|
private TransformWrite ( |
||
| gen | ||
| rightValue | System.Linq.Expressions | |
| return | ||
internal override MSA.Expression /*!*/ TransformRead(AstGenerator /*!*/ gen)
{
// TODO:
// {target}[{arguments}] op= rhs
// we need to evaluate {arguments} once: http://ironruby.codeplex.com/workitem/4525
// first, read target into a temp:
MSA.Expression transformedLeftTarget = _left.TransformTargetRead(gen);
MSA.Expression leftTargetTemp;
if (transformedLeftTarget != null)
{
leftTargetTemp = gen.CurrentScope.DefineHiddenVariable(String.Empty, transformedLeftTarget.Type);
}
else
{
leftTargetTemp = null;
}
MSA.Expression transformedRight = _right.TransformRead(gen);
// lhs &&= rhs --> lhs && (lhs = rhs)
// lhs ||= rhs --> lhs || (lhs = rhs)
if (Operation == Symbols.And || Operation == Symbols.Or)
{
MSA.Expression transformedLeftRead = _left.TransformRead(gen,
(transformedLeftTarget != null) ? Ast.Assign(leftTargetTemp, transformedLeftTarget) : null,
true // tryRead
);
MSA.Expression transformedWrite = _left.TransformWrite(gen, leftTargetTemp, transformedRight);
if (Operation == Symbols.And)
{
return(AndExpression.TransformRead(gen, transformedLeftRead, transformedWrite));
}
else
{
return(OrExpression.TransformRead(gen, transformedLeftRead, transformedWrite));
}
}
else
{
// lhs op= rhs --> lhs = lhs op rhs
if (Operation != null)
{
MSA.Expression transformedLeftRead = _left.TransformRead(gen, leftTargetTemp, false);
transformedRight = MethodCall.TransformRead(this, gen, false, Operation, transformedLeftRead, null, null, transformedRight, null);
}
// transform lhs write assigning lhs-target temp:
return(_left.TransformWrite(gen,
(transformedLeftTarget != null) ? Ast.Assign(leftTargetTemp, transformedLeftTarget) : null,
transformedRight
));
}
}
//
// rescue stmts ... if (StandardError === $!) { stmts; }
// rescue <types> stmts ... temp1 = type1; ...; if (<temp1> === $! || ...) { stmts; }
// rescue <types> => <lvalue> stmts ... temp1 = type1; ...; if (<temp1> === $! || ...) { <lvalue> = $!; stmts; }
//
internal IfStatementTest /*!*/ Transform(AstGenerator /*!*/ gen, ResultOperation resultOperation)
{
Assert.NotNull(gen);
MSA.Expression condition;
if (_types.Length != 0)
{
var comparisonSiteStorage = Ast.Constant(new BinaryOpStorage(gen.Context));
if (_types.Length == 1)
{
condition = MakeCompareException(gen, comparisonSiteStorage, _types[0].TransformRead(gen), _types[0] is SplattedArgument);
}
else
{
// forall{i}: <temps[i]> = evaluate type[i]
var temps = new MSA.Expression[_types.Length];
var exprs = new BlockBuilder();
for (int i = 0; i < _types.Length; i++)
{
var t = _types[i].TransformRead(gen);
var tmp = gen.CurrentScope.DefineHiddenVariable("#type_" + i, t.Type);
temps[i] = tmp;
exprs.Add(Ast.Assign(tmp, t));
}
// CompareException(<temps[0]>) || ... CompareException(<temps[n]>) || CompareSplattedExceptions(<splatTypes>)
condition = MakeCompareException(gen, comparisonSiteStorage, temps[0], _types[0] is SplattedArgument);
for (int i = 1; i < _types.Length; i++)
{
condition = Ast.OrElse(condition, MakeCompareException(gen, comparisonSiteStorage, temps[i], _types[i] is SplattedArgument));
}
// (temps[0] = type[0], ..., temps[n] == type[n], condition)
exprs.Add(condition);
condition = exprs;
}
}
else
{
condition = Methods.CompareDefaultException.OpCall(gen.CurrentScopeVariable);
}
return(AstUtils.IfCondition(condition,
gen.TransformStatements(
// <lvalue> = e;
(_target != null) ? _target.TransformWrite(gen, Methods.GetCurrentException.OpCall(gen.CurrentScopeVariable)) : null,
// body:
_statements,
resultOperation
)
));
}
private MSA.Expression /*!*/ TransformWrite(AstGenerator /*!*/ gen, AstExpressions /*!*/ rightValues, MSA.Expression splattedValue)
{
// We need to distinguish various special cases here.
// Each of the bool variables defined below is true iff the corresponding special form of LHS/RHS occurs.
// These flags drive the DLR AST being produced by this method.
// For parallel assignment specification, see "Ruby Language.docx/Runtime/Parallel Assignment".
// L(0,-) not applicable
Debug.Assert(!(_leftValues.Count == 0 && _unsplattedValue == null));
// L(1,-)?
bool leftOneNone = _leftValues.Count == 1 && _unsplattedValue == null;
// L(0,*)?
bool leftNoneSplat = _leftValues.Count == 0 && _unsplattedValue != null;
// R(0,*)?
bool rightNoneSplat = rightValues.Count == 0 && splattedValue != null;
// R(1,-)?
bool rightOneNone = rightValues.Count == 1 && splattedValue == null;
// R(1,*)?
bool rightOneSplat = rightValues.Count == 1 && splattedValue != null;
// R(0,-) not applicable
Debug.Assert(!(rightValues.Count == 0 && splattedValue == null));
MSA.Expression resultExpression;
if (leftOneNone)
{
// L(1,-):
// recurse right away (X) = RHS is equivalent to X = RHS:
CompoundLeftValue compound = _leftValues[0] as CompoundLeftValue;
if (compound != null)
{
return(compound.TransformWrite(gen, rightValues, splattedValue));
}
if (rightOneSplat)
{
// R(1,*)
resultExpression = Methods.SplatPair.OpCall(
AstUtils.Box(rightValues[0]),
AstUtils.LightDynamic(SplatAction.Make(gen.Context), typeof(IList), splattedValue)
);
}
else
{
// case 1: R(1,-)
// case 2: R(0,*)
// case 3: otherwise
resultExpression = Arguments.TransformRead(gen, rightValues, splattedValue, true /* Splat */);
}
return(_leftValues[0].TransformWrite(gen, resultExpression));
}
bool optimizeReads = true;
if (rightOneNone && !leftNoneSplat)
{
// R(1,-) && !L(0,*)
resultExpression = Methods.Unsplat.OpCall(
AstUtils.LightDynamic(ConvertToArraySplatAction.Make(gen.Context), rightValues[0])
);
optimizeReads = false;
}
else
{
// case 1: R(0,*) = L
// case 2: otherwise
resultExpression = Arguments.TransformRead(gen, rightValues, splattedValue, false /* Unsplat */);
optimizeReads = !rightNoneSplat;
}
var writes = new AstBlock();
MSA.Expression result = gen.CurrentScope.DefineHiddenVariable("#rhs", typeof(IList));
writes.Add(Ast.Assign(result, resultExpression));
MethodInfo itemGetter = Methods.IList_get_Item;
for (int i = 0; i < _leftValues.Count; i++)
{
MSA.Expression rvalue;
if (optimizeReads)
{
if (i < rightValues.Count)
{
// unchecked get item:
rvalue = Ast.Call(result, itemGetter, AstUtils.Constant(i));
}
else if (splattedValue != null)
{
// checked get item:
rvalue = Methods.GetArrayItem.OpCall(result, AstUtils.Constant(i));
}
else
{
// missing item:
rvalue = AstUtils.Constant(null);
}
}
else
{
rvalue = Methods.GetArrayItem.OpCall(result, AstUtils.Constant(i));
}
writes.Add(_leftValues[i].TransformWrite(gen, rvalue));
}
// unsplatting the rest of rhs values into an array:
if (_unsplattedValue != null)
{
// copies the rest of resulting array to the *LHS;
// the resulting array contains splatted *RHS - no need for additional appending:
MSA.Expression array = Methods.GetArraySuffix.OpCall(result, AstUtils.Constant(_leftValues.Count));
// assign the array (possibly empty) to *LHS:
writes.Add(_unsplattedValue.TransformWrite(gen, array));
}
writes.Add(result);
return(writes);
}
//
// rescue stmts ... if (StandardError === $!) { stmts; }
// rescue <types> stmts ... temp1 = type1; ...; if (<temp1> === $! || ...) { stmts; }
// rescue <types> => <lvalue> stmts ... temp1 = type1; ...; if (<temp1> === $! || ...) { <lvalue> = $!; stmts; }
//
internal IfStatementTest /*!*/ Transform(AstGenerator /*!*/ gen, ResultOperation resultOperation)
{
Assert.NotNull(gen);
MSA.Expression condition;
if (_types.Count != 0 || _splatType != null)
{
if (_types.Count == 0)
{
// splat only:
condition = MakeCompareSplattedExceptions(gen, TransformSplatType(gen));
}
else if (_types.Count == 1 && _splatType == null)
{
condition = MakeCompareException(gen, _types[0].TransformRead(gen));
}
else
{
// forall{i}: <temps[i]> = evaluate type[i]
var temps = new MSA.Expression[_types.Count + (_splatType != null ? 1 : 0)];
var exprs = new MSA.Expression[temps.Length + 1];
int i = 0;
while (i < _types.Count)
{
var tmp = gen.CurrentScope.DefineHiddenVariable("#type_" + i, typeof(object));
temps[i] = tmp;
exprs[i] = Ast.Assign(tmp, _types[i].TransformRead(gen));
i++;
}
if (_splatType != null)
{
var tmp = gen.CurrentScope.DefineHiddenVariable("#type_" + i, typeof(object));
temps[i] = tmp;
exprs[i] = Ast.Assign(tmp, TransformSplatType(gen));
i++;
}
Debug.Assert(i == temps.Length);
// CompareException(<temps[0]>) || ... CompareException(<temps[n]>) || CompareSplattedExceptions(<splatTypes>)
i = 0;
condition = MakeCompareException(gen, temps[i++]);
while (i < _types.Count)
{
condition = Ast.OrElse(condition, MakeCompareException(gen, temps[i++]));
}
if (_splatType != null)
{
condition = Ast.OrElse(condition, MakeCompareSplattedExceptions(gen, temps[i++]));
}
Debug.Assert(i == temps.Length);
// (temps[0] = type[0], ..., temps[n] == type[n], condition)
exprs[exprs.Length - 1] = condition;
condition = AstFactory.Block(exprs);
}
}
else
{
condition = Methods.CompareDefaultException.OpCall(gen.CurrentScopeVariable, gen.CurrentSelfVariable);
}
return(AstUtils.IfCondition(condition,
gen.TransformStatements(
// <lvalue> = e;
(_target != null) ? _target.TransformWrite(gen, Methods.GetCurrentException.OpCall(gen.CurrentScopeVariable)) : null,
// body:
_statements,
resultOperation
)
));
}
