private static int RelocateFunction(JsBlock block, int insertAt, JsFunctionObject funcDecl)
{
if (block[insertAt] != funcDecl)
{
// technically function declarations can only be direct children of the program or a function block.
// and since we are passing in such a block, the parent of the function declaration better be that
// block. If it isn't, we don't want to move it because it's not in an allowed place, and different
// browsers treat that situation differently. Some browsers would process such funcdecls as if
// they were a direct child of the main block. Others will treat it like a function expression with
// an external name, and only assign the function to the name if that line of code is actually
// executed. So since there's a difference, just leave them as-is and only move valid funcdecls.
if (funcDecl.Parent == block)
{
// remove the function from it's parent, which will take it away from where it is right now.
funcDecl.Parent.ReplaceChild(funcDecl, null);
// now insert it into the block at the new location, incrementing the location so the next function
// will be inserted after it. It is important that they be in the same order as the source, or the semantics
// will change when there are functions with the same name.
block.Insert(insertAt++, funcDecl);
}
}
else
{
// we're already in the right place. Just increment the pointer to move to the next position
// for next time
++insertAt;
}
// return the new position
return(insertAt);
}
private void PossiblyBreakExpressionList(JsBinaryOperator node, JsBlock parentBlock, JsAstNodeList nodeList)
{
// if the first item can be broken, then we an break it and be done.
// otherwise we're going to have to walk until we find a breaking place
if (CanBeBroken(nodeList[0]))
{
// break the first item. insert the left-hand side at our position and
// recurse it. Then rotate the node.
var index = parentBlock.IndexOf(node);
var temp = node.Operand1;
RotateOpeator(node, nodeList);
parentBlock.Insert(index, temp);
// assumes nothing will cause the node to be deleted, because then it
// would cause us to miss the following item
temp.Accept(this);
}
else
{
// the first one can't be broken, so find the first one that can (if any)
for (var ndx = 1; ndx < nodeList.Count; ++ndx)
{
if (CanBeBroken(nodeList[ndx]))
{
if (ndx == 1)
{
// the second item is where we are breaking it, so we're going to pull
// the first item, replace the list with that first item, then insert
// a new comma operator after the current node
var temp = nodeList[0];
nodeList.RemoveAt(0);
node.Operand2 = temp;
// if there's nothing left, then let it die. Otherwise split off
// the remainder and insert after the current item.
if (nodeList.Count > 0)
{
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, 0));
}
}
else
{
// split off items from the index where we want to split, and insert
// it after the current node and leave the node list where it is.
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, ndx));
}
// and now that we've broken it, bail.
break;
}
}
// regardless if anything changed, recurse this node now
base.Visit(node);
}
}
private static int RelocateDirectivePrologue(JsBlock block, int insertAt, JsDirectivePrologue directivePrologue)
{
// skip over any important comments
while (insertAt < block.Count && (block[insertAt] is JsImportantComment))
{
++insertAt;
}
// if the one we want to insert is already at this spot, then we're good to go
if (block[insertAt] != directivePrologue)
{
// remove it from where it is right now and insert it into the proper location
directivePrologue.Parent.ReplaceChild(directivePrologue, null);
block.Insert(insertAt, directivePrologue);
}
// and move up to the next slot
return(++insertAt);
}
private static int RelocateVar(JsBlock block, int insertAt, JsVar varStatement)
{
// if the var statement is at the next position to insert, then we don't need
// to do anything.
if (block[insertAt] != varStatement)
{
// check to see if the current position is a var and we are the NEXT statement.
// if that's the case, we don't need to break out the initializer, just append all the
// vardecls as-is to the current position.
var existingVar = block[insertAt] as JsVar;
if (existingVar != null && block[insertAt + 1] == varStatement)
{
// just append our vardecls to the insertion point, then delete our statement
existingVar.Append(varStatement);
block.RemoveAt(insertAt + 1);
}
else
{
// iterate through the decls and count how many have initializers
var initializerCount = 0;
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
if (varStatement[ndx].Initializer != null)
{
++initializerCount;
}
}
// if there are more than two decls with initializers, then we won't actually
// be gaining anything by moving the var to the top. We'll get rid of the four
// bytes for the "var ", but we'll be adding two bytes for the name and comma
// because name=init will still need to remain behind.
if (initializerCount <= 2)
{
// first iterate through all the declarations in the var statement,
// constructing an expression statement that is made up of assignment
// operators for each of the declarations that have initializers (if any)
// and removing all the initializers
var assignments = new List <JsAstNode>();
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
var varDecl = varStatement[ndx];
if (varDecl.Initializer != null)
{
if (varDecl.IsCCSpecialCase)
{
// create a vardecl with the same name and no initializer
var copyDecl = new JsVariableDeclaration(varDecl.Context, varDecl.Parser)
{
Identifier = varDecl.Identifier,
NameContext = varDecl.VariableField.OriginalContext,
VariableField = varDecl.VariableField
};
// replace the special vardecl with the copy
varStatement[ndx] = copyDecl;
// add the original vardecl to the list of "assignments"
assignments.Add(varDecl);
// add the new decl to the field's declaration list, and remove the old one
// because we're going to change that to an assignment.
varDecl.VariableField.Declarations.Add(copyDecl);
varDecl.VariableField.Declarations.Remove(varDecl);
}
else
{
// hold on to the object so we don't lose it to the GC
var initializer = varDecl.Initializer;
// remove it from the vardecl
varDecl.Initializer = null;
// create an assignment operator for a lookup to the name
// as the left, and the initializer as the right, and add it to the list
var lookup = new JsLookup(varDecl.VariableField.OriginalContext, varDecl.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField,
};
assignments.Add(new JsBinaryOperator(varDecl.Context, varDecl.Parser)
{
Operand1 = lookup,
Operand2 = initializer,
OperatorToken = JsToken.Assign,
OperatorContext = varDecl.AssignContext
});
// add the new lookup to the field's references
varDecl.VariableField.References.Add(lookup);
}
}
}
// now if there were any initializers...
if (assignments.Count > 0)
{
// we want to create one big expression from all the assignments and replace the
// var statement with the assignment(s) expression. Start at position n=1 and create
// a binary operator of n-1 as the left, n as the right, and using a comma operator.
var expression = assignments[0];
for (var ndx = 1; ndx < assignments.Count; ++ndx)
{
expression = JsCommaOperator.CombineWithComma(null, expression.Parser, expression, assignments[ndx]);
}
// replace the var with the expression.
// we still have a pointer to the var, so we can insert it back into the proper
// place next.
varStatement.Parent.ReplaceChild(varStatement, expression);
}
else
{
// no initializers.
// if the parent is a for-in statement...
var forInParent = varStatement.Parent as JsForIn;
if (forInParent != null)
{
// we want to replace the var statement with a lookup for the var
// there should be only one vardecl
var varDecl = varStatement[0];
var lookup = new JsLookup(varDecl.VariableField.OriginalContext, varStatement.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField
};
varStatement.Parent.ReplaceChild(varStatement, lookup);
varDecl.VariableField.References.Add(lookup);
}
else
{
// just remove the var statement altogether
varStatement.Parent.ReplaceChild(varStatement, null);
}
}
// if the statement at the insertion point is a var-statement already,
// then we just need to append our vardecls to it. Otherwise we'll insert our
// var statement at the right point
if (existingVar != null)
{
// append the varstatement we want to move to the existing var, which will
// transfer all the vardecls to it.
existingVar.Append(varStatement);
}
else
{
// move the var to the insert point, incrementing the position or next time
block.Insert(insertAt, varStatement);
}
}
}
}
return(insertAt);
}
private static int RelocateVar(JsBlock block, int insertAt, JsVar varStatement)
{
// if the var statement is at the next position to insert, then we don't need
// to do anything.
if (block[insertAt] != varStatement)
{
// check to see if the current position is a var and we are the NEXT statement.
// if that's the case, we don't need to break out the initializer, just append all the
// vardecls as-is to the current position.
var existingVar = block[insertAt] as JsVar;
if (existingVar != null && block[insertAt + 1] == varStatement)
{
// just append our vardecls to the insertion point, then delete our statement
existingVar.Append(varStatement);
block.RemoveAt(insertAt + 1);
}
else
{
// iterate through the decls and count how many have initializers
var initializerCount = 0;
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
if (varStatement[ndx].Initializer != null)
{
++initializerCount;
}
}
// if there are more than two decls with initializers, then we won't actually
// be gaining anything by moving the var to the top. We'll get rid of the four
// bytes for the "var ", but we'll be adding two bytes for the name and comma
// because name=init will still need to remain behind.
if (initializerCount <= 2)
{
// first iterate through all the declarations in the var statement,
// constructing an expression statement that is made up of assignment
// operators for each of the declarations that have initializers (if any)
// and removing all the initializers
var assignments = new List<JsAstNode>();
for (var ndx = 0; ndx < varStatement.Count; ++ndx)
{
var varDecl = varStatement[ndx];
if (varDecl.Initializer != null)
{
if (varDecl.IsCCSpecialCase)
{
// create a vardecl with the same name and no initializer
var copyDecl = new JsVariableDeclaration(varDecl.Context, varDecl.Parser)
{
Identifier = varDecl.Identifier,
NameContext = varDecl.VariableField.OriginalContext,
VariableField = varDecl.VariableField
};
// replace the special vardecl with the copy
varStatement[ndx] = copyDecl;
// add the original vardecl to the list of "assignments"
assignments.Add(varDecl);
// add the new decl to the field's declaration list, and remove the old one
// because we're going to change that to an assignment.
varDecl.VariableField.Declarations.Add(copyDecl);
varDecl.VariableField.Declarations.Remove(varDecl);
}
else
{
// hold on to the object so we don't lose it to the GC
var initializer = varDecl.Initializer;
// remove it from the vardecl
varDecl.Initializer = null;
// create an assignment operator for a lookup to the name
// as the left, and the initializer as the right, and add it to the list
var lookup = new JsLookup(varDecl.VariableField.OriginalContext, varDecl.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField,
};
assignments.Add(new JsBinaryOperator(varDecl.Context, varDecl.Parser)
{
Operand1 = lookup,
Operand2 = initializer,
OperatorToken = JsToken.Assign,
OperatorContext = varDecl.AssignContext
});
// add the new lookup to the field's references
varDecl.VariableField.References.Add(lookup);
}
}
}
// now if there were any initializers...
if (assignments.Count > 0)
{
// we want to create one big expression from all the assignments and replace the
// var statement with the assignment(s) expression. Start at position n=1 and create
// a binary operator of n-1 as the left, n as the right, and using a comma operator.
var expression = assignments[0];
for (var ndx = 1; ndx < assignments.Count; ++ndx)
{
expression = JsCommaOperator.CombineWithComma(null, expression.Parser, expression, assignments[ndx]);
}
// replace the var with the expression.
// we still have a pointer to the var, so we can insert it back into the proper
// place next.
varStatement.Parent.ReplaceChild(varStatement, expression);
}
else
{
// no initializers.
// if the parent is a for-in statement...
var forInParent = varStatement.Parent as JsForIn;
if (forInParent != null)
{
// we want to replace the var statement with a lookup for the var
// there should be only one vardecl
var varDecl = varStatement[0];
var lookup = new JsLookup(varDecl.VariableField.OriginalContext, varStatement.Parser)
{
Name = varDecl.Identifier,
VariableField = varDecl.VariableField
};
varStatement.Parent.ReplaceChild(varStatement, lookup);
varDecl.VariableField.References.Add(lookup);
}
else
{
// just remove the var statement altogether
varStatement.Parent.ReplaceChild(varStatement, null);
}
}
// if the statement at the insertion point is a var-statement already,
// then we just need to append our vardecls to it. Otherwise we'll insert our
// var statement at the right point
if (existingVar != null)
{
// append the varstatement we want to move to the existing var, which will
// transfer all the vardecls to it.
existingVar.Append(varStatement);
}
else
{
// move the var to the insert point, incrementing the position or next time
block.Insert(insertAt, varStatement);
}
}
}
}
return insertAt;
}
private static int RelocateFunction(JsBlock block, int insertAt, JsFunctionObject funcDecl)
{
if (block[insertAt] != funcDecl)
{
// technically function declarations can only be direct children of the program or a function block.
// and since we are passing in such a block, the parent of the function declaration better be that
// block. If it isn't, we don't want to move it because it's not in an allowed place, and different
// browsers treat that situation differently. Some browsers would process such funcdecls as if
// they were a direct child of the main block. Others will treat it like a function expression with
// an external name, and only assign the function to the name if that line of code is actually
// executed. So since there's a difference, just leave them as-is and only move valid funcdecls.
if (funcDecl.Parent == block)
{
// remove the function from it's parent, which will take it away from where it is right now.
funcDecl.Parent.ReplaceChild(funcDecl, null);
// now insert it into the block at the new location, incrementing the location so the next function
// will be inserted after it. It is important that they be in the same order as the source, or the semantics
// will change when there are functions with the same name.
block.Insert(insertAt++, funcDecl);
}
}
else
{
// we're already in the right place. Just increment the pointer to move to the next position
// for next time
++insertAt;
}
// return the new position
return insertAt;
}
private static int RelocateDirectivePrologue(JsBlock block, int insertAt, JsDirectivePrologue directivePrologue)
{
// skip over any important comments
while (insertAt < block.Count && (block[insertAt] is JsImportantComment))
{
++insertAt;
}
// if the one we want to insert is already at this spot, then we're good to go
if (block[insertAt] != directivePrologue)
{
// remove it from where it is right now and insert it into the proper location
directivePrologue.Parent.ReplaceChild(directivePrologue, null);
block.Insert(insertAt, directivePrologue);
}
// and move up to the next slot
return ++insertAt;
}
private void PossiblyBreakExpressionList(JsBinaryOperator node, JsBlock parentBlock, JsAstNodeList nodeList)
{
// if the first item can be broken, then we an break it and be done.
// otherwise we're going to have to walk until we find a breaking place
if (CanBeBroken(nodeList[0]))
{
// break the first item. insert the left-hand side at our position and
// recurse it. Then rotate the node.
var index = parentBlock.IndexOf(node);
var temp = node.Operand1;
RotateOpeator(node, nodeList);
parentBlock.Insert(index, temp);
// assumes nothing will cause the node to be deleted, because then it
// would cause us to miss the following item
temp.Accept(this);
}
else
{
// the first one can't be broken, so find the first one that can (if any)
for (var ndx = 1; ndx < nodeList.Count; ++ndx)
{
if (CanBeBroken(nodeList[ndx]))
{
if (ndx == 1)
{
// the second item is where we are breaking it, so we're going to pull
// the first item, replace the list with that first item, then insert
// a new comma operator after the current node
var temp = nodeList[0];
nodeList.RemoveAt(0);
node.Operand2 = temp;
// if there's nothing left, then let it die. Otherwise split off
// the remainder and insert after the current item.
if (nodeList.Count > 0)
{
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, 0));
}
}
else
{
// split off items from the index where we want to split, and insert
// it after the current node and leave the node list where it is.
parentBlock.InsertAfter(node, CreateSplitNodeFromEnd(nodeList, ndx));
}
// and now that we've broken it, bail.
break;
}
}
// regardless if anything changed, recurse this node now
base.Visit(node);
}
}
