| static private AddScopedVariable ( Expression body, System.Linq.Expressions.ParameterExpression variable, Expression variableInit ) : Expression | ||
| body | Expression | |
| variable | System.Linq.Expressions.ParameterExpression | |
| variableInit | Expression | |
| Результат | Expression | |
private Expression Rewrite(CodeContextScopeExpression ccs)
{
Expression saved = _context;
ParameterExpression nested = Expression.Variable(typeof(CodeContext), "$frame");
// rewrite body with nested context
_context = nested;
Expression body = Visit(ccs.Body);
_context = saved;
// wrap the body in a scope that initializes the nested context
return(AstUtils.AddScopedVariable(body, nested, Visit(ccs.NewContext)));
}
protected override Expression VisitLambda <T>(Expression <T> node)
{
_depth++;
try {
// Visit the lambda first, so we walk the tree and find any
// constants we need to rewrite.
node = (Expression <T>)base.VisitLambda(node);
if (_depth != 1)
{
return(node);
}
var body = node.Body;
if (_constants != null)
{
// Rewrite the constants, they can contain embedded
// CodeContextExpressions
for (int i = 0; i < _constants.Count; i++)
{
_constants[i] = Visit(_constants[i]);
}
// Add the consant pool variable to the top lambda
body = AstUtils.AddScopedVariable(
body,
_constantPool,
Expression.NewArrayInit(typeof(object), _constants)
);
}
// Rewrite the lambda
return(Expression.Lambda <T>(
body,
node.Name + "$" + Interlocked.Increment(ref _uniqueNameId),
node.TailCall,
node.Parameters
));
} finally {
_depth--;
}
}
protected override Expression VisitLambda <T>(Expression <T> node)
{
// Only run this for the top-level lambda
if (_array == null)
{
_array = Expression.Variable(typeof(ModuleGlobalWrapper[]), "$globals");
Expression body = AstUtils.AddScopedVariable(
node.Body,
_array,
Expression.Call(typeof(ScriptingRuntimeHelpers).GetMethod("GetGlobalArray"), Context)
);
Debug.Assert(node.NodeType == ExpressionType.Lambda);
node = Expression.Lambda <T>(
body,
node.Name,
node.Parameters
);
}
return(base.VisitLambda(node));
}
public Expression <DlrMainCallTarget> RewriteLambda(LambdaExpression lambda, string name)
{
Debug.Assert(_context == null);
Debug.Assert(lambda.Parameters.Count == 0);
// Fix up the top-level lambda to have a scope and language parameters
ParameterExpression scopeParameter = Expression.Parameter(typeof(Scope), "$scope");
ParameterExpression languageParameter = Expression.Parameter(typeof(LanguageContext), "$language");
ParameterExpression contextVariable = Expression.Variable(typeof(CodeContext), "$globalContext");
_context = contextVariable;
lambda = (LambdaExpression)Visit(lambda);
return(Expression.Lambda <DlrMainCallTarget>(
AstUtils.AddScopedVariable(
lambda.Body,
contextVariable,
Expression.Call(typeof(ScriptingRuntimeHelpers).GetMethod("CreateTopLevelCodeContext"), scopeParameter, languageParameter)
),
name,
new[] { scopeParameter, languageParameter }
));
}
