public JST.Identifier FreshenArgument(JST.Identifier id, TypeRef type)
{
var newid = NameSupply.GenSym();
var cell = new VariableCell(newid);
Bind(id, cell.Read());
CompEnv.AddVariable(newid, ArgLocal.Local, true, true, type);
return(newid);
}
// Rename every non-parameter in given compilation environment and include new parameter in
// this compilation environment
public void FreshenLocals(CompilationEnvironment inlinedCompEnv)
{
foreach (var kv in inlinedCompEnv.Variables)
{
if (kv.Value.ArgLocal == ArgLocal.Local)
{
var newid = NameSupply.GenSym();
var cell = new VariableCell(newid);
Bind(kv.Value.Id, cell.Read());
CompEnv.AddVariable(newid, kv.Value.ArgLocal, kv.Value.IsInit, kv.Value.IsReadOnly, kv.Value.Type);
}
}
}
private ExpressionStackEntry Eval(ISeq <Statement> statements, ExpressionStackEntry entry)
{
if (statements == null)
{
throw new ArgumentNullException("statements");
}
// Eval the expression and save it in a temporary. If result is a structure, make the implied
// value semantics explicit by cloning the value.
var id = gensym();
var cell = new VariableCell(id);
compEnv.AddVariable(id, ArgLocal.Local, false, true, compEnv.SubstituteType(entry.Expression.Type(compEnv)));
statements.Add(new ExpressionStatement(cell.Write(entry.Expression.CloneIfStruct(compEnv))));
// We never re-write to temporaries, so this stack entry now has no effects, not even a 'read' effect.
// Also, the result's Expression.IsValue will be true.
return(new ExpressionStackEntry(cell.Read(), bottom));
}
private bool Dump(ISeq <Statement> statements, MachineState state, int skip, int i)
{
if (statements == null)
{
return(Failed(false, "eval in flush"));
}
var id = state.PeekId(stack.Count - (1 + skip) - i, gensym);
var cell = new VariableCell(id);
var read = stack[i].Expression as ReadExpression;
if (read == null || !read.Address.Equals(cell.AddressOf()))
{
// Ok if id already added as temporary
compEnv.AddVariable(id, ArgLocal.Local, false, true, compEnv.SubstituteType(state.PeekType(stack.Count - (1 + skip) - i)));
statements.Add(new ExpressionStatement(cell.Write(stack[i].Expression.CloneIfStruct(compEnv))));
}
// else: stack entry has not changed, so no need to save it
return(true);
}
// Restore stack to match given machine state. Stack should currently be empty.
public bool Restore(MachineState stateAfterRestore, int skip)
{
if (skip > stateAfterRestore.Depth)
{
return(Failed(false, "underflow in restore"));
}
if (Depth != 0)
{
return(Failed(false, "cannot restore into non-empty stack"));
}
for (var i = 0; i < stateAfterRestore.Depth - skip; i++)
{
var id = stateAfterRestore.PeekId(stateAfterRestore.Depth - skip - 1 - i, gensym);
var cell = new VariableCell(id);
// Ok if already added as temporary
compEnv.AddVariable
(id, ArgLocal.Local, false, true, compEnv.SubstituteType(stateAfterRestore.PeekType(stateAfterRestore.Depth - skip - 1 - i)));
stack.Add(new ExpressionStackEntry(cell.Read(), bottom));
}
return(true);
}
