TypeOf($DynamicType(this));
}
axiom (forall t: Type :: $DynamicType($TypeOf(t)) == t);
function $ThreadDelegate(Ref) : Ref;
procedure {:inline 1} System.Threading.Thread.#ctor$System.Threading.ParameterizedThreadStart(this: Ref, start$in: Ref)
{
assume $ThreadDelegate(this) == start$in;
}
procedure {:inline 1} System.Threading.Thread.Start$System.Object(this: Ref, parameter$in: Ref)
{
call {:async} System.Threading.ParameterizedThreadStart.Invoke$System.Object($ThreadDelegate(this), parameter$in);
}
";
private Sink sink;
#endregion
public override bool MakeHeap(Sink sink, out Heap heap, out Bpl.Program/*?*/ program) {
this.sink = sink;
heap = this;
program = null;
string prelude = this.InitialPreludeText + this.DelegateEncodingText;
var b = RepresentationFor.ParsePrelude(prelude, this, out program);
if (b) {
this.BoxType = new Bpl.CtorType(this.BoxTypeDecl.tok, this.BoxTypeDecl, new Bpl.TypeSeq());
this.FieldType = new Bpl.CtorType(this.FieldTypeDecl.tok, this.FieldTypeDecl, new Bpl.TypeSeq());
this.TypeType = new Bpl.CtorType(this.TypeTypeDecl.tok, this.TypeTypeDecl, new Bpl.TypeSeq());
this.RefType = new Bpl.CtorType(this.RefTypeDecl.tok, this.RefTypeDecl, new Bpl.TypeSeq());
this.RealType = new Bpl.CtorType(this.RealTypeDecl.tok, this.RealTypeDecl, new Bpl.TypeSeq());
}
return b;
}
/// <summary>
/// Creates a fresh BPL variable to represent <paramref name="field"/>, deciding
/// on its type based on the heap representation.
/// </summary>
public override Bpl.Variable CreateFieldVariable(IFieldReference field) {
Bpl.Variable v;
string fieldname = TypeHelper.GetTypeName(field.ContainingType) + "." + field.Name.Value;
fieldname = TranslationHelper.TurnStringIntoValidIdentifier(fieldname);
Bpl.IToken tok = field.Token();
if (field.IsStatic) {
Bpl.Type t = this.sink.CciTypeToBoogie(field.Type.ResolvedType);
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, t);
v = new Bpl.GlobalVariable(tok, tident);
}
else {
Bpl.Type t = this.FieldType;
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, t);
v = new Bpl.Constant(tok, tident, true);
}
return v;
}
public override Bpl.Variable CreateEventVariable(IEventDefinition e) {
Bpl.Variable v;
string fieldname = TypeHelper.GetTypeName(e.ContainingType) + "." + e.Name.Value;
fieldname = TranslationHelper.TurnStringIntoValidIdentifier(fieldname);
Bpl.IToken tok = e.Token();
if (e.Adder.ResolvedMethod.IsStatic) {
Bpl.Type t = this.sink.CciTypeToBoogie(e.Type.ResolvedType);
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, t);
v = new Bpl.GlobalVariable(tok, tident);
}
else {
Bpl.Type t = this.FieldType;
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, fieldname, t);
v = new Bpl.Constant(tok, tident, true);
}
return v;
}
/// <summary>
/// Returns the (typed) BPL expression that corresponds to the value of the field
/// <paramref name="f"/> belonging to the object <paramref name="o"/> (which must be non-null).
/// </summary>
/// <param name="o">The expression that represents the object to be dereferenced.
/// </param>
/// <param name="f">The field that is used to dereference the object <paramref name="o"/>.
/// </param>
public override Bpl.Expr ReadHeap(Bpl.Expr/*?*/ o, Bpl.Expr f, AccessType accessType, Bpl.Type unboxType) {
Debug.Assert(o != null);
Bpl.NAryExpr callRead;
if (accessType == AccessType.Struct)
callRead = Bpl.Expr.Select(o, f);
else if (accessType == AccessType.Heap)
callRead = new Bpl.NAryExpr(f.tok, new Bpl.FunctionCall(this.Read), new Bpl.ExprSeq(new Bpl.IdentifierExpr(f.tok, this.HeapVariable), o, f));
else
callRead = Bpl.Expr.Select(Bpl.Expr.Select(Bpl.Expr.Ident(ArrayContentsVariable), o), f);
// wrap it in the right conversion function
var callExpr = Unbox(f.tok, unboxType, callRead);
return callExpr;
}
/// <summary>
/// Returns the BPL command that corresponds to assigning the value <paramref name="value"/>
/// to the field <paramref name="f"/> of the object <paramref name="o"/> (which should be non-null).
/// </summary>
public override Bpl.Cmd WriteHeap(Bpl.IToken tok, Bpl.Expr/*?*/ o, Bpl.Expr f, Bpl.Expr value, AccessType accessType, Bpl.Type boxType) {
Debug.Assert(o != null);
Bpl.IdentifierExpr h;
Bpl.NAryExpr callWrite;
var callConversion = Box(f.tok, boxType, value);
if (accessType == AccessType.Struct) {
h = (Bpl.IdentifierExpr)o;
callWrite = Bpl.Expr.Store(h, f, callConversion);
}
else if (accessType == AccessType.Heap) {
h = Bpl.Expr.Ident(HeapVariable);
callWrite = new Bpl.NAryExpr(f.tok, new Bpl.FunctionCall(this.Write), new Bpl.ExprSeq(h, o, f, callConversion));
}
else {
h = Bpl.Expr.Ident(ArrayContentsVariable);
callWrite = Bpl.Expr.Store(Bpl.Expr.Ident(ArrayContentsVariable), o, Bpl.Expr.Store(Bpl.Expr.Select(Bpl.Expr.Ident(ArrayContentsVariable), o), f, callConversion));
}
return Bpl.Cmd.SimpleAssign(f.tok, h, callWrite);
}
}
internal class RepresentationFor : Attribute {
internal string name;
internal string declaration;
internal bool required;
internal RepresentationFor(string name, string declaration) { this.name = name; this.declaration = declaration; this.required = true; }
internal RepresentationFor(string name, string declaration, bool required) { this.name = name; this.declaration = declaration; this.required = required; }
internal static bool ParsePrelude(string initialPreludeText, object instance, out Bpl.Program/*?*/ prelude) {
prelude = null;
var flags = BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance;
var type = instance.GetType();
FieldInfo/*?*/[] fields = type.GetFields(flags);
RepresentationFor[] rfs = new RepresentationFor[fields.Length];
for (int i = 0; i < fields.Length; i++) {
var field = fields[i];
object[] cas = field.GetCustomAttributes(typeof(RepresentationFor), false);
if (cas == null || cas.Length == 0) { // only look at fields that have the attribute
fields[i] = null;
}
else {
foreach (var a in cas) { // should be exactly one
RepresentationFor rf = a as RepresentationFor;
if (rf != null) {
rfs[i] = rf;
break;
}
}
}
}
#region Gather all of the Boogie declarations from the fields of this class
var preludeText = new StringBuilder(initialPreludeText);
for (int i = 0; i < fields.Length; i++) {
var field = fields[i];
if (field == null) continue;
preludeText.AppendLine(rfs[i].declaration);
}
#endregion
#region Parse the declarations
var ms = new MemoryStream(ASCIIEncoding.UTF8.GetBytes(preludeText.ToString()));
int errorCount = Bpl.Parser.Parse(ms, "foo", new List<string>(), out prelude);
if (prelude == null || errorCount > 0) {
prelude = null;
return false;
}
#endregion
#region Use the compiled program to get the ASTs
for (int i = 0; i < fields.Length; i++) {
var field = fields[i];
if (field == null) continue;
if (!rfs[i].required) continue;
var val = prelude.TopLevelDeclarations.First(d => { Bpl.NamedDeclaration nd = d as Bpl.NamedDeclaration; return nd != null && nd.Name.Equals(rfs[i].name); });
field.SetValue(instance, val);
}
#endregion
#region Check that every field in this class has been set
for (int i = 0; i < fields.Length; i++) {
var field = fields[i];
if (field == null) continue;
if (!rfs[i].required) continue;
if (field.GetValue(instance) == null) {
return false;
}
}
#endregion Check that every field in this class has been set
return true;
}
}
}
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