public override AST.Node ToAST(Env env)
{
/// An iteration statement is a block.
env.PushBlockScope();
/// The controlling expression should have scalar type.
AST.Expr e = expr.ToASTExpr(env);
if (!e.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should have scalar type");
}
/// The loop body is also a block.
env.PushBlockScope();
/// Add this loop to the environemnt.
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
env.PopScope();
return(new AST.While(breakLabel, continueLabel, secondPlusLabel, firstLabel, e, b));
}
public override AST.Node ToAST(Env env)
{
/// An iteration statement is a block.
env.PushBlockScope();
/// Check the expressions.
/// An omitted expression-2 is replaced by a nonzero constant.
var i = initExpr != null?initExpr.ToAST(env) : (initDecl != null ? initDecl.ToAST(env) : null);
var p = pred != null?pred.ToASTExpr(env) : new AST.ConstIntExpr(TInt.Instance, 1, env.ASTEnv);
var q = iter != null?iter.ToAST(env) : null;
/// The controlling expression of a iteration statement shall have scalar type.
if (!p.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should have scalar type");
}
/// Add this loop to the environment.
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
return(new AST.For(breakLabel, continueLabel, secondPlusLabel, firstLabel, i, p, q, b));
}
public override AST.Node ToAST(Env env)
{
env.PushBlockScope();
env.PushBlockScope();
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
AST.Expr e = expr.ToASTExpr(env);
if (!e.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should be have scalar type");
}
env.PopScope();
return(new AST.Do(breakLabel, continueLabel, secondPlusLabel, firstLabel, e, b));
}
public AST.CompoundStmt ToASTCompoundStmt(Env env)
{
env.PushBlockScope();
LinkedList <AST.Node> results = new LinkedList <AST.Node>();
foreach (var stmt in stmts)
{
results.AddLast(stmt.ToAST(env));
}
env.PopScope();
return(new AST.CompoundStmt(results));
}
/// <summary>
/// A selection statement is a block whose scope is a strict subset
/// of the scope of its enclosing block.
///
/// The controlling expression of an if statement shall have scalar type.
/// </summary>
/// <param name="env"></param>
/// <returns></returns>
public override AST.Node ToAST(Env env)
{
env.PushBlockScope();
AST.Expr e = expr.ToASTExpr(env);
if (!e.Type.IsScalar)
{
throw new ETypeError(Pos, string.Format("expecting scalar type, given {0}", e.Type));
}
AST.Node t = then.ToAST(env);
AST.Node o = other != null?other.ToAST(env) : null;
env.PopScope();
var labels = env.AllocIfLabel();
return(new AST.If(e, t, o, labels.Item1, labels.Item2));
}
