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//-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Cci;
using Microsoft.Cci.MetadataReader;
using Microsoft.Cci.MutableCodeModel;
using Microsoft.Cci.Contracts;
using Microsoft.Cci.ILToCodeModel;
using Bpl = Microsoft.Boogie;
namespace BytecodeTranslator {
/// <summary>
/// Implementations of this interface determine how the heap is represented in
/// the translated Boogie program.
/// </summary>
public interface IHeap {
/// <summary>
/// Creates a fresh BPL variable to represent <paramref name="field"/>, deciding
/// on its type based on the heap representation.
/// </summary>
Bpl.Variable CreateFieldVariable(IFieldReference field);
/// Creates a fresh BPL variable to represent <paramref name="type"/>, deciding
/// on its type based on the heap representation. I.e., the value of this
/// variable represents the value of the expression "typeof(type)".
/// </summary>
Bpl.Variable CreateTypeVariable(ITypeReference type);
Bpl.Variable CreateEventVariable(IEventDefinition e);
/// <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 should 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>
Bpl.Expr ReadHeap(Bpl.Expr/*?*/ o, Bpl.IdentifierExpr f, bool isStruct);
/// <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>
Bpl.Cmd WriteHeap(Bpl.IToken tok, Bpl.Expr/*?*/ o, Bpl.IdentifierExpr f, Bpl.Expr value, bool isStruct);
/// <summary>
/// Returns the BPL expression that corresponds to the value of the dynamic type
/// of the object represented by the expression <paramref name="o"/>.
/// </summary>
Bpl.Expr DynamicType(Bpl.Expr o);
}
public abstract class Heap : HeapFactory, IHeap
{
public abstract Bpl.Variable CreateFieldVariable(IFieldReference field);
[RepresentationFor("Field", "type Field;")]
public Bpl.TypeCtorDecl FieldTypeDecl = null;
public Bpl.CtorType FieldType;
[RepresentationFor("box", "type box;")]
public Bpl.TypeCtorDecl BoxTypeDecl = null;
public Bpl.CtorType BoxType;
[RepresentationFor("Type", "type Type;")]
protected Bpl.TypeCtorDecl TypeTypeDecl = null;
protected Bpl.CtorType TypeType;
/// <summary>
/// Creates a fresh BPL variable to represent <paramref name="type"/>, deciding
/// on its type based on the heap representation. I.e., the value of this
/// variable represents the value of the expression "typeof(type)".
/// </summary>
public Bpl.Variable CreateTypeVariable(ITypeReference type)
{
Bpl.Variable v;
string typename = TypeHelper.GetTypeName(type);
typename = TranslationHelper.TurnStringIntoValidIdentifier(typename);
Bpl.IToken tok = type.Token();
Bpl.Type t = this.TypeType;
Bpl.TypedIdent tident = new Bpl.TypedIdent(tok, typename, t);
tident.Type = this.TypeType;
v = new Bpl.Constant(tok, tident, true);
return v;
}
public abstract Bpl.Variable CreateEventVariable(IEventDefinition e);
public abstract Bpl.Expr ReadHeap(Bpl.Expr o, Bpl.IdentifierExpr f, bool isStruct);
public abstract Bpl.Cmd WriteHeap(Bpl.IToken tok, Bpl.Expr o, Bpl.IdentifierExpr f, Bpl.Expr value, bool isStruct);
[RepresentationFor("$DynamicType", "function $DynamicType(ref): Type;")]
protected Bpl.Function DynamicTypeFunction = null;
/// <summary>
/// Returns the BPL expression that corresponds to the value of the dynamic type
/// of the object represented by the expression <paramref name="o"/>.
/// </summary>
public Bpl.Expr DynamicType(Bpl.Expr o) {
// $DymamicType(o)
var callDynamicType = new Bpl.NAryExpr(
o.tok,
new Bpl.FunctionCall(this.DynamicTypeFunction),
new Bpl.ExprSeq(o)
);
return callDynamicType;
}
[RepresentationFor("$TypeOf", "function $TypeOf(Type): ref;")]
public Bpl.Function TypeOfFunction = null;
protected readonly string DelegateEncodingText =
@"procedure DelegateAdd(a: int, b: int) returns (c: int)
{
var m: int;
var o: int;
if (a == 0) {
c := b;
return;
} else if (b == 0) {
c := a;
return;
}
call m, o := GetFirstElement(b);
call c := Alloc();
$Head[c] := $Head[a];
$Next[c] := $Next[a];
$Method[c] := $Method[a];
$Receiver[c] := $Receiver[a];
call c := DelegateAddHelper(c, m, o);
}
procedure DelegateRemove(a: int, b: int) returns (c: int)
{
var m: int;
var o: int;
if (a == 0) {
c := 0;
return;
} else if (b == 0) {
c := a;
return;
}
call m, o := GetFirstElement(b);
call c := Alloc();
$Head[c] := $Head[a];
$Next[c] := $Next[a];
$Method[c] := $Method[a];
$Receiver[c] := $Receiver[a];
call c := DelegateRemoveHelper(c, m, o);
}
procedure GetFirstElement(i: int) returns (m: int, o: int)
{
var first: int;
first := $Next[i][$Head[i]];
m := $Method[i][first];
o := $Receiver[i][first];
}
procedure DelegateAddHelper(oldi: int, m: int, o: int) returns (i: int)
{
var x: int;
var h: int;
if (oldi == 0) {
call i := Alloc();
call x := Alloc();
$Head[i] := x;
$Next[i] := $Next[i][x := x];
} else {
i := oldi;
}
h := $Head[i];
$Method[i] := $Method[i][h := m];
$Receiver[i] := $Receiver[i][h := o];
call x := Alloc();
$Next[i] := $Next[i][x := $Next[i][h]];
$Next[i] := $Next[i][h := x];
$Head[i] := x;
}
procedure DelegateRemoveHelper(oldi: int, m: int, o: int) returns (i: int)
{
var prev: int;
var iter: int;
var niter: int;
i := oldi;
if (i == 0) {
return;
}
prev := 0;
iter := $Head[i];
while (true) {
niter := $Next[i][iter];
if (niter == $Head[i]) {
break;
}
if ($Method[i][niter] == m && $Receiver[i][niter] == o) {
prev := iter;
}
iter := niter;
}
if (prev == 0) {
return;
}
$Next[i] := $Next[i][prev := $Next[i][$Next[i][prev]]];
if ($Next[i][$Head[i]] == $Head[i]) {
i := 0;
}
}
";
[RepresentationFor("$Head", "var $Head: [int]int;")]
public Bpl.GlobalVariable DelegateHead = null;
[RepresentationFor("$Next", "var $Next: [int][int]int;")]
public Bpl.GlobalVariable DelegateNext = null;
[RepresentationFor("$Method", "var $Method: [int][int]int;")]
public Bpl.GlobalVariable DelegateMethod = null;
[RepresentationFor("$Receiver", "var $Receiver: [int][int]int;")]
public Bpl.GlobalVariable DelegateReceiver = null;
}
public abstract class HeapFactory {
/// <summary>
/// Returns two things: an object that determines the heap representation,
/// and (optionally) an initial program that contains declarations needed
/// for the heap representation.
/// </summary>
/// <param name="sink">
/// The heap might need to generate declarations so it needs access to the Sink.
/// </param>
/// <returns>
/// false if and only if an error occurrs and the heap and/or program are not in a
/// good state to be used.
/// </returns>
public abstract bool MakeHeap(Sink sink, out Heap heap, out Bpl.Program/*?*/ program);
}
}
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