private Expression Expand(Expression expr)
{
if (expr == null)
{
return(null);
}
else if (expr is Addr)
{
var addr = (Addr)expr;
var target = Expand(addr.Target);
return(new Addr(target));
}
else if (expr is Assign)
{
var ass = (Assign)expr;
var prop = ass.InvokedProp();
if (prop != null)
{
return(Expand(prop));
}
else
{
var rhs = Expand(ass.Rhs);
var lhs = Expand(ass.Lhs);
return(new Assign(lhs, rhs));
}
}
else if (expr is Operator)
{
var op = (Operator)expr;
if (op.OperatorType.IsAssign())
{
var prop = op.Children.AssertFirst().InvokedProp();
if (prop != null)
{
return(Expand(prop));
}
else
{
// todo. implement this with the use of SafeExpandOpAssign
var args = op.Args.Select(arg => Expand(arg));
return(Operator.Create(op.OperatorType, args));
}
}
else
{
var args = op.Args.Select(arg => Expand(arg));
return(Operator.Create(op.OperatorType, args));
}
}
else if (expr is Conditional)
{
var cond = (Conditional)expr;
var test = Expand(cond.Test);
var iftrue = Expand(cond.IfTrue);
var iffalse = Expand(cond.IfFalse);
return(new Conditional(test, iftrue, iffalse));
}
else if (expr is Const)
{
// do nothing - nowhere to drill into
return(expr);
}
else if (expr is Convert)
{
var cvt = (Convert)expr;
var source = Expand(cvt.Source);
return(new Convert(cvt.Type, source));
}
else if (expr is Deref)
{
var deref = (Deref)expr;
var target = Expand(deref.Target);
return(new Deref(target));
}
else if (expr is Fld)
{
var fld = (Fld)expr;
var @this = Expand(fld.This);
return(new Fld(fld.Field, @this));
}
else if (expr is Prop)
{
// basic investigations
var prop = (Prop)expr;
var is_instance = prop.Property.IsInstance();
var parent = prop.Parent;
var app = parent as Apply;
var is_indexer = app != null && app.Callee == prop;
if (is_indexer)
{
parent = parent.Parent;
}
// we have 5 different cases:
// 1) foo.P;
// 2) foo.P = bar;
// 3) qux = (foo.P = bar);
// 4) foo.P += bar;
// 4') foo.P++;
// 5) qux = (foo.P += bar);
// 5') qux = (foo.P++);
var ass = parent as Assign;
var is_assigned = ass != null && (ass.Lhs == prop || ass.Lhs == app);
var op = parent as Operator;
var is_opassigned = op != null && op.OperatorType.IsAssign();
is_assigned |= is_opassigned;
var is_rhs_reused = is_assigned && parent.Parent is Expression;
if (!is_assigned)
{
var impl = prop.Property.GetGetMethod(true);
var this_args = is_instance ? prop.This.MkArray() : Seq.Empty <Expression>();
var indexer_args = is_indexer ? app.Args : Seq.Empty <Expression>();
var args = Seq.Concat(this_args, indexer_args).ToReadOnly();
var style = prop.InvokedAsVirtual ? InvocationStyle.Virtual : InvocationStyle.NonVirtual;
return(Expand(new Eval(new Apply(new Lambda(impl, style), args))));
}
else
{
// abstract away the root
// todo. implement this with the use of SafeExpandOpAssign
var root = prop.This;
if (is_opassigned && !root.IsLvalue())
{
var opassroot = DeclareLocal("$opassroot", prop.This.Type());
Emit(new Assign(opassroot, prop.This));
root = opassroot;
}
// abstract away the RHS
var rhs = null as Expression;
if (ass != null)
{
rhs = ass.Rhs;
}
if (is_opassigned)
{
if (op.IsUnary())
{
rhs = new Const(1);
}
else if (op.IsBinary())
{
rhs = op.Children.AssertSecond().AssertCast <Expression>();
}
else
{
throw AssertionHelper.Fail();
}
}
// abstract away the equivalence transform
Func <Expression> equiv = () =>
{
Func <Expression> equivGetter = () =>
{
var impl = prop.Property.GetGetMethod(true);
var this_args = is_instance ? root.MkArray() : Seq.Empty <Expression>();
var indexer_args = is_indexer ? app.Args : Seq.Empty <Expression>();
var args = Seq.Concat(this_args, indexer_args).ToReadOnly();
var style = prop.InvokedAsVirtual ? InvocationStyle.Virtual : InvocationStyle.NonVirtual;
return(new Eval(new Apply(new Lambda(impl, style), args)));
};
Func <Expression, Expression> equivSetter = assigned_value =>
{
var impl = prop.Property.GetSetMethod(true);
var this_args = is_instance ? root.MkArray() : Seq.Empty <Expression>();
var indexer_args = is_indexer ? app.Args : Seq.Empty <Expression>();
var args = Seq.Concat(this_args, indexer_args, assigned_value.MkArray()).ToReadOnly();
var style = prop.InvokedAsVirtual ? InvocationStyle.Virtual : InvocationStyle.NonVirtual;
return(new Eval(new Apply(new Lambda(impl, style), args)));
};
if (is_opassigned)
{
return(equivSetter(Operator.Create(op.OperatorType, equivGetter(), rhs)));
}
else
{
return(equivSetter(rhs));
}
};
// final transform
if (is_rhs_reused)
{
var cached_rhs = DeclareLocal("$opassrhs", rhs.Type());
Emit(new Assign(cached_rhs, rhs));
rhs = cached_rhs;
Emit(equiv());
return(cached_rhs);
}
else
{
return(Expand(equiv()));
}
}
}
else if (expr is Ref)
{
var @ref = (Ref)expr;
var env = Env.GetOrDefault(@ref.Sym);
return(Expand(env) ?? @ref);
}
else if (expr is SizeOf)
{
// do nothing - nowhere to drill into
return(expr);
}
else if (expr is TypeAs)
{
var typeAs = (TypeAs)expr;
var target = Expand(typeAs.Target);
return(new TypeAs(typeAs.Type, target));
}
else if (expr is TypeIs)
{
var typeIs = (TypeIs)expr;
var target = Expand(typeIs.Target);
return(new TypeAs(typeIs.Type, target));
}
else if (expr is Default)
{
// do nothing - nowhere to drill into
return(expr);
}
else if (expr is CollectionInit)
{
var ci = (CollectionInit)expr;
if (ci.Elements.IsEmpty())
{
return(Expand(ci.Ctor));
}
else
{
var ctor_coll = ci.InvokedMethod().AssertThat(mb => mb.IsConstructor());
var t_coll = ctor_coll.DeclaringType;
var l_coll = DeclareLocal("$", t_coll);
Emit(new Assign(l_coll, ci.Ctor));
ci.Elements.ForEach((el, i) =>
{
if (t_coll.IsArray)
{
(t_coll.GetArrayRank() == 1).AssertTrue();
var m_set = t_coll.ArraySetter().AssertNotNull();
Emit(new Eval(new Apply(new Lambda(m_set), l_coll, new Const(i), el)));
}
else
{
var m_add = t_coll.GetMethods(BF.All).AssertSingle(m => m.Name == "Add");
Emit(new Eval(new Apply(new Lambda(m_add), l_coll, el)));
}
});
return(l_coll);
}
}
else if (expr is ObjectInit)
{
var oi = (ObjectInit)expr;
if (oi.Members.IsEmpty())
{
return(Expand(oi.Ctor));
}
else
{
var ctor_obj = oi.InvokedMethod().AssertThat(mb => mb.IsConstructor());
var t_obj = ctor_obj.DeclaringType;
var l_obj = DeclareLocal("$", t_obj);
Emit(new Assign(l_obj, oi.Ctor));
foreach (var mi in oi.Members)
{
if (mi is FieldInfo)
{
var fi = mi as FieldInfo;
Emit(new Assign(new Fld(fi, l_obj), oi.MemberInits[mi]));
}
else if (mi is PropertyInfo)
{
var pi = mi as PropertyInfo;
// todo. what about virtuality?!
Emit(new Assign(new Prop(pi, l_obj), oi.MemberInits[mi]));
}
else
{
throw AssertionHelper.Fail();
}
}
return(l_obj);
}
}
else if (expr is Eval)
{
var eval = (Eval)expr;
var lam = eval.InvokedLambda();
var m = eval.InvokedMethod();
var child_ctx = Ctx.SpinOff(m);
var status = Codebase.Classify(m);
(status != MethodStatus.MustNotBeExecutedOnDevice).AssertTrue();
var is_redirected = status == MethodStatus.IsRedirected;
if (is_redirected)
{
var redir = Codebase.Redirect(eval);
if (redir == null)
{
return(null);
}
else
{
var m_redir = redir.InvokedMethod();
if (m_redir.HasBody())
{
var raw_body = m_redir.ParseBody().Where(op => !(op is CilNop)).ToReadOnly();
if (raw_body.Count() == 2)
{
var first = raw_body.First() as CilNew;
var second = raw_body.Second() as CilThrow;
var tni_ctor = typeof(NotImplementedException).GetConstructor(Type.EmptyTypes);
if (first != null && first.Ctor == tni_ctor && second != null)
{
throw AssertionHelper.Fail();
}
}
}
return(Expand(redir));
}
}
else
{
var needsExpansion = status == MethodStatus.CanBeExecutedOnDevice;
var doesntNeedExpansion = status == MethodStatus.HasSpecialSemantics;
(needsExpansion ^ doesntNeedExpansion).AssertTrue();
if (needsExpansion)
{
// todo. think about what we can do here
(lam.InvocationStyle == InvocationStyle.Virtual).AssertFalse();
m.DeclaringType.IsInterface.AssertFalse();
}
var md = m.Decompile();
needsExpansion.AssertImplies(m.HasBody());
var p_ret = Seq.Empty <ParameterInfo>();
var mi = m as MethodInfo;
if (mi != null)
{
p_ret = mi.ReturnParameter.MkArray();
}
m.GetParameters().Concat(p_ret).ForEach(pi => pi.IsOptional.AssertFalse());
var args = eval.InvocationArgs();
var args_include_this = !lam.InvokedAsCtor && m.IsInstance();
var @params = m.GetParameters().AsEnumerable();
var p_fakethis = null as ParameterInfo;
if (args_include_this)
{
@params = p_fakethis.Concat(@params).ToReadOnly();
}
var l_args = @params.Zip(args, (p, actual_arg) =>
{
var p_sig = p == null ? md.Sig.Params.First() : md.Sig.Params.AssertSingle(p1 => p1.Metadata == p);
var p_type = p_sig.Type;
Func <Expression, Expression> expand_arg = null;
expand_arg = arg =>
{
Func <Expression, String, Expression> default_expand1 = (e, postfix) =>
{
var prefix = (m.IsConstructor() ? m.DeclaringType.Name : m.Name).ToLower();
var name = p_sig.Name + (postfix == null ? null : ("_" + postfix.ToLower()));
var full_name = String.Format("${0}_{1}", prefix, name);
var l_stub = DeclareLocal(full_name, p_type);
Emit(new Assign(l_stub, Expand(arg)));
return(l_stub);
};
Func <Expression, Expression> default_expand = e => default_expand1(e, null);
if (doesntNeedExpansion)
{
if (p_type.IsArray && p.IsVarargs())
{
var ctor = arg.InvokedCtor();
if (ctor != null && ctor.DeclaringType.IsArray)
{
var arg_eval = arg as Eval;
if (arg_eval != null)
{
var rank = ctor.DeclaringType.GetArrayRank();
if (rank == 1)
{
var sole_arg = arg.InvocationArgs().AssertSingle() as Const;
if (sole_arg != null &&
sole_arg.Value is int && (int)sole_arg.Value == 0)
{
return(arg);
}
}
}
var arg_ci = arg as CollectionInit;
if (arg_ci != null)
{
p_type.IsArray().AssertTrue();
(p_type.GetArrayRank() == 1).AssertTrue();
try
{
p_type = p_type.GetElementType();
var els = arg_ci.Elements.Select(expand_arg).ToReadOnly();
return(new CollectionInit(arg_ci.Ctor, els));
}
finally
{
p_type = p_type.MakeArrayType();
}
}
}
}
var needs_expansion = arg.Family().Any(c =>
c is Eval || c is Apply || c is Lambda || c is Prop || c is CollectionInit || c is ObjectInit);
if (!needs_expansion)
{
return(arg);
}
else
{
// todo. the stuff below works incorrectly in general case
// since it might disrupt evaluation order of parameters
//
// however for now I trade off introducing a potential bug
// for the ease of debugging and looking at traces
var old_stmtc = Stmts.Count();
var expanded = default_expand(arg).AssertCast <Ref>();
var new_stmtc = Stmts.Count();
(new_stmtc > old_stmtc).AssertTrue();
// todo. fix possible semantic disruption at the next line
if (new_stmtc - old_stmtc > 1)
{
return(expanded);
}
else
{
var ass = Stmts.Last().AssertCast <Assign>();
ass.Lhs.Equiv(expanded).AssertTrue();
Stmts.RemoveLast();
RemoveLocal(expanded);
return(ass.Rhs);
}
}
}
else
{
var p_reads = md.Body.Family().OfType <Ref>().Where(r => r.Sym == p_sig.Sym).ToReadOnly();
var p_asses = md.Body.Family().OfType <Assign>().Select(ass =>
{
var r_lhs = ass.Lhs as Ref;
var is_write = r_lhs != null && r_lhs.Sym == p_sig.Sym;
return(is_write ? ass : null);
}).Where(ass => ass != null).ToReadOnly();
var p_byref = md.Body.Family().OfType <Apply>().Select(app =>
{
var passes_byref = app.ArgsInfo.Zip((e, pi) =>
{
var e_ref = e as Ref;
var is_read = e_ref != null && e_ref.Sym == p_sig.Sym;
var is_byref = pi.Type.IsByRef;
return(is_read && is_byref);
}).Any();
return(passes_byref ? app : null);
}).Where(app => app != null).ToReadOnly();
var p_writes = Seq.Concat(p_asses.Cast <Expression>(), p_byref.Cast <Expression>()).ToReadOnly();
var p_usages = Seq.Concat(p_reads.Cast <Expression>(), p_writes.Cast <Expression>()).ToReadOnly();
// todo. below we might disrupt evaluation order
// by totally inlining an arg expression if it has a single usage
// strictly speaking, before doing that
// we need perform additional checks that eval-order is preserved
//
// note. this semi-correct solution is introduced
// solely for the convenience of the back-end
// and for the convenience of reading the resulting traces
var passed_by_ref = p == null || p.PassedByRef();
if (passed_by_ref)
{
var @ref = arg as Ref;
if (@ref != null)
{
return(arg);
}
var fld = arg as Fld;
if (fld != null)
{
fld.Field.IsInstance().AssertTrue();
// todo. fix possible semantic disruption at the next line
if (p_usages.Count() <= 1)
{
return(arg);
}
else
{
var root = fld.This;
var is_atom = root is Ref || root is Const;
if (is_atom)
{
return(arg);
}
else
{
var root_expanded = default_expand1(root, "root");
return(new Fld(fld.Field, root_expanded));
}
}
}
var eval1 = arg as Eval;
if (eval1 != null)
{
var m1 = eval1.InvokedMethod();
m1.IsArrayGetter().AssertTrue();
var args1 = eval1.InvocationArgs();
var lam1 = eval1.InvokedLambda();
var r_ee = eval1.Expand(Ctx.SpinOff(m1));
r_ee.Stmts.ForEach(Stmts.Add);
var ee = r_ee.Result.AssertCast <Eval>().AssertNotNull();
// todo. fix possible semantic disruption at the next line
if (p_usages.Count() <= 1)
{
return(ee);
}
else
{
var root = ee.Callee.Callee;
Func <Expression, bool> is_atom = e => e is Ref || e is Const;
if (is_atom(root) && ee.Callee.Args.All(is_atom))
{
return(ee);
}
else
{
var root_expanded = default_expand1(root, "root");
return(new Eval(new Apply(new Lambda(m1, lam1.InvocationStyle), root_expanded.Concat(args1))));
}
}
}
// arg isn't an lvalue, so it can't be passed by reference
throw AssertionHelper.Fail();
}
else
{
if (p_writes.IsEmpty())
{
// todo. fix possible semantic disruption at the next line
if (p_usages.Count() <= 1)
{
return(arg);
}
else
{
var is_atom = arg is Ref || arg is Const;
if (is_atom)
{
var is_value_type = p_type.IsValueType;
var is_primitive = p_type.IsPrimitive;
var needs_copying = is_value_type && !is_primitive;
return(needs_copying ? default_expand(arg) : arg);
}
else
{
return(default_expand(arg));
}
}
}
else
{
return(default_expand(arg));
}
}
}
};
var preprocessed_arg = actual_arg.Transform((Ref @ref) =>
{
var env = Env.GetOrDefault(@ref.Sym);
return(env ?? @ref);
}).AssertCast <Expression>();
var expanded_arg = expand_arg(preprocessed_arg);
expanded_arg = expanded_arg.Transform((Ref @ref) =>
{
var env = Env.GetOrDefault(@ref.Sym);
return(env ?? @ref);
}).AssertCast <Expression>();
if (needsExpansion)
{
child_ctx.Env.Add(p_sig.Sym, expanded_arg);
}
return(expanded_arg);
}).ToReadOnly();
if (needsExpansion)
{
var env_locals = lam.Body.LocalsRecursive().ToDictionary(l => l as Sym, l =>
{
var frames = Stack.Reverse().Skip(1).Concat(m);
var qualifier = frames.Select(sf => sf.Name.ToLower()).StringJoin("_");
var full_name = String.Format("${0}_{1}", qualifier, l.Name);
return(DeclareLocal(full_name, l.Type) as Expression);
}).ToReadOnly();
child_ctx.Env.AddElements(env_locals);
Action <Block> import_locals = blk =>
{
foreach (var local in blk.Locals.ToArray())
{
var env_ref = env_locals.GetOrDefault(local) as Ref;
var env = env_ref == null ? null : (Local)env_ref.Sym;
if (env != null)
{
blk.Locals.Remove(local);
blk.Locals.Add(env);
}
else
{
Scope.Locals.Add(local);
}
}
// todo. also import locals from embedded blocks
// here we need to take inlined stuff into account
};
if (lam.InvokedAsCtor)
{
var l_this = DeclareLocal(String.Format("${0}_this", m.DeclaringType.Name.ToLower()), m.DeclaringType);
child_ctx.Env.Add(lam.Sig.Syms[0], l_this);
var malloc = typeof(Ctm).GetMethod("Malloc", new [] { typeof(Type) }).AssertNotNull();
var malloc_type = new Const(m.DeclaringType);
Emit(new Assign(l_this, new Eval(new Apply(new Lambda(malloc), malloc_type))));
var body = lam.Body.Expand(child_ctx);
import_locals(body);
if (body.IsEmpty())
{
var last_stmt = Stmts.Last() as Assign;
var last_invoked = last_stmt == null ? null : last_stmt.Rhs.InvokedMethod();
(last_invoked == malloc).AssertTrue();
RemoveLocal(l_this);
Stmts.RemoveLast();
return(last_stmt.Rhs);
}
else
{
body.ForEach(Stmts.Add);
return(l_this);
}
}
else if (m.Ret() == typeof(void))
{
var body = lam.Body.Expand(child_ctx).AssertNotEmpty();
import_locals(body);
if (body.IsNotEmpty())
{
body.ForEach(Stmts.Add);
}
return(null);
}
else
{
(m.Ret().IsByRef || m.Ret().IsPointer).AssertFalse();
var name = String.Format("${0}_ret", m.Name.ToLower());
var l_ret = DeclareLocal(name, m.Ret());
child_ctx.Ret = l_ret;
var body = lam.Body.Expand(child_ctx).AssertNotEmpty();
import_locals(body);
var body_last = body.LastOrDefault();
if (body_last is Label)
{
body.ForEach(Stmts.Add);
return(l_ret);
}
else
{
var ass = body.AssertLast().AssertCast <Assign>();
ass.Lhs.Equiv(l_ret).AssertTrue();
RemoveLocal(l_ret);
body.SkipLast(1).ForEach(Stmts.Add);
return(ass.Rhs);
}
}
}
else
{
return(new Eval(new Apply(lam, l_args.Cast <Expression>())));
}
}
}
else
{
var app = expr as Apply;
var app_prop = app == null ? null : app.Callee as Prop;
if (app_prop != null)
{
return(Expand(app_prop));
}
// todo. also support indirect calls and partial applications
// i.e. process cases when Apply/Lambda nodes ain't wrapped in an Eval
throw AssertionHelper.Fail();
}
}
