protected void EmitUsed(List <AphidExpression> args, List <AphidExpression> body)
{
var argIds = args
.Select(x => x.ToIdentifier())
.ToArray();
var parentVariables = Scope
.SelectMany(x => x)
.Select(DeclarationHelper.GetDeclaredIdentifier)
.Where(x => x != null && !argIds.Any(y => x.Identifier == y.Identifier))
.Distinct()
.ToArray();
var locals = new LocalFinder()
.Find(body)
.Where(x => !parentVariables.Any(y => x.Identifier == y.Identifier))
.ToArray();
var used = new PhpUseIdFinder()
.Find(body)
.Cast <IdentifierExpression>()
.Select(x => x.Identifier)
.Distinct()
.Where(x =>
!argIds
.Concat(locals)
.Any(y => y.Identifier == x) &&
!IsBuildInFunction(x))
.Select(x => new IdentifierExpression(x))
.ToArray();
if (used.Length > 0)
{
Append("use (");
EmitTuple(used, prefix: "&");
Append(") ");
}
}
// For the first assignment to a local variable in a block before a control statement is hit,
// if the local variable is not mentioned previously, we turn this assignment into a local declaration.
private void AddDeclarationsWithInitialValues(IEnumerable <ILocalDefinition> localVariables, BasicBlock block)
{
List <ILocalDefinition> topLevelLocals = new List <ILocalDefinition>(localVariables);
List <ILocalDefinition> localsMet = new List <ILocalDefinition>();
for (int i = 0; i < block.Statements.Count; i++)
{
if (topLevelLocals.Count == 0)
{
break;
}
IExpressionStatement expressionStatement = block.Statements[i] as IExpressionStatement;
if (expressionStatement != null)
{
IAssignment assignment = expressionStatement.Expression as IAssignment;
if (assignment != null)
{
ILocalDefinition localDef = assignment.Target.Definition as ILocalDefinition;
if (localDef != null && topLevelLocals.Contains(localDef) && !localsMet.Contains(localDef) && !this.declaredLocals.ContainsKey(localDef))
{
LocalDeclarationStatement localDecl = new LocalDeclarationStatement()
{
LocalVariable = localDef, InitialValue = assignment.Source, Locations = new List <ILocation>(expressionStatement.Locations),
};
this.declaredLocals.Add(localDef, true);
block.Statements[i] = localDecl;
topLevelLocals.Remove(localDef);
localsMet.Add(localDef);
}
}
}
LocalFinder finder = new LocalFinder();
finder.Traverse(block.Statements[i]);
foreach (ILocalDefinition local in finder.FoundLocals)
{
if (!localsMet.Contains(local))
{
localsMet.Add(local);
}
}
//Once we see a statement that can transfer control somewhere else, we
//no longer know that any subsequent assignment dominates all references
//and hence cannot postpone adding the declaration until we can unify it with the assignment.
IGotoStatement gotoStatement = block.Statements[i] as IGotoStatement;
if (gotoStatement != null)
{
break;
}
IConditionalStatement conditionalStatement = block.Statements[i] as IConditionalStatement;
if (conditionalStatement != null)
{
break;
}
ISwitchStatement switchStatement = block.Statements[i] as ISwitchStatement;
if (switchStatement != null)
{
break;
}
IForEachStatement foreachStatement = block.Statements[i] as IForEachStatement;
if (foreachStatement != null)
{
break;
}
IForStatement forStatement = block.Statements[i] as IForStatement;
if (forStatement != null)
{
break;
}
ITryCatchFinallyStatement tryStatement = block.Statements[i] as ITryCatchFinallyStatement;
if (tryStatement != null)
{
break;
}
}
}
